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v3.1
   1/*
   2 * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   3 *
   4 *  Copyright (C) 2002 - 2011  Paul Mundt
 
   5 *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   6 *
   7 * based off of the old drivers/char/sh-sci.c by:
   8 *
   9 *   Copyright (C) 1999, 2000  Niibe Yutaka
  10 *   Copyright (C) 2000  Sugioka Toshinobu
  11 *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  12 *   Modified to support SecureEdge. David McCullough (2002)
  13 *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  14 *   Removed SH7300 support (Jul 2007).
  15 *
  16 * This file is subject to the terms and conditions of the GNU General Public
  17 * License.  See the file "COPYING" in the main directory of this archive
  18 * for more details.
  19 */
  20#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  21#define SUPPORT_SYSRQ
  22#endif
  23
  24#undef DEBUG
  25
  26#include <linux/module.h>
 
 
 
 
 
 
 
  27#include <linux/errno.h>
  28#include <linux/timer.h>
  29#include <linux/interrupt.h>
  30#include <linux/tty.h>
  31#include <linux/tty_flip.h>
  32#include <linux/serial.h>
  33#include <linux/major.h>
  34#include <linux/string.h>
  35#include <linux/sysrq.h>
  36#include <linux/ioport.h>
 
 
  37#include <linux/mm.h>
  38#include <linux/init.h>
  39#include <linux/delay.h>
  40#include <linux/console.h>
  41#include <linux/platform_device.h>
  42#include <linux/serial_sci.h>
  43#include <linux/notifier.h>
  44#include <linux/pm_runtime.h>
  45#include <linux/cpufreq.h>
  46#include <linux/clk.h>
  47#include <linux/ctype.h>
  48#include <linux/err.h>
  49#include <linux/dmaengine.h>
  50#include <linux/dma-mapping.h>
  51#include <linux/scatterlist.h>
 
 
 
  52#include <linux/slab.h>
 
 
 
 
 
  53
  54#ifdef CONFIG_SUPERH
  55#include <asm/sh_bios.h>
  56#endif
  57
 
  58#include "sh-sci.h"
  59
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  60struct sci_port {
  61	struct uart_port	port;
  62
  63	/* Platform configuration */
  64	struct plat_sci_port	*cfg;
 
 
 
 
 
 
 
  65
  66	/* Break timer */
  67	struct timer_list	break_timer;
  68	int			break_flag;
  69
  70	/* Interface clock */
  71	struct clk		*iclk;
  72	/* Function clock */
  73	struct clk		*fclk;
  74
 
  75	char			*irqstr[SCIx_NR_IRQS];
  76
  77	struct dma_chan			*chan_tx;
  78	struct dma_chan			*chan_rx;
  79
  80#ifdef CONFIG_SERIAL_SH_SCI_DMA
  81	struct dma_async_tx_descriptor	*desc_tx;
  82	struct dma_async_tx_descriptor	*desc_rx[2];
  83	dma_cookie_t			cookie_tx;
  84	dma_cookie_t			cookie_rx[2];
  85	dma_cookie_t			active_rx;
  86	struct scatterlist		sg_tx;
  87	unsigned int			sg_len_tx;
  88	struct scatterlist		sg_rx[2];
 
  89	size_t				buf_len_rx;
  90	struct sh_dmae_slave		param_tx;
  91	struct sh_dmae_slave		param_rx;
  92	struct work_struct		work_tx;
  93	struct work_struct		work_rx;
  94	struct timer_list		rx_timer;
  95	unsigned int			rx_timeout;
  96#endif
  97
  98	struct notifier_block		freq_transition;
  99
 100#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
 101	unsigned short saved_smr;
 102	unsigned short saved_fcr;
 103	unsigned char saved_brr;
 104#endif
 105};
 106
 107/* Function prototypes */
 108static void sci_start_tx(struct uart_port *port);
 109static void sci_stop_tx(struct uart_port *port);
 110static void sci_start_rx(struct uart_port *port);
 111
 112#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 113
 114static struct sci_port sci_ports[SCI_NPORTS];
 115static struct uart_driver sci_uart_driver;
 116
 117static inline struct sci_port *
 118to_sci_port(struct uart_port *uart)
 119{
 120	return container_of(uart, struct sci_port, port);
 121}
 122
 123struct plat_sci_reg {
 124	u8 offset, size;
 125};
 126
 127/* Helper for invalidating specific entries of an inherited map. */
 128#define sci_reg_invalid	{ .offset = 0, .size = 0 }
 129
 130static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
 131	[SCIx_PROBE_REGTYPE] = {
 132		[0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
 133	},
 134
 135	/*
 136	 * Common SCI definitions, dependent on the port's regshift
 137	 * value.
 138	 */
 139	[SCIx_SCI_REGTYPE] = {
 140		[SCSMR]		= { 0x00,  8 },
 141		[SCBRR]		= { 0x01,  8 },
 142		[SCSCR]		= { 0x02,  8 },
 143		[SCxTDR]	= { 0x03,  8 },
 144		[SCxSR]		= { 0x04,  8 },
 145		[SCxRDR]	= { 0x05,  8 },
 146		[SCFCR]		= sci_reg_invalid,
 147		[SCFDR]		= sci_reg_invalid,
 148		[SCTFDR]	= sci_reg_invalid,
 149		[SCRFDR]	= sci_reg_invalid,
 150		[SCSPTR]	= sci_reg_invalid,
 151		[SCLSR]		= sci_reg_invalid,
 
 
 
 
 
 152	},
 153
 154	/*
 155	 * Common definitions for legacy IrDA ports, dependent on
 156	 * regshift value.
 157	 */
 158	[SCIx_IRDA_REGTYPE] = {
 159		[SCSMR]		= { 0x00,  8 },
 160		[SCBRR]		= { 0x01,  8 },
 161		[SCSCR]		= { 0x02,  8 },
 162		[SCxTDR]	= { 0x03,  8 },
 163		[SCxSR]		= { 0x04,  8 },
 164		[SCxRDR]	= { 0x05,  8 },
 165		[SCFCR]		= { 0x06,  8 },
 166		[SCFDR]		= { 0x07, 16 },
 167		[SCTFDR]	= sci_reg_invalid,
 168		[SCRFDR]	= sci_reg_invalid,
 169		[SCSPTR]	= sci_reg_invalid,
 170		[SCLSR]		= sci_reg_invalid,
 
 
 
 
 
 171	},
 172
 173	/*
 174	 * Common SCIFA definitions.
 175	 */
 176	[SCIx_SCIFA_REGTYPE] = {
 177		[SCSMR]		= { 0x00, 16 },
 178		[SCBRR]		= { 0x04,  8 },
 179		[SCSCR]		= { 0x08, 16 },
 180		[SCxTDR]	= { 0x20,  8 },
 181		[SCxSR]		= { 0x14, 16 },
 182		[SCxRDR]	= { 0x24,  8 },
 183		[SCFCR]		= { 0x18, 16 },
 184		[SCFDR]		= { 0x1c, 16 },
 185		[SCTFDR]	= sci_reg_invalid,
 186		[SCRFDR]	= sci_reg_invalid,
 187		[SCSPTR]	= sci_reg_invalid,
 188		[SCLSR]		= sci_reg_invalid,
 
 
 
 
 
 189	},
 190
 191	/*
 192	 * Common SCIFB definitions.
 193	 */
 194	[SCIx_SCIFB_REGTYPE] = {
 195		[SCSMR]		= { 0x00, 16 },
 196		[SCBRR]		= { 0x04,  8 },
 197		[SCSCR]		= { 0x08, 16 },
 198		[SCxTDR]	= { 0x40,  8 },
 199		[SCxSR]		= { 0x14, 16 },
 200		[SCxRDR]	= { 0x60,  8 },
 201		[SCFCR]		= { 0x18, 16 },
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 202		[SCFDR]		= { 0x1c, 16 },
 203		[SCTFDR]	= sci_reg_invalid,
 204		[SCRFDR]	= sci_reg_invalid,
 205		[SCSPTR]	= sci_reg_invalid,
 206		[SCLSR]		= sci_reg_invalid,
 
 
 
 
 
 207	},
 208
 209	/*
 210	 * Common SH-3 SCIF definitions.
 211	 */
 212	[SCIx_SH3_SCIF_REGTYPE] = {
 213		[SCSMR]		= { 0x00,  8 },
 214		[SCBRR]		= { 0x02,  8 },
 215		[SCSCR]		= { 0x04,  8 },
 216		[SCxTDR]	= { 0x06,  8 },
 217		[SCxSR]		= { 0x08, 16 },
 218		[SCxRDR]	= { 0x0a,  8 },
 219		[SCFCR]		= { 0x0c,  8 },
 220		[SCFDR]		= { 0x0e, 16 },
 221		[SCTFDR]	= sci_reg_invalid,
 222		[SCRFDR]	= sci_reg_invalid,
 223		[SCSPTR]	= sci_reg_invalid,
 224		[SCLSR]		= sci_reg_invalid,
 
 
 
 
 
 225	},
 226
 227	/*
 228	 * Common SH-4(A) SCIF(B) definitions.
 229	 */
 230	[SCIx_SH4_SCIF_REGTYPE] = {
 231		[SCSMR]		= { 0x00, 16 },
 232		[SCBRR]		= { 0x04,  8 },
 233		[SCSCR]		= { 0x08, 16 },
 234		[SCxTDR]	= { 0x0c,  8 },
 235		[SCxSR]		= { 0x10, 16 },
 236		[SCxRDR]	= { 0x14,  8 },
 237		[SCFCR]		= { 0x18, 16 },
 238		[SCFDR]		= { 0x1c, 16 },
 239		[SCTFDR]	= sci_reg_invalid,
 240		[SCRFDR]	= sci_reg_invalid,
 241		[SCSPTR]	= { 0x20, 16 },
 242		[SCLSR]		= { 0x24, 16 },
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 243	},
 244
 245	/*
 246	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 247	 * register.
 248	 */
 249	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 250		[SCSMR]		= { 0x00, 16 },
 251		[SCBRR]		= { 0x04,  8 },
 252		[SCSCR]		= { 0x08, 16 },
 253		[SCxTDR]	= { 0x0c,  8 },
 254		[SCxSR]		= { 0x10, 16 },
 255		[SCxRDR]	= { 0x14,  8 },
 256		[SCFCR]		= { 0x18, 16 },
 257		[SCFDR]		= { 0x1c, 16 },
 258		[SCTFDR]	= sci_reg_invalid,
 259		[SCRFDR]	= sci_reg_invalid,
 260		[SCSPTR]	= sci_reg_invalid,
 261		[SCLSR]		= { 0x24, 16 },
 
 
 
 
 
 262	},
 263
 264	/*
 265	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 266	 * count registers.
 267	 */
 268	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 269		[SCSMR]		= { 0x00, 16 },
 270		[SCBRR]		= { 0x04,  8 },
 271		[SCSCR]		= { 0x08, 16 },
 272		[SCxTDR]	= { 0x0c,  8 },
 273		[SCxSR]		= { 0x10, 16 },
 274		[SCxRDR]	= { 0x14,  8 },
 275		[SCFCR]		= { 0x18, 16 },
 276		[SCFDR]		= { 0x1c, 16 },
 277		[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
 278		[SCRFDR]	= { 0x20, 16 },
 279		[SCSPTR]	= { 0x24, 16 },
 280		[SCLSR]		= { 0x28, 16 },
 
 
 
 
 
 281	},
 282
 283	/*
 284	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 285	 * registers.
 286	 */
 287	[SCIx_SH7705_SCIF_REGTYPE] = {
 288		[SCSMR]		= { 0x00, 16 },
 289		[SCBRR]		= { 0x04,  8 },
 290		[SCSCR]		= { 0x08, 16 },
 291		[SCxTDR]	= { 0x20,  8 },
 292		[SCxSR]		= { 0x14, 16 },
 293		[SCxRDR]	= { 0x24,  8 },
 294		[SCFCR]		= { 0x18, 16 },
 295		[SCFDR]		= { 0x1c, 16 },
 296		[SCTFDR]	= sci_reg_invalid,
 297		[SCRFDR]	= sci_reg_invalid,
 298		[SCSPTR]	= sci_reg_invalid,
 299		[SCLSR]		= sci_reg_invalid,
 
 
 
 
 
