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v6.8
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   4 *
   5 *  Copyright (C) 2002 - 2011  Paul Mundt
   6 *  Copyright (C) 2015 Glider bvba
   7 *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   8 *
   9 * based off of the old drivers/char/sh-sci.c by:
  10 *
  11 *   Copyright (C) 1999, 2000  Niibe Yutaka
  12 *   Copyright (C) 2000  Sugioka Toshinobu
  13 *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  14 *   Modified to support SecureEdge. David McCullough (2002)
  15 *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  16 *   Removed SH7300 support (Jul 2007).
  17 */
  18#undef DEBUG
  19
  20#include <linux/clk.h>
  21#include <linux/console.h>
  22#include <linux/ctype.h>
  23#include <linux/cpufreq.h>
  24#include <linux/delay.h>
  25#include <linux/dmaengine.h>
  26#include <linux/dma-mapping.h>
  27#include <linux/err.h>
  28#include <linux/errno.h>
  29#include <linux/init.h>
  30#include <linux/interrupt.h>
  31#include <linux/ioport.h>
  32#include <linux/ktime.h>
  33#include <linux/major.h>
  34#include <linux/minmax.h>
  35#include <linux/module.h>
  36#include <linux/mm.h>
  37#include <linux/of.h>
 
  38#include <linux/platform_device.h>
  39#include <linux/pm_runtime.h>
  40#include <linux/reset.h>
  41#include <linux/scatterlist.h>
  42#include <linux/serial.h>
  43#include <linux/serial_sci.h>
  44#include <linux/sh_dma.h>
  45#include <linux/slab.h>
  46#include <linux/string.h>
  47#include <linux/sysrq.h>
  48#include <linux/timer.h>
  49#include <linux/tty.h>
  50#include <linux/tty_flip.h>
  51
  52#ifdef CONFIG_SUPERH
  53#include <asm/sh_bios.h>
  54#include <asm/platform_early.h>
  55#endif
  56
  57#include "serial_mctrl_gpio.h"
  58#include "sh-sci.h"
  59
  60/* Offsets into the sci_port->irqs array */
  61enum {
  62	SCIx_ERI_IRQ,
  63	SCIx_RXI_IRQ,
  64	SCIx_TXI_IRQ,
  65	SCIx_BRI_IRQ,
  66	SCIx_DRI_IRQ,
  67	SCIx_TEI_IRQ,
  68	SCIx_NR_IRQS,
  69
  70	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
  71};
  72
  73#define SCIx_IRQ_IS_MUXED(port)			\
  74	((port)->irqs[SCIx_ERI_IRQ] ==	\
  75	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
  76	((port)->irqs[SCIx_ERI_IRQ] &&	\
  77	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
  78
  79enum SCI_CLKS {
  80	SCI_FCK,		/* Functional Clock */
  81	SCI_SCK,		/* Optional External Clock */
  82	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
  83	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
  84	SCI_NUM_CLKS
  85};
  86
  87/* Bit x set means sampling rate x + 1 is supported */
  88#define SCI_SR(x)		BIT((x) - 1)
  89#define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
  90
  91#define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
  92				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
  93				SCI_SR(19) | SCI_SR(27)
  94
  95#define min_sr(_port)		ffs((_port)->sampling_rate_mask)
  96#define max_sr(_port)		fls((_port)->sampling_rate_mask)
  97
  98/* Iterate over all supported sampling rates, from high to low */
  99#define for_each_sr(_sr, _port)						\
 100	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
 101		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
 102
 103struct plat_sci_reg {
 104	u8 offset, size;
 105};
 106
 107struct sci_port_params {
 108	const struct plat_sci_reg regs[SCIx_NR_REGS];
 109	unsigned int fifosize;
 110	unsigned int overrun_reg;
 111	unsigned int overrun_mask;
 112	unsigned int sampling_rate_mask;
 113	unsigned int error_mask;
 114	unsigned int error_clear;
 115};
 116
 117struct sci_port {
 118	struct uart_port	port;
 119
 120	/* Platform configuration */
 121	const struct sci_port_params *params;
 122	const struct plat_sci_port *cfg;
 123	unsigned int		sampling_rate_mask;
 124	resource_size_t		reg_size;
 125	struct mctrl_gpios	*gpios;
 126
 127	/* Clocks */
 128	struct clk		*clks[SCI_NUM_CLKS];
 129	unsigned long		clk_rates[SCI_NUM_CLKS];
 130
 131	int			irqs[SCIx_NR_IRQS];
 132	char			*irqstr[SCIx_NR_IRQS];
 133
 134	struct dma_chan			*chan_tx;
 135	struct dma_chan			*chan_rx;
 136
 137#ifdef CONFIG_SERIAL_SH_SCI_DMA
 138	struct dma_chan			*chan_tx_saved;
 139	struct dma_chan			*chan_rx_saved;
 140	dma_cookie_t			cookie_tx;
 141	dma_cookie_t			cookie_rx[2];
 142	dma_cookie_t			active_rx;
 143	dma_addr_t			tx_dma_addr;
 144	unsigned int			tx_dma_len;
 145	struct scatterlist		sg_rx[2];
 146	void				*rx_buf[2];
 147	size_t				buf_len_rx;
 148	struct work_struct		work_tx;
 149	struct hrtimer			rx_timer;
 150	unsigned int			rx_timeout;	/* microseconds */
 151#endif
 152	unsigned int			rx_frame;
 153	int				rx_trigger;
 154	struct timer_list		rx_fifo_timer;
 155	int				rx_fifo_timeout;
 156	u16				hscif_tot;
 157
 158	bool has_rtscts;
 159	bool autorts;
 160};
 161
 162#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 163
 164static struct sci_port sci_ports[SCI_NPORTS];
 165static unsigned long sci_ports_in_use;
 166static struct uart_driver sci_uart_driver;
 167
 168static inline struct sci_port *
 169to_sci_port(struct uart_port *uart)
 170{
 171	return container_of(uart, struct sci_port, port);
 172}
 173
 174static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
 175	/*
 176	 * Common SCI definitions, dependent on the port's regshift
 177	 * value.
 178	 */
 179	[SCIx_SCI_REGTYPE] = {
 180		.regs = {
 181			[SCSMR]		= { 0x00,  8 },
 182			[SCBRR]		= { 0x01,  8 },
 183			[SCSCR]		= { 0x02,  8 },
 184			[SCxTDR]	= { 0x03,  8 },
 185			[SCxSR]		= { 0x04,  8 },
 186			[SCxRDR]	= { 0x05,  8 },
 187		},
 188		.fifosize = 1,
 189		.overrun_reg = SCxSR,
 190		.overrun_mask = SCI_ORER,
 191		.sampling_rate_mask = SCI_SR(32),
 192		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 193		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 194	},
 195
 196	/*
 197	 * Common definitions for legacy IrDA ports.
 198	 */
 199	[SCIx_IRDA_REGTYPE] = {
 200		.regs = {
 201			[SCSMR]		= { 0x00,  8 },
 202			[SCBRR]		= { 0x02,  8 },
 203			[SCSCR]		= { 0x04,  8 },
 204			[SCxTDR]	= { 0x06,  8 },
 205			[SCxSR]		= { 0x08, 16 },
 206			[SCxRDR]	= { 0x0a,  8 },
 207			[SCFCR]		= { 0x0c,  8 },
 208			[SCFDR]		= { 0x0e, 16 },
 209		},
 210		.fifosize = 1,
 211		.overrun_reg = SCxSR,
 212		.overrun_mask = SCI_ORER,
 213		.sampling_rate_mask = SCI_SR(32),
 214		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 215		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 216	},
 217
 218	/*
 219	 * Common SCIFA definitions.
 220	 */
 221	[SCIx_SCIFA_REGTYPE] = {
 222		.regs = {
 223			[SCSMR]		= { 0x00, 16 },
 224			[SCBRR]		= { 0x04,  8 },
 225			[SCSCR]		= { 0x08, 16 },
 226			[SCxTDR]	= { 0x20,  8 },
 227			[SCxSR]		= { 0x14, 16 },
 228			[SCxRDR]	= { 0x24,  8 },
 229			[SCFCR]		= { 0x18, 16 },
 230			[SCFDR]		= { 0x1c, 16 },
 231			[SCPCR]		= { 0x30, 16 },
 232			[SCPDR]		= { 0x34, 16 },
 233		},
 234		.fifosize = 64,
 235		.overrun_reg = SCxSR,
 236		.overrun_mask = SCIFA_ORER,
 237		.sampling_rate_mask = SCI_SR_SCIFAB,
 238		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 239		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 240	},
 241
 242	/*
 243	 * Common SCIFB definitions.
 244	 */
 245	[SCIx_SCIFB_REGTYPE] = {
 246		.regs = {
 247			[SCSMR]		= { 0x00, 16 },
 248			[SCBRR]		= { 0x04,  8 },
 249			[SCSCR]		= { 0x08, 16 },
 250			[SCxTDR]	= { 0x40,  8 },
 251			[SCxSR]		= { 0x14, 16 },
 252			[SCxRDR]	= { 0x60,  8 },
 253			[SCFCR]		= { 0x18, 16 },
 254			[SCTFDR]	= { 0x38, 16 },
 255			[SCRFDR]	= { 0x3c, 16 },
 256			[SCPCR]		= { 0x30, 16 },
 257			[SCPDR]		= { 0x34, 16 },
 258		},
 259		.fifosize = 256,
 260		.overrun_reg = SCxSR,
 261		.overrun_mask = SCIFA_ORER,
 262		.sampling_rate_mask = SCI_SR_SCIFAB,
 263		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 264		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 265	},
 266
 267	/*
 268	 * Common SH-2(A) SCIF definitions for ports with FIFO data
 269	 * count registers.
 270	 */
 271	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
 272		.regs = {
 273			[SCSMR]		= { 0x00, 16 },
 274			[SCBRR]		= { 0x04,  8 },
 275			[SCSCR]		= { 0x08, 16 },
 276			[SCxTDR]	= { 0x0c,  8 },
 277			[SCxSR]		= { 0x10, 16 },
 278			[SCxRDR]	= { 0x14,  8 },
 279			[SCFCR]		= { 0x18, 16 },
 280			[SCFDR]		= { 0x1c, 16 },
 281			[SCSPTR]	= { 0x20, 16 },
 282			[SCLSR]		= { 0x24, 16 },
 283		},
 284		.fifosize = 16,
 285		.overrun_reg = SCLSR,
 286		.overrun_mask = SCLSR_ORER,
 287		.sampling_rate_mask = SCI_SR(32),
 288		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 289		.error_clear = SCIF_ERROR_CLEAR,
 290	},
 291
 292	/*
 293	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
 294	 * It looks like a normal SCIF with FIFO data, but with a
 295	 * compressed address space. Also, the break out of interrupts
 296	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
 297	 */
 298	[SCIx_RZ_SCIFA_REGTYPE] = {
 299		.regs = {
 300			[SCSMR]		= { 0x00, 16 },
 301			[SCBRR]		= { 0x02,  8 },
 302			[SCSCR]		= { 0x04, 16 },
 303			[SCxTDR]	= { 0x06,  8 },
 304			[SCxSR]		= { 0x08, 16 },
 305			[SCxRDR]	= { 0x0A,  8 },
 306			[SCFCR]		= { 0x0C, 16 },
 307			[SCFDR]		= { 0x0E, 16 },
 308			[SCSPTR]	= { 0x10, 16 },
 309			[SCLSR]		= { 0x12, 16 },
 310			[SEMR]		= { 0x14, 8 },
 311		},
 312		.fifosize = 16,
 313		.overrun_reg = SCLSR,
 314		.overrun_mask = SCLSR_ORER,
 315		.sampling_rate_mask = SCI_SR(32),
 316		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 317		.error_clear = SCIF_ERROR_CLEAR,
 318	},
 319
 320	/*
 321	 * Common SH-3 SCIF definitions.
 322	 */
 323	[SCIx_SH3_SCIF_REGTYPE] = {
 324		.regs = {
 325			[SCSMR]		= { 0x00,  8 },
 326			[SCBRR]		= { 0x02,  8 },
 327			[SCSCR]		= { 0x04,  8 },
 328			[SCxTDR]	= { 0x06,  8 },
 329			[SCxSR]		= { 0x08, 16 },
 330			[SCxRDR]	= { 0x0a,  8 },
 331			[SCFCR]		= { 0x0c,  8 },
 332			[SCFDR]		= { 0x0e, 16 },
 333		},
 334		.fifosize = 16,
 335		.overrun_reg = SCLSR,
 336		.overrun_mask = SCLSR_ORER,
 337		.sampling_rate_mask = SCI_SR(32),
 338		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 339		.error_clear = SCIF_ERROR_CLEAR,
 340	},
 341
 342	/*
 343	 * Common SH-4(A) SCIF(B) definitions.
 344	 */
 345	[SCIx_SH4_SCIF_REGTYPE] = {
 346		.regs = {
 347			[SCSMR]		= { 0x00, 16 },
 348			[SCBRR]		= { 0x04,  8 },
 349			[SCSCR]		= { 0x08, 16 },
 350			[SCxTDR]	= { 0x0c,  8 },
 351			[SCxSR]		= { 0x10, 16 },
 352			[SCxRDR]	= { 0x14,  8 },
 353			[SCFCR]		= { 0x18, 16 },
 354			[SCFDR]		= { 0x1c, 16 },
 355			[SCSPTR]	= { 0x20, 16 },
 356			[SCLSR]		= { 0x24, 16 },
 357		},
 358		.fifosize = 16,
 359		.overrun_reg = SCLSR,
 360		.overrun_mask = SCLSR_ORER,
 361		.sampling_rate_mask = SCI_SR(32),
 362		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 363		.error_clear = SCIF_ERROR_CLEAR,
 364	},
 365
 366	/*
 367	 * Common SCIF definitions for ports with a Baud Rate Generator for
 368	 * External Clock (BRG).
 369	 */
 370	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
 371		.regs = {
 372			[SCSMR]		= { 0x00, 16 },
 373			[SCBRR]		= { 0x04,  8 },
 374			[SCSCR]		= { 0x08, 16 },
 375			[SCxTDR]	= { 0x0c,  8 },
 376			[SCxSR]		= { 0x10, 16 },
 377			[SCxRDR]	= { 0x14,  8 },
 378			[SCFCR]		= { 0x18, 16 },
 379			[SCFDR]		= { 0x1c, 16 },
 380			[SCSPTR]	= { 0x20, 16 },
 381			[SCLSR]		= { 0x24, 16 },
 382			[SCDL]		= { 0x30, 16 },
 383			[SCCKS]		= { 0x34, 16 },
 384		},
 385		.fifosize = 16,
 386		.overrun_reg = SCLSR,
 387		.overrun_mask = SCLSR_ORER,
 388		.sampling_rate_mask = SCI_SR(32),
 389		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 390		.error_clear = SCIF_ERROR_CLEAR,
 391	},
 392
 393	/*
 394	 * Common HSCIF definitions.
 395	 */
 396	[SCIx_HSCIF_REGTYPE] = {
 397		.regs = {
 398			[SCSMR]		= { 0x00, 16 },
 399			[SCBRR]		= { 0x04,  8 },
 400			[SCSCR]		= { 0x08, 16 },
 401			[SCxTDR]	= { 0x0c,  8 },
 402			[SCxSR]		= { 0x10, 16 },
 403			[SCxRDR]	= { 0x14,  8 },
 404			[SCFCR]		= { 0x18, 16 },
 405			[SCFDR]		= { 0x1c, 16 },
 406			[SCSPTR]	= { 0x20, 16 },
 407			[SCLSR]		= { 0x24, 16 },
 408			[HSSRR]		= { 0x40, 16 },
 409			[SCDL]		= { 0x30, 16 },
 410			[SCCKS]		= { 0x34, 16 },
 411			[HSRTRGR]	= { 0x54, 16 },
 412			[HSTTRGR]	= { 0x58, 16 },
 413		},
 414		.fifosize = 128,
 415		.overrun_reg = SCLSR,
 416		.overrun_mask = SCLSR_ORER,
 417		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
 418		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 419		.error_clear = SCIF_ERROR_CLEAR,
 420	},
 421
 422	/*
 423	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 424	 * register.
 425	 */
 426	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 427		.regs = {
 428			[SCSMR]		= { 0x00, 16 },
 429			[SCBRR]		= { 0x04,  8 },
 430			[SCSCR]		= { 0x08, 16 },
 431			[SCxTDR]	= { 0x0c,  8 },
 432			[SCxSR]		= { 0x10, 16 },
 433			[SCxRDR]	= { 0x14,  8 },
 434			[SCFCR]		= { 0x18, 16 },
 435			[SCFDR]		= { 0x1c, 16 },
 436			[SCLSR]		= { 0x24, 16 },
 437		},
 438		.fifosize = 16,
 439		.overrun_reg = SCLSR,
 440		.overrun_mask = SCLSR_ORER,
 441		.sampling_rate_mask = SCI_SR(32),
 442		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 443		.error_clear = SCIF_ERROR_CLEAR,
 444	},
 445
 446	/*
 447	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 448	 * count registers.
 449	 */
 450	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 451		.regs = {
 452			[SCSMR]		= { 0x00, 16 },
 453			[SCBRR]		= { 0x04,  8 },
 454			[SCSCR]		= { 0x08, 16 },
 455			[SCxTDR]	= { 0x0c,  8 },
 456			[SCxSR]		= { 0x10, 16 },
 457			[SCxRDR]	= { 0x14,  8 },
 458			[SCFCR]		= { 0x18, 16 },
 459			[SCFDR]		= { 0x1c, 16 },
 460			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
 461			[SCRFDR]	= { 0x20, 16 },
 462			[SCSPTR]	= { 0x24, 16 },
 463			[SCLSR]		= { 0x28, 16 },
 464		},
 465		.fifosize = 16,
 466		.overrun_reg = SCLSR,
 467		.overrun_mask = SCLSR_ORER,
 468		.sampling_rate_mask = SCI_SR(32),
 469		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 470		.error_clear = SCIF_ERROR_CLEAR,
 471	},
 472
 473	/*
 474	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 475	 * registers.
 476	 */
 477	[SCIx_SH7705_SCIF_REGTYPE] = {
 478		.regs = {
 479			[SCSMR]		= { 0x00, 16 },
 480			[SCBRR]		= { 0x04,  8 },
 481			[SCSCR]		= { 0x08, 16 },
 482			[SCxTDR]	= { 0x20,  8 },
 483			[SCxSR]		= { 0x14, 16 },
 484			[SCxRDR]	= { 0x24,  8 },
 485			[SCFCR]		= { 0x18, 16 },
 486			[SCFDR]		= { 0x1c, 16 },
 487		},
 488		.fifosize = 64,
 489		.overrun_reg = SCxSR,
 490		.overrun_mask = SCIFA_ORER,
 491		.sampling_rate_mask = SCI_SR(16),
 492		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 493		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 494	},
 495};
 496
 497#define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
 498
 499/*
 500 * The "offset" here is rather misleading, in that it refers to an enum
 501 * value relative to the port mapping rather than the fixed offset
 502 * itself, which needs to be manually retrieved from the platform's
 503 * register map for the given port.
 504 */
 505static unsigned int sci_serial_in(struct uart_port *p, int offset)
 506{
 507	const struct plat_sci_reg *reg = sci_getreg(p, offset);
 508
 509	if (reg->size == 8)
 510		return ioread8(p->membase + (reg->offset << p->regshift));
 511	else if (reg->size == 16)
 512		return ioread16(p->membase + (reg->offset << p->regshift));
 513	else
 514		WARN(1, "Invalid register access\n");
 515
 516	return 0;
 517}
 518
 519static void sci_serial_out(struct uart_port *p, int offset, int value)
 520{
 521	const struct plat_sci_reg *reg = sci_getreg(p, offset);
 522
 523	if (reg->size == 8)
 524		iowrite8(value, p->membase + (reg->offset << p->regshift));
 525	else if (reg->size == 16)
 526		iowrite16(value, p->membase + (reg->offset << p->regshift));
 527	else
 528		WARN(1, "Invalid register access\n");
 529}
 530
 531static void sci_port_enable(struct sci_port *sci_port)
 532{
 533	unsigned int i;
 534
 535	if (!sci_port->port.dev)
 536		return;
 537
 538	pm_runtime_get_sync(sci_port->port.dev);
 539
 540	for (i = 0; i < SCI_NUM_CLKS; i++) {
 541		clk_prepare_enable(sci_port->clks[i]);
 542		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
 543	}
 544	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
 545}
 546
 547static void sci_port_disable(struct sci_port *sci_port)
 548{
 549	unsigned int i;
 550
 551	if (!sci_port->port.dev)
 552		return;
 553
 554	for (i = SCI_NUM_CLKS; i-- > 0; )
 555		clk_disable_unprepare(sci_port->clks[i]);
 556
 557	pm_runtime_put_sync(sci_port->port.dev);
 558}
 559
 560static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 561{
 562	/*
 563	 * Not all ports (such as SCIFA) will support REIE. Rather than
 564	 * special-casing the port type, we check the port initialization
 565	 * IRQ enable mask to see whether the IRQ is desired at all. If
 566	 * it's unset, it's logically inferred that there's no point in
 567	 * testing for it.
 568	 */
 569	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 570}
 571
 572static void sci_start_tx(struct uart_port *port)
 573{
 574	struct sci_port *s = to_sci_port(port);
 575	unsigned short ctrl;
 576
 577#ifdef CONFIG_SERIAL_SH_SCI_DMA
 578	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 579		u16 new, scr = serial_port_in(port, SCSCR);
 580		if (s->chan_tx)
 581			new = scr | SCSCR_TDRQE;
 582		else
 583			new = scr & ~SCSCR_TDRQE;
 584		if (new != scr)
 585			serial_port_out(port, SCSCR, new);
 586	}
 587
 588	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
 589	    dma_submit_error(s->cookie_tx)) {
 590		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
 591			/* Switch irq from SCIF to DMA */
 592			disable_irq_nosync(s->irqs[SCIx_TXI_IRQ]);
 593
 594		s->cookie_tx = 0;
 595		schedule_work(&s->work_tx);
 596	}
 597#endif
 598
 599	if (!s->chan_tx || s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE ||
 600	    port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 601		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
 602		ctrl = serial_port_in(port, SCSCR);
 603
 604		/*
 605		 * For SCI, TE (transmit enable) must be set after setting TIE
 606		 * (transmit interrupt enable) or in the same instruction to start
 607		 * the transmit process.
 608		 */
 609		if (port->type == PORT_SCI)
 610			ctrl |= SCSCR_TE;
 611
 612		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
 613	}
 614}
 615
 616static void sci_stop_tx(struct uart_port *port)
 617{
 618	unsigned short ctrl;
 619
 620	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
 621	ctrl = serial_port_in(port, SCSCR);
 622
 623	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 624		ctrl &= ~SCSCR_TDRQE;
 625
 626	ctrl &= ~SCSCR_TIE;
 627
 628	serial_port_out(port, SCSCR, ctrl);
 629
 630#ifdef CONFIG_SERIAL_SH_SCI_DMA
 631	if (to_sci_port(port)->chan_tx &&
 632	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
 633		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
 634		to_sci_port(port)->cookie_tx = -EINVAL;
 635	}
 636#endif
 637}
 638
 639static void sci_start_rx(struct uart_port *port)
 640{
 641	unsigned short ctrl;
 642
 643	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 644
 645	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 646		ctrl &= ~SCSCR_RDRQE;
 647
 648	serial_port_out(port, SCSCR, ctrl);
 649}
 650
 651static void sci_stop_rx(struct uart_port *port)
 652{
 653	unsigned short ctrl;
 654
 655	ctrl = serial_port_in(port, SCSCR);
 656
 657	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 658		ctrl &= ~SCSCR_RDRQE;
 659
 660	ctrl &= ~port_rx_irq_mask(port);
 661
 662	serial_port_out(port, SCSCR, ctrl);
 663}
 664
 665static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
 666{
 667	if (port->type == PORT_SCI) {
 668		/* Just store the mask */
 669		serial_port_out(port, SCxSR, mask);
 670	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
 671		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
 672		/* Only clear the status bits we want to clear */
 673		serial_port_out(port, SCxSR,
 674				serial_port_in(port, SCxSR) & mask);
 675	} else {
 676		/* Store the mask, clear parity/framing errors */
 677		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
 678	}
 679}
 680
 681#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
 682    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
 683
 684#ifdef CONFIG_CONSOLE_POLL
 685static int sci_poll_get_char(struct uart_port *port)
 686{
 687	unsigned short status;
 688	int c;
 689
 690	do {
 691		status = serial_port_in(port, SCxSR);
 692		if (status & SCxSR_ERRORS(port)) {
 693			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 694			continue;
 695		}
 696		break;
 697	} while (1);
 698
 699	if (!(status & SCxSR_RDxF(port)))
 700		return NO_POLL_CHAR;
 701
 702	c = serial_port_in(port, SCxRDR);
 703
 704	/* Dummy read */
 705	serial_port_in(port, SCxSR);
 706	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 707
 708	return c;
 709}
 710#endif
 711
 712static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 713{
 714	unsigned short status;
 715
 716	do {
 717		status = serial_port_in(port, SCxSR);
 718	} while (!(status & SCxSR_TDxE(port)));
 719
 720	serial_port_out(port, SCxTDR, c);
 721	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 722}
 723#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
 724	  CONFIG_SERIAL_SH_SCI_EARLYCON */
 725
 726static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 727{
 728	struct sci_port *s = to_sci_port(port);
 729
 730	/*
 731	 * Use port-specific handler if provided.
 732	 */
 733	if (s->cfg->ops && s->cfg->ops->init_pins) {
 734		s->cfg->ops->init_pins(port, cflag);
 735		return;
 736	}
 737
 738	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 739		u16 data = serial_port_in(port, SCPDR);
 740		u16 ctrl = serial_port_in(port, SCPCR);
 741
 742		/* Enable RXD and TXD pin functions */
 743		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
 744		if (to_sci_port(port)->has_rtscts) {
 745			/* RTS# is output, active low, unless autorts */
 746			if (!(port->mctrl & TIOCM_RTS)) {
 747				ctrl |= SCPCR_RTSC;
 748				data |= SCPDR_RTSD;
 749			} else if (!s->autorts) {
 750				ctrl |= SCPCR_RTSC;
 751				data &= ~SCPDR_RTSD;
 752			} else {
 753				/* Enable RTS# pin function */
 754				ctrl &= ~SCPCR_RTSC;
 755			}
 756			/* Enable CTS# pin function */
 757			ctrl &= ~SCPCR_CTSC;
 758		}
 759		serial_port_out(port, SCPDR, data);
 760		serial_port_out(port, SCPCR, ctrl);
 761	} else if (sci_getreg(port, SCSPTR)->size) {
 762		u16 status = serial_port_in(port, SCSPTR);
 763