 300	},
 301};
 302
 303#define sci_getreg(up, offset)		(sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
 304
 305/*
 306 * The "offset" here is rather misleading, in that it refers to an enum
 307 * value relative to the port mapping rather than the fixed offset
 308 * itself, which needs to be manually retrieved from the platform's
 309 * register map for the given port.
 310 */
 311static unsigned int sci_serial_in(struct uart_port *p, int offset)
 312{
 313	struct plat_sci_reg *reg = sci_getreg(p, offset);
 314
 315	if (reg->size == 8)
 316		return ioread8(p->membase + (reg->offset << p->regshift));
 317	else if (reg->size == 16)
 318		return ioread16(p->membase + (reg->offset << p->regshift));
 319	else
 320		WARN(1, "Invalid register access\n");
 321
 322	return 0;
 323}
 324
 325static void sci_serial_out(struct uart_port *p, int offset, int value)
 326{
 327	struct plat_sci_reg *reg = sci_getreg(p, offset);
 328
 329	if (reg->size == 8)
 330		iowrite8(value, p->membase + (reg->offset << p->regshift));
 331	else if (reg->size == 16)
 332		iowrite16(value, p->membase + (reg->offset << p->regshift));
 333	else
 334		WARN(1, "Invalid register access\n");
 335}
 336
 337#define sci_in(up, offset)		(up->serial_in(up, offset))
 338#define sci_out(up, offset, value)	(up->serial_out(up, offset, value))
 339
 340static int sci_probe_regmap(struct plat_sci_port *cfg)
 341{
 342	switch (cfg->type) {
 343	case PORT_SCI:
 344		cfg->regtype = SCIx_SCI_REGTYPE;
 345		break;
 346	case PORT_IRDA:
 347		cfg->regtype = SCIx_IRDA_REGTYPE;
 348		break;
 349	case PORT_SCIFA:
 350		cfg->regtype = SCIx_SCIFA_REGTYPE;
 351		break;
 352	case PORT_SCIFB:
 353		cfg->regtype = SCIx_SCIFB_REGTYPE;
 354		break;
 355	case PORT_SCIF:
 356		/*
 357		 * The SH-4 is a bit of a misnomer here, although that's
 358		 * where this particular port layout originated. This
 359		 * configuration (or some slight variation thereof)
 360		 * remains the dominant model for all SCIFs.
 361		 */
 362		cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
 363		break;
 
 
 
 364	default:
 365		printk(KERN_ERR "Can't probe register map for given port\n");
 366		return -EINVAL;
 367	}
 368
 369	return 0;
 370}
 371
 372static void sci_port_enable(struct sci_port *sci_port)
 373{
 
 
 374	if (!sci_port->port.dev)
 375		return;
 376
 377	pm_runtime_get_sync(sci_port->port.dev);
 378
 379	clk_enable(sci_port->iclk);
 380	sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
 381	clk_enable(sci_port->fclk);
 
 
 382}
 383
 384static void sci_port_disable(struct sci_port *sci_port)
 385{
 
 
 386	if (!sci_port->port.dev)
 387		return;
 388
 389	clk_disable(sci_port->fclk);
 390	clk_disable(sci_port->iclk);
 
 
 
 
 
 
 
 
 391
 392	pm_runtime_put_sync(sci_port->port.dev);
 393}
 394
 395#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 396
 397#ifdef CONFIG_CONSOLE_POLL
 398static int sci_poll_get_char(struct uart_port *port)
 399{
 400	unsigned short status;
 401	int c;
 402
 403	do {
 404		status = sci_in(port, SCxSR);
 405		if (status & SCxSR_ERRORS(port)) {
 406			sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
 407			continue;
 408		}
 409		break;
 410	} while (1);
 411
 412	if (!(status & SCxSR_RDxF(port)))
 413		return NO_POLL_CHAR;
 414
 415	c = sci_in(port, SCxRDR);
 416
 417	/* Dummy read */
 418	sci_in(port, SCxSR);
 419	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
 420
 421	return c;
 422}
 423#endif
 424
 425static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 426{
 427	unsigned short status;
 428
 429	do {
 430		status = sci_in(port, SCxSR);
 431	} while (!(status & SCxSR_TDxE(port)));
 432
 433	sci_out(port, SCxTDR, c);
 434	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 435}
 436#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */
 
 437
 438static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 439{
 440	struct sci_port *s = to_sci_port(port);
 441	struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR;
 442
 443	/*
 444	 * Use port-specific handler if provided.
 445	 */
 446	if (s->cfg->ops && s->cfg->ops->init_pins) {
 447		s->cfg->ops->init_pins(port, cflag);
 448		return;
 449	}
 450
 451	/*
 452	 * For the generic path SCSPTR is necessary. Bail out if that's
 453	 * unavailable, too.
 454	 */
 455	if (!reg->size)
 456		return;
 457
 458	if (!(cflag & CRTSCTS))
 459		sci_out(port, SCSPTR, 0x0080); /* Set RTS = 1 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 460}
 461
 462static int sci_txfill(struct uart_port *port)
 463{
 464	struct plat_sci_reg *reg;
 465
 466	reg = sci_getreg(port, SCTFDR);
 467	if (reg->size)
 468		return sci_in(port, SCTFDR) & 0xff;
 469
 470	reg = sci_getreg(port, SCFDR);
 471	if (reg->size)
 472		return sci_in(port, SCFDR) >> 8;
 473
 474	return !(sci_in(port, SCxSR) & SCI_TDRE);
 475}
 476
 477static int sci_txroom(struct uart_port *port)
 478{
 479	return port->fifosize - sci_txfill(port);
 480}
 481
 482static int sci_rxfill(struct uart_port *port)
 483{
 484	struct plat_sci_reg *reg;
 485
 486	reg = sci_getreg(port, SCRFDR);
 487	if (reg->size)
 488		return sci_in(port, SCRFDR) & 0xff;
 489
 490	reg = sci_getreg(port, SCFDR);
 491	if (reg->size)
 492		return sci_in(port, SCFDR) & ((port->fifosize << 1) - 1);
 493
 494	return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 495}
 496
 497/*
 498 * SCI helper for checking the state of the muxed port/RXD pins.
 499 */
 500static inline int sci_rxd_in(struct uart_port *port)
 501{
 502	struct sci_port *s = to_sci_port(port);
 503
 504	if (s->cfg->port_reg <= 0)
 505		return 1;
 506
 507	return !!__raw_readb(s->cfg->port_reg);
 
 508}
 509
 510/* ********************************************************************** *
 511 *                   the interrupt related routines                       *
 512 * ********************************************************************** */
 513
 514static void sci_transmit_chars(struct uart_port *port)
 515{
 516	struct circ_buf *xmit = &port->state->xmit;
 517	unsigned int stopped = uart_tx_stopped(port);
 518	unsigned short status;
 519	unsigned short ctrl;
 520	int count;
 521
 522	status = sci_in(port, SCxSR);
 523	if (!(status & SCxSR_TDxE(port))) {
 524		ctrl = sci_in(port, SCSCR);
 525		if (uart_circ_empty(xmit))
 526			ctrl &= ~SCSCR_TIE;
 527		else
 528			ctrl |= SCSCR_TIE;
 529		sci_out(port, SCSCR, ctrl);
 530		return;
 531	}
 532
 533	count = sci_txroom(port);
 534
 535	do {
 536		unsigned char c;
 537
 538		if (port->x_char) {
 539			c = port->x_char;
 540			port->x_char = 0;
 541		} else if (!uart_circ_empty(xmit) && !stopped) {
 542			c = xmit->buf[xmit->tail];
 543			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 544		} else {
 545			break;
 546		}
 547
 548		sci_out(port, SCxTDR, c);
 549
 550		port->icount.tx++;
 551	} while (--count > 0);
 552
 553	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
 554
 555	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 556		uart_write_wakeup(port);
 557	if (uart_circ_empty(xmit)) {
 558		sci_stop_tx(port);
 559	} else {
 560		ctrl = sci_in(port, SCSCR);
 561
 562		if (port->type != PORT_SCI) {
 563			sci_in(port, SCxSR); /* Dummy read */
 564			sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));
 565		}
 566
 567		ctrl |= SCSCR_TIE;
 568		sci_out(port, SCSCR, ctrl);
 569	}
 570}
 571
 572/* On SH3, SCIF may read end-of-break as a space->mark char */
 573#define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
 574
 575static void sci_receive_chars(struct uart_port *port)
 576{
 577	struct sci_port *sci_port = to_sci_port(port);
 578	struct tty_struct *tty = port->state->port.tty;
 579	int i, count, copied = 0;
 580	unsigned short status;
 581	unsigned char flag;
 582
 583	status = sci_in(port, SCxSR);
 584	if (!(status & SCxSR_RDxF(port)))
 585		return;
 586
 587	while (1) {
 588		/* Don't copy more bytes than there is room for in the buffer */
 589		count = tty_buffer_request_room(tty, sci_rxfill(port));
 590
 591		/* If for any reason we can't copy more data, we're done! */
 592		if (count == 0)
 593			break;
 594
 595		if (port->type == PORT_SCI) {
 596			char c = sci_in(port, SCxRDR);
 597			if (uart_handle_sysrq_char(port, c) ||
 598			    sci_port->break_flag)
 599				count = 0;
 600			else
 601				tty_insert_flip_char(tty, c, TTY_NORMAL);
 602		} else {
 603			for (i = 0; i < count; i++) {
 604				char c = sci_in(port, SCxRDR);
 605				status = sci_in(port, SCxSR);
 
 606#if defined(CONFIG_CPU_SH3)
 607				/* Skip "chars" during break */
 608				if (sci_port->break_flag) {
 609					if ((c == 0) &&
 610					    (status & SCxSR_FER(port))) {
 611						count--; i--;
 612						continue;
 613					}
 614
 615					/* Nonzero => end-of-break */
 616					dev_dbg(port->dev, "debounce<%02x>\n", c);
 617					sci_port->break_flag = 0;
 618
 619					if (STEPFN(c)) {
 620						count--; i--;
 621						continue;
 622					}
 623				}
 624#endif /* CONFIG_CPU_SH3 */
 625				if (uart_handle_sysrq_char(port, c)) {
 626					count--; i--;
 627					continue;
 628				}
 629
 630				/* Store data and status */
 631				if (status & SCxSR_FER(port)) {
 632					flag = TTY_FRAME;
 
 633					dev_notice(port->dev, "frame error\n");
 634				} else if (status & SCxSR_PER(port)) {
 635					flag = TTY_PARITY;
 
 636					dev_notice(port->dev, "parity error\n");
 637				} else
 638					flag = TTY_NORMAL;
 639
 640				tty_insert_flip_char(tty, c, flag);
 641			}
 642		}
 643
 644		sci_in(port, SCxSR); /* dummy read */
 645		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
 646
 647		copied += count;
 648		port->icount.rx += count;
 649	}
 650
 651	if (copied) {
 652		/* Tell the rest of the system the news. New characters! */
 653		tty_flip_buffer_push(tty);
 654	} else {
 655		sci_in(port, SCxSR); /* dummy read */
 656		sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
 657	}
 658}
 659
 660#define SCI_BREAK_JIFFIES (HZ/20)
 661
 662/*
 663 * The sci generates interrupts during the break,
 664 * 1 per millisecond or so during the break period, for 9600 baud.
 665 * So dont bother disabling interrupts.
 666 * But dont want more than 1 break event.
 667 * Use a kernel timer to periodically poll the rx line until
 668 * the break is finished.
 669 */
 670static inline void sci_schedule_break_timer(struct sci_port *port)
 671{
 672	mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
 673}
 674
 675/* Ensure that two consecutive samples find the break over. */
 676static void sci_break_timer(unsigned long data)
 677{
 678	struct sci_port *port = (struct sci_port *)data;
 679
 680	sci_port_enable(port);
 681
 682	if (sci_rxd_in(&port->port) == 0) {
 683		port->break_flag = 1;
 684		sci_schedule_break_timer(port);
 685	} else if (port->break_flag == 1) {
 686		/* break is over. */
 687		port->break_flag = 2;
 688		sci_schedule_break_timer(port);
 689	} else
 690		port->break_flag = 0;
 691
 692	sci_port_disable(port);
 693}
 694
 695static int sci_handle_errors(struct uart_port *port)
 696{
 697	int copied = 0;
 698	unsigned short status = sci_in(port, SCxSR);
 699	struct tty_struct *tty = port->state->port.tty;
 700	struct sci_port *s = to_sci_port(port);
 701
 702	/*
 703	 * Handle overruns, if supported.
 704	 */
 705	if (s->cfg->overrun_bit != SCIx_NOT_SUPPORTED) {
 706		if (status & (1 << s->cfg->overrun_bit)) {
 707			/* overrun error */
 708			if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
 709				copied++;
 710
 711			dev_notice(port->dev, "overrun error");
 712		}
 
 
 
 713	}
 714
 715	if (status & SCxSR_FER(port)) {
 716		if (sci_rxd_in(port) == 0) {
 717			/* Notify of BREAK */
 718			struct sci_port *sci_port = to_sci_port(port);
 719
 720			if (!sci_port->break_flag) {
 
 
 721				sci_port->break_flag = 1;
 722				sci_schedule_break_timer(sci_port);
 723
 724				/* Do sysrq handling. */
 725				if (uart_handle_break(port))
 726					return 0;
 727
 728				dev_dbg(port->dev, "BREAK detected\n");
 729
 730				if (tty_insert_flip_char(tty, 0, TTY_BREAK))
 731					copied++;
 732			}
 733
 734		} else {
 735			/* frame error */
 736			if (tty_insert_flip_char(tty, 0, TTY_FRAME))
 
 
 737				copied++;
 738
 739			dev_notice(port->dev, "frame error\n");
 740		}
 741	}
 742
 743	if (status & SCxSR_PER(port)) {
 744		/* parity error */
 745		if (tty_insert_flip_char(tty, 0, TTY_PARITY))
 
 
 746			copied++;
 747
 748		dev_notice(port->dev, "parity error");
 749	}
 750
 751	if (copied)
 752		tty_flip_buffer_push(tty);
 753
 754	return copied;
 755}
 756
 757static int sci_handle_fifo_overrun(struct uart_port *port)
 758{
 759	struct tty_struct *tty = port->state->port.tty;
 760	struct sci_port *s = to_sci_port(port);
 761	struct plat_sci_reg *reg;
 762	int copied = 0;
 
 763
 764	reg = sci_getreg(port, SCLSR);
 765	if (!reg->size)
 766		return 0;
 767
 768	if ((sci_in(port, SCLSR) & (1 << s->cfg->overrun_bit))) {
 769		sci_out(port, SCLSR, 0);
 
 
 770
 771		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 772		tty_flip_buffer_push(tty);
 773
 774		dev_notice(port->dev, "overrun error\n");
 
 
 
 775		copied++;
 776	}
 777
 778	return copied;
 779}
 780
 781static int sci_handle_breaks(struct uart_port *port)
 782{
 783	int copied = 0;
 784	unsigned short status = sci_in(port, SCxSR);
 785	struct tty_struct *tty = port->state->port.tty;
 786	struct sci_port *s = to_sci_port(port);
 787
 788	if (uart_handle_break(port))
 789		return 0;
 790
 791	if (!s->break_flag && status & SCxSR_BRK(port)) {
 792#if defined(CONFIG_CPU_SH3)
 793		/* Debounce break */
 794		s->break_flag = 1;
 795#endif
 
 
 
 796		/* Notify of BREAK */
 797		if (tty_insert_flip_char(tty, 0, TTY_BREAK))
 798			copied++;
 799
 800		dev_dbg(port->dev, "BREAK detected\n");
 801	}
 802
 803	if (copied)
 804		tty_flip_buffer_push(tty);
 805
 806	copied += sci_handle_fifo_overrun(port);
 807
 808	return copied;
 809}
 810
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 811static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 812{
 813#ifdef CONFIG_SERIAL_SH_SCI_DMA
 814	struct uart_port *port = ptr;
 815	struct sci_port *s = to_sci_port(port);
 816
 817	if (s->chan_rx) {
 818		u16 scr = sci_in(port, SCSCR);
 819		u16 ssr = sci_in(port, SCxSR);
 820
 821		/* Disable future Rx interrupts */
 822		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 823			disable_irq_nosync(irq);
 824			scr |= 0x4000;
 825		} else {
 826			scr &= ~SCSCR_RIE;
 
 827		}
 828		sci_out(port, SCSCR, scr);
 829		/* Clear current interrupt */
 830		sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
 
 831		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
 832			jiffies, s->rx_timeout);
 833		mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
 834
 835		return IRQ_HANDLED;
 836	}
 837#endif
 838
 839	/* I think sci_receive_chars has to be called irrespective
 840	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
 841	 * to be disabled?
 842	 */
 843	sci_receive_chars(ptr);
 844
 845	return IRQ_HANDLED;
 846}
 847
 848static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
 849{
 850	struct uart_port *port = ptr;
 851	unsigned long flags;
 852
 853	spin_lock_irqsave(&port->lock, flags);
 854	sci_transmit_chars(port);
 855	spin_unlock_irqrestore(&port->lock, flags);
 856
 857	return IRQ_HANDLED;
 858}
 859
 860static irqreturn_t sci_er_interrupt(int irq, void *ptr)
 861{
 862	struct uart_port *port = ptr;
 
 863
 864	/* Handle errors */
 865	if (port->type == PORT_SCI) {
 866		if (sci_handle_errors(port)) {
 867			/* discard character in rx buffer */
 868			sci_in(port, SCxSR);
 869			sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
 870		}
 871	} else {
 872		sci_handle_fifo_overrun(port);
 873		sci_rx_interrupt(irq, ptr);
 
 874	}
 875
 876	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
 877
 878	/* Kick the transmission */
 879	sci_tx_interrupt(irq, ptr);
 
 880
 881	return IRQ_HANDLED;
 882}
 883
 884static irqreturn_t sci_br_interrupt(int irq, void *ptr)
 885{
 886	struct uart_port *port = ptr;
 887
 888	/* Handle BREAKs */
 889	sci_handle_breaks(port);
 890	sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port));
 891
 892	return IRQ_HANDLED;
 893}
 894
 895static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 896{
 897	/*
 898	 * Not all ports (such as SCIFA) will support REIE. Rather than
 899	 * special-casing the port type, we check the port initialization
 900	 * IRQ enable mask to see whether the IRQ is desired at all. If
 901	 * it's unset, it's logically inferred that there's no point in
 902	 * testing for it.
 903	 */
 904	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 905}
 906
 907static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
 908{
 909	unsigned short ssr_status, scr_status, err_enabled;
 910	struct uart_port *port = ptr;
 911	struct sci_port *s = to_sci_port(port);
 912	irqreturn_t ret = IRQ_NONE;
 913
 914	ssr_status = sci_in(port, SCxSR);
 915	scr_status = sci_in(port, SCSCR);
 
 
 
 
 
 
 
 916	err_enabled = scr_status & port_rx_irq_mask(port);
 917
 918	/* Tx Interrupt */
 919	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
 920	    !s->chan_tx)
 921		ret = sci_tx_interrupt(irq, ptr);
 922
 923	/*
 924	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
 925	 * DR flags
 926	 */
 927	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
 928	    (scr_status & SCSCR_RIE))
 929		ret = sci_rx_interrupt(irq, ptr);
 930
 931	/* Error Interrupt */
 932	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
 933		ret = sci_er_interrupt(irq, ptr);
 934
 935	/* Break Interrupt */
 936	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
 937		ret = sci_br_interrupt(irq, ptr);
 938
 939	return ret;
 940}
 941
 942/*
 943 * Here we define a transition notifier so that we can update all of our
 944 * ports' baud rate when the peripheral clock changes.
 945 */
 946static int sci_notifier(struct notifier_block *self,
 947			unsigned long phase, void *p)
 948{
 949	struct sci_port *sci_port;
 950	unsigned long flags;
 951
 952	sci_port = container_of(self, struct sci_port, freq_transition);
 953
 954	if ((phase == CPUFREQ_POSTCHANGE) ||
 955	    (phase == CPUFREQ_RESUMECHANGE)) {
 956		struct uart_port *port = &sci_port->port;
 957
 958		spin_lock_irqsave(&port->lock, flags);
 959		port->uartclk = clk_get_rate(sci_port->iclk);
 960		spin_unlock_irqrestore(&port->lock, flags);
 961	}
 962
 963	return NOTIFY_OK;
 964}
 965
 966static struct sci_irq_desc {
 967	const char	*desc;
 968	irq_handler_t	handler;
 969} sci_irq_desc[] = {
 970	/*
 971	 * Split out handlers, the default case.
 972	 */
 973	[SCIx_ERI_IRQ] = {
 974		.desc = "rx err",
 975		.handler = sci_er_interrupt,
 976	},
 977
 978	[SCIx_RXI_IRQ] = {
 979		.desc = "rx full",
 980		.handler = sci_rx_interrupt,
 981	},
 982
 983	[SCIx_TXI_IRQ] = {
 984		.desc = "tx empty",
 985		.handler = sci_tx_interrupt,
 986	},
 987
 988	[SCIx_BRI_IRQ] = {
 989		.desc = "break",
 990		.handler = sci_br_interrupt,
 991	},
 992
 993	/*
 994	 * Special muxed handler.
 995	 */
 996	[SCIx_MUX_IRQ] = {
 997		.desc = "mux",
 998		.handler = sci_mpxed_interrupt,
 999	},
1000};
1001
1002static int sci_request_irq(struct sci_port *port)
1003{
1004	struct uart_port *up = &port->port;
1005	int i, j, ret = 0;
1006
1007	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1008		struct sci_irq_desc *desc;
1009		unsigned int irq;
1010
1011		if (SCIx_IRQ_IS_MUXED(port)) {
1012			i = SCIx_MUX_IRQ;
1013			irq = up->irq;
1014		} else
1015			irq = port->cfg->irqs[i];
 
 
 
 
 
 
 
 
1016
1017		desc = sci_irq_desc + i;
1018		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1019					    dev_name(up->dev), desc->desc);
1020		if (!port->irqstr[j]) {
1021			dev_err(up->dev, "Failed to allocate %s IRQ string\n",
1022				desc->desc);
1023			goto out_nomem;
1024		}
1025
1026		ret = request_irq(irq, desc->handler, up->irqflags,
1027				  port->irqstr[j], port);
1028		if (unlikely(ret)) {
1029			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1030			goto out_noirq;
1031		}
1032	}
1033
1034	return 0;
1035
1036out_noirq:
1037	while (--i >= 0)
1038		free_irq(port->cfg->irqs[i], port);
1039
1040out_nomem:
1041	while (--j >= 0)
1042		kfree(port->irqstr[j]);
1043
1044	return ret;
1045}
1046
1047static void sci_free_irq(struct sci_port *port)
1048{
1049	int i;
1050
1051	/*
1052	 * Intentionally in reverse order so we iterate over the muxed
1053	 * IRQ first.
1054	 */
1055	for (i = 0; i < SCIx_NR_IRQS; i++) {
1056		free_irq(port->cfg->irqs[i], port);
 
 
 
 
 
 
 
 
 
1057		kfree(port->irqstr[i]);
1058
1059		if (SCIx_IRQ_IS_MUXED(port)) {
1060			/* If there's only one IRQ, we're done. */
1061			return;
1062		}
1063	}
1064}
1065
1066static unsigned int sci_tx_empty(struct uart_port *port)
1067{
1068	unsigned short status = sci_in(port, SCxSR);
1069	unsigned short in_tx_fifo = sci_txfill(port);
1070
1071	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1072}
1073
1074static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1075{
1076	/* This routine is used for seting signals of: DTR, DCD, CTS/RTS */
1077	/* We use SCIF's hardware for CTS/RTS, so don't need any for that. */
1078	/* If you have signals for DTR and DCD, please implement here. */
1079}
1080
1081static unsigned int sci_get_mctrl(struct uart_port *port)
1082{
1083	/* This routine is used for getting signals of: DTR, DCD, DSR, RI,
1084	   and CTS/RTS */
1085
1086	return TIOCM_DTR | TIOCM_RTS | TIOCM_CTS | TIOCM_DSR;
1087}
1088
1089#ifdef CONFIG_SERIAL_SH_SCI_DMA
1090static void sci_dma_tx_complete(void *arg)
1091{
1092	struct sci_port *s = arg;
1093	struct uart_port *port = &s->port;
1094	struct circ_buf *xmit = &port->state->xmit;
1095	unsigned long flags;
1096
1097	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1098
1099	spin_lock_irqsave(&port->lock, flags);
1100
1101	xmit->tail += sg_dma_len(&s->sg_tx);
1102	xmit->tail &= UART_XMIT_SIZE - 1;
1103
1104	port->icount.tx += sg_dma_len(&s->sg_tx);
1105
1106	async_tx_ack(s->desc_tx);
1107	s->cookie_tx = -EINVAL;
1108	s->desc_tx = NULL;
1109
1110	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1111		uart_write_wakeup(port);
 
 
 
 
1112
1113	if (!uart_circ_empty(xmit)) {
1114		schedule_work(&s->work_tx);
1115	} else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1116		u16 ctrl = sci_in(port, SCSCR);
1117		sci_out(port, SCSCR, ctrl & ~SCSCR_TIE);
 
 
 
 
 
 
 
1118	}
1119
1120	spin_unlock_irqrestore(&port->lock, flags);
1121}
1122
1123/* Locking: called with port lock held */
1124static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,
1125			   size_t count)
1126{
1127	struct uart_port *port = &s->port;
1128	int i, active, room;
1129
1130	room = tty_buffer_request_room(tty, count);
1131
1132	if (s->active_rx == s->cookie_rx[0]) {
1133		active = 0;
1134	} else if (s->active_rx == s->cookie_rx[1]) {
1135		active = 1;
1136	} else {
1137		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1138		return 0;
1139	}
1140
1141	if (room < count)
1142		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
1143			 count - room);
1144	if (!room)
1145		return room;
1146
1147	for (i = 0; i < room; i++)
1148		tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
1149				     TTY_NORMAL);
1150
1151	port->icount.rx += room;
1152
1153	return room;
1154}
1155
1156static void sci_dma_rx_complete(void *arg)
1157{
1158	struct sci_port *s = arg;
1159	struct uart_port *port = &s->port;
1160	struct tty_struct *tty = port->state->port.tty;
1161	unsigned long flags;
1162	int count;
1163
1164	dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);
1165
1166	spin_lock_irqsave(&port->lock, flags);
1167
1168	count = sci_dma_rx_push(s, tty, s->buf_len_rx);
1169
1170	mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1171
1172	spin_unlock_irqrestore(&port->lock, flags);
1173
1174	if (count)
1175		tty_flip_buffer_push(tty);
1176
1177	schedule_work(&s->work_rx);
1178}
1179
1180static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1181{
1182	struct dma_chan *chan = s->chan_rx;
1183	struct uart_port *port = &s->port;
1184
1185	s->chan_rx = NULL;
1186	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1187	dma_release_channel(chan);
1188	if (sg_dma_address(&s->sg_rx[0]))
1189		dma_free_coherent(port->dev, s->buf_len_rx * 2,
1190				  sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
1191	if (enable_pio)
1192		sci_start_rx(port);
1193}
1194
1195static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1196{
1197	struct dma_chan *chan = s->chan_tx;
1198	struct uart_port *port = &s->port;
1199
1200	s->chan_tx = NULL;
1201	s->cookie_tx = -EINVAL;
1202	dma_release_channel(chan);
1203	if (enable_pio)
1204		sci_start_tx(port);
1205}
1206
1207static void sci_submit_rx(struct sci_port *s)
 