 764		/* RTS# is always output; and active low, unless autorts */
 765		status |= SCSPTR_RTSIO;
 766		if (!(port->mctrl & TIOCM_RTS))
 767			status |= SCSPTR_RTSDT;
 768		else if (!s->autorts)
 769			status &= ~SCSPTR_RTSDT;
 770		/* CTS# and SCK are inputs */
 771		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
 772		serial_port_out(port, SCSPTR, status);
 773	}
 774}
 775
 776static int sci_txfill(struct uart_port *port)
 777{
 778	struct sci_port *s = to_sci_port(port);
 779	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 780	const struct plat_sci_reg *reg;
 781
 782	reg = sci_getreg(port, SCTFDR);
 783	if (reg->size)
 784		return serial_port_in(port, SCTFDR) & fifo_mask;
 785
 786	reg = sci_getreg(port, SCFDR);
 787	if (reg->size)
 788		return serial_port_in(port, SCFDR) >> 8;
 789
 790	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
 791}
 792
 793static int sci_txroom(struct uart_port *port)
 794{
 795	return port->fifosize - sci_txfill(port);
 796}
 797
 798static int sci_rxfill(struct uart_port *port)
 799{
 800	struct sci_port *s = to_sci_port(port);
 801	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 802	const struct plat_sci_reg *reg;
 803
 804	reg = sci_getreg(port, SCRFDR);
 805	if (reg->size)
 806		return serial_port_in(port, SCRFDR) & fifo_mask;
 807
 808	reg = sci_getreg(port, SCFDR);
 809	if (reg->size)
 810		return serial_port_in(port, SCFDR) & fifo_mask;
 811
 812	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 813}
 814
 815/* ********************************************************************** *
 816 *                   the interrupt related routines                       *
 817 * ********************************************************************** */
 818
 819static void sci_transmit_chars(struct uart_port *port)
 820{
 821	struct circ_buf *xmit = &port->state->xmit;
 822	unsigned int stopped = uart_tx_stopped(port);
 823	unsigned short status;
 824	unsigned short ctrl;
 825	int count;
 826
 827	status = serial_port_in(port, SCxSR);
 828	if (!(status & SCxSR_TDxE(port))) {
 829		ctrl = serial_port_in(port, SCSCR);
 830		if (uart_circ_empty(xmit))
 831			ctrl &= ~SCSCR_TIE;
 832		else
 833			ctrl |= SCSCR_TIE;
 834		serial_port_out(port, SCSCR, ctrl);
 835		return;
 836	}
 837
 838	count = sci_txroom(port);
 839
 840	do {
 841		unsigned char c;
 842
 843		if (port->x_char) {
 844			c = port->x_char;
 845			port->x_char = 0;
 846		} else if (!uart_circ_empty(xmit) && !stopped) {
 847			c = xmit->buf[xmit->tail];
 848			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 849		} else if (port->type == PORT_SCI && uart_circ_empty(xmit)) {
 850			ctrl = serial_port_in(port, SCSCR);
 851			ctrl &= ~SCSCR_TE;
 852			serial_port_out(port, SCSCR, ctrl);
 853			return;
 854		} else {
 855			break;
 856		}
 857
 858		serial_port_out(port, SCxTDR, c);
 859
 860		port->icount.tx++;
 861	} while (--count > 0);
 862
 863	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 864
 865	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 866		uart_write_wakeup(port);
 867	if (uart_circ_empty(xmit)) {
 868		if (port->type == PORT_SCI) {
 869			ctrl = serial_port_in(port, SCSCR);
 870			ctrl &= ~SCSCR_TIE;
 871			ctrl |= SCSCR_TEIE;
 872			serial_port_out(port, SCSCR, ctrl);
 873		}
 874
 875		sci_stop_tx(port);
 876	}
 877}
 878
 879static void sci_receive_chars(struct uart_port *port)
 880{
 881	struct tty_port *tport = &port->state->port;
 882	int i, count, copied = 0;
 883	unsigned short status;
 884	unsigned char flag;
 885
 886	status = serial_port_in(port, SCxSR);
 887	if (!(status & SCxSR_RDxF(port)))
 888		return;
 889
 890	while (1) {
 891		/* Don't copy more bytes than there is room for in the buffer */
 892		count = tty_buffer_request_room(tport, sci_rxfill(port));
 893
 894		/* If for any reason we can't copy more data, we're done! */
 895		if (count == 0)
 896			break;
 897
 898		if (port->type == PORT_SCI) {
 899			char c = serial_port_in(port, SCxRDR);
 900			if (uart_handle_sysrq_char(port, c))
 901				count = 0;
 902			else
 903				tty_insert_flip_char(tport, c, TTY_NORMAL);
 904		} else {
 905			for (i = 0; i < count; i++) {
 906				char c;
 907
 908				if (port->type == PORT_SCIF ||
 909				    port->type == PORT_HSCIF) {
 910					status = serial_port_in(port, SCxSR);
 911					c = serial_port_in(port, SCxRDR);
 912				} else {
 913					c = serial_port_in(port, SCxRDR);
 914					status = serial_port_in(port, SCxSR);
 915				}
 916				if (uart_handle_sysrq_char(port, c)) {
 917					count--; i--;
 918					continue;
 919				}
 920
 921				/* Store data and status */
 922				if (status & SCxSR_FER(port)) {
 923					flag = TTY_FRAME;
 924					port->icount.frame++;
 925				} else if (status & SCxSR_PER(port)) {
 926					flag = TTY_PARITY;
 927					port->icount.parity++;
 928				} else
 929					flag = TTY_NORMAL;
 930
 931				tty_insert_flip_char(tport, c, flag);
 932			}
 933		}
 934
 935		serial_port_in(port, SCxSR); /* dummy read */
 936		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 937
 938		copied += count;
 939		port->icount.rx += count;
 940	}
 941
 942	if (copied) {
 943		/* Tell the rest of the system the news. New characters! */
 944		tty_flip_buffer_push(tport);
 945	} else {
 946		/* TTY buffers full; read from RX reg to prevent lockup */
 947		serial_port_in(port, SCxRDR);
 948		serial_port_in(port, SCxSR); /* dummy read */
 949		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 950	}
 951}
 952
 953static int sci_handle_errors(struct uart_port *port)
 954{
 955	int copied = 0;
 956	unsigned short status = serial_port_in(port, SCxSR);
 957	struct tty_port *tport = &port->state->port;
 958	struct sci_port *s = to_sci_port(port);
 959
 960	/* Handle overruns */
 961	if (status & s->params->overrun_mask) {
 962		port->icount.overrun++;
 963
 964		/* overrun error */
 965		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 966			copied++;
 967	}
 968
 969	if (status & SCxSR_FER(port)) {
 970		/* frame error */
 971		port->icount.frame++;
 972
 973		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
 974			copied++;
 975	}
 976
 977	if (status & SCxSR_PER(port)) {
 978		/* parity error */
 979		port->icount.parity++;
 980
 981		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
 982			copied++;
 983	}
 984
 985	if (copied)
 986		tty_flip_buffer_push(tport);
 987
 988	return copied;
 989}
 990
 991static int sci_handle_fifo_overrun(struct uart_port *port)
 992{
 993	struct tty_port *tport = &port->state->port;
 994	struct sci_port *s = to_sci_port(port);
 995	const struct plat_sci_reg *reg;
 996	int copied = 0;
 997	u16 status;
 998
 999	reg = sci_getreg(port, s->params->overrun_reg);
1000	if (!reg->size)
1001		return 0;
1002
1003	status = serial_port_in(port, s->params->overrun_reg);
1004	if (status & s->params->overrun_mask) {
1005		status &= ~s->params->overrun_mask;
1006		serial_port_out(port, s->params->overrun_reg, status);
1007
1008		port->icount.overrun++;
1009
1010		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1011		tty_flip_buffer_push(tport);
1012		copied++;
1013	}
1014
1015	return copied;
1016}
1017
1018static int sci_handle_breaks(struct uart_port *port)
1019{
1020	int copied = 0;
1021	unsigned short status = serial_port_in(port, SCxSR);
1022	struct tty_port *tport = &port->state->port;
1023
1024	if (uart_handle_break(port))
1025		return 0;
1026
1027	if (status & SCxSR_BRK(port)) {
1028		port->icount.brk++;
1029
1030		/* Notify of BREAK */
1031		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1032			copied++;
1033	}
1034
1035	if (copied)
1036		tty_flip_buffer_push(tport);
1037
1038	copied += sci_handle_fifo_overrun(port);
1039
1040	return copied;
1041}
1042
1043static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1044{
1045	unsigned int bits;
1046
1047	if (rx_trig >= port->fifosize)
1048		rx_trig = port->fifosize - 1;
1049	if (rx_trig < 1)
1050		rx_trig = 1;
1051
1052	/* HSCIF can be set to an arbitrary level. */
1053	if (sci_getreg(port, HSRTRGR)->size) {
1054		serial_port_out(port, HSRTRGR, rx_trig);
1055		return rx_trig;
1056	}
1057
1058	switch (port->type) {
1059	case PORT_SCIF:
1060		if (rx_trig < 4) {
1061			bits = 0;
1062			rx_trig = 1;
1063		} else if (rx_trig < 8) {
1064			bits = SCFCR_RTRG0;
1065			rx_trig = 4;
1066		} else if (rx_trig < 14) {
1067			bits = SCFCR_RTRG1;
1068			rx_trig = 8;
1069		} else {
1070			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1071			rx_trig = 14;
1072		}
1073		break;
1074	case PORT_SCIFA:
1075	case PORT_SCIFB:
1076		if (rx_trig < 16) {
1077			bits = 0;
1078			rx_trig = 1;
1079		} else if (rx_trig < 32) {
1080			bits = SCFCR_RTRG0;
1081			rx_trig = 16;
1082		} else if (rx_trig < 48) {
1083			bits = SCFCR_RTRG1;
1084			rx_trig = 32;
1085		} else {
1086			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1087			rx_trig = 48;
1088		}
1089		break;
1090	default:
1091		WARN(1, "unknown FIFO configuration");
1092		return 1;
1093	}
1094
1095	serial_port_out(port, SCFCR,
1096		(serial_port_in(port, SCFCR) &
1097		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1098
1099	return rx_trig;
1100}
1101
1102static int scif_rtrg_enabled(struct uart_port *port)
1103{
1104	if (sci_getreg(port, HSRTRGR)->size)
1105		return serial_port_in(port, HSRTRGR) != 0;
1106	else
1107		return (serial_port_in(port, SCFCR) &
1108			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1109}
1110
1111static void rx_fifo_timer_fn(struct timer_list *t)
1112{
1113	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1114	struct uart_port *port = &s->port;
1115
1116	dev_dbg(port->dev, "Rx timed out\n");
1117	scif_set_rtrg(port, 1);
1118}
1119
1120static ssize_t rx_fifo_trigger_show(struct device *dev,
1121				    struct device_attribute *attr, char *buf)
1122{
1123	struct uart_port *port = dev_get_drvdata(dev);
1124	struct sci_port *sci = to_sci_port(port);
1125
1126	return sprintf(buf, "%d\n", sci->rx_trigger);
1127}
1128
1129static ssize_t rx_fifo_trigger_store(struct device *dev,
1130				     struct device_attribute *attr,
1131				     const char *buf, size_t count)
1132{
1133	struct uart_port *port = dev_get_drvdata(dev);
1134	struct sci_port *sci = to_sci_port(port);
1135	int ret;
1136	long r;
1137
1138	ret = kstrtol(buf, 0, &r);
1139	if (ret)
1140		return ret;
1141
1142	sci->rx_trigger = scif_set_rtrg(port, r);
1143	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1144		scif_set_rtrg(port, 1);
1145
1146	return count;
1147}
1148
1149static DEVICE_ATTR_RW(rx_fifo_trigger);
1150
1151static ssize_t rx_fifo_timeout_show(struct device *dev,
1152			       struct device_attribute *attr,
1153			       char *buf)
1154{
1155	struct uart_port *port = dev_get_drvdata(dev);
1156	struct sci_port *sci = to_sci_port(port);
1157	int v;
1158
1159	if (port->type == PORT_HSCIF)
1160		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1161	else
1162		v = sci->rx_fifo_timeout;
1163
1164	return sprintf(buf, "%d\n", v);
1165}
1166
1167static ssize_t rx_fifo_timeout_store(struct device *dev,
1168				struct device_attribute *attr,
1169				const char *buf,
1170				size_t count)
1171{
1172	struct uart_port *port = dev_get_drvdata(dev);
1173	struct sci_port *sci = to_sci_port(port);
1174	int ret;
1175	long r;
1176
1177	ret = kstrtol(buf, 0, &r);
1178	if (ret)
1179		return ret;
1180
1181	if (port->type == PORT_HSCIF) {
1182		if (r < 0 || r > 3)
1183			return -EINVAL;
1184		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1185	} else {
1186		sci->rx_fifo_timeout = r;
1187		scif_set_rtrg(port, 1);
1188		if (r > 0)
1189			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1190	}
1191
1192	return count;
1193}
1194
1195static DEVICE_ATTR_RW(rx_fifo_timeout);
1196
1197
1198#ifdef CONFIG_SERIAL_SH_SCI_DMA
1199static void sci_dma_tx_complete(void *arg)
1200{
1201	struct sci_port *s = arg;
1202	struct uart_port *port = &s->port;
1203	struct circ_buf *xmit = &port->state->xmit;
1204	unsigned long flags;
1205
1206	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1207
1208	uart_port_lock_irqsave(port, &flags);
1209
1210	uart_xmit_advance(port, s->tx_dma_len);
1211
1212	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1213		uart_write_wakeup(port);
1214
1215	if (!uart_circ_empty(xmit)) {
1216		s->cookie_tx = 0;
1217		schedule_work(&s->work_tx);
1218	} else {
1219		s->cookie_tx = -EINVAL;
1220		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1221		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1222			u16 ctrl = serial_port_in(port, SCSCR);
1223			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1224			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1225				/* Switch irq from DMA to SCIF */
1226				dmaengine_pause(s->chan_tx_saved);
1227				enable_irq(s->irqs[SCIx_TXI_IRQ]);
1228			}
1229		}
1230	}
1231
1232	uart_port_unlock_irqrestore(port, flags);
1233}
1234
1235/* Locking: called with port lock held */
1236static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1237{
1238	struct uart_port *port = &s->port;
1239	struct tty_port *tport = &port->state->port;
1240	int copied;
1241
1242	copied = tty_insert_flip_string(tport, buf, count);
1243	if (copied < count)
1244		port->icount.buf_overrun++;
1245
1246	port->icount.rx += copied;
1247
1248	return copied;
1249}
1250
1251static int sci_dma_rx_find_active(struct sci_port *s)
1252{
1253	unsigned int i;
1254
1255	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1256		if (s->active_rx == s->cookie_rx[i])
1257			return i;
1258
1259	return -1;
1260}
1261
1262static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1263{
1264	unsigned int i;
1265
1266	s->chan_rx = NULL;
1267	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1268		s->cookie_rx[i] = -EINVAL;
1269	s->active_rx = 0;
1270}
1271
1272static void sci_dma_rx_release(struct sci_port *s)
1273{
1274	struct dma_chan *chan = s->chan_rx_saved;
1275
1276	s->chan_rx_saved = NULL;
1277	sci_dma_rx_chan_invalidate(s);
1278	dmaengine_terminate_sync(chan);
1279	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1280			  sg_dma_address(&s->sg_rx[0]));
1281	dma_release_channel(chan);
1282}
1283
1284static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1285{
1286	long sec = usec / 1000000;
1287	long nsec = (usec % 1000000) * 1000;
1288	ktime_t t = ktime_set(sec, nsec);
1289
1290	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1291}
1292
1293static void sci_dma_rx_reenable_irq(struct sci_port *s)
1294{
1295	struct uart_port *port = &s->port;
1296	u16 scr;
1297
1298	/* Direct new serial port interrupts back to CPU */
1299	scr = serial_port_in(port, SCSCR);
1300	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1301	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1302		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1303		if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1304			scif_set_rtrg(port, s->rx_trigger);
1305		else
1306			scr &= ~SCSCR_RDRQE;
1307	}
1308	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1309}
1310
1311static void sci_dma_rx_complete(void *arg)
1312{
1313	struct sci_port *s = arg;
1314	struct dma_chan *chan = s->chan_rx;
1315	struct uart_port *port = &s->port;
1316	struct dma_async_tx_descriptor *desc;
1317	unsigned long flags;
1318	int active, count = 0;
1319
1320	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1321		s->active_rx);
1322
1323	uart_port_lock_irqsave(port, &flags);
1324
1325	active = sci_dma_rx_find_active(s);
1326	if (active >= 0)
1327		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1328
1329	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1330
1331	if (count)
1332		tty_flip_buffer_push(&port->state->port);
1333
1334	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1335				       DMA_DEV_TO_MEM,
1336				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1337	if (!desc)
1338		goto fail;
1339
1340	desc->callback = sci_dma_rx_complete;
1341	desc->callback_param = s;
1342	s->cookie_rx[active] = dmaengine_submit(desc);
1343	if (dma_submit_error(s->cookie_rx[active]))
1344		goto fail;
1345
1346	s->active_rx = s->cookie_rx[!active];
1347
1348	dma_async_issue_pending(chan);
1349
1350	uart_port_unlock_irqrestore(port, flags);
1351	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1352		__func__, s->cookie_rx[active], active, s->active_rx);
1353	return;
1354
1355fail:
1356	uart_port_unlock_irqrestore(port, flags);
1357	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1358	/* Switch to PIO */
1359	uart_port_lock_irqsave(port, &flags);
1360	dmaengine_terminate_async(chan);
1361	sci_dma_rx_chan_invalidate(s);
1362	sci_dma_rx_reenable_irq(s);
1363	uart_port_unlock_irqrestore(port, flags);
1364}
1365
1366static void sci_dma_tx_release(struct sci_port *s)
1367{
1368	struct dma_chan *chan = s->chan_tx_saved;
1369
1370	cancel_work_sync(&s->work_tx);
1371	s->chan_tx_saved = s->chan_tx = NULL;
1372	s->cookie_tx = -EINVAL;
1373	dmaengine_terminate_sync(chan);
1374	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1375			 DMA_TO_DEVICE);
1376	dma_release_channel(chan);
1377}
1378
1379static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1380{
1381	struct dma_chan *chan = s->chan_rx;
1382	struct uart_port *port = &s->port;
1383	unsigned long flags;
1384	int i;
1385
1386	for (i = 0; i < 2; i++) {
1387		struct scatterlist *sg = &s->sg_rx[i];
1388		struct dma_async_tx_descriptor *desc;
1389
1390		desc = dmaengine_prep_slave_sg(chan,
1391			sg, 1, DMA_DEV_TO_MEM,
1392			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1393		if (!desc)
1394			goto fail;
1395
1396		desc->callback = sci_dma_rx_complete;
1397		desc->callback_param = s;
1398		s->cookie_rx[i] = dmaengine_submit(desc);
1399		if (dma_submit_error(s->cookie_rx[i]))
1400			goto fail;
1401
1402	}
1403
1404	s->active_rx = s->cookie_rx[0];
1405
1406	dma_async_issue_pending(chan);
1407	return 0;
1408
1409fail:
1410	/* Switch to PIO */
1411	if (!port_lock_held)
1412		uart_port_lock_irqsave(port, &flags);
1413	if (i)
1414		dmaengine_terminate_async(chan);
1415	sci_dma_rx_chan_invalidate(s);
1416	sci_start_rx(port);
1417	if (!port_lock_held)
1418		uart_port_unlock_irqrestore(port, flags);
1419	return -EAGAIN;
1420}
1421
1422static void sci_dma_tx_work_fn(struct work_struct *work)
1423{
1424	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1425	struct dma_async_tx_descriptor *desc;
1426	struct dma_chan *chan = s->chan_tx;
1427	struct uart_port *port = &s->port;
1428	struct circ_buf *xmit = &port->state->xmit;
1429	unsigned long flags;
1430	dma_addr_t buf;
1431	int head, tail;
1432
1433	/*
1434	 * DMA is idle now.
1435	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1436	 * offsets and lengths. Since it is a circular buffer, we have to
1437	 * transmit till the end, and then the rest. Take the port lock to get a
1438	 * consistent xmit buffer state.
1439	 */
1440	uart_port_lock_irq(port);
1441	head = xmit->head;
1442	tail = xmit->tail;
1443	buf = s->tx_dma_addr + tail;
1444	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
1445	if (!s->tx_dma_len) {
1446		/* Transmit buffer has been flushed */
1447		uart_port_unlock_irq(port);
1448		return;
1449	}
1450
1451	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1452					   DMA_MEM_TO_DEV,
1453					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1454	if (!desc) {
1455		uart_port_unlock_irq(port);
1456		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1457		goto switch_to_pio;
1458	}
1459
1460	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1461				   DMA_TO_DEVICE);
1462
1463	desc->callback = sci_dma_tx_complete;
1464	desc->callback_param = s;
1465	s->cookie_tx = dmaengine_submit(desc);
1466	if (dma_submit_error(s->cookie_tx)) {
1467		uart_port_unlock_irq(port);
1468		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1469		goto switch_to_pio;
1470	}
1471
1472	uart_port_unlock_irq(port);
1473	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1474		__func__, xmit->buf, tail, head, s->cookie_tx);
1475
1476	dma_async_issue_pending(chan);
1477	return;
1478
1479switch_to_pio:
1480	uart_port_lock_irqsave(port, &flags);
1481	s->chan_tx = NULL;
1482	sci_start_tx(port);
1483	uart_port_unlock_irqrestore(port, flags);
1484	return;
1485}
1486
1487static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1488{
1489	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1490	struct dma_chan *chan = s->chan_rx;
1491	struct uart_port *port = &s->port;
1492	struct dma_tx_state state;
1493	enum dma_status status;
1494	unsigned long flags;
1495	unsigned int read;
1496	int active, count;
1497
1498	dev_dbg(port->dev, "DMA Rx timed out\n");
1499
1500	uart_port_lock_irqsave(port, &flags);
1501
1502	active = sci_dma_rx_find_active(s);
1503	if (active < 0) {
1504		uart_port_unlock_irqrestore(port, flags);
1505		return HRTIMER_NORESTART;
1506	}
1507
1508	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1509	if (status == DMA_COMPLETE) {
1510		uart_port_unlock_irqrestore(port, flags);
1511		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1512			s->active_rx, active);
1513
1514		/* Let packet complete handler take care of the packet */
1515		return HRTIMER_NORESTART;
1516	}
1517
1518	dmaengine_pause(chan);
1519
1520	/*
1521	 * sometimes DMA transfer doesn't stop even if it is stopped and
1522	 * data keeps on coming until transaction is complete so check
1523	 * for DMA_COMPLETE again
1524	 * Let packet complete handler take care of the packet
1525	 */
1526	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1527	if (status == DMA_COMPLETE) {
1528		uart_port_unlock_irqrestore(port, flags);
1529		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1530		return HRTIMER_NORESTART;
1531	}
1532
1533	/* Handle incomplete DMA receive */
1534	dmaengine_terminate_async(s->chan_rx);
1535	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1536
1537	if (read) {
1538		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1539		if (count)
1540			tty_flip_buffer_push(&port->state->port);
1541	}
1542
1543	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1544	    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1545		sci_dma_rx_submit(s, true);
1546
1547	sci_dma_rx_reenable_irq(s);
1548
1549	uart_port_unlock_irqrestore(port, flags);
1550
1551	return HRTIMER_NORESTART;
1552}
1553
1554static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1555					     enum dma_transfer_direction dir)
1556{
1557	struct dma_chan *chan;
1558	struct dma_slave_config cfg;
1559	int ret;
1560
1561	chan = dma_request_chan(port->dev, dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1562	if (IS_ERR(chan)) {
1563		dev_dbg(port->dev, "dma_request_chan failed\n");
 