 
 
 
 
 
 
 
 
 
 
 
1208{
1209	struct dma_chan *chan = s->chan_rx;
1210	int i;
1211
1212	for (i = 0; i < 2; i++) {
1213		struct scatterlist *sg = &s->sg_rx[i];
1214		struct dma_async_tx_descriptor *desc;
1215
1216		desc = chan->device->device_prep_slave_sg(chan,
1217			sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);
1218
1219		if (desc) {
1220			s->desc_rx[i] = desc;
1221			desc->callback = sci_dma_rx_complete;
1222			desc->callback_param = s;
1223			s->cookie_rx[i] = desc->tx_submit(desc);
1224		}
1225
1226		if (!desc || s->cookie_rx[i] < 0) {
1227			if (i) {
1228				async_tx_ack(s->desc_rx[0]);
1229				s->cookie_rx[0] = -EINVAL;
1230			}
1231			if (desc) {
1232				async_tx_ack(desc);
1233				s->cookie_rx[i] = -EINVAL;
1234			}
1235			dev_warn(s->port.dev,
1236				 "failed to re-start DMA, using PIO\n");
1237			sci_rx_dma_release(s, true);
1238			return;
1239		}
1240		dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
1241			s->cookie_rx[i], i);
1242	}
1243
1244	s->active_rx = s->cookie_rx[0];
1245
1246	dma_async_issue_pending(chan);
1247}
1248
1249static void work_fn_rx(struct work_struct *work)
1250{
1251	struct sci_port *s = container_of(work, struct sci_port, work_rx);
1252	struct uart_port *port = &s->port;
1253	struct dma_async_tx_descriptor *desc;
1254	int new;
1255
1256	if (s->active_rx == s->cookie_rx[0]) {
1257		new = 0;
1258	} else if (s->active_rx == s->cookie_rx[1]) {
1259		new = 1;
1260	} else {
1261		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);
1262		return;
 
1263	}
1264	desc = s->desc_rx[new];
1265
1266	if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=
1267	    DMA_SUCCESS) {
1268		/* Handle incomplete DMA receive */
1269		struct tty_struct *tty = port->state->port.tty;
1270		struct dma_chan *chan = s->chan_rx;
1271		struct sh_desc *sh_desc = container_of(desc, struct sh_desc,
1272						       async_tx);
1273		unsigned long flags;
1274		int count;
1275
1276		chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
1277		dev_dbg(port->dev, "Read %u bytes with cookie %d\n",
1278			sh_desc->partial, sh_desc->cookie);
1279
1280		spin_lock_irqsave(&port->lock, flags);
1281		count = sci_dma_rx_push(s, tty, sh_desc->partial);
1282		spin_unlock_irqrestore(&port->lock, flags);
1283
1284		if (count)
1285			tty_flip_buffer_push(tty);
1286
1287		sci_submit_rx(s);
1288
1289		return;
1290	}
1291
1292	s->cookie_rx[new] = desc->tx_submit(desc);
1293	if (s->cookie_rx[new] < 0) {
1294		dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1295		sci_rx_dma_release(s, true);
1296		return;
1297	}
1298
1299	s->active_rx = s->cookie_rx[!new];
1300
1301	dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
1302		s->cookie_rx[new], new, s->active_rx);
1303}
1304
1305static void work_fn_tx(struct work_struct *work)
1306{
1307	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1308	struct dma_async_tx_descriptor *desc;
1309	struct dma_chan *chan = s->chan_tx;
1310	struct uart_port *port = &s->port;
1311	struct circ_buf *xmit = &port->state->xmit;
1312	struct scatterlist *sg = &s->sg_tx;
1313
1314	/*
1315	 * DMA is idle now.
1316	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1317	 * offsets and lengths. Since it is a circular buffer, we have to
1318	 * transmit till the end, and then the rest. Take the port lock to get a
1319	 * consistent xmit buffer state.
1320	 */
1321	spin_lock_irq(&port->lock);
1322	sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
1323	sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
1324		sg->offset;
1325	sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1326		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1327	spin_unlock_irq(&port->lock);
1328
1329	BUG_ON(!sg_dma_len(sg));
1330
1331	desc = chan->device->device_prep_slave_sg(chan,
1332			sg, s->sg_len_tx, DMA_TO_DEVICE,
1333			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1334	if (!desc) {
1335		/* switch to PIO */
1336		sci_tx_dma_release(s, true);
1337		return;
1338	}
1339
1340	dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
1341
1342	spin_lock_irq(&port->lock);
1343	s->desc_tx = desc;
1344	desc->callback = sci_dma_tx_complete;
1345	desc->callback_param = s;
1346	spin_unlock_irq(&port->lock);
1347	s->cookie_tx = desc->tx_submit(desc);
1348	if (s->cookie_tx < 0) {
1349		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1350		/* switch to PIO */
1351		sci_tx_dma_release(s, true);
1352		return;
1353	}
1354
1355	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,
1356		xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1357
1358	dma_async_issue_pending(chan);
1359}
1360#endif
1361
1362static void sci_start_tx(struct uart_port *port)
1363{
1364	struct sci_port *s = to_sci_port(port);
1365	unsigned short ctrl;
1366
1367#ifdef CONFIG_SERIAL_SH_SCI_DMA
1368	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1369		u16 new, scr = sci_in(port, SCSCR);
1370		if (s->chan_tx)
1371			new = scr | 0x8000;
1372		else
1373			new = scr & ~0x8000;
1374		if (new != scr)
1375			sci_out(port, SCSCR, new);
1376	}
1377
1378	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
1379	    s->cookie_tx < 0)
1380		schedule_work(&s->work_tx);
1381#endif
1382
1383	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1384		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
1385		ctrl = sci_in(port, SCSCR);
1386		sci_out(port, SCSCR, ctrl | SCSCR_TIE);
 
 
 
 
 
1387	}
1388}
1389
1390static void sci_stop_tx(struct uart_port *port)
1391{
1392	unsigned short ctrl;
1393
1394	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
1395	ctrl = sci_in(port, SCSCR);
1396
1397	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1398		ctrl &= ~0x8000;
1399
1400	ctrl &= ~SCSCR_TIE;
1401
1402	sci_out(port, SCSCR, ctrl);
1403}
1404
1405static void sci_start_rx(struct uart_port *port)
1406{
1407	unsigned short ctrl;
1408
1409	ctrl = sci_in(port, SCSCR) | port_rx_irq_mask(port);
1410
1411	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1412		ctrl &= ~0x4000;
1413
1414	sci_out(port, SCSCR, ctrl);
1415}
1416
1417static void sci_stop_rx(struct uart_port *port)
1418{
1419	unsigned short ctrl;
1420
1421	ctrl = sci_in(port, SCSCR);
1422
1423	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1424		ctrl &= ~0x4000;
1425
1426	ctrl &= ~port_rx_irq_mask(port);
1427
1428	sci_out(port, SCSCR, ctrl);
1429}
1430
1431static void sci_enable_ms(struct uart_port *port)
1432{
1433	/* Nothing here yet .. */
1434}
1435
1436static void sci_break_ctl(struct uart_port *port, int break_state)
1437{
1438	/* Nothing here yet .. */
1439}
1440
1441#ifdef CONFIG_SERIAL_SH_SCI_DMA
1442static bool filter(struct dma_chan *chan, void *slave)
1443{
1444	struct sh_dmae_slave *param = slave;
1445
1446	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
1447		param->slave_id);
1448
1449	if (param->dma_dev == chan->device->dev) {
1450		chan->private = param;
1451		return true;
1452	} else {
1453		return false;
1454	}
1455}
1456
1457static void rx_timer_fn(unsigned long arg)
1458{
1459	struct sci_port *s = (struct sci_port *)arg;
1460	struct uart_port *port = &s->port;
1461	u16 scr = sci_in(port, SCSCR);
1462
1463	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1464		scr &= ~0x4000;
1465		enable_irq(s->cfg->irqs[1]);
1466	}
1467	sci_out(port, SCSCR, scr | SCSCR_RIE);
1468	dev_dbg(port->dev, "DMA Rx timed out\n");
1469	schedule_work(&s->work_rx);
1470}
1471
1472static void sci_request_dma(struct uart_port *port)
1473{
1474	struct sci_port *s = to_sci_port(port);
1475	struct sh_dmae_slave *param;
1476	struct dma_chan *chan;
1477	dma_cap_mask_t mask;
1478	int nent;
1479
1480	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
1481		port->line, s->cfg->dma_dev);
1482
1483	if (!s->cfg->dma_dev)
1484		return;
1485
1486	dma_cap_zero(mask);
1487	dma_cap_set(DMA_SLAVE, mask);
1488
1489	param = &s->param_tx;
1490
1491	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
1492	param->slave_id = s->cfg->dma_slave_tx;
1493	param->dma_dev = s->cfg->dma_dev;
1494
1495	s->cookie_tx = -EINVAL;
1496	chan = dma_request_channel(mask, filter, param);
1497	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1498	if (chan) {
1499		s->chan_tx = chan;
1500		sg_init_table(&s->sg_tx, 1);
1501		/* UART circular tx buffer is an aligned page. */
1502		BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);
1503		sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
1504			    UART_XMIT_SIZE, (int)port->state->xmit.buf & ~PAGE_MASK);
1505		nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
1506		if (!nent)
1507			sci_tx_dma_release(s, false);
1508		else
1509			dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,
1510				sg_dma_len(&s->sg_tx),
1511				port->state->xmit.buf, sg_dma_address(&s->sg_tx));
1512
1513		s->sg_len_tx = nent;
1514
1515		INIT_WORK(&s->work_tx, work_fn_tx);
1516	}
1517
1518	param = &s->param_rx;
1519
1520	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
1521	param->slave_id = s->cfg->dma_slave_rx;
1522	param->dma_dev = s->cfg->dma_dev;
1523
1524	chan = dma_request_channel(mask, filter, param);
1525	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1526	if (chan) {
1527		dma_addr_t dma[2];
1528		void *buf[2];
1529		int i;
1530
1531		s->chan_rx = chan;
1532
1533		s->buf_len_rx = 2 * max(16, (int)port->fifosize);
1534		buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
1535					    &dma[0], GFP_KERNEL);
1536
1537		if (!buf[0]) {
1538			dev_warn(port->dev,
1539				 "failed to allocate dma buffer, using PIO\n");
1540			sci_rx_dma_release(s, true);
1541			return;
1542		}
1543
1544		buf[1] = buf[0] + s->buf_len_rx;
1545		dma[1] = dma[0] + s->buf_len_rx;
1546
1547		for (i = 0; i < 2; i++) {
1548			struct scatterlist *sg = &s->sg_rx[i];
1549
1550			sg_init_table(sg, 1);
1551			sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
1552				    (int)buf[i] & ~PAGE_MASK);
1553			sg_dma_address(sg) = dma[i];
1554		}
1555
1556		INIT_WORK(&s->work_rx, work_fn_rx);
1557		setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1558
1559		sci_submit_rx(s);
1560	}
1561}
1562
1563static void sci_free_dma(struct uart_port *port)
1564{
1565	struct sci_port *s = to_sci_port(port);
1566
1567	if (!s->cfg->dma_dev)
1568		return;
1569
1570	if (s->chan_tx)
1571		sci_tx_dma_release(s, false);
1572	if (s->chan_rx)
1573		sci_rx_dma_release(s, false);
1574}
1575#else
1576static inline void sci_request_dma(struct uart_port *port)
1577{
1578}
1579
1580static inline void sci_free_dma(struct uart_port *port)
1581{
1582}
1583#endif
1584
1585static int sci_startup(struct uart_port *port)
1586{
1587	struct sci_port *s = to_sci_port(port);
1588	int ret;
1589
1590	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1591
1592	sci_port_enable(s);
1593
1594	ret = sci_request_irq(s);
1595	if (unlikely(ret < 0))
1596		return ret;
1597
1598	sci_request_dma(port);
1599
1600	sci_start_tx(port);
1601	sci_start_rx(port);
1602
1603	return 0;
1604}
1605
1606static void sci_shutdown(struct uart_port *port)
1607{
1608	struct sci_port *s = to_sci_port(port);
 
 
1609
1610	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1611
 
 
 
 
1612	sci_stop_rx(port);
1613	sci_stop_tx(port);
 
 
 
 
 
 
 
 
 
 
 
 
1614
1615	sci_free_dma(port);
1616	sci_free_irq(s);
 
1617
1618	sci_port_disable(s);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1619}
1620
1621static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps,
1622				   unsigned long freq)
 
1623{
1624	switch (algo_id) {
1625	case SCBRR_ALGO_1:
1626		return ((freq + 16 * bps) / (16 * bps) - 1);
1627	case SCBRR_ALGO_2:
1628		return ((freq + 16 * bps) / (32 * bps) - 1);
1629	case SCBRR_ALGO_3:
1630		return (((freq * 2) + 16 * bps) / (16 * bps) - 1);
1631	case SCBRR_ALGO_4:
1632		return (((freq * 2) + 16 * bps) / (32 * bps) - 1);
1633	case SCBRR_ALGO_5:
1634		return (((freq * 1000 / 32) / bps) - 1);
 
 
 
 
 
 
 
 
 
1635	}
1636
1637	/* Warn, but use a safe default */
1638	WARN_ON(1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1639
1640	return ((freq + 16 * bps) / (32 * bps) - 1);
 
 
 
 
 
 
 
 
1641}
1642
1643static void sci_reset(struct uart_port *port)
1644{
 
1645	unsigned int status;
1646
1647	do {
1648		status = sci_in(port, SCxSR);
1649	} while (!(status & SCxSR_TEND(port)));
1650
1651	sci_out(port, SCSCR, 0x00);	/* TE=0, RE=0, CKE1=0 */
 
 
 
 
1652
1653	if (port->type != PORT_SCI)
1654		sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
 
 
 
 
 
 
1655}
1656
1657static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
1658			    struct ktermios *old)
1659{
 
 
 
1660	struct sci_port *s = to_sci_port(port);
1661	unsigned int baud, smr_val, max_baud;
1662	int t = -1;
1663	u16 scfcr = 0;
 
 
 
 
 
 
 
 
 
 
1664
1665	/*
1666	 * earlyprintk comes here early on with port->uartclk set to zero.
1667	 * the clock framework is not up and running at this point so here
1668	 * we assume that 115200 is the maximum baud rate. please note that
1669	 * the baud rate is not programmed during earlyprintk - it is assumed
1670	 * that the previous boot loader has enabled required clocks and
1671	 * setup the baud rate generator hardware for us already.
1672	 */
1673	max_baud = port->uartclk ? port->uartclk / 16 : 115200;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1674
1675	baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
1676	if (likely(baud && port->uartclk))
1677		t = sci_scbrr_calc(s->cfg->scbrr_algo_id, baud, port->uartclk);
 
 
 
 
 
 
 
 
 
 
 
 
1678
1679	sci_port_enable(s);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1680
1681	sci_reset(port);
 
 
 
 
 
 
 
 
 
1682
1683	smr_val = sci_in(port, SCSMR) & 3;
 
 
 
1684
1685	if ((termios->c_cflag & CSIZE) == CS7)
1686		smr_val |= 0x40;
1687	if (termios->c_cflag & PARENB)
1688		smr_val |= 0x20;
1689	if (termios->c_cflag & PARODD)
1690		smr_val |= 0x30;
1691	if (termios->c_cflag & CSTOPB)
1692		smr_val |= 0x08;
1693
1694	uart_update_timeout(port, termios->c_cflag, baud);
 
 
 
 
 
 
 
1695
1696	sci_out(port, SCSMR, smr_val);
1697
1698	dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,
1699		s->cfg->scscr);
1700
1701	if (t > 0) {
1702		if (t >= 256) {
1703			sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
1704			t >>= 2;
1705		} else
1706			sci_out(port, SCSMR, sci_in(port, SCSMR) & ~3);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1707
1708		sci_out(port, SCBRR, t);
1709		udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
 
 
 
 
 
 
 
 
1710	}
1711
1712	sci_init_pins(port, termios->c_cflag);
1713	sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));
1714
1715	sci_out(port, SCSCR, s->cfg->scscr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1716
1717#ifdef CONFIG_SERIAL_SH_SCI_DMA
1718	/*
1719	 * Calculate delay for 1.5 DMA buffers: see
1720	 * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
1721	 * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
1722	 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
1723	 * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
1724	 * sizes), but it has been found out experimentally, that this is not
1725	 * enough: the driver too often needlessly runs on a DMA timeout. 20ms
1726	 * as a minimum seem to work perfectly.
1727	 */
1728	if (s->chan_rx) {
1729		s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
1730			port->fifosize / 2;
1731		dev_dbg(port->dev,
1732			"DMA Rx t-out %ums, tty t-out %u jiffies\n",
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1733			s->rx_timeout * 1000 / HZ, port->timeout);
1734		if (s->rx_timeout < msecs_to_jiffies(20))
1735			s->rx_timeout = msecs_to_jiffies(20);
1736	}
1737#endif
1738
1739	if ((termios->c_cflag & CREAD) != 0)
1740		sci_start_rx(port);
1741
1742	sci_port_disable(s);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1743}
1744
1745static const char *sci_type(struct uart_port *port)
1746{
1747	switch (port->type) {
1748	case PORT_IRDA:
1749		return "irda";
1750	case PORT_SCI:
1751		return "sci";
1752	case PORT_SCIF:
1753		return "scif";
1754	case PORT_SCIFA:
1755		return "scifa";
1756	case PORT_SCIFB:
1757		return "scifb";
 
 
1758	}
1759
1760	return NULL;
1761}
1762
1763static inline unsigned long sci_port_size(struct uart_port *port)
1764{
1765	/*
1766	 * Pick an arbitrary size that encapsulates all of the base
1767	 * registers by default. This can be optimized later, or derived
1768	 * from platform resource data at such a time that ports begin to
1769	 * behave more erratically.
1770	 */
1771	return 64;
1772}
1773
1774static int sci_remap_port(struct uart_port *port)
1775{
1776	unsigned long size = sci_port_size(port);
1777
1778	/*
1779	 * Nothing to do if there's already an established membase.
1780	 */
1781	if (port->membase)
1782		return 0;
1783
1784	if (port->flags & UPF_IOREMAP) {
1785		port->membase = ioremap_nocache(port->mapbase, size);
1786		if (unlikely(!port->membase)) {
1787			dev_err(port->dev, "can't remap port#%d\n", port->line);
1788			return -ENXIO;
1789		}
1790	} else {
1791		/*
1792		 * For the simple (and majority of) cases where we don't
1793		 * need to do any remapping, just cast the cookie
1794		 * directly.
1795		 */
1796		port->membase = (void __iomem *)port->mapbase;
1797	}
1798
1799	return 0;
1800}
1801
1802static void sci_release_port(struct uart_port *port)
1803{
 
 
1804	if (port->flags & UPF_IOREMAP) {
1805		iounmap(port->membase);
1806		port->membase = NULL;
1807	}
1808
1809	release_mem_region(port->mapbase, sci_port_size(port));
1810}
1811
1812static int sci_request_port(struct uart_port *port)
1813{
1814	unsigned long size = sci_port_size(port);
1815	struct resource *res;
 
1816	int ret;
1817
1818	res = request_mem_region(port->mapbase, size, dev_name(port->dev));
1819	if (unlikely(res == NULL))
 
 
1820		return -EBUSY;
 
1821
1822	ret = sci_remap_port(port);
1823	if (unlikely(ret != 0)) {
1824		release_resource(res);
1825		return ret;
1826	}
1827
1828	return 0;
1829}
1830
1831static void sci_config_port(struct uart_port *port, int flags)
1832{
1833	if (flags & UART_CONFIG_TYPE) {
1834		struct sci_port *sport = to_sci_port(port);
1835
1836		port->type = sport->cfg->type;
1837		sci_request_port(port);
1838	}
1839}
1840
1841static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
1842{
1843	struct sci_port *s = to_sci_port(port);
1844
1845	if (ser->irq != s->cfg->irqs[SCIx_TXI_IRQ] || ser->irq > nr_irqs)
1846		return -EINVAL;
1847	if (ser->baud_base < 2400)
1848		/* No paper tape reader for Mitch.. */
1849		return -EINVAL;
1850
1851	return 0;
1852}
1853
1854static struct uart_ops sci_uart_ops = {
1855	.tx_empty	= sci_tx_empty,
1856	.set_mctrl	= sci_set_mctrl,
1857	.get_mctrl	= sci_get_mctrl,
1858	.start_tx	= sci_start_tx,
1859	.stop_tx	= sci_stop_tx,
1860	.stop_rx	= sci_stop_rx,
1861	.enable_ms	= sci_enable_ms,
1862	.break_ctl	= sci_break_ctl,
1863	.startup	= sci_startup,
1864	.shutdown	= sci_shutdown,
1865	.set_termios	= sci_set_termios,
 
1866	.type		= sci_type,
1867	.release_port	= sci_release_port,
1868	.request_port	= sci_request_port,
1869	.config_port	= sci_config_port,
1870	.verify_port	= sci_verify_port,
1871#ifdef CONFIG_CONSOLE_POLL
1872	.poll_get_char	= sci_poll_get_char,
1873	.poll_put_char	= sci_poll_put_char,
1874#endif
1875};
1876
1877static int __devinit sci_init_single(struct platform_device *dev,
1878				     struct sci_port *sci_port,
1879				     unsigned int index,
1880				     struct plat_sci_port *p)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1881{
1882	struct uart_port *port = &sci_port->port;
 
 
1883	int ret;
1884
 
 
1885	port->ops	= &sci_uart_ops;
1886	port->iotype	= UPIO_MEM;
1887	port->line	= index;
1888
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1889	switch (p->type) {
1890	case PORT_SCIFB:
1891		port->fifosize = 256;
 
 
 
 
 
 
 
 
 
1892		break;
1893	case PORT_SCIFA:
1894		port->fifosize = 64;
 
 
 
1895		break;
1896	case PORT_SCIF:
1897		port->fifosize = 16;
 
 
 
 
 
 
 
 
 
1898		break;
1899	default:
1900		port->fifosize = 1;
 
 
 
1901		break;
1902	}
1903
1904	if (p->regtype == SCIx_PROBE_REGTYPE) {
1905		ret = sci_probe_regmap(p);
1906		if (unlikely(ret))
 
 
 
 
 
 
 
1907			return ret;
1908	}
1909
1910	if (dev) {
1911		sci_port->iclk = clk_get(&dev->dev, "sci_ick");
1912		if (IS_ERR(sci_port->iclk)) {
1913			sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
1914			if (IS_ERR(sci_port->iclk)) {
1915				dev_err(&dev->dev, "can't get iclk\n");
1916				return PTR_ERR(sci_port->iclk);
1917			}
1918		}
1919
1920		/*
1921		 * The function clock is optional, ignore it if we can't
1922		 * find it.
1923		 */
1924		sci_port->fclk = clk_get(&dev->dev, "sci_fck");
1925		if (IS_ERR(sci_port->fclk))
1926			sci_port->fclk = NULL;
1927
1928		port->dev = &dev->dev;
1929
1930		pm_runtime_irq_safe(&dev->dev);
1931		pm_runtime_enable(&dev->dev);
1932	}
1933
1934	sci_port->break_timer.data = (unsigned long)sci_port;
1935	sci_port->break_timer.function = sci_break_timer;
1936	init_timer(&sci_port->break_timer);
1937
1938	/*
1939	 * Establish some sensible defaults for the error detection.
1940	 */
1941	if (!p->error_mask)
1942		p->error_mask = (p->type == PORT_SCI) ?
1943			SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK;
 
 
 
 
1944
1945	/*
1946	 * Establish sensible defaults for the overrun detection, unless
1947	 * the part has explicitly disabled support for it.
1948	 */
1949	if (p->overrun_bit != SCIx_NOT_SUPPORTED) {
1950		if (p->type == PORT_SCI)
1951			p->overrun_bit = 5;
1952		else if (p->scbrr_algo_id == SCBRR_ALGO_4)
1953			p->overrun_bit = 9;
1954		else
1955			p->overrun_bit = 0;
1956
1957		/*
1958		 * Make the error mask inclusive of overrun detection, if
1959		 * supported.
1960		 */
1961		p->error_mask |= (1 << p->overrun_bit);
1962	}
1963
1964	sci_port->cfg		= p;
1965
1966	port->mapbase		= p->mapbase;
1967	port->type		= p->type;
1968	port->flags		= p->flags;
1969	port->regshift		= p->regshift;
1970
1971	/*
1972	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
1973	 * for the multi-IRQ ports, which is where we are primarily
1974	 * concerned with the shutdown path synchronization.
1975	 *
1976	 * For the muxed case there's nothing more to do.
1977	 */
1978	port->irq		= p->irqs[SCIx_RXI_IRQ];
1979	port->irqflags		= IRQF_DISABLED;
1980
1981	port->serial_in		= sci_serial_in;
1982	port->serial_out	= sci_serial_out;
1983
1984	if (p->dma_dev)
1985		dev_dbg(port->dev, "DMA device %p, tx %d, rx %d\n",
1986			p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
1987
1988	return 0;
1989}
1990
1991#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
 
 
 
 
 
 
1992static void serial_console_putchar(struct uart_port *port, int ch)
1993{
1994	sci_poll_put_char(port, ch);
1995}
1996
1997/*
1998 *	Print a string to the serial port trying not to disturb
1999 *	any possible real use of the port...
2000 */
2001static void serial_console_write(struct console *co, const char *s,
2002				 unsigned count)
2003{
2004	struct sci_port *sci_port = &sci_ports[co->index];
2005	struct uart_port *port = &sci_port->port;
2006	unsigned short bits;
 