1564		return NULL;
1565	}
1566
1567	memset(&cfg, 0, sizeof(cfg));
1568	cfg.direction = dir;
1569	cfg.dst_addr = port->mapbase +
1570		(sci_getreg(port, SCxTDR)->offset << port->regshift);
1571	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1572	cfg.src_addr = port->mapbase +
1573		(sci_getreg(port, SCxRDR)->offset << port->regshift);
1574	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 
 
 
1575
1576	ret = dmaengine_slave_config(chan, &cfg);
1577	if (ret) {
1578		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1579		dma_release_channel(chan);
1580		return NULL;
1581	}
1582
1583	return chan;
1584}
1585
1586static void sci_request_dma(struct uart_port *port)
1587{
1588	struct sci_port *s = to_sci_port(port);
1589	struct dma_chan *chan;
1590
1591	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1592
1593	/*
1594	 * DMA on console may interfere with Kernel log messages which use
1595	 * plain putchar(). So, simply don't use it with a console.
1596	 */
1597	if (uart_console(port))
1598		return;
1599
1600	if (!port->dev->of_node)
1601		return;
1602
1603	s->cookie_tx = -EINVAL;
1604
1605	/*
1606	 * Don't request a dma channel if no channel was specified
1607	 * in the device tree.
1608	 */
1609	if (!of_property_present(port->dev->of_node, "dmas"))
1610		return;
1611
1612	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1613	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1614	if (chan) {
1615		/* UART circular tx buffer is an aligned page. */
1616		s->tx_dma_addr = dma_map_single(chan->device->dev,
1617						port->state->xmit.buf,
1618						UART_XMIT_SIZE,
1619						DMA_TO_DEVICE);
1620		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1621			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1622			dma_release_channel(chan);
1623		} else {
1624			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1625				__func__, UART_XMIT_SIZE,
1626				port->state->xmit.buf, &s->tx_dma_addr);
1627
1628			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1629			s->chan_tx_saved = s->chan_tx = chan;
1630		}
1631	}
1632
1633	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1634	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1635	if (chan) {
1636		unsigned int i;
1637		dma_addr_t dma;
1638		void *buf;
1639
1640		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1641		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1642					 &dma, GFP_KERNEL);
1643		if (!buf) {
1644			dev_warn(port->dev,
1645				 "Failed to allocate Rx dma buffer, using PIO\n");
1646			dma_release_channel(chan);
1647			return;
1648		}
1649
1650		for (i = 0; i < 2; i++) {
1651			struct scatterlist *sg = &s->sg_rx[i];
1652
1653			sg_init_table(sg, 1);
1654			s->rx_buf[i] = buf;
1655			sg_dma_address(sg) = dma;
1656			sg_dma_len(sg) = s->buf_len_rx;
1657
1658			buf += s->buf_len_rx;
1659			dma += s->buf_len_rx;
1660		}
1661
1662		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1663		s->rx_timer.function = sci_dma_rx_timer_fn;
1664
1665		s->chan_rx_saved = s->chan_rx = chan;
1666
1667		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1668		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)
1669			sci_dma_rx_submit(s, false);
1670	}
1671}
1672
1673static void sci_free_dma(struct uart_port *port)
1674{
1675	struct sci_port *s = to_sci_port(port);
1676
1677	if (s->chan_tx_saved)
1678		sci_dma_tx_release(s);
1679	if (s->chan_rx_saved)
1680		sci_dma_rx_release(s);
1681}
1682
1683static void sci_flush_buffer(struct uart_port *port)
1684{
1685	struct sci_port *s = to_sci_port(port);
1686
1687	/*
1688	 * In uart_flush_buffer(), the xmit circular buffer has just been
1689	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1690	 * pending transfers
1691	 */
1692	s->tx_dma_len = 0;
1693	if (s->chan_tx) {
1694		dmaengine_terminate_async(s->chan_tx);
1695		s->cookie_tx = -EINVAL;
1696	}
1697}
1698#else /* !CONFIG_SERIAL_SH_SCI_DMA */
1699static inline void sci_request_dma(struct uart_port *port)
1700{
1701}
1702
1703static inline void sci_free_dma(struct uart_port *port)
1704{
1705}
1706
1707#define sci_flush_buffer	NULL
1708#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1709
1710static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1711{
1712	struct uart_port *port = ptr;
1713	struct sci_port *s = to_sci_port(port);
1714
1715#ifdef CONFIG_SERIAL_SH_SCI_DMA
1716	if (s->chan_rx) {
1717		u16 scr = serial_port_in(port, SCSCR);
1718		u16 ssr = serial_port_in(port, SCxSR);
1719
1720		/* Disable future Rx interrupts */
1721		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
1722		    s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1723			disable_irq_nosync(s->irqs[SCIx_RXI_IRQ]);
1724			if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE) {
1725				scif_set_rtrg(port, 1);
1726				scr |= SCSCR_RIE;
1727			} else {
1728				scr |= SCSCR_RDRQE;
1729			}
1730		} else {
1731			if (sci_dma_rx_submit(s, false) < 0)
1732				goto handle_pio;
1733
1734			scr &= ~SCSCR_RIE;
1735		}
1736		serial_port_out(port, SCSCR, scr);
1737		/* Clear current interrupt */
1738		serial_port_out(port, SCxSR,
1739				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1740		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1741			jiffies, s->rx_timeout);
1742		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1743
1744		return IRQ_HANDLED;
1745	}
1746
1747handle_pio:
1748#endif
1749
1750	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1751		if (!scif_rtrg_enabled(port))
1752			scif_set_rtrg(port, s->rx_trigger);
1753
1754		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1755			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1756	}
1757
1758	/* I think sci_receive_chars has to be called irrespective
1759	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1760	 * to be disabled?
1761	 */
1762	sci_receive_chars(port);
1763
1764	return IRQ_HANDLED;
1765}
1766
1767static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1768{
1769	struct uart_port *port = ptr;
1770	unsigned long flags;
1771
1772	uart_port_lock_irqsave(port, &flags);
1773	sci_transmit_chars(port);
1774	uart_port_unlock_irqrestore(port, flags);
1775
1776	return IRQ_HANDLED;
1777}
1778
1779static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
1780{
1781	struct uart_port *port = ptr;
1782	unsigned long flags;
1783	unsigned short ctrl;
1784
1785	if (port->type != PORT_SCI)
1786		return sci_tx_interrupt(irq, ptr);
1787
1788	uart_port_lock_irqsave(port, &flags);
1789	ctrl = serial_port_in(port, SCSCR);
1790	ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
1791	serial_port_out(port, SCSCR, ctrl);
1792	uart_port_unlock_irqrestore(port, flags);
1793
1794	return IRQ_HANDLED;
1795}
1796
1797static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1798{
1799	struct uart_port *port = ptr;
1800
1801	/* Handle BREAKs */
1802	sci_handle_breaks(port);
1803
1804	/* drop invalid character received before break was detected */
1805	serial_port_in(port, SCxRDR);
1806
1807	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1808
1809	return IRQ_HANDLED;
1810}
1811
1812static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1813{
1814	struct uart_port *port = ptr;
1815	struct sci_port *s = to_sci_port(port);
1816
1817	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1818		/* Break and Error interrupts are muxed */
1819		unsigned short ssr_status = serial_port_in(port, SCxSR);
1820
1821		/* Break Interrupt */
1822		if (ssr_status & SCxSR_BRK(port))
1823			sci_br_interrupt(irq, ptr);
1824
1825		/* Break only? */
1826		if (!(ssr_status & SCxSR_ERRORS(port)))
1827			return IRQ_HANDLED;
1828	}
1829
1830	/* Handle errors */
1831	if (port->type == PORT_SCI) {
1832		if (sci_handle_errors(port)) {
1833			/* discard character in rx buffer */
1834			serial_port_in(port, SCxSR);
1835			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1836		}
1837	} else {
1838		sci_handle_fifo_overrun(port);
1839		if (!s->chan_rx)
1840			sci_receive_chars(port);
1841	}
1842
1843	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1844
1845	/* Kick the transmission */
1846	if (!s->chan_tx)
1847		sci_tx_interrupt(irq, ptr);
1848
1849	return IRQ_HANDLED;
1850}
1851
1852static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1853{
1854	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1855	struct uart_port *port = ptr;
1856	struct sci_port *s = to_sci_port(port);
1857	irqreturn_t ret = IRQ_NONE;
1858
1859	ssr_status = serial_port_in(port, SCxSR);
1860	scr_status = serial_port_in(port, SCSCR);
1861	if (s->params->overrun_reg == SCxSR)
1862		orer_status = ssr_status;
1863	else if (sci_getreg(port, s->params->overrun_reg)->size)
1864		orer_status = serial_port_in(port, s->params->overrun_reg);
1865
1866	err_enabled = scr_status & port_rx_irq_mask(port);
1867
1868	/* Tx Interrupt */
1869	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1870	    !s->chan_tx)
1871		ret = sci_tx_interrupt(irq, ptr);
1872
1873	/*
1874	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1875	 * DR flags
1876	 */
1877	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1878	    (scr_status & SCSCR_RIE))
1879		ret = sci_rx_interrupt(irq, ptr);
1880
1881	/* Error Interrupt */
1882	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1883		ret = sci_er_interrupt(irq, ptr);
1884
1885	/* Break Interrupt */
1886	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1887	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1888		ret = sci_br_interrupt(irq, ptr);
1889
1890	/* Overrun Interrupt */
1891	if (orer_status & s->params->overrun_mask) {
1892		sci_handle_fifo_overrun(port);
1893		ret = IRQ_HANDLED;
1894	}
1895
1896	return ret;
1897}
1898
1899static const struct sci_irq_desc {
1900	const char	*desc;
1901	irq_handler_t	handler;
1902} sci_irq_desc[] = {
1903	/*
1904	 * Split out handlers, the default case.
1905	 */
1906	[SCIx_ERI_IRQ] = {
1907		.desc = "rx err",
1908		.handler = sci_er_interrupt,
1909	},
1910
1911	[SCIx_RXI_IRQ] = {
1912		.desc = "rx full",
1913		.handler = sci_rx_interrupt,
1914	},
1915
1916	[SCIx_TXI_IRQ] = {
1917		.desc = "tx empty",
1918		.handler = sci_tx_interrupt,
1919	},
1920
1921	[SCIx_BRI_IRQ] = {
1922		.desc = "break",
1923		.handler = sci_br_interrupt,
1924	},
1925
1926	[SCIx_DRI_IRQ] = {
1927		.desc = "rx ready",
1928		.handler = sci_rx_interrupt,
1929	},
1930
1931	[SCIx_TEI_IRQ] = {
1932		.desc = "tx end",
1933		.handler = sci_tx_end_interrupt,
1934	},
1935
1936	/*
1937	 * Special muxed handler.
1938	 */
1939	[SCIx_MUX_IRQ] = {
1940		.desc = "mux",
1941		.handler = sci_mpxed_interrupt,
1942	},
1943};
1944
1945static int sci_request_irq(struct sci_port *port)
1946{
1947	struct uart_port *up = &port->port;
1948	int i, j, w, ret = 0;
1949
1950	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1951		const struct sci_irq_desc *desc;
1952		int irq;
1953
1954		/* Check if already registered (muxed) */
1955		for (w = 0; w < i; w++)
1956			if (port->irqs[w] == port->irqs[i])
1957				w = i + 1;
1958		if (w > i)
1959			continue;
1960
1961		if (SCIx_IRQ_IS_MUXED(port)) {
1962			i = SCIx_MUX_IRQ;
1963			irq = up->irq;
1964		} else {
1965			irq = port->irqs[i];
1966
1967			/*
1968			 * Certain port types won't support all of the
1969			 * available interrupt sources.
1970			 */
1971			if (unlikely(irq < 0))
1972				continue;
1973		}
1974
1975		desc = sci_irq_desc + i;
1976		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1977					    dev_name(up->dev), desc->desc);
1978		if (!port->irqstr[j]) {
1979			ret = -ENOMEM;
1980			goto out_nomem;
1981		}
1982
1983		ret = request_irq(irq, desc->handler, up->irqflags,
1984				  port->irqstr[j], port);
1985		if (unlikely(ret)) {
1986			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1987			goto out_noirq;
1988		}
1989	}
1990
1991	return 0;
1992
1993out_noirq:
1994	while (--i >= 0)
1995		free_irq(port->irqs[i], port);
1996
1997out_nomem:
1998	while (--j >= 0)
1999		kfree(port->irqstr[j]);
2000
2001	return ret;
2002}
2003
2004static void sci_free_irq(struct sci_port *port)
2005{
2006	int i, j;
2007
2008	/*
2009	 * Intentionally in reverse order so we iterate over the muxed
2010	 * IRQ first.
2011	 */
2012	for (i = 0; i < SCIx_NR_IRQS; i++) {
2013		int irq = port->irqs[i];
2014
2015		/*
2016		 * Certain port types won't support all of the available
2017		 * interrupt sources.
2018		 */
2019		if (unlikely(irq < 0))
2020			continue;
2021
2022		/* Check if already freed (irq was muxed) */
2023		for (j = 0; j < i; j++)
2024			if (port->irqs[j] == irq)
2025				j = i + 1;
2026		if (j > i)
2027			continue;
2028
2029		free_irq(port->irqs[i], port);
2030		kfree(port->irqstr[i]);
2031
2032		if (SCIx_IRQ_IS_MUXED(port)) {
2033			/* If there's only one IRQ, we're done. */
2034			return;
2035		}
2036	}
2037}
2038
2039static unsigned int sci_tx_empty(struct uart_port *port)
2040{
2041	unsigned short status = serial_port_in(port, SCxSR);
2042	unsigned short in_tx_fifo = sci_txfill(port);
2043
2044	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
2045}
2046
2047static void sci_set_rts(struct uart_port *port, bool state)
2048{
2049	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2050		u16 data = serial_port_in(port, SCPDR);
2051
2052		/* Active low */
2053		if (state)
2054			data &= ~SCPDR_RTSD;
2055		else
2056			data |= SCPDR_RTSD;
2057		serial_port_out(port, SCPDR, data);
2058
2059		/* RTS# is output */
2060		serial_port_out(port, SCPCR,
2061				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2062	} else if (sci_getreg(port, SCSPTR)->size) {
2063		u16 ctrl = serial_port_in(port, SCSPTR);
2064
2065		/* Active low */
2066		if (state)
2067			ctrl &= ~SCSPTR_RTSDT;
2068		else
2069			ctrl |= SCSPTR_RTSDT;
2070		serial_port_out(port, SCSPTR, ctrl);
2071	}
2072}
2073
2074static bool sci_get_cts(struct uart_port *port)
2075{
2076	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2077		/* Active low */
2078		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2079	} else if (sci_getreg(port, SCSPTR)->size) {
2080		/* Active low */
2081		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2082	}
2083
2084	return true;
2085}
2086
2087/*
2088 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2089 * CTS/RTS is supported in hardware by at least one port and controlled
2090 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2091 * handled via the ->init_pins() op, which is a bit of a one-way street,
2092 * lacking any ability to defer pin control -- this will later be
2093 * converted over to the GPIO framework).
2094 *
2095 * Other modes (such as loopback) are supported generically on certain
2096 * port types, but not others. For these it's sufficient to test for the
2097 * existence of the support register and simply ignore the port type.
2098 */
2099static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2100{
2101	struct sci_port *s = to_sci_port(port);
2102
2103	if (mctrl & TIOCM_LOOP) {
2104		const struct plat_sci_reg *reg;
2105
2106		/*
2107		 * Standard loopback mode for SCFCR ports.
2108		 */
2109		reg = sci_getreg(port, SCFCR);
2110		if (reg->size)
2111			serial_port_out(port, SCFCR,
2112					serial_port_in(port, SCFCR) |
2113					SCFCR_LOOP);
2114	}
2115
2116	mctrl_gpio_set(s->gpios, mctrl);
2117
2118	if (!s->has_rtscts)
2119		return;
2120
2121	if (!(mctrl & TIOCM_RTS)) {
2122		/* Disable Auto RTS */
2123		serial_port_out(port, SCFCR,
2124				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2125
2126		/* Clear RTS */
2127		sci_set_rts(port, 0);
2128	} else if (s->autorts) {
2129		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2130			/* Enable RTS# pin function */
2131			serial_port_out(port, SCPCR,
2132				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2133		}
2134
2135		/* Enable Auto RTS */
2136		serial_port_out(port, SCFCR,
2137				serial_port_in(port, SCFCR) | SCFCR_MCE);
2138	} else {
2139		/* Set RTS */
2140		sci_set_rts(port, 1);
2141	}
2142}
2143
2144static unsigned int sci_get_mctrl(struct uart_port *port)
2145{
2146	struct sci_port *s = to_sci_port(port);
2147	struct mctrl_gpios *gpios = s->gpios;
2148	unsigned int mctrl = 0;
2149
2150	mctrl_gpio_get(gpios, &mctrl);
2151
2152	/*
2153	 * CTS/RTS is handled in hardware when supported, while nothing
2154	 * else is wired up.
2155	 */
2156	if (s->autorts) {
2157		if (sci_get_cts(port))
2158			mctrl |= TIOCM_CTS;
2159	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2160		mctrl |= TIOCM_CTS;
2161	}
2162	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2163		mctrl |= TIOCM_DSR;
2164	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2165		mctrl |= TIOCM_CAR;
2166
2167	return mctrl;
2168}
2169
2170static void sci_enable_ms(struct uart_port *port)
2171{
2172	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2173}
2174
2175static void sci_break_ctl(struct uart_port *port, int break_state)
2176{
2177	unsigned short scscr, scsptr;
2178	unsigned long flags;
2179
2180	/* check whether the port has SCSPTR */
2181	if (!sci_getreg(port, SCSPTR)->size) {
2182		/*
2183		 * Not supported by hardware. Most parts couple break and rx
2184		 * interrupts together, with break detection always enabled.
2185		 */
2186		return;
2187	}
2188
2189	uart_port_lock_irqsave(port, &flags);
2190	scsptr = serial_port_in(port, SCSPTR);
2191	scscr = serial_port_in(port, SCSCR);
2192
2193	if (break_state == -1) {
2194		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2195		scscr &= ~SCSCR_TE;
2196	} else {
2197		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2198		scscr |= SCSCR_TE;
2199	}
2200
2201	serial_port_out(port, SCSPTR, scsptr);
2202	serial_port_out(port, SCSCR, scscr);
2203	uart_port_unlock_irqrestore(port, flags);
2204}
2205
2206static int sci_startup(struct uart_port *port)
2207{
2208	struct sci_port *s = to_sci_port(port);
2209	int ret;
2210
2211	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2212
2213	sci_request_dma(port);
2214
2215	ret = sci_request_irq(s);
2216	if (unlikely(ret < 0)) {
2217		sci_free_dma(port);
2218		return ret;
2219	}
2220
2221	return 0;
2222}
2223
2224static void sci_shutdown(struct uart_port *port)
2225{
2226	struct sci_port *s = to_sci_port(port);
2227	unsigned long flags;
2228	u16 scr;
2229
2230	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2231
2232	s->autorts = false;
2233	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2234
2235	uart_port_lock_irqsave(port, &flags);
2236	sci_stop_rx(port);
2237	sci_stop_tx(port);
2238	/*
2239	 * Stop RX and TX, disable related interrupts, keep clock source
2240	 * and HSCIF TOT bits
2241	 */
2242	scr = serial_port_in(port, SCSCR);
2243	serial_port_out(port, SCSCR, scr &
2244			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2245	uart_port_unlock_irqrestore(port, flags);
2246
2247#ifdef CONFIG_SERIAL_SH_SCI_DMA
2248	if (s->chan_rx_saved) {
2249		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2250			port->line);
2251		hrtimer_cancel(&s->rx_timer);
2252	}
2253#endif
2254
2255	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2256		del_timer_sync(&s->rx_fifo_timer);
2257	sci_free_irq(s);
2258	sci_free_dma(port);
2259}
2260
2261static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2262			unsigned int *srr)
2263{
2264	unsigned long freq = s->clk_rates[SCI_SCK];
2265	int err, min_err = INT_MAX;
2266	unsigned int sr;
2267
2268	if (s->port.type != PORT_HSCIF)
2269		freq *= 2;
2270
2271	for_each_sr(sr, s) {
2272		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2273		if (abs(err) >= abs(min_err))
2274			continue;
2275
2276		min_err = err;
2277		*srr = sr - 1;
2278
2279		if (!err)
2280			break;
2281	}
2282
2283	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2284		*srr + 1);
2285	return min_err;
2286}
2287
2288static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2289			unsigned long freq, unsigned int *dlr,
2290			unsigned int *srr)
2291{
2292	int err, min_err = INT_MAX;
2293	unsigned int sr, dl;
2294
2295	if (s->port.type != PORT_HSCIF)
2296		freq *= 2;
2297
2298	for_each_sr(sr, s) {
2299		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2300		dl = clamp(dl, 1U, 65535U);
2301
2302		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2303		if (abs(err) >= abs(min_err))
2304			continue;
2305
2306		min_err = err;
2307		*dlr = dl;
2308		*srr = sr - 1;
2309
2310		if (!err)
2311			break;
2312	}
2313
2314	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2315		min_err, *dlr, *srr + 1);
2316	return min_err;
2317}
2318
2319/* calculate sample rate, BRR, and clock select */
2320static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2321			  unsigned int *brr, unsigned int *srr,
2322			  unsigned int *cks)
2323{
2324	unsigned long freq = s->clk_rates[SCI_FCK];
2325	unsigned int sr, br, prediv, scrate, c;
2326	int err, min_err = INT_MAX;
2327
2328	if (s->port.type != PORT_HSCIF)
2329		freq *= 2;
2330
2331	/*
2332	 * Find the combination of sample rate and clock select with the
2333	 * smallest deviation from the desired baud rate.
2334	 * Prefer high sample rates to maximise the receive margin.
2335	 *
2336	 * M: Receive margin (%)
2337	 * N: Ratio of bit rate to clock (N = sampling rate)
2338	 * D: Clock duty (D = 0 to 1.0)
2339	 * L: Frame length (L = 9 to 12)
2340	 * F: Absolute value of clock frequency deviation
2341	 *
2342	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2343	 *      (|D - 0.5| / N * (1 + F))|
2344	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2345	 */
2346	for_each_sr(sr, s) {
2347		for (c = 0; c <= 3; c++) {
2348			/* integerized formulas from HSCIF documentation */
2349			prediv = sr << (2 * c + 1);
2350
2351			/*
2352			 * We need to calculate:
2353			 *
2354			 *     br = freq / (prediv * bps) clamped to [1..256]
2355			 *     err = freq / (br * prediv) - bps
2356			 *
2357			 * Watch out for overflow when calculating the desired
2358			 * sampling clock rate!
2359			 */
2360			if (bps > UINT_MAX / prediv)
2361				break;
2362
2363			scrate = prediv * bps;
2364			br = DIV_ROUND_CLOSEST(freq, scrate);
2365			br = clamp(br, 1U, 256U);
2366
2367			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2368			if (abs(err) >= abs(min_err))
2369				continue;
2370
2371			min_err = err;
2372			*brr = br - 1;
2373			*srr = sr - 1;
2374			*cks = c;
2375
2376			if (!err)
2377				goto found;
2378		}
2379	}
2380
2381found:
2382	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2383		min_err, *brr, *srr + 1, *cks);
2384	return min_err;
2385}
2386
2387static void sci_reset(struct uart_port *port)
2388{
2389	const struct plat_sci_reg *reg;
2390	unsigned int status;
2391	struct sci_port *s = to_sci_port(port);
2392
2393	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2394
2395	reg = sci_getreg(port, SCFCR);
2396	if (reg->size)
2397		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2398
2399	sci_clear_SCxSR(port,
2400			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2401			SCxSR_BREAK_CLEAR(port));
2402	if (sci_getreg(port, SCLSR)->size) {
2403		status = serial_port_in(port, SCLSR);
2404		status &= ~(SCLSR_TO | SCLSR_ORER);
2405		serial_port_out(port, SCLSR, status);
2406	}
2407
2408	if (s->rx_trigger > 1) {
2409		if (s->rx_fifo_timeout) {
2410			scif_set_rtrg(port, 1);
2411			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2412		} else {
2413			if (port->type == PORT_SCIFA ||
2414			    port->type == PORT_SCIFB)
2415				scif_set_rtrg(port, 1);
2416			else
2417				scif_set_rtrg(port, s->rx_trigger);
2418		}
2419	}
2420}
2421
2422static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2423		            const struct ktermios *old)
2424{
2425	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2426	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2427	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2428	struct sci_port *s = to_sci_port(port);
2429	const struct plat_sci_reg *reg;
2430	int min_err = INT_MAX, err;
2431	unsigned long max_freq = 0;
2432	int best_clk = -1;
2433	unsigned long flags;
2434
2435	if ((termios->c_cflag & CSIZE) == CS7) {
2436		smr_val |= SCSMR_CHR;
2437	} else {
2438		termios->c_cflag &= ~CSIZE;
2439		termios->c_cflag |= CS8;
2440	}
2441	if (termios->c_cflag & PARENB)
2442		smr_val |= SCSMR_PE;
2443	if (termios->c_cflag & PARODD)
2444		smr_val |= SCSMR_PE | SCSMR_ODD;
2445	if (termios->c_cflag & CSTOPB)
2446		smr_val |= SCSMR_STOP;
2447
2448	/*
2449	 * earlyprintk comes here early on with port->uartclk set to zero.
2450	 * the clock framework is not up and running at this point so here
2451	 * we assume that 115200 is the maximum baud rate. please note that
2452	 * the baud rate is not programmed during earlyprintk - it is assumed
2453	 * that the previous boot loader has enabled required clocks and
2454	 * setup the baud rate generator hardware for us already.
2455	 */
2456	if (!port->uartclk) {
2457		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2458		goto done;
2459	}
2460
2461	for (i = 0; i < SCI_NUM_CLKS; i++)
2462		max_freq = max(max_freq, s->clk_rates[i]);
2463
2464	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2465	if (!baud)
2466		goto done;
2467
2468	/*
2469	 * There can be multiple sources for the sampling clock.  Find the one
2470	 * that gives us the smallest deviation from the desired baud rate.
2471	 */
2472
2473	/* Optional Undivided External Clock */
2474	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2475	    port->type != PORT_SCIFB) {
2476		err = sci_sck_calc(s, baud, &srr1);
2477		if (abs(err) < abs(min_err)) {
2478			best_clk = SCI_SCK;
2479			scr_val = SCSCR_CKE1;
2480			sccks = SCCKS_CKS;
2481			min_err = err;
2482			srr = srr1;
2483			if (!err)
2484				goto done;
2485		}
2486	}
2487
2488	/* Optional BRG Frequency Divided External Clock */
2489	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2490		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2491				   &srr1);
2492		if (abs(err) < abs(min_err)) {
2493			best_clk = SCI_SCIF_CLK;
2494			scr_val = SCSCR_CKE1;
2495			sccks = 0;
2496			min_err = err;
2497			dl = dl1;
2498			srr = srr1;
2499			if (!err)
2500				goto done;
2501		}
2502	}
2503
2504	/* Optional BRG Frequency Divided Internal Clock */
2505	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2506		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2507				   &srr1);
2508		if (abs(err) < abs(min_err)) {
2509			best_clk = SCI_BRG_INT;
2510			scr_val = SCSCR_CKE1;
2511			sccks = SCCKS_XIN;
2512			min_err = err;
2513			dl = dl1;
2514			srr = srr1;
2515			if (!min_err)
2516				goto done;
2517		}
2518	}
2519
2520	/* Divided Functional Clock using standard Bit Rate Register */
2521	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2522	if (abs(err) < abs(min_err)) {
2523		best_clk = SCI_FCK;
2524		scr_val = 0;
2525		min_err = err;
2526		brr = brr1;
2527		srr = srr1;
2528		cks = cks1;
2529	}
2530
2531done:
2532	if (best_clk >= 0)
2533		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2534			s->clks[best_clk], baud, min_err);
2535
2536	sci_port_enable(s);
2537
2538	/*
2539	 * Program the optional External Baud Rate Generator (BRG) first.
2540	 * It controls the mux to select (H)SCK or frequency divided clock.
2541	 */
2542	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2543		serial_port_out(port, SCDL, dl);
2544		serial_port_out(port, SCCKS, sccks);
2545	}
2546
2547	uart_port_lock_irqsave(port, &flags);
2548
2549	sci_reset(port);
2550
2551	uart_update_timeout(port, termios->c_cflag, baud);
2552
2553	/* byte size and parity */
2554	bits = tty_get_frame_size(termios->c_cflag);
2555
2556	if (sci_getreg(port, SEMR)->size)
2557		serial_port_out(port, SEMR, 0);
2558
2559	if (best_clk >= 0) {
2560		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2561			switch (srr + 1) {
2562			case 5:  smr_val |= SCSMR_SRC_5;  break;
2563			case 7:  smr_val |= SCSMR_SRC_7;  break;
2564			case 11: smr_val |= SCSMR_SRC_11; break;
2565			case 13: smr_val |= SCSMR_SRC_13; break;
2566			case 16: smr_val |= SCSMR_SRC_16; break;
2567			case 17: smr_val |= SCSMR_SRC_17; break;
2568			case 19: smr_val |= SCSMR_SRC_19; break;
2569			case 27: smr_val |= SCSMR_SRC_27; break;
2570			}
2571		smr_val |= cks;
2572		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2573		serial_port_out(port, SCSMR, smr_val);
2574		serial_port_out(port, SCBRR, brr);
2575		if (sci_getreg(port, HSSRR)->size) {
2576			unsigned int hssrr = srr | HSCIF_SRE;
2577			/* Calculate deviation from intended rate at the
2578			 * center of the last stop bit in sampling clocks.
2579			 */
2580			int last_stop = bits * 2 - 1;
2581			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2582							  (int)(srr + 1),
2583							  2 * (int)baud);
2584
2585			if (abs(deviation) >= 2) {
2586				/* At least two sampling clocks off at the
2587				 * last stop bit; we can increase the error
2588				 * margin by shifting the sampling point.
2589				 */
2590				int shift = clamp(deviation / 2, -8, 7);
2591
2592				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2593					 HSCIF_SRHP_MASK;
2594				hssrr |= HSCIF_SRDE;
2595			}
2596			serial_port_out(port, HSSRR, hssrr);
2597		}
2598
2599		/* Wait one bit interval */
2600		udelay((1000000 + (baud - 1)) / baud);
2601	} else {
2602		/* Don't touch the bit rate configuration */
2603		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2604		smr_val |= serial_port_in(port, SCSMR) &
2605			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2606		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2607		serial_port_out(port, SCSMR, smr_val);
2608	}
2609
2610	sci_init_pins(port, termios->c_cflag);
2611
2612	port->status &= ~UPSTAT_AUTOCTS;
2613	s->autorts = false;
2614	reg = sci_getreg(port, SCFCR);
2615	if (reg->size) {
2616		unsigned short ctrl = serial_port_in(port, SCFCR);
2617
2618		if ((port->flags & UPF_HARD_FLOW) &&
2619		    (termios->c_cflag & CRTSCTS)) {
2620			/* There is no CTS interrupt to restart the hardware */
2621			port->status |= UPSTAT_AUTOCTS;
2622			/* MCE is enabled when RTS is raised */
2623			s->autorts = true;
2624		}
2625
2626		/*
2627		 * As we've done a sci_reset() above, ensure we don't
2628		 * interfere with the FIFOs while toggling MCE. As the
2629		 * reset values could still be set, simply mask them out.
2630		 */
2631		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2632
2633		serial_port_out(port, SCFCR, ctrl);
2634	}
2635	if (port->flags & UPF_HARD_FLOW) {
2636		/* Refresh (Auto) RTS */
2637		sci_set_mctrl(port, port->mctrl);
2638	}
2639
2640	/*
2641	 * For SCI, TE (transmit enable) must be set after setting TIE
2642	 * (transmit interrupt enable) or in the same instruction to
2643	 * start the transmitting process. So skip setting TE here for SCI.
2644	 */
2645	if (port->type != PORT_SCI)
2646		scr_val |= SCSCR_TE;
2647	scr_val |= SCSCR_RE | (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2648	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2649	if ((srr + 1 == 5) &&
2650	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2651		/*
2652		 * In asynchronous mode, when the sampling rate is 1/5, first
2653		 * received data may become invalid on some SCIFA and SCIFB.
2654		 * To avoid this problem wait more than 1 serial data time (1
2655		 * bit time x serial data number) after setting SCSCR.RE = 1.
2656		 */
2657		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2658	}
2659
2660	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2661	s->rx_frame = (10000 * bits) / (baud / 100);
2662#ifdef CONFIG_SERIAL_SH_SCI_DMA
2663	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2664#endif
2665
2666	if ((termios->c_cflag & CREAD) != 0)
2667		sci_start_rx(port);
2668
2669	uart_port_unlock_irqrestore(port, flags);
2670
2671	sci_port_disable(s);
2672
2673	if (UART_ENABLE_MS(port, termios->c_cflag))
2674		sci_enable_ms(port);
2675}
2676
2677static void sci_pm(struct uart_port *port, unsigned int state,
2678		   unsigned int oldstate)
2679{
2680	struct sci_port *sci_port = to_sci_port(port);
2681
2682	switch (state) {
2683	case UART_PM_STATE_OFF:
2684		sci_port_disable(sci_port);
2685		break;
2686	default:
2687		sci_port_enable(sci_port);
2688		break;
2689	}
2690}
2691
2692static const char *sci_type(struct uart_port *port)
2693{
2694	switch (port->type) {
2695	case PORT_IRDA:
2696		return "irda";
2697	case PORT_SCI:
2698		return "sci";
2699	case PORT_SCIF:
2700		return "scif";
2701	case PORT_SCIFA:
2702		return "scifa";
2703	case PORT_SCIFB:
2704		return "scifb";
2705	case PORT_HSCIF:
2706		return "hscif";
2707	}
2708
2709	return NULL;
2710}
2711
2712static int sci_remap_port(struct uart_port *port)
2713{
2714	struct sci_port *sport = to_sci_port(port);
2715
2716	/*
2717	 * Nothing to do if there's already an established membase.
2718	 */
2719	if (port->membase)
2720		return 0;
2721
2722	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2723		port->membase = ioremap(port->mapbase, sport->reg_size);
2724		if (unlikely(!port->membase)) {
2725			dev_err(port->dev, "can't remap port#%d\n", port->line);
2726			return -ENXIO;
2727		}
2728	} else {
2729		/*
2730		 * For the simple (and majority of) cases where we don't
2731		 * need to do any remapping, just cast the cookie
2732		 * directly.
2733		 */
2734		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2735	}
2736
2737	return 0;
2738}
2739
2740static void sci_release_port(struct uart_port *port)
2741{
2742	struct sci_port *sport = to_sci_port(port);
2743
2744	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2745		iounmap(port->membase);
2746		port->membase = NULL;
2747	}
2748
2749	release_mem_region(port->mapbase, sport->reg_size);
2750}
2751
2752static int sci_request_port(struct uart_port *port)
2753{
2754	struct resource *res;
2755	struct sci_port *sport = to_sci_port(port);
2756	int ret;
2757
2758	res = request_mem_region(port->mapbase, sport->reg_size,
2759				 dev_name(port->dev));
2760	if (unlikely(res == NULL)) {
2761		dev_err(port->dev, "request_mem_region failed.");
2762		return -EBUSY;
2763	}
2764
2765	ret = sci_remap_port(port);
2766	if (unlikely(ret != 0)) {
2767		release_resource(res);
2768		return ret;
2769	}
2770
2771	return 0;
2772}
2773
2774static void sci_config_port(struct uart_port *port, int flags)
2775{
2776	if (flags & UART_CONFIG_TYPE) {
2777		struct sci_port *sport = to_sci_port(port);
2778
2779		port->type = sport->cfg->type;
2780		sci_request_port(port);
2781	}
2782}
2783
2784static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2785{
2786	if (ser->baud_base < 2400)
2787		/* No paper tape reader for Mitch.. */
2788		return -EINVAL;
2789
2790	return 0;
2791}
2792
2793static const struct uart_ops sci_uart_ops = {
2794	.tx_empty	= sci_tx_empty,
2795	.set_mctrl	= sci_set_mctrl,
2796	.get_mctrl	= sci_get_mctrl,
2797	.start_tx	= sci_start_tx,
2798	.stop_tx	= sci_stop_tx,
2799	.stop_rx	= sci_stop_rx,
2800	.enable_ms	= sci_enable_ms,
2801	.break_ctl	= sci_break_ctl,
2802	.startup	= sci_startup,
2803	.shutdown	= sci_shutdown,
2804	.flush_buffer	= sci_flush_buffer,
2805	.set_termios	= sci_set_termios,
2806	.pm		= sci_pm,
2807	.type		= sci_type,
2808	.release_port	= sci_release_port,
2809	.request_port	= sci_request_port,
2810	.config_port	= sci_config_port,
2811	.verify_port	= sci_verify_port,
2812#ifdef CONFIG_CONSOLE_POLL
2813	.poll_get_char	= sci_poll_get_char,
2814	.poll_put_char	= sci_poll_put_char,
2815#endif
2816};
2817
2818static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2819{
2820	const char *clk_names[] = {
2821		[SCI_FCK] = "fck",
2822		[SCI_SCK] = "sck",
2823		[SCI_BRG_INT] = "brg_int",
2824		[SCI_SCIF_CLK] = "scif_clk",
2825	};
2826	struct clk *clk;
2827	unsigned int i;
2828
2829	if (sci_port->cfg->type == PORT_HSCIF)
2830		clk_names[SCI_SCK] = "hsck";
2831
2832	for (i = 0; i < SCI_NUM_CLKS; i++) {
2833		clk = devm_clk_get_optional(dev, clk_names[i]);
2834		if (IS_ERR(clk))
2835			return PTR_ERR(clk);
2836
2837		if (!clk && i == SCI_FCK) {
2838			/*
2839			 * Not all SH platforms declare a clock lookup entry
2840			 * for SCI devices, in which case we need to get the
2841			 * global "peripheral_clk" clock.
2842			 */
2843			clk = devm_clk_get(dev, "peripheral_clk");
2844			if (IS_ERR(clk))
2845				return dev_err_probe(dev, PTR_ERR(clk),
2846						     "failed to get %s\n",
2847						     clk_names[i]);
2848		}
2849
2850		if (!clk)
2851			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2852		else
2853			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2854				clk, clk_get_rate(clk));
2855		sci_port->clks[i] = clk;
2856	}
2857	return 0;
2858}
2859
2860static const struct sci_port_params *
2861sci_probe_regmap(const struct plat_sci_port *cfg)
2862{
2863	unsigned int regtype;
2864
2865	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2866		return &sci_port_params[cfg->regtype];
2867
2868	switch (cfg->type) {
2869	case PORT_SCI:
2870		regtype = SCIx_SCI_REGTYPE;
2871		break;
2872	case PORT_IRDA:
2873		regtype = SCIx_IRDA_REGTYPE;
2874		break;
2875	case PORT_SCIFA:
2876		regtype = SCIx_SCIFA_REGTYPE;
2877		break;
2878	case PORT_SCIFB:
2879		regtype = SCIx_SCIFB_REGTYPE;
2880		break;
2881	case PORT_SCIF:
2882		/*
2883		 * The SH-4 is a bit of a misnomer here, although that's
2884		 * where this particular port layout originated. This
2885		 * configuration (or some slight variation thereof)
2886		 * remains the dominant model for all SCIFs.
2887		 */
2888		regtype = SCIx_SH4_SCIF_REGTYPE;
2889		break;
2890	case PORT_HSCIF:
2891		regtype = SCIx_HSCIF_REGTYPE;
2892		break;
2893	default:
2894		pr_err("Can't probe register map for given port\n");
2895		return NULL;
2896	}
2897
2898	return &sci_port_params[regtype];
2899}
2900
2901static int sci_init_single(struct platform_device *dev,
2902			   struct sci_port *sci_port, unsigned int index,
2903			   const struct plat_sci_port *p, bool early)
2904{
2905	struct uart_port *port = &sci_port->port;
2906	const struct resource *res;
2907	unsigned int i;
2908	int ret;
2909
2910	sci_port->cfg	= p;
2911
2912	port->ops	= &sci_uart_ops;
2913	port->iotype	= UPIO_MEM;
2914	port->line	= index;
2915	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2916
2917	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2918	if (res == NULL)
2919		return -ENOMEM;
2920
2921	port->mapbase = res->start;
2922	sci_port->reg_size = resource_size(res);
2923
2924	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2925		if (i)
2926			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2927		else
2928			sci_port->irqs[i] = platform_get_irq(dev, i);
2929	}
2930
2931	/*
2932	 * The fourth interrupt on SCI port is transmit end interrupt, so
2933	 * shuffle the interrupts.
2934	 */
2935	if (p->type == PORT_SCI)
2936		swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]);
2937
2938	/* The SCI generates several interrupts. They can be muxed together or
2939	 * connected to different interrupt lines. In the muxed case only one
2940	 * interrupt resource is specified as there is only one interrupt ID.
2941	 * In the non-muxed case, up to 6 interrupt signals might be generated
2942	 * from the SCI, however those signals might have their own individual
2943	 * interrupt ID numbers, or muxed together with another interrupt.
2944	 */
2945	if (sci_port->irqs[0] < 0)
2946		return -ENXIO;
2947
2948	if (sci_port->irqs[1] < 0)
2949		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2950			sci_port->irqs[i] = sci_port->irqs[0];
2951
2952	sci_port->params = sci_probe_regmap(p);
2953	if (unlikely(sci_port->params == NULL))
2954		return -EINVAL;
2955
2956	switch (p->type) {
2957	case PORT_SCIFB:
2958		sci_port->rx_trigger = 48;
2959		break;
2960	case PORT_HSCIF:
2961		sci_port->rx_trigger = 64;
2962		break;
2963	case PORT_SCIFA:
2964		sci_port->rx_trigger = 32;
2965		break;
2966	case PORT_SCIF:
2967		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2968			/* RX triggering not implemented for this IP */
2969			sci_port->rx_trigger = 1;
2970		else
2971			sci_port->rx_trigger = 8;
2972		break;
2973	default:
2974		sci_port->rx_trigger = 1;
2975		break;
2976	}
2977
2978	sci_port->rx_fifo_timeout = 0;
2979	sci_port->hscif_tot = 0;
2980
2981	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2982	 * match the SoC datasheet, this should be investigated. Let platform
2983	 * data override the sampling rate for now.
2984	 */
2985	sci_port->sampling_rate_mask = p->sampling_rate
2986				     ? SCI_SR(p->sampling_rate)
2987				     : sci_port->params->sampling_rate_mask;
2988
2989	if (!early) {
2990		ret = sci_init_clocks(sci_port, &dev->dev);
2991		if (ret < 0)
2992			return ret;
2993
2994		port->dev = &dev->dev;
2995
2996		pm_runtime_enable(&dev->dev);
2997	}
2998
2999	port->type		= p->type;
3000	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
3001	port->fifosize		= sci_port->params->fifosize;
3002
3003	if (port->type == PORT_SCI && !dev->dev.of_node) {
3004		if (sci_port->reg_size >= 0x20)
3005			port->regshift = 2;
3006		else
3007			port->regshift = 1;
3008	}
3009
3010	/*
3011	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
3012	 * for the multi-IRQ ports, which is where we are primarily
3013	 * concerned with the shutdown path synchronization.
3014	 *
3015	 * For the muxed case there's nothing more to do.
3016	 */
3017	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
3018	port->irqflags		= 0;
3019
3020	port->serial_in		= sci_serial_in;
3021	port->serial_out	= sci_serial_out;
3022
3023	return 0;
3024}
3025
3026static void sci_cleanup_single(struct sci_port *port)
3027{
3028	pm_runtime_disable(port->port.dev);
3029}
3030
3031#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3032    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3033static void serial_console_putchar(struct uart_port *port, unsigned char ch)
3034{
3035	sci_poll_put_char(port, ch);
3036}
3037
3038/*
3039 *	Print a string to the serial port trying not to disturb
3040 *	any possible real use of the port...
3041 */
3042static void serial_console_write(struct console *co, const char *s,
3043				 unsigned count)
3044{
3045	struct sci_port *sci_port = &sci_ports[co->index];
3046	struct uart_port *port = &sci_port->port;
3047	unsigned short bits, ctrl, ctrl_temp;
3048	unsigned long flags;
3049	int locked = 1;
3050
3051	if (port->sysrq)
3052		locked = 0;
3053	else if (oops_in_progress)
3054		locked = uart_port_trylock_irqsave(port, &flags);
3055	else
3056		uart_port_lock_irqsave(port, &flags);
3057
3058	/* first save SCSCR then disable interrupts, keep clock source */
3059	ctrl = serial_port_in(port, SCSCR);
3060	ctrl_temp = SCSCR_RE | SCSCR_TE |
3061		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3062		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3063	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3064
3065	uart_console_write(port, s, count, serial_console_putchar);
3066
3067	/* wait until fifo is empty and last bit has been transmitted */
3068	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3069	while ((serial_port_in(port, SCxSR) & bits) != bits)
3070		cpu_relax();
3071
3072	/* restore the SCSCR */
3073	serial_port_out(port, SCSCR, ctrl);
3074
3075	if (locked)
3076		uart_port_unlock_irqrestore(port, flags);
3077}
3078
3079static int serial_console_setup(struct console *co, char *options)
3080{
3081	struct sci_port *sci_port;
3082	struct uart_port *port;
3083	int baud = 115200;
3084	int bits = 8;
3085	int parity = 'n';
3086	int flow = 'n';
3087	int ret;
3088
3089	/*
3090	 * Refuse to handle any bogus ports.
3091	 */
3092	if (co->index < 0 || co->index >= SCI_NPORTS)
3093		return -ENODEV;
3094
3095	sci_port = &sci_ports[co->index];
3096	port = &sci_port->port;
3097
3098	/*
3099	 * Refuse to handle uninitialized ports.
3100	 */
3101	if (!port->ops)
3102		return -ENODEV;
3103
3104	ret = sci_remap_port(port);
3105	if (unlikely(ret != 0))
3106		return ret;
3107
3108	if (options)
3109		uart_parse_options(options, &baud, &parity, &bits, &flow);
3110
3111	return uart_set_options(port, co, baud, parity, bits, flow);
3112}
3113
3114static struct console serial_console = {
3115	.name		= "ttySC",
3116	.device		= uart_console_device,
3117	.write		= serial_console_write,
3118	.setup		= serial_console_setup,
3119	.flags		= CON_PRINTBUFFER,
3120	.index		= -1,
3121	.data		= &sci_uart_driver,
3122};
3123
3124#ifdef CONFIG_SUPERH
3125static char early_serial_buf[32];
3126
3127static int early_serial_console_setup(struct console *co, char *options)
3128{
3129	/*
3130	 * This early console is always registered using the earlyprintk=
3131	 * parameter, which does not call add_preferred_console(). Thus
3132	 * @options is always NULL and the options for this early console
3133	 * are passed using a custom buffer.
3134	 */
3135	WARN_ON(options);
3136
3137	return serial_console_setup(co, early_serial_buf);
3138}
3139
3140static struct console early_serial_console = {
3141	.name           = "early_ttySC",
3142	.write          = serial_console_write,
3143	.setup		= early_serial_console_setup,
3144	.flags          = CON_PRINTBUFFER,
3145	.index		= -1,
3146};
3147
3148static int sci_probe_earlyprintk(struct platform_device *pdev)
3149{
3150	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3151
3152	if (early_serial_console.data)
3153		return -EEXIST;
3154
3155	early_serial_console.index = pdev->id;
3156
3157	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3158
3159	if (!strstr(early_serial_buf, "keep"))
3160		early_serial_console.flags |= CON_BOOT;
3161
3162	register_console(&early_serial_console);
3163	return 0;
3164}
3165#endif
3166
3167#define SCI_CONSOLE	(&serial_console)
3168
3169#else
3170static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3171{
3172	return -EINVAL;
3173}
3174
3175#define SCI_CONSOLE	NULL
3176
3177#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3178
3179static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3180
3181static DEFINE_MUTEX(sci_uart_registration_lock);
3182static struct uart_driver sci_uart_driver = {
3183	.owner		= THIS_MODULE,
3184	.driver_name	= "sci",
3185	.dev_name	= "ttySC",
3186	.major		= SCI_MAJOR,
3187	.minor		= SCI_MINOR_START,
3188	.nr		= SCI_NPORTS,
3189	.cons		= SCI_CONSOLE,
3190};
3191
3192static void sci_remove(struct platform_device *dev)
3193{
3194	struct sci_port *port = platform_get_drvdata(dev);
3195	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3196
3197	sci_ports_in_use &= ~BIT(port->port.line);
3198	uart_remove_one_port(&sci_uart_driver, &port->port);
3199
3200	sci_cleanup_single(port);
3201
3202	if (port->port.fifosize > 1)
3203		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3204	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3205		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
 