 
2007
2008	sci_port_enable(sci_port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2009
2010	uart_console_write(port, s, count, serial_console_putchar);
2011
2012	/* wait until fifo is empty and last bit has been transmitted */
2013	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2014	while ((sci_in(port, SCxSR) & bits) != bits)
2015		cpu_relax();
2016
2017	sci_port_disable(sci_port);
 
 
 
 
 
2018}
2019
2020static int __devinit serial_console_setup(struct console *co, char *options)
2021{
2022	struct sci_port *sci_port;
2023	struct uart_port *port;
2024	int baud = 115200;
2025	int bits = 8;
2026	int parity = 'n';
2027	int flow = 'n';
2028	int ret;
2029
2030	/*
2031	 * Refuse to handle any bogus ports.
2032	 */
2033	if (co->index < 0 || co->index >= SCI_NPORTS)
2034		return -ENODEV;
2035
2036	sci_port = &sci_ports[co->index];
2037	port = &sci_port->port;
2038
2039	/*
2040	 * Refuse to handle uninitialized ports.
2041	 */
2042	if (!port->ops)
2043		return -ENODEV;
2044
2045	ret = sci_remap_port(port);
2046	if (unlikely(ret != 0))
2047		return ret;
2048
2049	sci_port_enable(sci_port);
2050
2051	if (options)
2052		uart_parse_options(options, &baud, &parity, &bits, &flow);
2053
2054	sci_port_disable(sci_port);
2055
2056	return uart_set_options(port, co, baud, parity, bits, flow);
2057}
2058
2059static struct console serial_console = {
2060	.name		= "ttySC",
2061	.device		= uart_console_device,
2062	.write		= serial_console_write,
2063	.setup		= serial_console_setup,
2064	.flags		= CON_PRINTBUFFER,
2065	.index		= -1,
2066	.data		= &sci_uart_driver,
2067};
2068
2069static struct console early_serial_console = {
2070	.name           = "early_ttySC",
2071	.write          = serial_console_write,
2072	.flags          = CON_PRINTBUFFER,
2073	.index		= -1,
2074};
2075
2076static char early_serial_buf[32];
2077
2078static int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
2079{
2080	struct plat_sci_port *cfg = pdev->dev.platform_data;
2081
2082	if (early_serial_console.data)
2083		return -EEXIST;
2084
2085	early_serial_console.index = pdev->id;
2086
2087	sci_init_single(NULL, &sci_ports[pdev->id], pdev->id, cfg);
2088
2089	serial_console_setup(&early_serial_console, early_serial_buf);
2090
2091	if (!strstr(early_serial_buf, "keep"))
2092		early_serial_console.flags |= CON_BOOT;
2093
2094	register_console(&early_serial_console);
2095	return 0;
2096}
2097
2098#define uart_console(port)	((port)->cons->index == (port)->line)
2099
2100static int sci_runtime_suspend(struct device *dev)
2101{
2102	struct sci_port *sci_port = dev_get_drvdata(dev);
2103	struct uart_port *port = &sci_port->port;
2104
2105	if (uart_console(port)) {
2106		sci_port->saved_smr = sci_in(port, SCSMR);
2107		sci_port->saved_brr = sci_in(port, SCBRR);
2108		sci_port->saved_fcr = sci_in(port, SCFCR);
2109	}
2110	return 0;
2111}
2112
2113static int sci_runtime_resume(struct device *dev)
2114{
2115	struct sci_port *sci_port = dev_get_drvdata(dev);
2116	struct uart_port *port = &sci_port->port;
2117
2118	if (uart_console(port)) {
2119		sci_reset(port);
2120		sci_out(port, SCSMR, sci_port->saved_smr);
2121		sci_out(port, SCBRR, sci_port->saved_brr);
2122		sci_out(port, SCFCR, sci_port->saved_fcr);
2123		sci_out(port, SCSCR, sci_port->cfg->scscr);
2124	}
2125	return 0;
2126}
2127
2128#define SCI_CONSOLE	(&serial_console)
2129
2130#else
2131static inline int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
2132{
2133	return -EINVAL;
2134}
2135
2136#define SCI_CONSOLE	NULL
2137#define sci_runtime_suspend	NULL
2138#define sci_runtime_resume	NULL
2139
2140#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
2141
2142static char banner[] __initdata =
2143	KERN_INFO "SuperH SCI(F) driver initialized\n";
2144
2145static struct uart_driver sci_uart_driver = {
2146	.owner		= THIS_MODULE,
2147	.driver_name	= "sci",
2148	.dev_name	= "ttySC",
2149	.major		= SCI_MAJOR,
2150	.minor		= SCI_MINOR_START,
2151	.nr		= SCI_NPORTS,
2152	.cons		= SCI_CONSOLE,
2153};
2154
2155static int sci_remove(struct platform_device *dev)
2156{
2157	struct sci_port *port = platform_get_drvdata(dev);
2158
2159	cpufreq_unregister_notifier(&port->freq_transition,
2160				    CPUFREQ_TRANSITION_NOTIFIER);
2161
2162	uart_remove_one_port(&sci_uart_driver, &port->port);
2163
2164	clk_put(port->iclk);
2165	clk_put(port->fclk);
2166
2167	pm_runtime_disable(&dev->dev);
2168	return 0;
2169}
2170
2171static int __devinit sci_probe_single(struct platform_device *dev,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2172				      unsigned int index,
2173				      struct plat_sci_port *p,
2174				      struct sci_port *sciport)
2175{
2176	int ret;
2177
2178	/* Sanity check */
2179	if (unlikely(index >= SCI_NPORTS)) {
2180		dev_notice(&dev->dev, "Attempting to register port "
2181			   "%d when only %d are available.\n",
2182			   index+1, SCI_NPORTS);
2183		dev_notice(&dev->dev, "Consider bumping "
2184			   "CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
2185		return 0;
2186	}
2187
2188	ret = sci_init_single(dev, sciport, index, p);
2189	if (ret)
2190		return ret;
2191
2192	return uart_add_one_port(&sci_uart_driver, &sciport->port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2193}
2194
2195static int __devinit sci_probe(struct platform_device *dev)
2196{
2197	struct plat_sci_port *p = dev->dev.platform_data;
2198	struct sci_port *sp = &sci_ports[dev->id];
 
2199	int ret;
2200
2201	/*
2202	 * If we've come here via earlyprintk initialization, head off to
2203	 * the special early probe. We don't have sufficient device state
2204	 * to make it beyond this yet.
2205	 */
2206	if (is_early_platform_device(dev))
2207		return sci_probe_earlyprintk(dev);
2208
2209	platform_set_drvdata(dev, sp);
 
 
 
 
 
 
 
 
 
2210
2211	ret = sci_probe_single(dev, dev->id, p, sp);
2212	if (ret)
2213		goto err_unreg;
2214
2215	sp->freq_transition.notifier_call = sci_notifier;
 
2216
2217	ret = cpufreq_register_notifier(&sp->freq_transition,
2218					CPUFREQ_TRANSITION_NOTIFIER);
2219	if (unlikely(ret < 0))
2220		goto err_unreg;
2221
2222#ifdef CONFIG_SH_STANDARD_BIOS
2223	sh_bios_gdb_detach();
2224#endif
2225
2226	return 0;
2227
2228err_unreg:
2229	sci_remove(dev);
2230	return ret;
2231}
2232
2233static int sci_suspend(struct device *dev)
2234{
2235	struct sci_port *sport = dev_get_drvdata(dev);
2236
2237	if (sport)
2238		uart_suspend_port(&sci_uart_driver, &sport->port);
2239
2240	return 0;
2241}
2242
2243static int sci_resume(struct device *dev)
2244{
2245	struct sci_port *sport = dev_get_drvdata(dev);
2246
2247	if (sport)
2248		uart_resume_port(&sci_uart_driver, &sport->port);
2249
2250	return 0;
2251}
2252
2253static const struct dev_pm_ops sci_dev_pm_ops = {
2254	.runtime_suspend = sci_runtime_suspend,
2255	.runtime_resume = sci_runtime_resume,
2256	.suspend	= sci_suspend,
2257	.resume		= sci_resume,
2258};
2259
2260static struct platform_driver sci_driver = {
2261	.probe		= sci_probe,
2262	.remove		= sci_remove,
2263	.driver		= {
2264		.name	= "sh-sci",
2265		.owner	= THIS_MODULE,
2266		.pm	= &sci_dev_pm_ops,
 
2267	},
2268};
2269
2270static int __init sci_init(void)
2271{
2272	int ret;
2273
2274	printk(banner);
2275
2276	ret = uart_register_driver(&sci_uart_driver);
2277	if (likely(ret == 0)) {
2278		ret = platform_driver_register(&sci_driver);
2279		if (unlikely(ret))
2280			uart_unregister_driver(&sci_uart_driver);
2281	}
2282
2283	return ret;
2284}
2285
2286static void __exit sci_exit(void)
2287{
2288	platform_driver_unregister(&sci_driver);
2289	uart_unregister_driver(&sci_uart_driver);
2290}
2291
2292#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
2293early_platform_init_buffer("earlyprintk", &sci_driver,
2294			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
2295#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2296module_init(sci_init);
2297module_exit(sci_exit);
2298
2299MODULE_LICENSE("GPL");
2300MODULE_ALIAS("platform:sh-sci");
2301MODULE_AUTHOR("Paul Mundt");
2302MODULE_DESCRIPTION("SuperH SCI(F) serial driver");
v4.10.11
   1/*
   2 * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   3 *
   4 *  Copyright (C) 2002 - 2011  Paul Mundt
   5 *  Copyright (C) 2015 Glider bvba
   6 *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   7 *
   8 * based off of the old drivers/char/sh-sci.c by:
   9 *
  10 *   Copyright (C) 1999, 2000  Niibe Yutaka
  11 *   Copyright (C) 2000  Sugioka Toshinobu
  12 *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  13 *   Modified to support SecureEdge. David McCullough (2002)
  14 *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  15 *   Removed SH7300 support (Jul 2007).
  16 *
  17 * This file is subject to the terms and conditions of the GNU General Public
  18 * License.  See the file "COPYING" in the main directory of this archive
  19 * for more details.
  20 */
  21#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  22#define SUPPORT_SYSRQ
  23#endif
  24
  25#undef DEBUG
  26
  27#include <linux/clk.h>
  28#include <linux/console.h>
  29#include <linux/ctype.h>
  30#include <linux/cpufreq.h>
  31#include <linux/delay.h>
  32#include <linux/dmaengine.h>
  33#include <linux/dma-mapping.h>
  34#include <linux/err.h>
  35#include <linux/errno.h>
  36#include <linux/init.h>
  37#include <linux/interrupt.h>
 
 
 
 
 
 
  38#include <linux/ioport.h>
  39#include <linux/major.h>
  40#include <linux/module.h>
  41#include <linux/mm.h>
  42#include <linux/of.h>
 
 
  43#include <linux/platform_device.h>
 
 
  44#include <linux/pm_runtime.h>
 
 
 
 
 
 
  45#include <linux/scatterlist.h>
  46#include <linux/serial.h>
  47#include <linux/serial_sci.h>
  48#include <linux/sh_dma.h>
  49#include <linux/slab.h>
  50#include <linux/string.h>
  51#include <linux/sysrq.h>
  52#include <linux/timer.h>
  53#include <linux/tty.h>
  54#include <linux/tty_flip.h>
  55
  56#ifdef CONFIG_SUPERH
  57#include <asm/sh_bios.h>
  58#endif
  59
  60#include "serial_mctrl_gpio.h"
  61#include "sh-sci.h"
  62
  63/* Offsets into the sci_port->irqs array */
  64enum {
  65	SCIx_ERI_IRQ,
  66	SCIx_RXI_IRQ,
  67	SCIx_TXI_IRQ,
  68	SCIx_BRI_IRQ,
  69	SCIx_NR_IRQS,
  70
  71	SCIx_MUX_IRQ = SCIx_NR_IRQS,	/* special case */
  72};
  73
  74#define SCIx_IRQ_IS_MUXED(port)			\
  75	((port)->irqs[SCIx_ERI_IRQ] ==	\
  76	 (port)->irqs[SCIx_RXI_IRQ]) ||	\
  77	((port)->irqs[SCIx_ERI_IRQ] &&	\
  78	 ((port)->irqs[SCIx_RXI_IRQ] < 0))
  79
  80enum SCI_CLKS {
  81	SCI_FCK,		/* Functional Clock */
  82	SCI_SCK,		/* Optional External Clock */
  83	SCI_BRG_INT,		/* Optional BRG Internal Clock Source */
  84	SCI_SCIF_CLK,		/* Optional BRG External Clock Source */
  85	SCI_NUM_CLKS
  86};
  87
  88/* Bit x set means sampling rate x + 1 is supported */
  89#define SCI_SR(x)		BIT((x) - 1)
  90#define SCI_SR_RANGE(x, y)	GENMASK((y) - 1, (x) - 1)
  91
  92#define SCI_SR_SCIFAB		SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
  93				SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
  94				SCI_SR(19) | SCI_SR(27)
  95
  96#define min_sr(_port)		ffs((_port)->sampling_rate_mask)
  97#define max_sr(_port)		fls((_port)->sampling_rate_mask)
  98
  99/* Iterate over all supported sampling rates, from high to low */
 100#define for_each_sr(_sr, _port)						\
 101	for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)	\
 102		if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
 103
 104struct sci_port {
 105	struct uart_port	port;
 106
 107	/* Platform configuration */
 108	struct plat_sci_port	*cfg;
 109	unsigned int		overrun_reg;
 110	unsigned int		overrun_mask;
 111	unsigned int		error_mask;
 112	unsigned int		error_clear;
 113	unsigned int		sampling_rate_mask;
 114	resource_size_t		reg_size;
 115	struct mctrl_gpios	*gpios;
 116
 117	/* Break timer */
 118	struct timer_list	break_timer;
 119	int			break_flag;
 120
 121	/* Clocks */
 122	struct clk		*clks[SCI_NUM_CLKS];
 123	unsigned long		clk_rates[SCI_NUM_CLKS];
 