 
3206}
3207
3208
3209#define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3210#define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3211#define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3212
3213static const struct of_device_id of_sci_match[] __maybe_unused = {
3214	/* SoC-specific types */
3215	{
3216		.compatible = "renesas,scif-r7s72100",
3217		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3218	},
3219	{
3220		.compatible = "renesas,scif-r7s9210",
3221		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3222	},
3223	{
3224		.compatible = "renesas,scif-r9a07g044",
3225		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3226	},
3227	/* Family-specific types */
3228	{
3229		.compatible = "renesas,rcar-gen1-scif",
3230		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3231	}, {
3232		.compatible = "renesas,rcar-gen2-scif",
3233		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3234	}, {
3235		.compatible = "renesas,rcar-gen3-scif",
3236		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3237	}, {
3238		.compatible = "renesas,rcar-gen4-scif",
3239		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3240	},
3241	/* Generic types */
3242	{
3243		.compatible = "renesas,scif",
3244		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3245	}, {
3246		.compatible = "renesas,scifa",
3247		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3248	}, {
3249		.compatible = "renesas,scifb",
3250		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3251	}, {
3252		.compatible = "renesas,hscif",
3253		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3254	}, {
3255		.compatible = "renesas,sci",
3256		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3257	}, {
3258		/* Terminator */
3259	},
3260};
3261MODULE_DEVICE_TABLE(of, of_sci_match);
3262
3263static void sci_reset_control_assert(void *data)
3264{
3265	reset_control_assert(data);
3266}
3267
3268static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3269					  unsigned int *dev_id)
3270{
3271	struct device_node *np = pdev->dev.of_node;
3272	struct reset_control *rstc;
3273	struct plat_sci_port *p;
3274	struct sci_port *sp;
3275	const void *data;
3276	int id, ret;
3277
3278	if (!IS_ENABLED(CONFIG_OF) || !np)
3279		return ERR_PTR(-EINVAL);
3280
3281	data = of_device_get_match_data(&pdev->dev);
3282
3283	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3284	if (IS_ERR(rstc))
3285		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3286					     "failed to get reset ctrl\n"));
3287
3288	ret = reset_control_deassert(rstc);
3289	if (ret) {
3290		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3291		return ERR_PTR(ret);
3292	}
3293
3294	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3295	if (ret) {
3296		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3297			ret);
3298		return ERR_PTR(ret);
3299	}
3300
3301	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3302	if (!p)
3303		return ERR_PTR(-ENOMEM);
3304
3305	/* Get the line number from the aliases node. */
3306	id = of_alias_get_id(np, "serial");
3307	if (id < 0 && ~sci_ports_in_use)
3308		id = ffz(sci_ports_in_use);
3309	if (id < 0) {
3310		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3311		return ERR_PTR(-EINVAL);
3312	}
3313	if (id >= ARRAY_SIZE(sci_ports)) {
3314		dev_err(&pdev->dev, "serial%d out of range\n", id);
3315		return ERR_PTR(-EINVAL);
3316	}
3317
3318	sp = &sci_ports[id];
3319	*dev_id = id;
3320
3321	p->type = SCI_OF_TYPE(data);
3322	p->regtype = SCI_OF_REGTYPE(data);
3323
3324	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3325
3326	return p;
3327}
3328
3329static int sci_probe_single(struct platform_device *dev,
3330				      unsigned int index,
3331				      struct plat_sci_port *p,
3332				      struct sci_port *sciport)
3333{
3334	int ret;
3335
3336	/* Sanity check */
3337	if (unlikely(index >= SCI_NPORTS)) {
3338		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3339			   index+1, SCI_NPORTS);
3340		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3341		return -EINVAL;
3342	}
3343	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3344	if (sci_ports_in_use & BIT(index))
3345		return -EBUSY;
3346
3347	mutex_lock(&sci_uart_registration_lock);
3348	if (!sci_uart_driver.state) {
3349		ret = uart_register_driver(&sci_uart_driver);
3350		if (ret) {
3351			mutex_unlock(&sci_uart_registration_lock);
3352			return ret;
3353		}
3354	}
3355	mutex_unlock(&sci_uart_registration_lock);
3356
3357	ret = sci_init_single(dev, sciport, index, p, false);
3358	if (ret)
3359		return ret;
3360
3361	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3362	if (IS_ERR(sciport->gpios))
3363		return PTR_ERR(sciport->gpios);
3364
3365	if (sciport->has_rtscts) {
3366		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3367		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3368			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3369			return -EINVAL;
3370		}
3371		sciport->port.flags |= UPF_HARD_FLOW;
3372	}
3373
3374	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3375	if (ret) {
3376		sci_cleanup_single(sciport);
3377		return ret;
3378	}
3379
3380	return 0;
3381}
3382
3383static int sci_probe(struct platform_device *dev)
3384{
3385	struct plat_sci_port *p;
3386	struct sci_port *sp;
3387	unsigned int dev_id;
3388	int ret;
3389
3390	/*
3391	 * If we've come here via earlyprintk initialization, head off to
3392	 * the special early probe. We don't have sufficient device state
3393	 * to make it beyond this yet.
3394	 */
3395#ifdef CONFIG_SUPERH
3396	if (is_sh_early_platform_device(dev))
3397		return sci_probe_earlyprintk(dev);
3398#endif
3399
3400	if (dev->dev.of_node) {
3401		p = sci_parse_dt(dev, &dev_id);
3402		if (IS_ERR(p))
3403			return PTR_ERR(p);
3404	} else {
3405		p = dev->dev.platform_data;
3406		if (p == NULL) {
3407			dev_err(&dev->dev, "no platform data supplied\n");
3408			return -EINVAL;
3409		}
3410
3411		dev_id = dev->id;
3412	}
3413
3414	sp = &sci_ports[dev_id];
3415	platform_set_drvdata(dev, sp);
3416
3417	ret = sci_probe_single(dev, dev_id, p, sp);
3418	if (ret)
3419		return ret;
3420
3421	if (sp->port.fifosize > 1) {
3422		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3423		if (ret)
3424			return ret;
3425	}
3426	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3427	    sp->port.type == PORT_HSCIF) {
3428		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3429		if (ret) {
3430			if (sp->port.fifosize > 1) {
3431				device_remove_file(&dev->dev,
3432						   &dev_attr_rx_fifo_trigger);
3433			}
3434			return ret;
3435		}
3436	}
3437
3438#ifdef CONFIG_SH_STANDARD_BIOS
3439	sh_bios_gdb_detach();
3440#endif
3441
3442	sci_ports_in_use |= BIT(dev_id);
3443	return 0;
3444}
3445
3446static __maybe_unused int sci_suspend(struct device *dev)
3447{
3448	struct sci_port *sport = dev_get_drvdata(dev);
3449
3450	if (sport)
3451		uart_suspend_port(&sci_uart_driver, &sport->port);
3452
3453	return 0;
3454}
3455
3456static __maybe_unused int sci_resume(struct device *dev)
3457{
3458	struct sci_port *sport = dev_get_drvdata(dev);
3459
3460	if (sport)
3461		uart_resume_port(&sci_uart_driver, &sport->port);
3462
3463	return 0;
3464}
3465
3466static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3467
3468static struct platform_driver sci_driver = {
3469	.probe		= sci_probe,
3470	.remove_new	= sci_remove,
3471	.driver		= {
3472		.name	= "sh-sci",
3473		.pm	= &sci_dev_pm_ops,
3474		.of_match_table = of_match_ptr(of_sci_match),
3475	},
3476};
3477
3478static int __init sci_init(void)
3479{
3480	pr_info("%s\n", banner);
3481
3482	return platform_driver_register(&sci_driver);
3483}
3484
3485static void __exit sci_exit(void)
3486{
3487	platform_driver_unregister(&sci_driver);
3488
3489	if (sci_uart_driver.state)
3490		uart_unregister_driver(&sci_uart_driver);
3491}
3492
3493#if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3494sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3495			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3496#endif
3497#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3498static struct plat_sci_port port_cfg __initdata;
3499
3500static int __init early_console_setup(struct earlycon_device *device,
3501				      int type)
3502{
3503	if (!device->port.membase)
3504		return -ENODEV;
3505
3506	device->port.serial_in = sci_serial_in;
3507	device->port.serial_out	= sci_serial_out;
3508	device->port.type = type;
3509	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3510	port_cfg.type = type;
3511	sci_ports[0].cfg = &port_cfg;
3512	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3513	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3514	sci_serial_out(&sci_ports[0].port, SCSCR,
3515		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3516
3517	device->con->write = serial_console_write;
3518	return 0;
3519}
3520static int __init sci_early_console_setup(struct earlycon_device *device,
3521					  const char *opt)
3522{
3523	return early_console_setup(device, PORT_SCI);
3524}
3525static int __init scif_early_console_setup(struct earlycon_device *device,
3526					  const char *opt)
3527{
3528	return early_console_setup(device, PORT_SCIF);
3529}
3530static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3531					  const char *opt)
3532{
3533	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3534	return early_console_setup(device, PORT_SCIF);
3535}
3536
3537static int __init scifa_early_console_setup(struct earlycon_device *device,
3538					  const char *opt)
3539{
3540	return early_console_setup(device, PORT_SCIFA);
3541}
3542static int __init scifb_early_console_setup(struct earlycon_device *device,
3543					  const char *opt)
3544{
3545	return early_console_setup(device, PORT_SCIFB);
3546}
3547static int __init hscif_early_console_setup(struct earlycon_device *device,
3548					  const char *opt)
3549{
3550	return early_console_setup(device, PORT_HSCIF);
3551}
3552
3553OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3554OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3555OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3556OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3557OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3558OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3559OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3560#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3561
3562module_init(sci_init);
3563module_exit(sci_exit);
3564
3565MODULE_LICENSE("GPL");
3566MODULE_ALIAS("platform:sh-sci");
3567MODULE_AUTHOR("Paul Mundt");
3568MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");
v6.2
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   4 *
   5 *  Copyright (C) 2002 - 2011  Paul Mundt
   6 *  Copyright (C) 2015 Glider bvba
   7 *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   8 *
   9 * based off of the old drivers/char/sh-sci.c by:
  10 *
  11 *   Copyright (C) 1999, 2000  Niibe Yutaka
  12 *   Copyright (C) 2000  Sugioka Toshinobu
  13 *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  14 *   Modified to support SecureEdge. David McCullough (2002)
  15 *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  16 *   Removed SH7300 support (Jul 2007).
  17 */
  18#undef DEBUG
  19
  20#include <linux/clk.h>
  21#include <linux/console.h>
  22#include <linux/ctype.h>
  23#include <linux/cpufreq.h>
  24#include <linux/delay.h>
  25#include <linux/dmaengine.h>
  26#include <linux/dma-mapping.h>
  27#include <linux/err.h>
  28#include <linux/errno.h>
  29#include <linux/init.h>
  30#include <linux/interrupt.h>
  31#include <linux/ioport.h>
  32#include <linux/ktime.h>
  33#include <linux/major.h>
 