 124
 125	int			irqs[SCIx_NR_IRQS];
 126	char			*irqstr[SCIx_NR_IRQS];
 127
 128	struct dma_chan			*chan_tx;
 129	struct dma_chan			*chan_rx;
 130
 131#ifdef CONFIG_SERIAL_SH_SCI_DMA
 
 
 132	dma_cookie_t			cookie_tx;
 133	dma_cookie_t			cookie_rx[2];
 134	dma_cookie_t			active_rx;
 135	dma_addr_t			tx_dma_addr;
 136	unsigned int			tx_dma_len;
 137	struct scatterlist		sg_rx[2];
 138	void				*rx_buf[2];
 139	size_t				buf_len_rx;
 
 
 140	struct work_struct		work_tx;
 
 141	struct timer_list		rx_timer;
 142	unsigned int			rx_timeout;
 143#endif
 144
 145	bool autorts;
 
 
 
 
 
 
 146};
 147
 
 
 
 
 
 148#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 149
 150static struct sci_port sci_ports[SCI_NPORTS];
 151static struct uart_driver sci_uart_driver;
 152
 153static inline struct sci_port *
 154to_sci_port(struct uart_port *uart)
 155{
 156	return container_of(uart, struct sci_port, port);
 157}
 158
 159struct plat_sci_reg {
 160	u8 offset, size;
 161};
 162
 163/* Helper for invalidating specific entries of an inherited map. */
 164#define sci_reg_invalid	{ .offset = 0, .size = 0 }
 165
 166static const struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
 167	[SCIx_PROBE_REGTYPE] = {
 168		[0 ... SCIx_NR_REGS - 1] = sci_reg_invalid,
 169	},
 170
 171	/*
 172	 * Common SCI definitions, dependent on the port's regshift
 173	 * value.
 174	 */
 175	[SCIx_SCI_REGTYPE] = {
 176		[SCSMR]		= { 0x00,  8 },
 177		[SCBRR]		= { 0x01,  8 },
 178		[SCSCR]		= { 0x02,  8 },
 179		[SCxTDR]	= { 0x03,  8 },
 180		[SCxSR]		= { 0x04,  8 },
 181		[SCxRDR]	= { 0x05,  8 },
 182		[SCFCR]		= sci_reg_invalid,
 183		[SCFDR]		= sci_reg_invalid,
 184		[SCTFDR]	= sci_reg_invalid,
 185		[SCRFDR]	= sci_reg_invalid,
 186		[SCSPTR]	= sci_reg_invalid,
 187		[SCLSR]		= sci_reg_invalid,
 188		[HSSRR]		= sci_reg_invalid,
 189		[SCPCR]		= sci_reg_invalid,
 190		[SCPDR]		= sci_reg_invalid,
 191		[SCDL]		= sci_reg_invalid,
 192		[SCCKS]		= sci_reg_invalid,
 193	},
 194
 195	/*
 196	 * Common definitions for legacy IrDA ports, dependent on
 197	 * regshift value.
 198	 */
 199	[SCIx_IRDA_REGTYPE] = {
 200		[SCSMR]		= { 0x00,  8 },
 201		[SCBRR]		= { 0x01,  8 },
 202		[SCSCR]		= { 0x02,  8 },
 203		[SCxTDR]	= { 0x03,  8 },
 204		[SCxSR]		= { 0x04,  8 },
 205		[SCxRDR]	= { 0x05,  8 },
 206		[SCFCR]		= { 0x06,  8 },
 207		[SCFDR]		= { 0x07, 16 },
 208		[SCTFDR]	= sci_reg_invalid,
 209		[SCRFDR]	= sci_reg_invalid,
 210		[SCSPTR]	= sci_reg_invalid,
 211		[SCLSR]		= sci_reg_invalid,
 212		[HSSRR]		= sci_reg_invalid,
 213		[SCPCR]		= sci_reg_invalid,
 214		[SCPDR]		= sci_reg_invalid,
 215		[SCDL]		= sci_reg_invalid,
 216		[SCCKS]		= sci_reg_invalid,
 217	},
 218
 219	/*
 220	 * Common SCIFA definitions.
 221	 */
 222	[SCIx_SCIFA_REGTYPE] = {
 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		[SCTFDR]	= sci_reg_invalid,
 232		[SCRFDR]	= sci_reg_invalid,
 233		[SCSPTR]	= sci_reg_invalid,
 234		[SCLSR]		= sci_reg_invalid,
 235		[HSSRR]		= sci_reg_invalid,
 236		[SCPCR]		= { 0x30, 16 },
 237		[SCPDR]		= { 0x34, 16 },
 238		[SCDL]		= sci_reg_invalid,
 239		[SCCKS]		= sci_reg_invalid,
 240	},
 241
 242	/*
 243	 * Common SCIFB definitions.
 244	 */
 245	[SCIx_SCIFB_REGTYPE] = {
 246		[SCSMR]		= { 0x00, 16 },
 247		[SCBRR]		= { 0x04,  8 },
 248		[SCSCR]		= { 0x08, 16 },
 249		[SCxTDR]	= { 0x40,  8 },
 250		[SCxSR]		= { 0x14, 16 },
 251		[SCxRDR]	= { 0x60,  8 },
 252		[SCFCR]		= { 0x18, 16 },
 253		[SCFDR]		= sci_reg_invalid,
 254		[SCTFDR]	= { 0x38, 16 },
 255		[SCRFDR]	= { 0x3c, 16 },
 256		[SCSPTR]	= sci_reg_invalid,
 257		[SCLSR]		= sci_reg_invalid,
 258		[HSSRR]		= sci_reg_invalid,
 259		[SCPCR]		= { 0x30, 16 },
 260		[SCPDR]		= { 0x34, 16 },
 261		[SCDL]		= sci_reg_invalid,
 262		[SCCKS]		= sci_reg_invalid,
 263	},
 264
 265	/*
 266	 * Common SH-2(A) SCIF definitions for ports with FIFO data
 267	 * count registers.
 268	 */
 269	[SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
 270		[SCSMR]		= { 0x00, 16 },
 271		[SCBRR]		= { 0x04,  8 },
 272		[SCSCR]		= { 0x08, 16 },
 273		[SCxTDR]	= { 0x0c,  8 },
 274		[SCxSR]		= { 0x10, 16 },
 275		[SCxRDR]	= { 0x14,  8 },
 276		[SCFCR]		= { 0x18, 16 },
 277		[SCFDR]		= { 0x1c, 16 },
 278		[SCTFDR]	= sci_reg_invalid,
 279		[SCRFDR]	= sci_reg_invalid,
 280		[SCSPTR]	= { 0x20, 16 },
 281		[SCLSR]		= { 0x24, 16 },
 282		[HSSRR]		= sci_reg_invalid,
 283		[SCPCR]		= sci_reg_invalid,
 284		[SCPDR]		= sci_reg_invalid,
 285		[SCDL]		= sci_reg_invalid,
 286		[SCCKS]		= sci_reg_invalid,
 287	},
 288
 289	/*
 290	 * Common SH-3 SCIF definitions.
 291	 */
 292	[SCIx_SH3_SCIF_REGTYPE] = {
 293		[SCSMR]		= { 0x00,  8 },
 294		[SCBRR]		= { 0x02,  8 },
 295		[SCSCR]		= { 0x04,  8 },
 296		[SCxTDR]	= { 0x06,  8 },
 297		[SCxSR]		= { 0x08, 16 },
 298		[SCxRDR]	= { 0x0a,  8 },
 299		[SCFCR]		= { 0x0c,  8 },
 300		[SCFDR]		= { 0x0e, 16 },
 301		[SCTFDR]	= sci_reg_invalid,
 302		[SCRFDR]	= sci_reg_invalid,
 303		[SCSPTR]	= sci_reg_invalid,
 304		[SCLSR]		= sci_reg_invalid,
 305		[HSSRR]		= sci_reg_invalid,
 306		[SCPCR]		= sci_reg_invalid,
 307		[SCPDR]		= sci_reg_invalid,
 308		[SCDL]		= sci_reg_invalid,
 309		[SCCKS]		= sci_reg_invalid,
 310	},
 311
 312	/*
 313	 * Common SH-4(A) SCIF(B) definitions.
 314	 */
 315	[SCIx_SH4_SCIF_REGTYPE] = {
 316		[SCSMR]		= { 0x00, 16 },
 317		[SCBRR]		= { 0x04,  8 },
 318		[SCSCR]		= { 0x08, 16 },
 319		[SCxTDR]	= { 0x0c,  8 },
 320		[SCxSR]		= { 0x10, 16 },
 321		[SCxRDR]	= { 0x14,  8 },
 322		[SCFCR]		= { 0x18, 16 },
 323		[SCFDR]		= { 0x1c, 16 },
 324		[SCTFDR]	= sci_reg_invalid,
 325		[SCRFDR]	= sci_reg_invalid,
 326		[SCSPTR]	= { 0x20, 16 },
 327		[SCLSR]		= { 0x24, 16 },
 328		[HSSRR]		= sci_reg_invalid,
 329		[SCPCR]		= sci_reg_invalid,
 330		[SCPDR]		= sci_reg_invalid,
 331		[SCDL]		= sci_reg_invalid,
 332		[SCCKS]		= sci_reg_invalid,
 333	},
 334
 335	/*
 336	 * Common SCIF definitions for ports with a Baud Rate Generator for
 337	 * External Clock (BRG).
 338	 */
 339	[SCIx_SH4_SCIF_BRG_REGTYPE] = {
 340		[SCSMR]		= { 0x00, 16 },
 341		[SCBRR]		= { 0x04,  8 },
 342		[SCSCR]		= { 0x08, 16 },
 343		[SCxTDR]	= { 0x0c,  8 },
 344		[SCxSR]		= { 0x10, 16 },
 345		[SCxRDR]	= { 0x14,  8 },
 346		[SCFCR]		= { 0x18, 16 },
 347		[SCFDR]		= { 0x1c, 16 },
 348		[SCTFDR]	= sci_reg_invalid,
 349		[SCRFDR]	= sci_reg_invalid,
 350		[SCSPTR]	= { 0x20, 16 },
 351		[SCLSR]		= { 0x24, 16 },
 352		[HSSRR]		= sci_reg_invalid,
 353		[SCPCR]		= sci_reg_invalid,
 354		[SCPDR]		= sci_reg_invalid,
 355		[SCDL]		= { 0x30, 16 },
 356		[SCCKS]		= { 0x34, 16 },
 357	},
 358
 359	/*
 360	 * Common HSCIF definitions.
 361	 */
 362	[SCIx_HSCIF_REGTYPE] = {
 363		[SCSMR]		= { 0x00, 16 },
 364		[SCBRR]		= { 0x04,  8 },
 365		[SCSCR]		= { 0x08, 16 },
 366		[SCxTDR]	= { 0x0c,  8 },
 367		[SCxSR]		= { 0x10, 16 },
 368		[SCxRDR]	= { 0x14,  8 },
 369		[SCFCR]		= { 0x18, 16 },
 370		[SCFDR]		= { 0x1c, 16 },
 371		[SCTFDR]	= sci_reg_invalid,
 372		[SCRFDR]	= sci_reg_invalid,
 373		[SCSPTR]	= { 0x20, 16 },
 374		[SCLSR]		= { 0x24, 16 },
 375		[HSSRR]		= { 0x40, 16 },
 376		[SCPCR]		= sci_reg_invalid,
 377		[SCPDR]		= sci_reg_invalid,
 378		[SCDL]		= { 0x30, 16 },
 379		[SCCKS]		= { 0x34, 16 },
 380	},
 381
 382	/*
 383	 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 384	 * register.
 385	 */
 386	[SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 387		[SCSMR]		= { 0x00, 16 },
 388		[SCBRR]		= { 0x04,  8 },
 389		[SCSCR]		= { 0x08, 16 },
 390		[SCxTDR]	= { 0x0c,  8 },
 391		[SCxSR]		= { 0x10, 16 },
 392		[SCxRDR]	= { 0x14,  8 },
 393		[SCFCR]		= { 0x18, 16 },
 394		[SCFDR]		= { 0x1c, 16 },
 395		[SCTFDR]	= sci_reg_invalid,
 396		[SCRFDR]	= sci_reg_invalid,
 397		[SCSPTR]	= sci_reg_invalid,
 398		[SCLSR]		= { 0x24, 16 },
 399		[HSSRR]		= sci_reg_invalid,
 400		[SCPCR]		= sci_reg_invalid,
 401		[SCPDR]		= sci_reg_invalid,
 402		[SCDL]		= sci_reg_invalid,
 403		[SCCKS]		= sci_reg_invalid,
 404	},
 405
 406	/*
 407	 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 408	 * count registers.
 409	 */
 410	[SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 411		[SCSMR]		= { 0x00, 16 },
 412		[SCBRR]		= { 0x04,  8 },
 413		[SCSCR]		= { 0x08, 16 },
 414		[SCxTDR]	= { 0x0c,  8 },
 415		[SCxSR]		= { 0x10, 16 },
 416		[SCxRDR]	= { 0x14,  8 },
 417		[SCFCR]		= { 0x18, 16 },
 418		[SCFDR]		= { 0x1c, 16 },
 419		[SCTFDR]	= { 0x1c, 16 },	/* aliased to SCFDR */
 420		[SCRFDR]	= { 0x20, 16 },
 421		[SCSPTR]	= { 0x24, 16 },
 422		[SCLSR]		= { 0x28, 16 },
 423		[HSSRR]		= sci_reg_invalid,
 424		[SCPCR]		= sci_reg_invalid,
 425		[SCPDR]		= sci_reg_invalid,
 426		[SCDL]		= sci_reg_invalid,
 427		[SCCKS]		= sci_reg_invalid,
 428	},
 429
 430	/*
 431	 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 432	 * registers.
 433	 */
 434	[SCIx_SH7705_SCIF_REGTYPE] = {
 435		[SCSMR]		= { 0x00, 16 },
 436		[SCBRR]		= { 0x04,  8 },
 437		[SCSCR]		= { 0x08, 16 },
 438		[SCxTDR]	= { 0x20,  8 },
 439		[SCxSR]		= { 0x14, 16 },
 440		[SCxRDR]	= { 0x24,  8 },
 441		[SCFCR]		= { 0x18, 16 },
 442		[SCFDR]		= { 0x1c, 16 },
 443		[SCTFDR]	= sci_reg_invalid,
 444		[SCRFDR]	= sci_reg_invalid,
 445		[SCSPTR]	= sci_reg_invalid,
 446		[SCLSR]		= sci_reg_invalid,
 447		[HSSRR]		= sci_reg_invalid,
 448		[SCPCR]		= sci_reg_invalid,
 449		[SCPDR]		= sci_reg_invalid,
 450		[SCDL]		= sci_reg_invalid,
 451		[SCCKS]		= sci_reg_invalid,
 452	},
 453};
 454
 455#define sci_getreg(up, offset)		(sci_regmap[to_sci_port(up)->cfg->regtype] + offset)
 456
 457/*
 458 * The "offset" here is rather misleading, in that it refers to an enum
 459 * value relative to the port mapping rather than the fixed offset
 460 * itself, which needs to be manually retrieved from the platform's
 461 * register map for the given port.
 462 */
 463static unsigned int sci_serial_in(struct uart_port *p, int offset)
 464{
 465	const struct plat_sci_reg *reg = sci_getreg(p, offset);
 466
 467	if (reg->size == 8)
 468		return ioread8(p->membase + (reg->offset << p->regshift));
 469	else if (reg->size == 16)
 470		return ioread16(p->membase + (reg->offset << p->regshift));
 471	else
 472		WARN(1, "Invalid register access\n");
 473
 474	return 0;
 475}
 476
 477static void sci_serial_out(struct uart_port *p, int offset, int value)
 478{
 479	const struct plat_sci_reg *reg = sci_getreg(p, offset);
 480
 481	if (reg->size == 8)
 482		iowrite8(value, p->membase + (reg->offset << p->regshift));
 483	else if (reg->size == 16)
 484		iowrite16(value, p->membase + (reg->offset << p->regshift));
 485	else
 486		WARN(1, "Invalid register access\n");
 487}
 488
 