  34#include <linux/module.h>
  35#include <linux/mm.h>
  36#include <linux/of.h>
  37#include <linux/of_device.h>
  38#include <linux/platform_device.h>
  39#include <linux/pm_runtime.h>
  40#include <linux/reset.h>
  41#include <linux/scatterlist.h>
  42#include <linux/serial.h>
  43#include <linux/serial_sci.h>
  44#include <linux/sh_dma.h>
  45#include <linux/slab.h>
  46#include <linux/string.h>
  47#include <linux/sysrq.h>
  48#include <linux/timer.h>
  49#include <linux/tty.h>
  50#include <linux/tty_flip.h>
  51
  52#ifdef CONFIG_SUPERH
  53#include <asm/sh_bios.h>
  54#include <asm/platform_early.h>
  55#endif
  56
  57#include "serial_mctrl_gpio.h"
  58#include "sh-sci.h"
  59
  60/* Offsets into the sci_port->irqs array */
  61enum {
  62	SCIx_ERI_IRQ,
  63	SCIx_RXI_IRQ,
  64	SCIx_TXI_IRQ,
  65	SCIx_BRI_IRQ,
  66	SCIx_DRI_IRQ,
  67	SCIx_TEI_IRQ,
  68	SCIx_NR_IRQS,
  69
  70	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
  71};
  72
  73#define SCIx_IRQ_IS_MUXED(port)			\
  74	((port)->irqs[SCIx_ERI_IRQ] ==	\
  75	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
  76	((port)->irqs[SCIx_ERI_IRQ] &&	\
  77	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
  78
  79enum SCI_CLKS {
  80	SCI_FCK,		/* Functional Clock */
  81	SCI_SCK,		/* Optional External Clock */
  82	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
  83	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
  84	SCI_NUM_CLKS
  85};
  86
  87/* Bit x set means sampling rate x + 1 is supported */
  88#define SCI_SR(x)		BIT((x) - 1)
  89#define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
  90
  91#define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
  92				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
  93				SCI_SR(19) | SCI_SR(27)
  94
  95#define min_sr(_port)		ffs((_port)->sampling_rate_mask)
  96#define max_sr(_port)		fls((_port)->sampling_rate_mask)
  97
  98/* Iterate over all supported sampling rates, from high to low */
  99#define for_each_sr(_sr, _port)						\
 100	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
 101		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
 102
 103struct plat_sci_reg {
 104	u8 offset, size;
 105};
 106
 107struct sci_port_params {
 108	const struct plat_sci_reg regs[SCIx_NR_REGS];
 109	unsigned int fifosize;
 110	unsigned int overrun_reg;
 111	unsigned int overrun_mask;
 112	unsigned int sampling_rate_mask;
 113	unsigned int error_mask;
 114	unsigned int error_clear;
 115};
 116
 117struct sci_port {
 118	struct uart_port	port;
 119
 120	/* Platform configuration */
 121	const struct sci_port_params *params;
 122	const struct plat_sci_port *cfg;
 123	unsigned int		sampling_rate_mask;
 124	resource_size_t		reg_size;
 125	struct mctrl_gpios	*gpios;
 126
 127	/* Clocks */
 128	struct clk		*clks[SCI_NUM_CLKS];
 129	unsigned long		clk_rates[SCI_NUM_CLKS];
 130
 131	int			irqs[SCIx_NR_IRQS];
 132	char			*irqstr[SCIx_NR_IRQS];
 133
 134	struct dma_chan			*chan_tx;
 135	struct dma_chan			*chan_rx;
 136
 137#ifdef CONFIG_SERIAL_SH_SCI_DMA
 138	struct dma_chan			*chan_tx_saved;
 139	struct dma_chan			*chan_rx_saved;
 140	dma_cookie_t			cookie_tx;
 141	dma_cookie_t			cookie_rx[2];
 142	dma_cookie_t			active_rx;
 143	dma_addr_t			tx_dma_addr;
 144	unsigned int			tx_dma_len;
 145	struct scatterlist		sg_rx[2];
 146	void				*rx_buf[2];
 147	size_t				buf_len_rx;
 148	struct work_struct		work_tx;
 149	struct hrtimer			rx_timer;
 150	unsigned int			rx_timeout;	/* microseconds */
 151#endif
 152	unsigned int			rx_frame;
 153	int				rx_trigger;
 154	struct timer_list		rx_fifo_timer;
 155	int				rx_fifo_timeout;
 156	u16				hscif_tot;
 157
 158	bool has_rtscts;
 159	bool autorts;
 160};
 161
 162#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 163
 164static struct sci_port sci_ports[SCI_NPORTS];
 165static unsigned long sci_ports_in_use;
 166static struct uart_driver sci_uart_driver;
 167
 168static inline struct sci_port *
 169to_sci_port(struct uart_port *uart)
 170{
 171	return container_of(uart, struct sci_port, port);
 172}
 173
 174static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
 175	/*
 176	 * Common SCI definitions, dependent on the port's regshift
 177	 * value.
 178	 */
 179	[SCIx_SCI_REGTYPE] = {
 180		.regs = {
 181			[SCSMR]		= { 0x00,  8 },
 182			[SCBRR]		= { 0x01,  8 },
 183			[SCSCR]		= { 0x02,  8 },
 184			[SCxTDR]	= { 0x03,  8 },
 185			[SCxSR]		= { 0x04,  8 },
 186			[SCxRDR]	= { 0x05,  8 },
 187		},
 188		.fifosize = 1,
 189		.overrun_reg = SCxSR,
 190		.overrun_mask = SCI_ORER,
 191		.sampling_rate_mask = SCI_SR(32),
 192		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 193		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 194	},
 195
 196	/*
 197	 * Common definitions for legacy IrDA ports.
 198	 */
 199	[SCIx_IRDA_REGTYPE] = {
 200		.regs = {
 201			[SCSMR]		= { 0x00,  8 },
 202			[SCBRR]		= { 0x02,  8 },
 203			[SCSCR]		= { 0x04,  8 },
 204			[SCxTDR]	= { 0x06,  8 },
 205			[SCxSR]		= { 0x08, 16 },
 206			[SCxRDR]	= { 0x0a,  8 },
 207			[SCFCR]		= { 0x0c,  8 },
 208			[SCFDR]		= { 0x0e, 16 },
 209		},
 210		.fifosize = 1,
 211		.overrun_reg = SCxSR,
 212		.overrun_mask = SCI_ORER,
 213		.sampling_rate_mask = SCI_SR(32),
 214		.error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 215		.error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 216	},
 217
 218	/*
 219	 * Common SCIFA definitions.
 220	 */
 221	[SCIx_SCIFA_REGTYPE] = {
 222		.regs = {
 223			[SCSMR]		= { 0x00, 16 },
 224			[SCBRR]		= { 0x04,  8 },
 225			[SCSCR]		= { 0x08, 16 },
 226			[SCxTDR]	= { 0x20,  8 },
 227			[SCxSR]		= { 0x14, 16 },
 228			[SCxRDR]	= { 0x24,  8 },
 229			[SCFCR]		= { 0x18, 16 },
 230			[SCFDR]		= { 0x1c, 16 },
 231			[SCPCR]		= { 0x30, 16 },
 232			[SCPDR]		= { 0x34, 16 },
 233		},
 234		.fifosize = 64,
 235		.overrun_reg = SCxSR,
 236		.overrun_mask = SCIFA_ORER,
 237		.sampling_rate_mask = SCI_SR_SCIFAB,
 238		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 239		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 240	},
 241
 242	/*
 243	 * Common SCIFB definitions.
 244	 */
 245	[SCIx_SCIFB_REGTYPE] = {
 246		.regs = {
 247			[SCSMR]		= { 0x00, 16 },
 248			[SCBRR]		= { 0x04,  8 },
 249			[SCSCR]		= { 0x08, 16 },
 250			[SCxTDR]	= { 0x40,  8 },
 251			[SCxSR]		= { 0x14, 16 },
 252			[SCxRDR]	= { 0x60,  8 },
 253			[SCFCR]		= { 0x18, 16 },
 254			[SCTFDR]	= { 0x38, 16 },
 255			[SCRFDR]	= { 0x3c, 16 },
 256			[SCPCR]		= { 0x30, 16 },
 257			[SCPDR]		= { 0x34, 16 },
 258		},
 259		.fifosize = 256,
 260		.overrun_reg = SCxSR,
 261		.overrun_mask = SCIFA_ORER,
 262		.sampling_rate_mask = SCI_SR_SCIFAB,
 263		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 264		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 265	},
 266
 267	/*
 268	 * Common SH-2(A) SCIF definitions for ports with FIFO data
 269	 * count registers.
 270	 */
 271	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
 272		.regs = {
 273			[SCSMR]		= { 0x00, 16 },
 274			[SCBRR]		= { 0x04,  8 },
 275			[SCSCR]		= { 0x08, 16 },
 276			[SCxTDR]	= { 0x0c,  8 },
 277			[SCxSR]		= { 0x10, 16 },
 278			[SCxRDR]	= { 0x14,  8 },
 279			[SCFCR]		= { 0x18, 16 },
 280			[SCFDR]		= { 0x1c, 16 },
 281			[SCSPTR]	= { 0x20, 16 },
 282			[SCLSR]		= { 0x24, 16 },
 283		},
 284		.fifosize = 16,
 285		.overrun_reg = SCLSR,
 286		.overrun_mask = SCLSR_ORER,
 287		.sampling_rate_mask = SCI_SR(32),
 288		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 289		.error_clear = SCIF_ERROR_CLEAR,
 290	},
 291
 292	/*
 293	 * The "SCIFA" that is in RZ/A2, RZ/G2L and RZ/T.
 294	 * It looks like a normal SCIF with FIFO data, but with a
 295	 * compressed address space. Also, the break out of interrupts
 296	 * are different: ERI/BRI, RXI, TXI, TEI, DRI.
 297	 */
 298	[SCIx_RZ_SCIFA_REGTYPE] = {
 299		.regs = {
 300			[SCSMR]		= { 0x00, 16 },
 301			[SCBRR]		= { 0x02,  8 },
 302			[SCSCR]		= { 0x04, 16 },
 303			[SCxTDR]	= { 0x06,  8 },
 304			[SCxSR]		= { 0x08, 16 },
 305			[SCxRDR]	= { 0x0A,  8 },
 306			[SCFCR]		= { 0x0C, 16 },
 307			[SCFDR]		= { 0x0E, 16 },
 308			[SCSPTR]	= { 0x10, 16 },
 309			[SCLSR]		= { 0x12, 16 },
 310			[SEMR]		= { 0x14, 8 },
 311		},
 312		.fifosize = 16,
 313		.overrun_reg = SCLSR,
 314		.overrun_mask = SCLSR_ORER,
 315		.sampling_rate_mask = SCI_SR(32),
 316		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 317		.error_clear = SCIF_ERROR_CLEAR,
 318	},
 319
 320	/*
 321	 * Common SH-3 SCIF definitions.
 322	 */
 323	[SCIx_SH3_SCIF_REGTYPE] = {
 324		.regs = {
 325			[SCSMR]		= { 0x00,  8 },
 326			[SCBRR]		= { 0x02,  8 },
 327			[SCSCR]		= { 0x04,  8 },
 328			[SCxTDR]	= { 0x06,  8 },
 329			[SCxSR]		= { 0x08, 16 },
 330			[SCxRDR]	= { 0x0a,  8 },
 331			[SCFCR]		= { 0x0c,  8 },
 332			[SCFDR]		= { 0x0e, 16 },
 333		},
 334		.fifosize = 16,
 335		.overrun_reg = SCLSR,
 336		.overrun_mask = SCLSR_ORER,
 337		.sampling_rate_mask = SCI_SR(32),
 338		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 339		.error_clear = SCIF_ERROR_CLEAR,
 340	},
 341
 342	/*
 343	 * Common SH-4(A) SCIF(B) definitions.
 344	 */
 345	[SCIx_SH4_SCIF_REGTYPE] = {
 346		.regs = {
 347			[SCSMR]		= { 0x00, 16 },
 348			[SCBRR]		= { 0x04,  8 },
 349			[SCSCR]		= { 0x08, 16 },
 350			[SCxTDR]	= { 0x0c,  8 },
 351			[SCxSR]		= { 0x10, 16 },
 352			[SCxRDR]	= { 0x14,  8 },
 353			[SCFCR]		= { 0x18, 16 },
 354			[SCFDR]		= { 0x1c, 16 },
 355			[SCSPTR]	= { 0x20, 16 },
 356			[SCLSR]		= { 0x24, 16 },
 357		},
 358		.fifosize = 16,
 359		.overrun_reg = SCLSR,
 360		.overrun_mask = SCLSR_ORER,
 361		.sampling_rate_mask = SCI_SR(32),
 362		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 363		.error_clear = SCIF_ERROR_CLEAR,
 364	},
 365
 366	/*
 367	 * Common SCIF definitions for ports with a Baud Rate Generator for
 368	 * External Clock (BRG).
 369	 */
 370	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
 371		.regs = {
 372			[SCSMR]		= { 0x00, 16 },
 373			[SCBRR]		= { 0x04,  8 },
 374			[SCSCR]		= { 0x08, 16 },
 375			[SCxTDR]	= { 0x0c,  8 },
 376			[SCxSR]		= { 0x10, 16 },
 377			[SCxRDR]	= { 0x14,  8 },
 378			[SCFCR]		= { 0x18, 16 },
 379			[SCFDR]		= { 0x1c, 16 },
 380			[SCSPTR]	= { 0x20, 16 },
 381			[SCLSR]		= { 0x24, 16 },
 382			[SCDL]		= { 0x30, 16 },
 383			[SCCKS]		= { 0x34, 16 },
 384		},
 385		.fifosize = 16,
 386		.overrun_reg = SCLSR,
 387		.overrun_mask = SCLSR_ORER,
 388		.sampling_rate_mask = SCI_SR(32),
 389		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 390		.error_clear = SCIF_ERROR_CLEAR,
 391	},
 392
 393	/*
 394	 * Common HSCIF definitions.
 395	 */
 396	[SCIx_HSCIF_REGTYPE] = {
 397		.regs = {
 398			[SCSMR]		= { 0x00, 16 },
 399			[SCBRR]		= { 0x04,  8 },
 400			[SCSCR]		= { 0x08, 16 },
 401			[SCxTDR]	= { 0x0c,  8 },
 402			[SCxSR]		= { 0x10, 16 },
 403			[SCxRDR]	= { 0x14,  8 },
 404			[SCFCR]		= { 0x18, 16 },
 405			[SCFDR]		= { 0x1c, 16 },
 406			[SCSPTR]	= { 0x20, 16 },
 407			[SCLSR]		= { 0x24, 16 },
 408			[HSSRR]		= { 0x40, 16 },
 409			[SCDL]		= { 0x30, 16 },
 410			[SCCKS]		= { 0x34, 16 },
 411			[HSRTRGR]	= { 0x54, 16 },
 412			[HSTTRGR]	= { 0x58, 16 },
 413		},
 414		.fifosize = 128,
 415		.overrun_reg = SCLSR,
 416		.overrun_mask = SCLSR_ORER,
 417		.sampling_rate_mask = SCI_SR_RANGE(8, 32),
 418		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 419		.error_clear = SCIF_ERROR_CLEAR,
 420	},
 421
 422	/*
 423	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 424	 * register.
 425	 */
 426	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 427		.regs = {
 428			[SCSMR]		= { 0x00, 16 },
 429			[SCBRR]		= { 0x04,  8 },
 430			[SCSCR]		= { 0x08, 16 },
 431			[SCxTDR]	= { 0x0c,  8 },
 432			[SCxSR]		= { 0x10, 16 },
 433			[SCxRDR]	= { 0x14,  8 },
 434			[SCFCR]		= { 0x18, 16 },
 435			[SCFDR]		= { 0x1c, 16 },
 436			[SCLSR]		= { 0x24, 16 },
 437		},
 438		.fifosize = 16,
 439		.overrun_reg = SCLSR,
 440		.overrun_mask = SCLSR_ORER,
 441		.sampling_rate_mask = SCI_SR(32),
 442		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 443		.error_clear = SCIF_ERROR_CLEAR,
 444	},
 445
 446	/*
 447	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 448	 * count registers.
 449	 */
 450	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 451		.regs = {
 452			[SCSMR]		= { 0x00, 16 },
 453			[SCBRR]		= { 0x04,  8 },
 454			[SCSCR]		= { 0x08, 16 },
 455			[SCxTDR]	= { 0x0c,  8 },
 456			[SCxSR]		= { 0x10, 16 },
 457			[SCxRDR]	= { 0x14,  8 },
 458			[SCFCR]		= { 0x18, 16 },
 459			[SCFDR]		= { 0x1c, 16 },
 460			[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
 461			[SCRFDR]	= { 0x20, 16 },
 462			[SCSPTR]	= { 0x24, 16 },
 463			[SCLSR]		= { 0x28, 16 },
 464		},
 465		.fifosize = 16,
 466		.overrun_reg = SCLSR,
 467		.overrun_mask = SCLSR_ORER,
 468		.sampling_rate_mask = SCI_SR(32),
 469		.error_mask = SCIF_DEFAULT_ERROR_MASK,
 470		.error_clear = SCIF_ERROR_CLEAR,
 471	},
 472
 473	/*
 474	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 475	 * registers.
 476	 */
 477	[SCIx_SH7705_SCIF_REGTYPE] = {
 478		.regs = {
 479			[SCSMR]		= { 0x00, 16 },
 480			[SCBRR]		= { 0x04,  8 },
 481			[SCSCR]		= { 0x08, 16 },
 482			[SCxTDR]	= { 0x20,  8 },
 483			[SCxSR]		= { 0x14, 16 },
 484			[SCxRDR]	= { 0x24,  8 },
 485			[SCFCR]		= { 0x18, 16 },
 486			[SCFDR]		= { 0x1c, 16 },
 487		},
 488		.fifosize = 64,
 489		.overrun_reg = SCxSR,
 490		.overrun_mask = SCIFA_ORER,
 491		.sampling_rate_mask = SCI_SR(16),
 492		.error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 493		.error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 494	},
 495};
 496
 497#define sci_getreg(up, offset)		(&to_sci_port(up)->params->regs[offset])
 498
 499/*
 500 * The "offset" here is rather misleading, in that it refers to an enum
 501 * value relative to the port mapping rather than the fixed offset
 502 * itself, which needs to be manually retrieved from the platform's
 503 * register map for the given port.
 504 */
 505static unsigned int sci_serial_in(struct uart_port *p, int offset)
 506{
 507	const struct plat_sci_reg *reg = sci_getreg(p, offset);
 508
 509	if (reg->size == 8)
 510		return ioread8(p->membase + (reg->offset << p->regshift));
 511	else if (reg->size == 16)
 512		return ioread16(p->membase + (reg->offset << p->regshift));
 513	else
 514		WARN(1, "Invalid register access\n");
 515
 516	return 0;
 517}
 518
 519static void sci_serial_out(struct uart_port *p, int offset, int value)
 520{
 521	const struct plat_sci_reg *reg = sci_getreg(p, offset);
 522
 523	if (reg->size == 8)
 524		iowrite8(value, p->membase + (reg->offset << p->regshift));
 525	else if (reg->size == 16)
 526		iowrite16(value, p->membase + (reg->offset << p->regshift));
 527	else
 528		WARN(1, "Invalid register access\n");
 529}
 530
 531static void sci_port_enable(struct sci_port *sci_port)
 532{
 533	unsigned int i;
 534
 535	if (!sci_port->port.dev)
 536		return;
 537
 538	pm_runtime_get_sync(sci_port->port.dev);
 539
 540	for (i = 0; i < SCI_NUM_CLKS; i++) {
 541		clk_prepare_enable(sci_port->clks[i]);
 542		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
 543	}
 544	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
 545}
 546
 547static void sci_port_disable(struct sci_port *sci_port)
 548{
 549	unsigned int i;
 550
 551	if (!sci_port->port.dev)
 552		return;
 553
 554	for (i = SCI_NUM_CLKS; i-- > 0; )
 555		clk_disable_unprepare(sci_port->clks[i]);
 556
 557	pm_runtime_put_sync(sci_port->port.dev);
 558}
 559
 560static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 561{
 562	/*
 563	 * Not all ports (such as SCIFA) will support REIE. Rather than
 564	 * special-casing the port type, we check the port initialization
 565	 * IRQ enable mask to see whether the IRQ is desired at all. If
 566	 * it's unset, it's logically inferred that there's no point in
 567	 * testing for it.
 568	 */
 569	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 570}
 571
 572static void sci_start_tx(struct uart_port *port)
 573{
 574	struct sci_port *s = to_sci_port(port);
 575	unsigned short ctrl;
 576
 577#ifdef CONFIG_SERIAL_SH_SCI_DMA
 578	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 579		u16 new, scr = serial_port_in(port, SCSCR);
 580		if (s->chan_tx)
 581			new = scr | SCSCR_TDRQE;
 582		else
 583			new = scr & ~SCSCR_TDRQE;
 584		if (new != scr)
 585			serial_port_out(port, SCSCR, new);
 586	}
 587
 588	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
 589	    dma_submit_error(s->cookie_tx)) {
 
 
 
 
 590		s->cookie_tx = 0;
 591		schedule_work(&s->work_tx);
 592	}
 593#endif
 594
 595	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 
 596		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
 597		ctrl = serial_port_in(port, SCSCR);
 
 
 
 
 
 
 
 
 
 598		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
 599	}
 600}
 601
 602static void sci_stop_tx(struct uart_port *port)
 603{
 604	unsigned short ctrl;
 605
 606	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
 607	ctrl = serial_port_in(port, SCSCR);
 608
 609	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 610		ctrl &= ~SCSCR_TDRQE;
 611
 612	ctrl &= ~SCSCR_TIE;
 613
 614	serial_port_out(port, SCSCR, ctrl);
 615
 616#ifdef CONFIG_SERIAL_SH_SCI_DMA
 617	if (to_sci_port(port)->chan_tx &&
 618	    !dma_submit_error(to_sci_port(port)->cookie_tx)) {
 619		dmaengine_terminate_async(to_sci_port(port)->chan_tx);
 620		to_sci_port(port)->cookie_tx = -EINVAL;
 621	}
 622#endif
 623}
 624
 625static void sci_start_rx(struct uart_port *port)
 626{
 627	unsigned short ctrl;
 628
 629	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 630
 631	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 632		ctrl &= ~SCSCR_RDRQE;
 633
 634	serial_port_out(port, SCSCR, ctrl);
 635}
 636
 637static void sci_stop_rx(struct uart_port *port)
 638{
 639	unsigned short ctrl;
 640
 641	ctrl = serial_port_in(port, SCSCR);
 642
 643	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 644		ctrl &= ~SCSCR_RDRQE;
 645
 646	ctrl &= ~port_rx_irq_mask(port);
 647
 648	serial_port_out(port, SCSCR, ctrl);
 649}
 650
 651static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
 652{
 653	if (port->type == PORT_SCI) {
 654		/* Just store the mask */
 655		serial_port_out(port, SCxSR, mask);
 656	} else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
 657		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
 658		/* Only clear the status bits we want to clear */
 659		serial_port_out(port, SCxSR,
 660				serial_port_in(port, SCxSR) & mask);
 661	} else {
 662		/* Store the mask, clear parity/framing errors */
 663		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
 664	}
 665}
 666
 667#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
 668    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
 669
 670#ifdef CONFIG_CONSOLE_POLL
 671static int sci_poll_get_char(struct uart_port *port)
 672{
 673	unsigned short status;
 674	int c;
 675
 676	do {
 677		status = serial_port_in(port, SCxSR);
 678		if (status & SCxSR_ERRORS(port)) {
 679			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 680			continue;
 681		}
 682		break;
 683	} while (1);
 684
 685	if (!(status & SCxSR_RDxF(port)))
 686		return NO_POLL_CHAR;
 687
 688	c = serial_port_in(port, SCxRDR);
 689
 690	/* Dummy read */
 691	serial_port_in(port, SCxSR);
 692	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 693
 694	return c;
 695}
 696#endif
 697
 698static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 699{
 700	unsigned short status;
 701
 702	do {
 703		status = serial_port_in(port, SCxSR);
 704	} while (!(status & SCxSR_TDxE(port)));
 705
 706	serial_port_out(port, SCxTDR, c);
 707	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 708}
 709#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
 710	  CONFIG_SERIAL_SH_SCI_EARLYCON */
 711
 712static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 713{
 714	struct sci_port *s = to_sci_port(port);
 715
 716	/*
 717	 * Use port-specific handler if provided.
 718	 */
 719	if (s->cfg->ops && s->cfg->ops->init_pins) {
 720		s->cfg->ops->init_pins(port, cflag);
 721		return;
 722	}
 723
 724	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 725		u16 data = serial_port_in(port, SCPDR);
 726		u16 ctrl = serial_port_in(port, SCPCR);
 727
 728		/* Enable RXD and TXD pin functions */
 729		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
 730		if (to_sci_port(port)->has_rtscts) {
 731			/* RTS# is output, active low, unless autorts */
 732			if (!(port->mctrl & TIOCM_RTS)) {
 733				ctrl |= SCPCR_RTSC;
 734				data |= SCPDR_RTSD;
 735			} else if (!s->autorts) {
 736				ctrl |= SCPCR_RTSC;
 737				data &= ~SCPDR_RTSD;
 738			} else {
 739				/* Enable RTS# pin function */
 740				ctrl &= ~SCPCR_RTSC;
 741			}
 742			/* Enable CTS# pin function */
 743			ctrl &= ~SCPCR_CTSC;
 744		}
 745		serial_port_out(port, SCPDR, data);
 746		serial_port_out(port, SCPCR, ctrl);
 747	} else if (sci_getreg(port, SCSPTR)->size) {
 748		u16 status = serial_port_in(port, SCSPTR);
 749
 750		/* RTS# is always output; and active low, unless autorts */
 751		status |= SCSPTR_RTSIO;
 752		if (!(port->mctrl & TIOCM_RTS))
 753			status |= SCSPTR_RTSDT;
 754		else if (!s->autorts)
 755			status &= ~SCSPTR_RTSDT;
 756		/* CTS# and SCK are inputs */
 757		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
 758		serial_port_out(port, SCSPTR, status);
 759	}
 760}
 761
 762static int sci_txfill(struct uart_port *port)
 763{
 764	struct sci_port *s = to_sci_port(port);
 765	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 766	const struct plat_sci_reg *reg;
 767
 768	reg = sci_getreg(port, SCTFDR);
 769	if (reg->size)
 770		return serial_port_in(port, SCTFDR) & fifo_mask;
 771
 772	reg = sci_getreg(port, SCFDR);
 773	if (reg->size)
 774		return serial_port_in(port, SCFDR) >> 8;
 775
 776	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
 777}
 778
 779static int sci_txroom(struct uart_port *port)
 780{
 781	return port->fifosize - sci_txfill(port);
 782}
 783
 784static int sci_rxfill(struct uart_port *port)
 785{
 786	struct sci_port *s = to_sci_port(port);
 787	unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 788	const struct plat_sci_reg *reg;
 789
 790	reg = sci_getreg(port, SCRFDR);
 791	if (reg->size)
 792		return serial_port_in(port, SCRFDR) & fifo_mask;
 793
 794	reg = sci_getreg(port, SCFDR);
 795	if (reg->size)
 796		return serial_port_in(port, SCFDR) & fifo_mask;
 797
 798	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 799}
 800
 801/* ********************************************************************** *
 802 *                   the interrupt related routines                       *
 803 * ********************************************************************** */
 804
 805static void sci_transmit_chars(struct uart_port *port)
 806{
 807	struct circ_buf *xmit = &port->state->xmit;
 808	unsigned int stopped = uart_tx_stopped(port);
 809	unsigned short status;
 810	unsigned short ctrl;
 811	int count;
 812
 813	status = serial_port_in(port, SCxSR);
 814	if (!(status & SCxSR_TDxE(port))) {
 815		ctrl = serial_port_in(port, SCSCR);
 816		if (uart_circ_empty(xmit))
 817			ctrl &= ~SCSCR_TIE;
 818		else
 819			ctrl |= SCSCR_TIE;
 820		serial_port_out(port, SCSCR, ctrl);
 821		return;
 822	}
 823
 824	count = sci_txroom(port);
 825
 826	do {
 827		unsigned char c;
 828
 829		if (port->x_char) {
 830			c = port->x_char;
 831			port->x_char = 0;
 832		} else if (!uart_circ_empty(xmit) && !stopped) {
 833			c = xmit->buf[xmit->tail];
 834			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 
 
 
 
 
 835		} else {
 836			break;
 837		}
 838
 839		serial_port_out(port, SCxTDR, c);
 840
 841		port->icount.tx++;
 842	} while (--count > 0);
 843
 844	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 845
 846	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 847		uart_write_wakeup(port);
 848	if (uart_circ_empty(xmit))
 
 
 
 
 
 
 
 849		sci_stop_tx(port);
 850
 851}
 852
 853static void sci_receive_chars(struct uart_port *port)
 854{
 855	struct tty_port *tport = &port->state->port;
 856	int i, count, copied = 0;
 857	unsigned short status;
 858	unsigned char flag;
 859
 860	status = serial_port_in(port, SCxSR);
 861	if (!(status & SCxSR_RDxF(port)))
 862		return;
 863
 864	while (1) {
 865		/* Don't copy more bytes than there is room for in the buffer */
 866		count = tty_buffer_request_room(tport, sci_rxfill(port));
 867
 868		/* If for any reason we can't copy more data, we're done! */
 869		if (count == 0)
 870			break;
 871
 872		if (port->type == PORT_SCI) {
 873			char c = serial_port_in(port, SCxRDR);
 874			if (uart_handle_sysrq_char(port, c))
 875				count = 0;
 876			else
 877				tty_insert_flip_char(tport, c, TTY_NORMAL);
 878		} else {
 879			for (i = 0; i < count; i++) {
 880				char c;
 881
 882				if (port->type == PORT_SCIF ||
 883				    port->type == PORT_HSCIF) {
 884					status = serial_port_in(port, SCxSR);
 885					c = serial_port_in(port, SCxRDR);
 886				} else {
 887					c = serial_port_in(port, SCxRDR);
 888					status = serial_port_in(port, SCxSR);
 889				}
 890				if (uart_handle_sysrq_char(port, c)) {
 891					count--; i--;
 892					continue;
 893				}
 894
 895				/* Store data and status */
 896				if (status & SCxSR_FER(port)) {
 897					flag = TTY_FRAME;
 898					port->icount.frame++;
 899				} else if (status & SCxSR_PER(port)) {
 900					flag = TTY_PARITY;
 901					port->icount.parity++;
 902				} else
 903					flag = TTY_NORMAL;
 904
 905				tty_insert_flip_char(tport, c, flag);
 906			}
 907		}
 908
 909		serial_port_in(port, SCxSR); /* dummy read */
 910		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 911
 912		copied += count;
 913		port->icount.rx += count;
 914	}
 915
 916	if (copied) {
 917		/* Tell the rest of the system the news. New characters! */
 918		tty_flip_buffer_push(tport);
 919	} else {
 920		/* TTY buffers full; read from RX reg to prevent lockup */
 921		serial_port_in(port, SCxRDR);
 922		serial_port_in(port, SCxSR); /* dummy read */
 923		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 924	}
 925}
 926
 927static int sci_handle_errors(struct uart_port *port)
 928{
 929	int copied = 0;
 930	unsigned short status = serial_port_in(port, SCxSR);
 931	struct tty_port *tport = &port->state->port;
 932	struct sci_port *s = to_sci_port(port);
 933
 934	/* Handle overruns */
 935	if (status & s->params->overrun_mask) {
 936		port->icount.overrun++;
 937
 938		/* overrun error */
 939		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 940			copied++;
 941	}
 942
 943	if (status & SCxSR_FER(port)) {
 944		/* frame error */
 945		port->icount.frame++;
 946
 947		if (tty_insert_flip_char(tport, 0, TTY_FRAME))
 948			copied++;
 949	}
 950
 951	if (status & SCxSR_PER(port)) {
 952		/* parity error */
 953		port->icount.parity++;
 954
 955		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
 956			copied++;
 957	}
 958
 959	if (copied)
 960		tty_flip_buffer_push(tport);
 961
 962	return copied;
 963}
 964
 965static int sci_handle_fifo_overrun(struct uart_port *port)
 966{
 967	struct tty_port *tport = &port->state->port;
 968	struct sci_port *s = to_sci_port(port);
 969	const struct plat_sci_reg *reg;
 970	int copied = 0;
 971	u16 status;
 972
 973	reg = sci_getreg(port, s->params->overrun_reg);
 974	if (!reg->size)
 975		return 0;
 976
 977	status = serial_port_in(port, s->params->overrun_reg);
 978	if (status & s->params->overrun_mask) {
 979		status &= ~s->params->overrun_mask;
 980		serial_port_out(port, s->params->overrun_reg, status);
 981
 982		port->icount.overrun++;
 983
 984		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 985		tty_flip_buffer_push(tport);
 986		copied++;
 987	}
 988
 989	return copied;
 990}
 991
 992static int sci_handle_breaks(struct uart_port *port)
 993{
 994	int copied = 0;
 995	unsigned short status = serial_port_in(port, SCxSR);
 996	struct tty_port *tport = &port->state->port;
 997
 998	if (uart_handle_break(port))
 999		return 0;
1000
1001	if (status & SCxSR_BRK(port)) {
1002		port->icount.brk++;
1003
1004		/* Notify of BREAK */
1005		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1006			copied++;
1007	}
1008
1009	if (copied)
1010		tty_flip_buffer_push(tport);
1011
1012	copied += sci_handle_fifo_overrun(port);
1013
1014	return copied;
1015}
1016
1017static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1018{
1019	unsigned int bits;
1020
1021	if (rx_trig >= port->fifosize)
1022		rx_trig = port->fifosize - 1;
1023	if (rx_trig < 1)
1024		rx_trig = 1;
1025
1026	/* HSCIF can be set to an arbitrary level. */
1027	if (sci_getreg(port, HSRTRGR)->size) {
1028		serial_port_out(port, HSRTRGR, rx_trig);
1029		return rx_trig;
1030	}
1031
1032	switch (port->type) {
1033	case PORT_SCIF:
1034		if (rx_trig < 4) {
1035			bits = 0;
1036			rx_trig = 1;
1037		} else if (rx_trig < 8) {
1038			bits = SCFCR_RTRG0;
1039			rx_trig = 4;
1040		} else if (rx_trig < 14) {
1041			bits = SCFCR_RTRG1;
1042			rx_trig = 8;
1043		} else {
1044			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1045			rx_trig = 14;
1046		}
1047		break;
1048	case PORT_SCIFA:
1049	case PORT_SCIFB:
1050		if (rx_trig < 16) {
1051			bits = 0;
1052			rx_trig = 1;
1053		} else if (rx_trig < 32) {
1054			bits = SCFCR_RTRG0;
1055			rx_trig = 16;
1056		} else if (rx_trig < 48) {
1057			bits = SCFCR_RTRG1;
1058			rx_trig = 32;
1059		} else {
1060			bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1061			rx_trig = 48;
1062		}
1063		break;
1064	default:
1065		WARN(1, "unknown FIFO configuration");
1066		return 1;
1067	}
1068
1069	serial_port_out(port, SCFCR,
1070		(serial_port_in(port, SCFCR) &
1071		~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1072
1073	return rx_trig;
1074}
1075
1076static int scif_rtrg_enabled(struct uart_port *port)
1077{
1078	if (sci_getreg(port, HSRTRGR)->size)
1079		return serial_port_in(port, HSRTRGR) != 0;
1080	else
1081		return (serial_port_in(port, SCFCR) &
1082			(SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1083}
1084
1085static void rx_fifo_timer_fn(struct timer_list *t)
1086{
1087	struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1088	struct uart_port *port = &s->port;
1089
1090	dev_dbg(port->dev, "Rx timed out\n");
1091	scif_set_rtrg(port, 1);
1092}
1093
1094static ssize_t rx_fifo_trigger_show(struct device *dev,
1095				    struct device_attribute *attr, char *buf)
1096{
1097	struct uart_port *port = dev_get_drvdata(dev);
1098	struct sci_port *sci = to_sci_port(port);
1099
1100	return sprintf(buf, "%d\n", sci->rx_trigger);
1101}
1102
1103static ssize_t rx_fifo_trigger_store(struct device *dev,
1104				     struct device_attribute *attr,
1105				     const char *buf, size_t count)
1106{
1107	struct uart_port *port = dev_get_drvdata(dev);
1108	struct sci_port *sci = to_sci_port(port);
1109	int ret;
1110	long r;
1111
1112	ret = kstrtol(buf, 0, &r);
1113	if (ret)
1114		return ret;
1115
1116	sci->rx_trigger = scif_set_rtrg(port, r);
1117	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1118		scif_set_rtrg(port, 1);
1119
1120	return count;
1121}
1122
1123static DEVICE_ATTR_RW(rx_fifo_trigger);
1124
1125static ssize_t rx_fifo_timeout_show(struct device *dev,
1126			       struct device_attribute *attr,
1127			       char *buf)
1128{
1129	struct uart_port *port = dev_get_drvdata(dev);
1130	struct sci_port *sci = to_sci_port(port);
1131	int v;
1132
1133	if (port->type == PORT_HSCIF)
1134		v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1135	else
1136		v = sci->rx_fifo_timeout;
1137
1138	return sprintf(buf, "%d\n", v);
1139}
1140
1141static ssize_t rx_fifo_timeout_store(struct device *dev,
1142				struct device_attribute *attr,
1143				const char *buf,
1144				size_t count)
1145{
1146	struct uart_port *port = dev_get_drvdata(dev);
1147	struct sci_port *sci = to_sci_port(port);
1148	int ret;
1149	long r;
1150
1151	ret = kstrtol(buf, 0, &r);
1152	if (ret)
1153		return ret;
1154
1155	if (port->type == PORT_HSCIF) {
1156		if (r < 0 || r > 3)
1157			return -EINVAL;
1158		sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1159	} else {
1160		sci->rx_fifo_timeout = r;
1161		scif_set_rtrg(port, 1);
1162		if (r > 0)
1163			timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1164	}
1165
1166	return count;
1167}
1168
1169static DEVICE_ATTR_RW(rx_fifo_timeout);
1170
1171
1172#ifdef CONFIG_SERIAL_SH_SCI_DMA
1173static void sci_dma_tx_complete(void *arg)
1174{
1175	struct sci_port *s = arg;
1176	struct uart_port *port = &s->port;
1177	struct circ_buf *xmit = &port->state->xmit;
1178	unsigned long flags;
1179
1180	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1181
1182	spin_lock_irqsave(&port->lock, flags);
1183
1184	uart_xmit_advance(port, s->tx_dma_len);
1185
1186	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1187		uart_write_wakeup(port);
1188
1189	if (!uart_circ_empty(xmit)) {
1190		s->cookie_tx = 0;
1191		schedule_work(&s->work_tx);
1192	} else {
1193		s->cookie_tx = -EINVAL;
1194		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 
1195			u16 ctrl = serial_port_in(port, SCSCR);
1196			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
 
 
 
 
 
1197		}
1198	}
1199
1200	spin_unlock_irqrestore(&port->lock, flags);
1201}
1202
1203/* Locking: called with port lock held */
1204static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1205{
1206	struct uart_port *port = &s->port;
1207	struct tty_port *tport = &port->state->port;
1208	int copied;
1209
1210	copied = tty_insert_flip_string(tport, buf, count);
1211	if (copied < count)
1212		port->icount.buf_overrun++;
1213
1214	port->icount.rx += copied;
1215
1216	return copied;
1217}
1218
1219static int sci_dma_rx_find_active(struct sci_port *s)
1220{
1221	unsigned int i;
1222
1223	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1224		if (s->active_rx == s->cookie_rx[i])
1225			return i;
1226
1227	return -1;
1228}
1229
1230static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1231{
1232	unsigned int i;
1233
1234	s->chan_rx = NULL;
1235	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1236		s->cookie_rx[i] = -EINVAL;
1237	s->active_rx = 0;
1238}
1239
1240static void sci_dma_rx_release(struct sci_port *s)
1241{
1242	struct dma_chan *chan = s->chan_rx_saved;
1243
1244	s->chan_rx_saved = NULL;
1245	sci_dma_rx_chan_invalidate(s);
1246	dmaengine_terminate_sync(chan);
1247	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1248			  sg_dma_address(&s->sg_rx[0]));
1249	dma_release_channel(chan);
1250}
1251
1252static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1253{
1254	long sec = usec / 1000000;
1255	long nsec = (usec % 1000000) * 1000;
1256	ktime_t t = ktime_set(sec, nsec);
1257
1258	hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1259}
1260
1261static void sci_dma_rx_reenable_irq(struct sci_port *s)
1262{
1263	struct uart_port *port = &s->port;
1264	u16 scr;
1265
1266	/* Direct new serial port interrupts back to CPU */
1267	scr = serial_port_in(port, SCSCR);
1268	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1269		scr &= ~SCSCR_RDRQE;
1270		enable_irq(s->irqs[SCIx_RXI_IRQ]);
 
 
 
 
1271	}
1272	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1273}
1274
1275static void sci_dma_rx_complete(void *arg)
1276{
1277	struct sci_port *s = arg;
1278	struct dma_chan *chan = s->chan_rx;
1279	struct uart_port *port = &s->port;
1280	struct dma_async_tx_descriptor *desc;
1281	unsigned long flags;
1282	int active, count = 0;
1283
1284	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1285		s->active_rx);
1286
1287	spin_lock_irqsave(&port->lock, flags);
1288
1289	active = sci_dma_rx_find_active(s);
1290	if (active >= 0)
1291		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1292
1293	start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1294
1295	if (count)
1296		tty_flip_buffer_push(&port->state->port);
1297
1298	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1299				       DMA_DEV_TO_MEM,
1300				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1301	if (!desc)
1302		goto fail;
1303
1304	desc->callback = sci_dma_rx_complete;
1305	desc->callback_param = s;
1306	s->cookie_rx[active] = dmaengine_submit(desc);
1307	if (dma_submit_error(s->cookie_rx[active]))
1308		goto fail;
1309
1310	s->active_rx = s->cookie_rx[!active];
1311
1312	dma_async_issue_pending(chan);
1313
1314	spin_unlock_irqrestore(&port->lock, flags);
1315	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1316		__func__, s->cookie_rx[active], active, s->active_rx);
1317	return;
1318
1319fail:
1320	spin_unlock_irqrestore(&port->lock, flags);
1321	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1322	/* Switch to PIO */
1323	spin_lock_irqsave(&port->lock, flags);
1324	dmaengine_terminate_async(chan);
1325	sci_dma_rx_chan_invalidate(s);
1326	sci_dma_rx_reenable_irq(s);
1327	spin_unlock_irqrestore(&port->lock, flags);
1328}
1329
1330static void sci_dma_tx_release(struct sci_port *s)
1331{
1332	struct dma_chan *chan = s->chan_tx_saved;
1333
1334	cancel_work_sync(&s->work_tx);
1335	s->chan_tx_saved = s->chan_tx = NULL;
1336	s->cookie_tx = -EINVAL;
1337	dmaengine_terminate_sync(chan);
1338	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1339			 DMA_TO_DEVICE);
1340	dma_release_channel(chan);
1341}
1342
1343static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1344{
1345	struct dma_chan *chan = s->chan_rx;
1346	struct uart_port *port = &s->port;
1347	unsigned long flags;
1348	int i;
1349
1350	for (i = 0; i < 2; i++) {
1351		struct scatterlist *sg = &s->sg_rx[i];
1352		struct dma_async_tx_descriptor *desc;
1353
1354		desc = dmaengine_prep_slave_sg(chan,
1355			sg, 1, DMA_DEV_TO_MEM,
1356			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1357		if (!desc)
1358			goto fail;
1359
1360		desc->callback = sci_dma_rx_complete;
1361		desc->callback_param = s;
1362		s->cookie_rx[i] = dmaengine_submit(desc);
1363		if (dma_submit_error(s->cookie_rx[i]))
1364			goto fail;
1365
1366	}
1367
1368	s->active_rx = s->cookie_rx[0];
1369
1370	dma_async_issue_pending(chan);
1371	return 0;
1372
1373fail:
1374	/* Switch to PIO */
1375	if (!port_lock_held)
1376		spin_lock_irqsave(&port->lock, flags);
1377	if (i)
1378		dmaengine_terminate_async(chan);
1379	sci_dma_rx_chan_invalidate(s);
1380	sci_start_rx(port);
1381	if (!port_lock_held)
1382		spin_unlock_irqrestore(&port->lock, flags);
1383	return -EAGAIN;
1384}
1385
1386static void sci_dma_tx_work_fn(struct work_struct *work)
1387{
1388	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1389	struct dma_async_tx_descriptor *desc;
1390	struct dma_chan *chan = s->chan_tx;
1391	struct uart_port *port = &s->port;
1392	struct circ_buf *xmit = &port->state->xmit;
1393	unsigned long flags;
1394	dma_addr_t buf;
1395	int head, tail;
1396
1397	/*
1398	 * DMA is idle now.
1399	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1400	 * offsets and lengths. Since it is a circular buffer, we have to
1401	 * transmit till the end, and then the rest. Take the port lock to get a
1402	 * consistent xmit buffer state.
1403	 */
1404	spin_lock_irq(&port->lock);
1405	head = xmit->head;
1406	tail = xmit->tail;
1407	buf = s->tx_dma_addr + tail;
1408	s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE);
1409	if (!s->tx_dma_len) {
1410		/* Transmit buffer has been flushed */
1411		spin_unlock_irq(&port->lock);
1412		return;
1413	}
1414
1415	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1416					   DMA_MEM_TO_DEV,
1417					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1418	if (!desc) {
1419		spin_unlock_irq(&port->lock);
1420		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1421		goto switch_to_pio;
1422	}
1423
1424	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1425				   DMA_TO_DEVICE);
1426
1427	desc->callback = sci_dma_tx_complete;
1428	desc->callback_param = s;
1429	s->cookie_tx = dmaengine_submit(desc);
1430	if (dma_submit_error(s->cookie_tx)) {
1431		spin_unlock_irq(&port->lock);
1432		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1433		goto switch_to_pio;
1434	}
1435
1436	spin_unlock_irq(&port->lock);
1437	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1438		__func__, xmit->buf, tail, head, s->cookie_tx);
1439
1440	dma_async_issue_pending(chan);
1441	return;
1442
1443switch_to_pio:
1444	spin_lock_irqsave(&port->lock, flags);
1445	s->chan_tx = NULL;
1446	sci_start_tx(port);
1447	spin_unlock_irqrestore(&port->lock, flags);
1448	return;
1449}
1450
1451static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1452{
1453	struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1454	struct dma_chan *chan = s->chan_rx;
1455	struct uart_port *port = &s->port;
1456	struct dma_tx_state state;
1457	enum dma_status status;
1458	unsigned long flags;
1459	unsigned int read;
1460	int active, count;
1461
1462	dev_dbg(port->dev, "DMA Rx timed out\n");
1463
1464	spin_lock_irqsave(&port->lock, flags);
1465
1466	active = sci_dma_rx_find_active(s);
1467	if (active < 0) {
1468		spin_unlock_irqrestore(&port->lock, flags);
1469		return HRTIMER_NORESTART;
1470	}
1471
1472	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1473	if (status == DMA_COMPLETE) {
1474		spin_unlock_irqrestore(&port->lock, flags);
1475		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1476			s->active_rx, active);
1477
1478		/* Let packet complete handler take care of the packet */
1479		return HRTIMER_NORESTART;
1480	}
1481
1482	dmaengine_pause(chan);
1483
1484	/*
1485	 * sometimes DMA transfer doesn't stop even if it is stopped and
1486	 * data keeps on coming until transaction is complete so check
1487	 * for DMA_COMPLETE again
1488	 * Let packet complete handler take care of the packet
1489	 */
1490	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1491	if (status == DMA_COMPLETE) {
1492		spin_unlock_irqrestore(&port->lock, flags);
1493		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1494		return HRTIMER_NORESTART;
1495	}
1496
1497	/* Handle incomplete DMA receive */
1498	dmaengine_terminate_async(s->chan_rx);
1499	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1500
1501	if (read) {
1502		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1503		if (count)
1504			tty_flip_buffer_push(&port->state->port);
1505	}
1506
1507	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 
1508		sci_dma_rx_submit(s, true);
1509
1510	sci_dma_rx_reenable_irq(s);
1511
1512	spin_unlock_irqrestore(&port->lock, flags);
1513
1514	return HRTIMER_NORESTART;
1515}
1516
1517static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1518					     enum dma_transfer_direction dir)
1519{
1520	struct dma_chan *chan;
1521	struct dma_slave_config cfg;
1522	int ret;
1523
1524	chan = dma_request_slave_channel(port->dev,
1525					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1526	if (!chan) {
1527		dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1528		return NULL;
1529	}
1530
1531	memset(&cfg, 0, sizeof(cfg));
1532	cfg.direction = dir;
1533	if (dir == DMA_MEM_TO_DEV) {
1534		cfg.dst_addr = port->mapbase +
1535			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1536		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1537	} else {
1538		cfg.src_addr = port->mapbase +
1539			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1540		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1541	}
1542
1543	ret = dmaengine_slave_config(chan, &cfg);
1544	if (ret) {
1545		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1546		dma_release_channel(chan);
1547		return NULL;
1548	}
1549
1550	return chan;
1551}
1552
1553static void sci_request_dma(struct uart_port *port)
1554{
1555	struct sci_port *s = to_sci_port(port);
1556	struct dma_chan *chan;
1557
1558	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1559
1560	/*
1561	 * DMA on console may interfere with Kernel log messages which use
1562	 * plain putchar(). So, simply don't use it with a console.
1563	 */
1564	if (uart_console(port))
1565		return;
1566
1567	if (!port->dev->of_node)
1568		return;
1569
1570	s->cookie_tx = -EINVAL;
1571
1572	/*
1573	 * Don't request a dma channel if no channel was specified
1574	 * in the device tree.
1575	 */
1576	if (!of_find_property(port->dev->of_node, "dmas", NULL))
1577		return;
1578
1579	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1580	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1581	if (chan) {
1582		/* UART circular tx buffer is an aligned page. */
1583		s->tx_dma_addr = dma_map_single(chan->device->dev,
1584						port->state->xmit.buf,
1585						UART_XMIT_SIZE,
1586						DMA_TO_DEVICE);
1587		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1588			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1589			dma_release_channel(chan);
1590		} else {
1591			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1592				__func__, UART_XMIT_SIZE,
1593				port->state->xmit.buf, &s->tx_dma_addr);
1594
1595			INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1596			s->chan_tx_saved = s->chan_tx = chan;
1597		}
1598	}
1599
1600	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1601	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1602	if (chan) {
1603		unsigned int i;
1604		dma_addr_t dma;
1605		void *buf;
1606
1607		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1608		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1609					 &dma, GFP_KERNEL);
1610		if (!buf) {
1611			dev_warn(port->dev,
1612				 "Failed to allocate Rx dma buffer, using PIO\n");
1613			dma_release_channel(chan);
1614			return;
1615		}
1616
1617		for (i = 0; i < 2; i++) {
1618			struct scatterlist *sg = &s->sg_rx[i];
1619
1620			sg_init_table(sg, 1);
1621			s->rx_buf[i] = buf;
1622			sg_dma_address(sg) = dma;
1623			sg_dma_len(sg) = s->buf_len_rx;
1624
1625			buf += s->buf_len_rx;
1626			dma += s->buf_len_rx;
1627		}
1628
1629		hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1630		s->rx_timer.function = sci_dma_rx_timer_fn;
1631
1632		s->chan_rx_saved = s->chan_rx = chan;
1633
1634		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 
1635			sci_dma_rx_submit(s, false);
1636	}
1637}
1638
1639static void sci_free_dma(struct uart_port *port)
1640{
1641	struct sci_port *s = to_sci_port(port);
1642
1643	if (s->chan_tx_saved)
1644		sci_dma_tx_release(s);
1645	if (s->chan_rx_saved)
1646		sci_dma_rx_release(s);
1647}
1648
1649static void sci_flush_buffer(struct uart_port *port)
1650{
1651	struct sci_port *s = to_sci_port(port);
1652
1653	/*
1654	 * In uart_flush_buffer(), the xmit circular buffer has just been
1655	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
1656	 * pending transfers
1657	 */
1658	s->tx_dma_len = 0;
1659	if (s->chan_tx) {
1660		dmaengine_terminate_async(s->chan_tx);
1661		s->cookie_tx = -EINVAL;
1662	}
1663}
1664#else /* !CONFIG_SERIAL_SH_SCI_DMA */
1665static inline void sci_request_dma(struct uart_port *port)
1666{
1667}
1668
1669static inline void sci_free_dma(struct uart_port *port)
1670{
1671}
1672
1673#define sci_flush_buffer	NULL
1674#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1675
1676static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1677{
1678	struct uart_port *port = ptr;
1679	struct sci_port *s = to_sci_port(port);
1680
1681#ifdef CONFIG_SERIAL_SH_SCI_DMA
1682	if (s->chan_rx) {
1683		u16 scr = serial_port_in(port, SCSCR);
1684		u16 ssr = serial_port_in(port, SCxSR);
1685
1686		/* Disable future Rx interrupts */
1687		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1688			disable_irq_nosync(irq);
1689			scr |= SCSCR_RDRQE;
 
 
 
 
 
 
1690		} else {
1691			if (sci_dma_rx_submit(s, false) < 0)
1692				goto handle_pio;
1693
1694			scr &= ~SCSCR_RIE;
1695		}
1696		serial_port_out(port, SCSCR, scr);
1697		/* Clear current interrupt */
1698		serial_port_out(port, SCxSR,
1699				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1700		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1701			jiffies, s->rx_timeout);
1702		start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1703
1704		return IRQ_HANDLED;
1705	}
1706
1707handle_pio:
1708#endif
1709
1710	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1711		if (!scif_rtrg_enabled(port))
1712			scif_set_rtrg(port, s->rx_trigger);
1713
1714		mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1715			  s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1716	}
1717
1718	/* I think sci_receive_chars has to be called irrespective
1719	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1720	 * to be disabled?
1721	 */
1722	sci_receive_chars(port);
1723
1724	return IRQ_HANDLED;
1725}
1726
1727static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1728{
1729	struct uart_port *port = ptr;
1730	unsigned long flags;
1731
1732	spin_lock_irqsave(&port->lock, flags);
1733	sci_transmit_chars(port);
1734	spin_unlock_irqrestore(&port->lock, flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1735
1736	return IRQ_HANDLED;
1737}
1738
1739static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1740{
1741	struct uart_port *port = ptr;
1742
1743	/* Handle BREAKs */
1744	sci_handle_breaks(port);
1745
1746	/* drop invalid character received before break was detected */
1747	serial_port_in(port, SCxRDR);
1748
1749	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1750
1751	return IRQ_HANDLED;
1752}
1753
1754static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1755{
1756	struct uart_port *port = ptr;
1757	struct sci_port *s = to_sci_port(port);
1758
1759	if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1760		/* Break and Error interrupts are muxed */
1761		unsigned short ssr_status = serial_port_in(port, SCxSR);
1762
1763		/* Break Interrupt */
1764		if (ssr_status & SCxSR_BRK(port))
1765			sci_br_interrupt(irq, ptr);
1766
1767		/* Break only? */
1768		if (!(ssr_status & SCxSR_ERRORS(port)))
1769			return IRQ_HANDLED;
1770	}
1771
1772	/* Handle errors */
1773	if (port->type == PORT_SCI) {
1774		if (sci_handle_errors(port)) {
1775			/* discard character in rx buffer */
1776			serial_port_in(port, SCxSR);
1777			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1778		}
1779	} else {
1780		sci_handle_fifo_overrun(port);
1781		if (!s->chan_rx)
1782			sci_receive_chars(port);
1783	}
1784
1785	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1786
1787	/* Kick the transmission */
1788	if (!s->chan_tx)
1789		sci_tx_interrupt(irq, ptr);
1790
1791	return IRQ_HANDLED;
1792}
1793
1794static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1795{
1796	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1797	struct uart_port *port = ptr;
1798	struct sci_port *s = to_sci_port(port);
1799	irqreturn_t ret = IRQ_NONE;
1800
1801	ssr_status = serial_port_in(port, SCxSR);
1802	scr_status = serial_port_in(port, SCSCR);
1803	if (s->params->overrun_reg == SCxSR)
1804		orer_status = ssr_status;
1805	else if (sci_getreg(port, s->params->overrun_reg)->size)
1806		orer_status = serial_port_in(port, s->params->overrun_reg);
1807
1808	err_enabled = scr_status & port_rx_irq_mask(port);
1809
1810	/* Tx Interrupt */
1811	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1812	    !s->chan_tx)
1813		ret = sci_tx_interrupt(irq, ptr);
1814
1815	/*
1816	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1817	 * DR flags
1818	 */
1819	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1820	    (scr_status & SCSCR_RIE))
1821		ret = sci_rx_interrupt(irq, ptr);
1822
1823	/* Error Interrupt */
1824	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1825		ret = sci_er_interrupt(irq, ptr);
1826
1827	/* Break Interrupt */
1828	if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] &&
1829	    (ssr_status & SCxSR_BRK(port)) && err_enabled)
1830		ret = sci_br_interrupt(irq, ptr);
1831
1832	/* Overrun Interrupt */
1833	if (orer_status & s->params->overrun_mask) {
1834		sci_handle_fifo_overrun(port);
1835		ret = IRQ_HANDLED;
1836	}
1837
1838	return ret;
1839}
1840
1841static const struct sci_irq_desc {
1842	const char	*desc;
1843	irq_handler_t	handler;
1844} sci_irq_desc[] = {
1845	/*
1846	 * Split out handlers, the default case.
1847	 */
1848	[SCIx_ERI_IRQ] = {
1849		.desc = "rx err",
1850		.handler = sci_er_interrupt,
1851	},
1852
1853	[SCIx_RXI_IRQ] = {
1854		.desc = "rx full",
1855		.handler = sci_rx_interrupt,
1856	},
1857
1858	[SCIx_TXI_IRQ] = {
1859		.desc = "tx empty",
1860		.handler = sci_tx_interrupt,
1861	},
1862
1863	[SCIx_BRI_IRQ] = {
1864		.desc = "break",
1865		.handler = sci_br_interrupt,
1866	},
1867
1868	[SCIx_DRI_IRQ] = {
1869		.desc = "rx ready",
1870		.handler = sci_rx_interrupt,
1871	},
1872
1873	[SCIx_TEI_IRQ] = {
1874		.desc = "tx end",
1875		.handler = sci_tx_interrupt,
1876	},
1877
1878	/*
1879	 * Special muxed handler.
1880	 */
1881	[SCIx_MUX_IRQ] = {
1882		.desc = "mux",
1883		.handler = sci_mpxed_interrupt,
1884	},
1885};
1886
1887static int sci_request_irq(struct sci_port *port)
1888{
1889	struct uart_port *up = &port->port;
1890	int i, j, w, ret = 0;
1891
1892	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1893		const struct sci_irq_desc *desc;
1894		int irq;
1895
1896		/* Check if already registered (muxed) */
1897		for (w = 0; w < i; w++)
1898			if (port->irqs[w] == port->irqs[i])
1899				w = i + 1;
1900		if (w > i)
1901			continue;
1902
1903		if (SCIx_IRQ_IS_MUXED(port)) {
1904			i = SCIx_MUX_IRQ;
1905			irq = up->irq;
1906		} else {
1907			irq = port->irqs[i];
1908
1909			/*
1910			 * Certain port types won't support all of the
1911			 * available interrupt sources.
1912			 */
1913			if (unlikely(irq < 0))
1914				continue;
1915		}
1916
1917		desc = sci_irq_desc + i;
1918		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1919					    dev_name(up->dev), desc->desc);
1920		if (!port->irqstr[j]) {
1921			ret = -ENOMEM;
1922			goto out_nomem;
1923		}
1924
1925		ret = request_irq(irq, desc->handler, up->irqflags,
1926				  port->irqstr[j], port);
1927		if (unlikely(ret)) {
1928			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1929			goto out_noirq;
1930		}
1931	}
1932
1933	return 0;
1934
1935out_noirq:
1936	while (--i >= 0)
1937		free_irq(port->irqs[i], port);
1938
1939out_nomem:
1940	while (--j >= 0)
1941		kfree(port->irqstr[j]);
1942
1943	return ret;
1944}
1945
1946static void sci_free_irq(struct sci_port *port)
1947{
1948	int i, j;
1949
1950	/*
1951	 * Intentionally in reverse order so we iterate over the muxed
1952	 * IRQ first.
1953	 */
1954	for (i = 0; i < SCIx_NR_IRQS; i++) {
1955		int irq = port->irqs[i];
1956
1957		/*
1958		 * Certain port types won't support all of the available
1959		 * interrupt sources.
1960		 */
1961		if (unlikely(irq < 0))
1962			continue;
1963
1964		/* Check if already freed (irq was muxed) */
1965		for (j = 0; j < i; j++)
1966			if (port->irqs[j] == irq)
1967				j = i + 1;
1968		if (j > i)
1969			continue;
1970
1971		free_irq(port->irqs[i], port);
1972		kfree(port->irqstr[i]);
1973
1974		if (SCIx_IRQ_IS_MUXED(port)) {
1975			/* If there's only one IRQ, we're done. */
1976			return;
1977		}
1978	}
1979}
1980
1981static unsigned int sci_tx_empty(struct uart_port *port)
1982{
1983	unsigned short status = serial_port_in(port, SCxSR);
1984	unsigned short in_tx_fifo = sci_txfill(port);
1985
1986	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1987}
1988
1989static void sci_set_rts(struct uart_port *port, bool state)
1990{
1991	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1992		u16 data = serial_port_in(port, SCPDR);
1993
1994		/* Active low */
1995		if (state)
1996			data &= ~SCPDR_RTSD;
1997		else
1998			data |= SCPDR_RTSD;
1999		serial_port_out(port, SCPDR, data);
2000
2001		/* RTS# is output */
2002		serial_port_out(port, SCPCR,
2003				serial_port_in(port, SCPCR) | SCPCR_RTSC);
2004	} else if (sci_getreg(port, SCSPTR)->size) {
2005		u16 ctrl = serial_port_in(port, SCSPTR);
2006
2007		/* Active low */
2008		if (state)
2009			ctrl &= ~SCSPTR_RTSDT;
2010		else
2011			ctrl |= SCSPTR_RTSDT;
2012		serial_port_out(port, SCSPTR, ctrl);
2013	}
2014}
2015
2016static bool sci_get_cts(struct uart_port *port)
2017{
2018	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2019		/* Active low */
2020		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2021	} else if (sci_getreg(port, SCSPTR)->size) {
2022		/* Active low */
2023		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2024	}
2025
2026	return true;
2027}
2028
2029/*
2030 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2031 * CTS/RTS is supported in hardware by at least one port and controlled
2032 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2033 * handled via the ->init_pins() op, which is a bit of a one-way street,
2034 * lacking any ability to defer pin control -- this will later be
2035 * converted over to the GPIO framework).
2036 *
2037 * Other modes (such as loopback) are supported generically on certain
2038 * port types, but not others. For these it's sufficient to test for the
2039 * existence of the support register and simply ignore the port type.
2040 */
2041static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2042{
2043	struct sci_port *s = to_sci_port(port);
2044
2045	if (mctrl & TIOCM_LOOP) {
2046		const struct plat_sci_reg *reg;
2047
2048		/*
2049		 * Standard loopback mode for SCFCR ports.
2050		 */
2051		reg = sci_getreg(port, SCFCR);
2052		if (reg->size)
2053			serial_port_out(port, SCFCR,
2054					serial_port_in(port, SCFCR) |
2055					SCFCR_LOOP);
2056	}
2057
2058	mctrl_gpio_set(s->gpios, mctrl);
2059
2060	if (!s->has_rtscts)
2061		return;
2062
2063	if (!(mctrl & TIOCM_RTS)) {
2064		/* Disable Auto RTS */
2065		serial_port_out(port, SCFCR,
2066				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2067
2068		/* Clear RTS */
2069		sci_set_rts(port, 0);
2070	} else if (s->autorts) {
2071		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2072			/* Enable RTS# pin function */
2073			serial_port_out(port, SCPCR,
2074				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2075		}
2076
2077		/* Enable Auto RTS */
2078		serial_port_out(port, SCFCR,
2079				serial_port_in(port, SCFCR) | SCFCR_MCE);
2080	} else {
2081		/* Set RTS */
2082		sci_set_rts(port, 1);
2083	}
2084}
2085
2086static unsigned int sci_get_mctrl(struct uart_port *port)
2087{
2088	struct sci_port *s = to_sci_port(port);
2089	struct mctrl_gpios *gpios = s->gpios;
2090	unsigned int mctrl = 0;
2091
2092	mctrl_gpio_get(gpios, &mctrl);
2093
2094	/*
2095	 * CTS/RTS is handled in hardware when supported, while nothing
2096	 * else is wired up.
2097	 */
2098	if (s->autorts) {
2099		if (sci_get_cts(port))
2100			mctrl |= TIOCM_CTS;
2101	} else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2102		mctrl |= TIOCM_CTS;
2103	}
2104	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2105		mctrl |= TIOCM_DSR;
2106	if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2107		mctrl |= TIOCM_CAR;
2108
2109	return mctrl;
2110}
2111
2112static void sci_enable_ms(struct uart_port *port)
2113{
2114	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2115}
2116
2117static void sci_break_ctl(struct uart_port *port, int break_state)
2118{
2119	unsigned short scscr, scsptr;
2120	unsigned long flags;
2121
2122	/* check whether the port has SCSPTR */
2123	if (!sci_getreg(port, SCSPTR)->size) {
2124		/*
2125		 * Not supported by hardware. Most parts couple break and rx
2126		 * interrupts together, with break detection always enabled.
2127		 */
2128		return;
2129	}
2130
2131	spin_lock_irqsave(&port->lock, flags);
2132	scsptr = serial_port_in(port, SCSPTR);
2133	scscr = serial_port_in(port, SCSCR);
2134
2135	if (break_state == -1) {
2136		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2137		scscr &= ~SCSCR_TE;
2138	} else {
2139		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2140		scscr |= SCSCR_TE;
2141	}
2142
2143	serial_port_out(port, SCSPTR, scsptr);
2144	serial_port_out(port, SCSCR, scscr);
2145	spin_unlock_irqrestore(&port->lock, flags);
2146}
2147
2148static int sci_startup(struct uart_port *port)
2149{
2150	struct sci_port *s = to_sci_port(port);
2151	int ret;
2152
2153	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2154
2155	sci_request_dma(port);
2156
2157	ret = sci_request_irq(s);
2158	if (unlikely(ret < 0)) {
2159		sci_free_dma(port);
2160		return ret;
2161	}
2162
2163	return 0;
2164}
2165
2166static void sci_shutdown(struct uart_port *port)
2167{
2168	struct sci_port *s = to_sci_port(port);
2169	unsigned long flags;
2170	u16 scr;
2171
2172	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2173
2174	s->autorts = false;
2175	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2176
2177	spin_lock_irqsave(&port->lock, flags);
2178	sci_stop_rx(port);
2179	sci_stop_tx(port);
2180	/*
2181	 * Stop RX and TX, disable related interrupts, keep clock source
2182	 * and HSCIF TOT bits
2183	 */
2184	scr = serial_port_in(port, SCSCR);
2185	serial_port_out(port, SCSCR, scr &
2186			(SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2187	spin_unlock_irqrestore(&port->lock, flags);
2188
2189#ifdef CONFIG_SERIAL_SH_SCI_DMA
2190	if (s->chan_rx_saved) {
2191		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2192			port->line);
2193		hrtimer_cancel(&s->rx_timer);
2194	}
2195#endif
2196
2197	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2198		del_timer_sync(&s->rx_fifo_timer);
2199	sci_free_irq(s);
2200	sci_free_dma(port);
2201}
2202
2203static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2204			unsigned int *srr)
2205{
2206	unsigned long freq = s->clk_rates[SCI_SCK];
2207	int err, min_err = INT_MAX;
2208	unsigned int sr;
2209
2210	if (s->port.type != PORT_HSCIF)
2211		freq *= 2;
2212
2213	for_each_sr(sr, s) {
2214		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2215		if (abs(err) >= abs(min_err))
2216			continue;
2217
2218		min_err = err;
2219		*srr = sr - 1;
2220
2221		if (!err)
2222			break;
2223	}
2224
2225	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2226		*srr + 1);
2227	return min_err;
2228}
2229
2230static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2231			unsigned long freq, unsigned int *dlr,
2232			unsigned int *srr)
2233{
2234	int err, min_err = INT_MAX;
2235	unsigned int sr, dl;
2236
2237	if (s->port.type != PORT_HSCIF)
2238		freq *= 2;
2239
2240	for_each_sr(sr, s) {
2241		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2242		dl = clamp(dl, 1U, 65535U);
2243
2244		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2245		if (abs(err) >= abs(min_err))
2246			continue;
2247
2248		min_err = err;
2249		*dlr = dl;
2250		*srr = sr - 1;
2251
2252		if (!err)
2253			break;
2254	}
2255
2256	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2257		min_err, *dlr, *srr + 1);
2258	return min_err;
2259}
2260
2261/* calculate sample rate, BRR, and clock select */
2262static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2263			  unsigned int *brr, unsigned int *srr,
2264			  unsigned int *cks)
2265{
2266	unsigned long freq = s->clk_rates[SCI_FCK];
2267	unsigned int sr, br, prediv, scrate, c;
2268	int err, min_err = INT_MAX;
2269
2270	if (s->port.type != PORT_HSCIF)
2271		freq *= 2;
2272
2273	/*
2274	 * Find the combination of sample rate and clock select with the
2275	 * smallest deviation from the desired baud rate.
2276	 * Prefer high sample rates to maximise the receive margin.
2277	 *
2278	 * M: Receive margin (%)
2279	 * N: Ratio of bit rate to clock (N = sampling rate)
2280	 * D: Clock duty (D = 0 to 1.0)
2281	 * L: Frame length (L = 9 to 12)
2282	 * F: Absolute value of clock frequency deviation
2283	 *
2284	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2285	 *      (|D - 0.5| / N * (1 + F))|
2286	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2287	 */
2288	for_each_sr(sr, s) {
2289		for (c = 0; c <= 3; c++) {
2290			/* integerized formulas from HSCIF documentation */
2291			prediv = sr << (2 * c + 1);
2292
2293			/*
2294			 * We need to calculate:
2295			 *
2296			 *     br = freq / (prediv * bps) clamped to [1..256]
2297			 *     err = freq / (br * prediv) - bps
2298			 *
2299			 * Watch out for overflow when calculating the desired
2300			 * sampling clock rate!
2301			 */
2302			if (bps > UINT_MAX / prediv)
2303				break;
2304
2305			scrate = prediv * bps;
2306			br = DIV_ROUND_CLOSEST(freq, scrate);
2307			br = clamp(br, 1U, 256U);
2308
2309			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2310			if (abs(err) >= abs(min_err))
2311				continue;
2312
2313			min_err = err;
2314			*brr = br - 1;
2315			*srr = sr - 1;
2316			*cks = c;
2317
2318			if (!err)
2319				goto found;
2320		}
2321	}
2322
2323found:
2324	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2325		min_err, *brr, *srr + 1, *cks);
2326	return min_err;
2327}
2328
2329static void sci_reset(struct uart_port *port)
2330{
2331	const struct plat_sci_reg *reg;
2332	unsigned int status;
2333	struct sci_port *s = to_sci_port(port);
2334
2335	serial_port_out(port, SCSCR, s->hscif_tot);	/* TE=0, RE=0, CKE1=0 */
2336
2337	reg = sci_getreg(port, SCFCR);
2338	if (reg->size)
2339		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2340
2341	sci_clear_SCxSR(port,
2342			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2343			SCxSR_BREAK_CLEAR(port));
2344	if (sci_getreg(port, SCLSR)->size) {
2345		status = serial_port_in(port, SCLSR);
2346		status &= ~(SCLSR_TO | SCLSR_ORER);
2347		serial_port_out(port, SCLSR, status);
2348	}
2349
2350	if (s->rx_trigger > 1) {
2351		if (s->rx_fifo_timeout) {
2352			scif_set_rtrg(port, 1);
2353			timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2354		} else {
2355			if (port->type == PORT_SCIFA ||
2356			    port->type == PORT_SCIFB)
2357				scif_set_rtrg(port, 1);
2358			else
2359				scif_set_rtrg(port, s->rx_trigger);
2360		}
2361	}
2362}
2363
2364static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2365		            const struct ktermios *old)
2366{
2367	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2368	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2369	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2370	struct sci_port *s = to_sci_port(port);
2371	const struct plat_sci_reg *reg;
2372	int min_err = INT_MAX, err;
2373	unsigned long max_freq = 0;
2374	int best_clk = -1;
2375	unsigned long flags;
2376
2377	if ((termios->c_cflag & CSIZE) == CS7) {
2378		smr_val |= SCSMR_CHR;
2379	} else {
2380		termios->c_cflag &= ~CSIZE;
2381		termios->c_cflag |= CS8;
2382	}
2383	if (termios->c_cflag & PARENB)
2384		smr_val |= SCSMR_PE;
2385	if (termios->c_cflag & PARODD)
2386		smr_val |= SCSMR_PE | SCSMR_ODD;
2387	if (termios->c_cflag & CSTOPB)
2388		smr_val |= SCSMR_STOP;
2389
2390	/*
2391	 * earlyprintk comes here early on with port->uartclk set to zero.
2392	 * the clock framework is not up and running at this point so here
2393	 * we assume that 115200 is the maximum baud rate. please note that
2394	 * the baud rate is not programmed during earlyprintk - it is assumed
2395	 * that the previous boot loader has enabled required clocks and
2396	 * setup the baud rate generator hardware for us already.
2397	 */
2398	if (!port->uartclk) {
2399		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2400		goto done;
2401	}
2402
2403	for (i = 0; i < SCI_NUM_CLKS; i++)
2404		max_freq = max(max_freq, s->clk_rates[i]);
2405
2406	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2407	if (!baud)
2408		goto done;
2409
2410	/*
2411	 * There can be multiple sources for the sampling clock.  Find the one
2412	 * that gives us the smallest deviation from the desired baud rate.
2413	 */
2414
2415	/* Optional Undivided External Clock */
2416	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2417	    port->type != PORT_SCIFB) {
2418		err = sci_sck_calc(s, baud, &srr1);
2419		if (abs(err) < abs(min_err)) {
2420			best_clk = SCI_SCK;
2421			scr_val = SCSCR_CKE1;
2422			sccks = SCCKS_CKS;
2423			min_err = err;
2424			srr = srr1;
2425			if (!err)
2426				goto done;
2427		}
2428	}
2429
2430	/* Optional BRG Frequency Divided External Clock */
2431	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2432		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2433				   &srr1);
2434		if (abs(err) < abs(min_err)) {
2435			best_clk = SCI_SCIF_CLK;
2436			scr_val = SCSCR_CKE1;
2437			sccks = 0;
2438			min_err = err;
2439			dl = dl1;
2440			srr = srr1;
2441			if (!err)
2442				goto done;
2443		}
2444	}
2445
2446	/* Optional BRG Frequency Divided Internal Clock */
2447	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2448		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2449				   &srr1);
2450		if (abs(err) < abs(min_err)) {
2451			best_clk = SCI_BRG_INT;
2452			scr_val = SCSCR_CKE1;
2453			sccks = SCCKS_XIN;
2454			min_err = err;
2455			dl = dl1;
2456			srr = srr1;
2457			if (!min_err)
2458				goto done;
2459		}
2460	}
2461
2462	/* Divided Functional Clock using standard Bit Rate Register */
2463	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2464	if (abs(err) < abs(min_err)) {
2465		best_clk = SCI_FCK;
2466		scr_val = 0;
2467		min_err = err;
2468		brr = brr1;
2469		srr = srr1;
2470		cks = cks1;
2471	}
2472
2473done:
2474	if (best_clk >= 0)
2475		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2476			s->clks[best_clk], baud, min_err);
2477
2478	sci_port_enable(s);
2479
2480	/*
2481	 * Program the optional External Baud Rate Generator (BRG) first.
2482	 * It controls the mux to select (H)SCK or frequency divided clock.
2483	 */
2484	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2485		serial_port_out(port, SCDL, dl);
2486		serial_port_out(port, SCCKS, sccks);
2487	}
2488
2489	spin_lock_irqsave(&port->lock, flags);
2490
2491	sci_reset(port);
2492
2493	uart_update_timeout(port, termios->c_cflag, baud);
2494
2495	/* byte size and parity */
2496	bits = tty_get_frame_size(termios->c_cflag);
2497
2498	if (sci_getreg(port, SEMR)->size)
2499		serial_port_out(port, SEMR, 0);
2500
2501	if (best_clk >= 0) {
2502		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2503			switch (srr + 1) {
2504			case 5:  smr_val |= SCSMR_SRC_5;  break;
2505			case 7:  smr_val |= SCSMR_SRC_7;  break;
2506			case 11: smr_val |= SCSMR_SRC_11; break;
2507			case 13: smr_val |= SCSMR_SRC_13; break;
2508			case 16: smr_val |= SCSMR_SRC_16; break;
2509			case 17: smr_val |= SCSMR_SRC_17; break;
2510			case 19: smr_val |= SCSMR_SRC_19; break;
2511			case 27: smr_val |= SCSMR_SRC_27; break;
2512			}
2513		smr_val |= cks;
2514		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2515		serial_port_out(port, SCSMR, smr_val);
2516		serial_port_out(port, SCBRR, brr);
2517		if (sci_getreg(port, HSSRR)->size) {
2518			unsigned int hssrr = srr | HSCIF_SRE;
2519			/* Calculate deviation from intended rate at the
2520			 * center of the last stop bit in sampling clocks.
2521			 */
2522			int last_stop = bits * 2 - 1;
2523			int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2524							  (int)(srr + 1),
2525							  2 * (int)baud);
2526
2527			if (abs(deviation) >= 2) {
2528				/* At least two sampling clocks off at the
2529				 * last stop bit; we can increase the error
2530				 * margin by shifting the sampling point.
2531				 */
2532				int shift = clamp(deviation / 2, -8, 7);
2533
2534				hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2535					 HSCIF_SRHP_MASK;
2536				hssrr |= HSCIF_SRDE;
2537			}
2538			serial_port_out(port, HSSRR, hssrr);
2539		}
2540
2541		/* Wait one bit interval */
2542		udelay((1000000 + (baud - 1)) / baud);
2543	} else {
2544		/* Don't touch the bit rate configuration */
2545		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2546		smr_val |= serial_port_in(port, SCSMR) &
2547			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2548		serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2549		serial_port_out(port, SCSMR, smr_val);
2550	}
2551
2552	sci_init_pins(port, termios->c_cflag);
2553
2554	port->status &= ~UPSTAT_AUTOCTS;
2555	s->autorts = false;
2556	reg = sci_getreg(port, SCFCR);
2557	if (reg->size) {
2558		unsigned short ctrl = serial_port_in(port, SCFCR);
2559
2560		if ((port->flags & UPF_HARD_FLOW) &&
2561		    (termios->c_cflag & CRTSCTS)) {
2562			/* There is no CTS interrupt to restart the hardware */
2563			port->status |= UPSTAT_AUTOCTS;
2564			/* MCE is enabled when RTS is raised */
2565			s->autorts = true;
2566		}
2567
2568		/*
2569		 * As we've done a sci_reset() above, ensure we don't
2570		 * interfere with the FIFOs while toggling MCE. As the
2571		 * reset values could still be set, simply mask them out.
2572		 */
2573		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2574
2575		serial_port_out(port, SCFCR, ctrl);
2576	}
2577	if (port->flags & UPF_HARD_FLOW) {
2578		/* Refresh (Auto) RTS */
2579		sci_set_mctrl(port, port->mctrl);
2580	}
2581
2582	scr_val |= SCSCR_RE | SCSCR_TE |
2583		   (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
 
 
 
 
 
 
2584	serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2585	if ((srr + 1 == 5) &&
2586	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2587		/*
2588		 * In asynchronous mode, when the sampling rate is 1/5, first
2589		 * received data may become invalid on some SCIFA and SCIFB.
2590		 * To avoid this problem wait more than 1 serial data time (1
2591		 * bit time x serial data number) after setting SCSCR.RE = 1.
2592		 */
2593		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2594	}
2595
2596	/* Calculate delay for 2 DMA buffers (4 FIFO). */
2597	s->rx_frame = (10000 * bits) / (baud / 100);
2598#ifdef CONFIG_SERIAL_SH_SCI_DMA
2599	s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2600#endif
2601
2602	if ((termios->c_cflag & CREAD) != 0)
2603		sci_start_rx(port);
2604
2605	spin_unlock_irqrestore(&port->lock, flags);
2606
2607	sci_port_disable(s);
2608
2609	if (UART_ENABLE_MS(port, termios->c_cflag))
2610		sci_enable_ms(port);
2611}
2612
2613static void sci_pm(struct uart_port *port, unsigned int state,
2614		   unsigned int oldstate)
2615{
2616	struct sci_port *sci_port = to_sci_port(port);
2617
2618	switch (state) {
2619	case UART_PM_STATE_OFF:
2620		sci_port_disable(sci_port);
2621		break;
2622	default:
2623		sci_port_enable(sci_port);
2624		break;
2625	}
2626}
2627
2628static const char *sci_type(struct uart_port *port)
2629{
2630	switch (port->type) {
2631	case PORT_IRDA:
2632		return "irda";
2633	case PORT_SCI:
2634		return "sci";
2635	case PORT_SCIF:
2636		return "scif";
2637	case PORT_SCIFA:
2638		return "scifa";
2639	case PORT_SCIFB:
2640		return "scifb";
2641	case PORT_HSCIF:
2642		return "hscif";
2643	}
2644
2645	return NULL;
2646}
2647
2648static int sci_remap_port(struct uart_port *port)
2649{
2650	struct sci_port *sport = to_sci_port(port);
2651
2652	/*
2653	 * Nothing to do if there's already an established membase.
2654	 */
2655	if (port->membase)
2656		return 0;
2657
2658	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2659		port->membase = ioremap(port->mapbase, sport->reg_size);
2660		if (unlikely(!port->membase)) {
2661			dev_err(port->dev, "can't remap port#%d\n", port->line);
2662			return -ENXIO;
2663		}
2664	} else {
2665		/*
2666		 * For the simple (and majority of) cases where we don't
2667		 * need to do any remapping, just cast the cookie
2668		 * directly.
2669		 */
2670		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2671	}
2672
2673	return 0;
2674}
2675
2676static void sci_release_port(struct uart_port *port)
2677{
2678	struct sci_port *sport = to_sci_port(port);
2679
2680	if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2681		iounmap(port->membase);
2682		port->membase = NULL;
2683	}
2684
2685	release_mem_region(port->mapbase, sport->reg_size);
2686}
2687
2688static int sci_request_port(struct uart_port *port)
2689{
2690	struct resource *res;
2691	struct sci_port *sport = to_sci_port(port);
2692	int ret;
2693
2694	res = request_mem_region(port->mapbase, sport->reg_size,
2695				 dev_name(port->dev));
2696	if (unlikely(res == NULL)) {
2697		dev_err(port->dev, "request_mem_region failed.");
2698		return -EBUSY;
2699	}
2700
2701	ret = sci_remap_port(port);
2702	if (unlikely(ret != 0)) {
2703		release_resource(res);
2704		return ret;
2705	}
2706
2707	return 0;
2708}
2709
2710static void sci_config_port(struct uart_port *port, int flags)
2711{
2712	if (flags & UART_CONFIG_TYPE) {
2713		struct sci_port *sport = to_sci_port(port);
2714
2715		port->type = sport->cfg->type;
2716		sci_request_port(port);
2717	}
2718}
2719
2720static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2721{
2722	if (ser->baud_base < 2400)
2723		/* No paper tape reader for Mitch.. */
2724		return -EINVAL;
2725
2726	return 0;
2727}
2728
2729static const struct uart_ops sci_uart_ops = {
2730	.tx_empty	= sci_tx_empty,
2731	.set_mctrl	= sci_set_mctrl,
2732	.get_mctrl	= sci_get_mctrl,
2733	.start_tx	= sci_start_tx,
2734	.stop_tx	= sci_stop_tx,
2735	.stop_rx	= sci_stop_rx,
2736	.enable_ms	= sci_enable_ms,
2737	.break_ctl	= sci_break_ctl,
2738	.startup	= sci_startup,
2739	.shutdown	= sci_shutdown,
2740	.flush_buffer	= sci_flush_buffer,
2741	.set_termios	= sci_set_termios,
2742	.pm		= sci_pm,
2743	.type		= sci_type,
2744	.release_port	= sci_release_port,
2745	.request_port	= sci_request_port,
2746	.config_port	= sci_config_port,
2747	.verify_port	= sci_verify_port,
2748#ifdef CONFIG_CONSOLE_POLL
2749	.poll_get_char	= sci_poll_get_char,
2750	.poll_put_char	= sci_poll_put_char,
2751#endif
2752};
2753
2754static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2755{
2756	const char *clk_names[] = {
2757		[SCI_FCK] = "fck",
2758		[SCI_SCK] = "sck",
2759		[SCI_BRG_INT] = "brg_int",
2760		[SCI_SCIF_CLK] = "scif_clk",
2761	};
2762	struct clk *clk;
2763	unsigned int i;
2764
2765	if (sci_port->cfg->type == PORT_HSCIF)
2766		clk_names[SCI_SCK] = "hsck";
2767
2768	for (i = 0; i < SCI_NUM_CLKS; i++) {
2769		clk = devm_clk_get_optional(dev, clk_names[i]);
2770		if (IS_ERR(clk))
2771			return PTR_ERR(clk);
2772
2773		if (!clk && i == SCI_FCK) {
2774			/*
2775			 * Not all SH platforms declare a clock lookup entry
2776			 * for SCI devices, in which case we need to get the
2777			 * global "peripheral_clk" clock.
2778			 */
2779			clk = devm_clk_get(dev, "peripheral_clk");
2780			if (IS_ERR(clk))
2781				return dev_err_probe(dev, PTR_ERR(clk),
2782						     "failed to get %s\n",
2783						     clk_names[i]);
2784		}
2785
2786		if (!clk)
2787			dev_dbg(dev, "failed to get %s\n", clk_names[i]);
2788		else
2789			dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2790				clk, clk_get_rate(clk));
2791		sci_port->clks[i] = clk;
2792	}
2793	return 0;
2794}
2795
2796static const struct sci_port_params *
2797sci_probe_regmap(const struct plat_sci_port *cfg)
2798{
2799	unsigned int regtype;
2800
2801	if (cfg->regtype != SCIx_PROBE_REGTYPE)
2802		return &sci_port_params[cfg->regtype];
2803
2804	switch (cfg->type) {
2805	case PORT_SCI:
2806		regtype = SCIx_SCI_REGTYPE;
2807		break;
2808	case PORT_IRDA:
2809		regtype = SCIx_IRDA_REGTYPE;
2810		break;
2811	case PORT_SCIFA:
2812		regtype = SCIx_SCIFA_REGTYPE;
2813		break;
2814	case PORT_SCIFB:
2815		regtype = SCIx_SCIFB_REGTYPE;
2816		break;
2817	case PORT_SCIF:
2818		/*
2819		 * The SH-4 is a bit of a misnomer here, although that's
2820		 * where this particular port layout originated. This
2821		 * configuration (or some slight variation thereof)
2822		 * remains the dominant model for all SCIFs.
2823		 */
2824		regtype = SCIx_SH4_SCIF_REGTYPE;
2825		break;
2826	case PORT_HSCIF:
2827		regtype = SCIx_HSCIF_REGTYPE;
2828		break;
2829	default:
2830		pr_err("Can't probe register map for given port\n");
2831		return NULL;
2832	}
2833
2834	return &sci_port_params[regtype];
2835}
2836
2837static int sci_init_single(struct platform_device *dev,
2838			   struct sci_port *sci_port, unsigned int index,
2839			   const struct plat_sci_port *p, bool early)
2840{
2841	struct uart_port *port = &sci_port->port;
2842	const struct resource *res;
2843	unsigned int i;
2844	int ret;
2845
2846	sci_port->cfg	= p;
2847
2848	port->ops	= &sci_uart_ops;
2849	port->iotype	= UPIO_MEM;
2850	port->line	= index;
2851	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE);
2852
2853	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2854	if (res == NULL)
2855		return -ENOMEM;
2856
2857	port->mapbase = res->start;
2858	sci_port->reg_size = resource_size(res);
2859
2860	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2861		if (i)
2862			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2863		else
2864			sci_port->irqs[i] = platform_get_irq(dev, i);
2865	}
2866
 
 
 
 
 
 
 
2867	/* The SCI generates several interrupts. They can be muxed together or
2868	 * connected to different interrupt lines. In the muxed case only one
2869	 * interrupt resource is specified as there is only one interrupt ID.
2870	 * In the non-muxed case, up to 6 interrupt signals might be generated
2871	 * from the SCI, however those signals might have their own individual
2872	 * interrupt ID numbers, or muxed together with another interrupt.
2873	 */
2874	if (sci_port->irqs[0] < 0)
2875		return -ENXIO;
2876
2877	if (sci_port->irqs[1] < 0)
2878		for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2879			sci_port->irqs[i] = sci_port->irqs[0];
2880
2881	sci_port->params = sci_probe_regmap(p);
2882	if (unlikely(sci_port->params == NULL))
2883		return -EINVAL;
2884
2885	switch (p->type) {
2886	case PORT_SCIFB:
2887		sci_port->rx_trigger = 48;
2888		break;
2889	case PORT_HSCIF:
2890		sci_port->rx_trigger = 64;
2891		break;
2892	case PORT_SCIFA:
2893		sci_port->rx_trigger = 32;
2894		break;
2895	case PORT_SCIF:
2896		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2897			/* RX triggering not implemented for this IP */
2898			sci_port->rx_trigger = 1;
2899		else
2900			sci_port->rx_trigger = 8;
2901		break;
2902	default:
2903		sci_port->rx_trigger = 1;
2904		break;
2905	}
2906
2907	sci_port->rx_fifo_timeout = 0;
2908	sci_port->hscif_tot = 0;
2909
2910	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2911	 * match the SoC datasheet, this should be investigated. Let platform
2912	 * data override the sampling rate for now.
2913	 */
2914	sci_port->sampling_rate_mask = p->sampling_rate
2915				     ? SCI_SR(p->sampling_rate)
2916				     : sci_port->params->sampling_rate_mask;
2917
2918	if (!early) {
2919		ret = sci_init_clocks(sci_port, &dev->dev);
2920		if (ret < 0)
2921			return ret;
2922
2923		port->dev = &dev->dev;
2924
2925		pm_runtime_enable(&dev->dev);
2926	}
2927
2928	port->type		= p->type;
2929	port->flags		= UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2930	port->fifosize		= sci_port->params->fifosize;
2931
2932	if (port->type == PORT_SCI) {
2933		if (sci_port->reg_size >= 0x20)
2934			port->regshift = 2;
2935		else
2936			port->regshift = 1;
2937	}
2938
2939	/*
2940	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2941	 * for the multi-IRQ ports, which is where we are primarily
2942	 * concerned with the shutdown path synchronization.
2943	 *
2944	 * For the muxed case there's nothing more to do.
2945	 */
2946	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2947	port->irqflags		= 0;
2948
2949	port->serial_in		= sci_serial_in;
2950	port->serial_out	= sci_serial_out;
2951
2952	return 0;
2953}
2954
2955static void sci_cleanup_single(struct sci_port *port)
2956{
2957	pm_runtime_disable(port->port.dev);
2958}
2959
2960#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2961    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2962static void serial_console_putchar(struct uart_port *port, unsigned char ch)
2963{
2964	sci_poll_put_char(port, ch);
2965}
2966
2967/*
2968 *	Print a string to the serial port trying not to disturb
2969 *	any possible real use of the port...
2970 */
2971static void serial_console_write(struct console *co, const char *s,
2972				 unsigned count)
2973{
2974	struct sci_port *sci_port = &sci_ports[co->index];
2975	struct uart_port *port = &sci_port->port;
2976	unsigned short bits, ctrl, ctrl_temp;
2977	unsigned long flags;
2978	int locked = 1;
2979
2980	if (port->sysrq)
2981		locked = 0;
2982	else if (oops_in_progress)
2983		locked = spin_trylock_irqsave(&port->lock, flags);
2984	else
2985		spin_lock_irqsave(&port->lock, flags);
2986
2987	/* first save SCSCR then disable interrupts, keep clock source */
2988	ctrl = serial_port_in(port, SCSCR);
2989	ctrl_temp = SCSCR_RE | SCSCR_TE |
2990		    (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2991		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2992	serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
2993
2994	uart_console_write(port, s, count, serial_console_putchar);
2995
2996	/* wait until fifo is empty and last bit has been transmitted */
2997	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2998	while ((serial_port_in(port, SCxSR) & bits) != bits)
2999		cpu_relax();
3000
3001	/* restore the SCSCR */
3002	serial_port_out(port, SCSCR, ctrl);
3003
3004	if (locked)
3005		spin_unlock_irqrestore(&port->lock, flags);
3006}
3007
3008static int serial_console_setup(struct console *co, char *options)
3009{
3010	struct sci_port *sci_port;
3011	struct uart_port *port;
3012	int baud = 115200;
3013	int bits = 8;
3014	int parity = 'n';
3015	int flow = 'n';
3016	int ret;
3017
3018	/*
3019	 * Refuse to handle any bogus ports.
3020	 */
3021	if (co->index < 0 || co->index >= SCI_NPORTS)
3022		return -ENODEV;
3023
3024	sci_port = &sci_ports[co->index];
3025	port = &sci_port->port;
3026
3027	/*
3028	 * Refuse to handle uninitialized ports.
3029	 */
3030	if (!port->ops)
3031		return -ENODEV;
3032
3033	ret = sci_remap_port(port);
3034	if (unlikely(ret != 0))
3035		return ret;
3036
3037	if (options)
3038		uart_parse_options(options, &baud, &parity, &bits, &flow);
3039
3040	return uart_set_options(port, co, baud, parity, bits, flow);
3041}
3042
3043static struct console serial_console = {
3044	.name		= "ttySC",
3045	.device		= uart_console_device,
3046	.write		= serial_console_write,
3047	.setup		= serial_console_setup,
3048	.flags		= CON_PRINTBUFFER,
3049	.index		= -1,
3050	.data		= &sci_uart_driver,
3051};
3052
3053#ifdef CONFIG_SUPERH
3054static char early_serial_buf[32];
3055
3056static int early_serial_console_setup(struct console *co, char *options)
3057{
3058	/*
3059	 * This early console is always registered using the earlyprintk=
3060	 * parameter, which does not call add_preferred_console(). Thus
3061	 * @options is always NULL and the options for this early console
3062	 * are passed using a custom buffer.
3063	 */
3064	WARN_ON(options);
3065
3066	return serial_console_setup(co, early_serial_buf);
3067}
3068
3069static struct console early_serial_console = {
3070	.name           = "early_ttySC",
3071	.write          = serial_console_write,
3072	.setup		= early_serial_console_setup,
3073	.flags          = CON_PRINTBUFFER,
3074	.index		= -1,
3075};
3076
3077static int sci_probe_earlyprintk(struct platform_device *pdev)
3078{
3079	const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3080
3081	if (early_serial_console.data)
3082		return -EEXIST;
3083
3084	early_serial_console.index = pdev->id;
3085
3086	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3087
3088	if (!strstr(early_serial_buf, "keep"))
3089		early_serial_console.flags |= CON_BOOT;
3090
3091	register_console(&early_serial_console);
3092	return 0;
3093}
3094#endif
3095
3096#define SCI_CONSOLE	(&serial_console)
3097
3098#else
3099static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3100{
3101	return -EINVAL;
3102}
3103
3104#define SCI_CONSOLE	NULL
3105
3106#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3107
3108static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3109
3110static DEFINE_MUTEX(sci_uart_registration_lock);
3111static struct uart_driver sci_uart_driver = {
3112	.owner		= THIS_MODULE,
3113	.driver_name	= "sci",
3114	.dev_name	= "ttySC",
3115	.major		= SCI_MAJOR,
3116	.minor		= SCI_MINOR_START,
3117	.nr		= SCI_NPORTS,
3118	.cons		= SCI_CONSOLE,
3119};
3120
3121static int sci_remove(struct platform_device *dev)
3122{
3123	struct sci_port *port = platform_get_drvdata(dev);
3124	unsigned int type = port->port.type;	/* uart_remove_... clears it */
3125
3126	sci_ports_in_use &= ~BIT(port->port.line);
3127	uart_remove_one_port(&sci_uart_driver, &port->port);
3128
3129	sci_cleanup_single(port);
3130
3131	if (port->port.fifosize > 1)
3132		device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3133	if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3134		device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3135
3136	return 0;
3137}
3138
3139
3140#define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
3141#define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
3142#define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
3143
3144static const struct of_device_id of_sci_match[] = {
3145	/* SoC-specific types */
3146	{
3147		.compatible = "renesas,scif-r7s72100",
3148		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3149	},
3150	{
3151		.compatible = "renesas,scif-r7s9210",
3152		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3153	},
3154	{
3155		.compatible = "renesas,scif-r9a07g044",
3156		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3157	},
3158	/* Family-specific types */
3159	{
3160		.compatible = "renesas,rcar-gen1-scif",
3161		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3162	}, {
3163		.compatible = "renesas,rcar-gen2-scif",
3164		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3165	}, {
3166		.compatible = "renesas,rcar-gen3-scif",
3167		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3168	}, {
3169		.compatible = "renesas,rcar-gen4-scif",
3170		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3171	},
3172	/* Generic types */
3173	{
3174		.compatible = "renesas,scif",
3175		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3176	}, {
3177		.compatible = "renesas,scifa",
3178		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3179	}, {
3180		.compatible = "renesas,scifb",
3181		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3182	}, {
3183		.compatible = "renesas,hscif",
3184		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3185	}, {
3186		.compatible = "renesas,sci",
3187		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3188	}, {
3189		/* Terminator */
3190	},
3191};
3192MODULE_DEVICE_TABLE(of, of_sci_match);
3193
3194static void sci_reset_control_assert(void *data)
3195{
3196	reset_control_assert(data);
3197}
3198
3199static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3200					  unsigned int *dev_id)
3201{
3202	struct device_node *np = pdev->dev.of_node;
3203	struct reset_control *rstc;
3204	struct plat_sci_port *p;
3205	struct sci_port *sp;
3206	const void *data;
3207	int id, ret;
3208
3209	if (!IS_ENABLED(CONFIG_OF) || !np)
3210		return ERR_PTR(-EINVAL);
3211
3212	data = of_device_get_match_data(&pdev->dev);
3213
3214	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
3215	if (IS_ERR(rstc))
3216		return ERR_PTR(dev_err_probe(&pdev->dev, PTR_ERR(rstc),
3217					     "failed to get reset ctrl\n"));
3218
3219	ret = reset_control_deassert(rstc);
3220	if (ret) {
3221		dev_err(&pdev->dev, "failed to deassert reset %d\n", ret);
3222		return ERR_PTR(ret);
3223	}
3224
3225	ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
3226	if (ret) {
3227		dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
3228			ret);
3229		return ERR_PTR(ret);
3230	}
3231
3232	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3233	if (!p)
3234		return ERR_PTR(-ENOMEM);
3235
3236	/* Get the line number from the aliases node. */
3237	id = of_alias_get_id(np, "serial");
3238	if (id < 0 && ~sci_ports_in_use)
3239		id = ffz(sci_ports_in_use);
3240	if (id < 0) {
3241		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3242		return ERR_PTR(-EINVAL);
3243	}
3244	if (id >= ARRAY_SIZE(sci_ports)) {
3245		dev_err(&pdev->dev, "serial%d out of range\n", id);
3246		return ERR_PTR(-EINVAL);
3247	}
3248
3249	sp = &sci_ports[id];
3250	*dev_id = id;
3251
3252	p->type = SCI_OF_TYPE(data);
3253	p->regtype = SCI_OF_REGTYPE(data);
3254
3255	sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3256
3257	return p;
3258}
3259
3260static int sci_probe_single(struct platform_device *dev,
3261				      unsigned int index,
3262				      struct plat_sci_port *p,
3263				      struct sci_port *sciport)
3264{
3265	int ret;
3266
3267	/* Sanity check */
3268	if (unlikely(index >= SCI_NPORTS)) {
3269		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3270			   index+1, SCI_NPORTS);
3271		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3272		return -EINVAL;
3273	}
3274	BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3275	if (sci_ports_in_use & BIT(index))
3276		return -EBUSY;
3277
3278	mutex_lock(&sci_uart_registration_lock);
3279	if (!sci_uart_driver.state) {
3280		ret = uart_register_driver(&sci_uart_driver);
3281		if (ret) {
3282			mutex_unlock(&sci_uart_registration_lock);
3283			return ret;
3284		}
3285	}
3286	mutex_unlock(&sci_uart_registration_lock);
3287
3288	ret = sci_init_single(dev, sciport, index, p, false);
3289	if (ret)
3290		return ret;
3291
3292	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3293	if (IS_ERR(sciport->gpios))
3294		return PTR_ERR(sciport->gpios);
3295
3296	if (sciport->has_rtscts) {
3297		if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3298		    mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3299			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3300			return -EINVAL;
3301		}
3302		sciport->port.flags |= UPF_HARD_FLOW;
3303	}
3304
3305	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3306	if (ret) {
3307		sci_cleanup_single(sciport);
3308		return ret;
3309	}
3310
3311	return 0;
3312}
3313
3314static int sci_probe(struct platform_device *dev)
3315{
3316	struct plat_sci_port *p;
3317	struct sci_port *sp;
3318	unsigned int dev_id;
3319	int ret;
3320
3321	/*
3322	 * If we've come here via earlyprintk initialization, head off to
3323	 * the special early probe. We don't have sufficient device state
3324	 * to make it beyond this yet.
3325	 */
3326#ifdef CONFIG_SUPERH
3327	if (is_sh_early_platform_device(dev))
3328		return sci_probe_earlyprintk(dev);
3329#endif
3330
3331	if (dev->dev.of_node) {
3332		p = sci_parse_dt(dev, &dev_id);
3333		if (IS_ERR(p))
3334			return PTR_ERR(p);
3335	} else {
3336		p = dev->dev.platform_data;
3337		if (p == NULL) {
3338			dev_err(&dev->dev, "no platform data supplied\n");
3339			return -EINVAL;
3340		}
3341
3342		dev_id = dev->id;
3343	}
3344
3345	sp = &sci_ports[dev_id];
3346	platform_set_drvdata(dev, sp);
3347
3348	ret = sci_probe_single(dev, dev_id, p, sp);
3349	if (ret)
3350		return ret;
3351
3352	if (sp->port.fifosize > 1) {
3353		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3354		if (ret)
3355			return ret;
3356	}
3357	if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3358	    sp->port.type == PORT_HSCIF) {
3359		ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3360		if (ret) {
3361			if (sp->port.fifosize > 1) {
3362				device_remove_file(&dev->dev,
3363						   &dev_attr_rx_fifo_trigger);
3364			}
3365			return ret;
3366		}
3367	}
3368
3369#ifdef CONFIG_SH_STANDARD_BIOS
3370	sh_bios_gdb_detach();
3371#endif
3372
3373	sci_ports_in_use |= BIT(dev_id);
3374	return 0;
3375}
3376
3377static __maybe_unused int sci_suspend(struct device *dev)
3378{
3379	struct sci_port *sport = dev_get_drvdata(dev);
3380
3381	if (sport)
3382		uart_suspend_port(&sci_uart_driver, &sport->port);
3383
3384	return 0;
3385}
3386
3387static __maybe_unused int sci_resume(struct device *dev)
3388{
3389	struct sci_port *sport = dev_get_drvdata(dev);
3390
3391	if (sport)
3392		uart_resume_port(&sci_uart_driver, &sport->port);
3393
3394	return 0;
3395}
3396
3397static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3398
3399static struct platform_driver sci_driver = {
3400	.probe		= sci_probe,
3401	.remove		= sci_remove,
3402	.driver		= {
3403		.name	= "sh-sci",
3404		.pm	= &sci_dev_pm_ops,
3405		.of_match_table = of_match_ptr(of_sci_match),
3406	},
3407};
3408
3409static int __init sci_init(void)
3410{
3411	pr_info("%s\n", banner);
3412
3413	return platform_driver_register(&sci_driver);
3414}
3415
3416static void __exit sci_exit(void)
3417{
3418	platform_driver_unregister(&sci_driver);
3419
3420	if (sci_uart_driver.state)
3421		uart_unregister_driver(&sci_uart_driver);
3422}
3423
3424#if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
3425sh_early_platform_init_buffer("earlyprintk", &sci_driver,
3426			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3427#endif
3428#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3429static struct plat_sci_port port_cfg __initdata;
3430
3431static int __init early_console_setup(struct earlycon_device *device,
3432				      int type)
3433{
3434	if (!device->port.membase)
3435		return -ENODEV;
3436
3437	device->port.serial_in = sci_serial_in;
3438	device->port.serial_out	= sci_serial_out;
3439	device->port.type = type;
3440	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3441	port_cfg.type = type;
3442	sci_ports[0].cfg = &port_cfg;
3443	sci_ports[0].params = sci_probe_regmap(&port_cfg);
3444	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3445	sci_serial_out(&sci_ports[0].port, SCSCR,
3446		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3447
3448	device->con->write = serial_console_write;
3449	return 0;
3450}
3451static int __init sci_early_console_setup(struct earlycon_device *device,
3452					  const char *opt)
3453{
3454	return early_console_setup(device, PORT_SCI);
3455}
3456static int __init scif_early_console_setup(struct earlycon_device *device,
3457					  const char *opt)
3458{
3459	return early_console_setup(device, PORT_SCIF);
3460}
3461static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3462					  const char *opt)
3463{
3464	port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3465	return early_console_setup(device, PORT_SCIF);
3466}
3467
3468static int __init scifa_early_console_setup(struct earlycon_device *device,
3469					  const char *opt)
3470{
3471	return early_console_setup(device, PORT_SCIFA);
3472}
3473static int __init scifb_early_console_setup(struct earlycon_device *device,
3474					  const char *opt)
3475{
3476	return early_console_setup(device, PORT_SCIFB);
3477}
3478static int __init hscif_early_console_setup(struct earlycon_device *device,
3479					  const char *opt)
3480{
3481	return early_console_setup(device, PORT_HSCIF);
3482}
3483
3484OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3485OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3486OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3487OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
3488OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3489OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3490OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3491#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3492
3493module_init(sci_init);
3494module_exit(sci_exit);
3495
3496MODULE_LICENSE("GPL");
3497MODULE_ALIAS("platform:sh-sci");
3498MODULE_AUTHOR("Paul Mundt");
3499MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");