 
 
 489static int sci_probe_regmap(struct plat_sci_port *cfg)
 490{
 491	switch (cfg->type) {
 492	case PORT_SCI:
 493		cfg->regtype = SCIx_SCI_REGTYPE;
 494		break;
 495	case PORT_IRDA:
 496		cfg->regtype = SCIx_IRDA_REGTYPE;
 497		break;
 498	case PORT_SCIFA:
 499		cfg->regtype = SCIx_SCIFA_REGTYPE;
 500		break;
 501	case PORT_SCIFB:
 502		cfg->regtype = SCIx_SCIFB_REGTYPE;
 503		break;
 504	case PORT_SCIF:
 505		/*
 506		 * The SH-4 is a bit of a misnomer here, although that's
 507		 * where this particular port layout originated. This
 508		 * configuration (or some slight variation thereof)
 509		 * remains the dominant model for all SCIFs.
 510		 */
 511		cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
 512		break;
 513	case PORT_HSCIF:
 514		cfg->regtype = SCIx_HSCIF_REGTYPE;
 515		break;
 516	default:
 517		pr_err("Can't probe register map for given port\n");
 518		return -EINVAL;
 519	}
 520
 521	return 0;
 522}
 523
 524static void sci_port_enable(struct sci_port *sci_port)
 525{
 526	unsigned int i;
 527
 528	if (!sci_port->port.dev)
 529		return;
 530
 531	pm_runtime_get_sync(sci_port->port.dev);
 532
 533	for (i = 0; i < SCI_NUM_CLKS; i++) {
 534		clk_prepare_enable(sci_port->clks[i]);
 535		sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
 536	}
 537	sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
 538}
 539
 540static void sci_port_disable(struct sci_port *sci_port)
 541{
 542	unsigned int i;
 543
 544	if (!sci_port->port.dev)
 545		return;
 546
 547	/* Cancel the break timer to ensure that the timer handler will not try
 548	 * to access the hardware with clocks and power disabled. Reset the
 549	 * break flag to make the break debouncing state machine ready for the
 550	 * next break.
 551	 */
 552	del_timer_sync(&sci_port->break_timer);
 553	sci_port->break_flag = 0;
 554
 555	for (i = SCI_NUM_CLKS; i-- > 0; )
 556		clk_disable_unprepare(sci_port->clks[i]);
 557
 558	pm_runtime_put_sync(sci_port->port.dev);
 559}
 560
 561static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 562{
 563	/*
 564	 * Not all ports (such as SCIFA) will support REIE. Rather than
 565	 * special-casing the port type, we check the port initialization
 566	 * IRQ enable mask to see whether the IRQ is desired at all. If
 567	 * it's unset, it's logically inferred that there's no point in
 568	 * testing for it.
 569	 */
 570	return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 571}
 572
 573static void sci_start_tx(struct uart_port *port)
 574{
 575	struct sci_port *s = to_sci_port(port);
 576	unsigned short ctrl;
 577
 578#ifdef CONFIG_SERIAL_SH_SCI_DMA
 579	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 580		u16 new, scr = serial_port_in(port, SCSCR);
 581		if (s->chan_tx)
 582			new = scr | SCSCR_TDRQE;
 583		else
 584			new = scr & ~SCSCR_TDRQE;
 585		if (new != scr)
 586			serial_port_out(port, SCSCR, new);
 587	}
 588
 589	if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
 590	    dma_submit_error(s->cookie_tx)) {
 591		s->cookie_tx = 0;
 592		schedule_work(&s->work_tx);
 593	}
 594#endif
 595
 596	if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 597		/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
 598		ctrl = serial_port_in(port, SCSCR);
 599		serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
 600	}
 601}
 602
 603static void sci_stop_tx(struct uart_port *port)
 604{
 605	unsigned short ctrl;
 606
 607	/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
 608	ctrl = serial_port_in(port, SCSCR);
 609
 610	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 611		ctrl &= ~SCSCR_TDRQE;
 612
 613	ctrl &= ~SCSCR_TIE;
 614
 615	serial_port_out(port, SCSCR, ctrl);
 616}
 617
 618static void sci_start_rx(struct uart_port *port)
 619{
 620	unsigned short ctrl;
 621
 622	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 623
 624	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 625		ctrl &= ~SCSCR_RDRQE;
 626
 627	serial_port_out(port, SCSCR, ctrl);
 628}
 629
 630static void sci_stop_rx(struct uart_port *port)
 631{
 632	unsigned short ctrl;
 633
 634	ctrl = serial_port_in(port, SCSCR);
 635
 636	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 637		ctrl &= ~SCSCR_RDRQE;
 638
 639	ctrl &= ~port_rx_irq_mask(port);
 640
 641	serial_port_out(port, SCSCR, ctrl);
 642}
 643
 644static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
 645{
 646	if (port->type == PORT_SCI) {
 647		/* Just store the mask */
 648		serial_port_out(port, SCxSR, mask);
 649	} else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) {
 650		/* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
 651		/* Only clear the status bits we want to clear */
 652		serial_port_out(port, SCxSR,
 653				serial_port_in(port, SCxSR) & mask);
 654	} else {
 655		/* Store the mask, clear parity/framing errors */
 656		serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
 657	}
 658}
 659
 660#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
 661    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
 662
 663#ifdef CONFIG_CONSOLE_POLL
 664static int sci_poll_get_char(struct uart_port *port)
 665{
 666	unsigned short status;
 667	int c;
 668
 669	do {
 670		status = serial_port_in(port, SCxSR);
 671		if (status & SCxSR_ERRORS(port)) {
 672			sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 673			continue;
 674		}
 675		break;
 676	} while (1);
 677
 678	if (!(status & SCxSR_RDxF(port)))
 679		return NO_POLL_CHAR;
 680
 681	c = serial_port_in(port, SCxRDR);
 682
 683	/* Dummy read */
 684	serial_port_in(port, SCxSR);
 685	sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 686
 687	return c;
 688}
 689#endif
 690
 691static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 692{
 693	unsigned short status;
 694
 695	do {
 696		status = serial_port_in(port, SCxSR);
 697	} while (!(status & SCxSR_TDxE(port)));
 698
 699	serial_port_out(port, SCxTDR, c);
 700	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 701}
 702#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
 703	  CONFIG_SERIAL_SH_SCI_EARLYCON */
 704
 705static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 706{
 707	struct sci_port *s = to_sci_port(port);
 
 708
 709	/*
 710	 * Use port-specific handler if provided.
 711	 */
 712	if (s->cfg->ops && s->cfg->ops->init_pins) {
 713		s->cfg->ops->init_pins(port, cflag);
 714		return;
 715	}
 716
 717	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 718		u16 ctrl = serial_port_in(port, SCPCR);
 
 
 
 
 719
 720		/* Enable RXD and TXD pin functions */
 721		ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
 722		if (to_sci_port(port)->cfg->capabilities & SCIx_HAVE_RTSCTS) {
 723			/* RTS# is output, driven 1 */
 724			ctrl |= SCPCR_RTSC;
 725			serial_port_out(port, SCPDR,
 726				serial_port_in(port, SCPDR) | SCPDR_RTSD);
 727			/* Enable CTS# pin function */
 728			ctrl &= ~SCPCR_CTSC;
 729		}
 730		serial_port_out(port, SCPCR, ctrl);
 731	} else if (sci_getreg(port, SCSPTR)->size) {
 732		u16 status = serial_port_in(port, SCSPTR);
 733
 734		/* RTS# is output, driven 1 */
 735		status |= SCSPTR_RTSIO | SCSPTR_RTSDT;
 736		/* CTS# and SCK are inputs */
 737		status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
 738		serial_port_out(port, SCSPTR, status);
 739	}
 740}
 741
 742static int sci_txfill(struct uart_port *port)
 743{
 744	const struct plat_sci_reg *reg;
 745
 746	reg = sci_getreg(port, SCTFDR);
 747	if (reg->size)
 748		return serial_port_in(port, SCTFDR) & ((port->fifosize << 1) - 1);
 749
 750	reg = sci_getreg(port, SCFDR);
 751	if (reg->size)
 752		return serial_port_in(port, SCFDR) >> 8;
 753
 754	return !(serial_port_in(port, SCxSR) & SCI_TDRE);
 755}
 756
 757static int sci_txroom(struct uart_port *port)
 758{
 759	return port->fifosize - sci_txfill(port);
 760}
 761
 762static int sci_rxfill(struct uart_port *port)
 763{
 764	const struct plat_sci_reg *reg;
 765
 766	reg = sci_getreg(port, SCRFDR);
 767	if (reg->size)
 768		return serial_port_in(port, SCRFDR) & ((port->fifosize << 1) - 1);
 769
 770	reg = sci_getreg(port, SCFDR);
 771	if (reg->size)
 772		return serial_port_in(port, SCFDR) & ((port->fifosize << 1) - 1);
 773
 774	return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 775}
 776
 777/*
 778 * SCI helper for checking the state of the muxed port/RXD pins.
 779 */
 780static inline int sci_rxd_in(struct uart_port *port)
 781{
 782	struct sci_port *s = to_sci_port(port);
 783
 784	if (s->cfg->port_reg <= 0)
 785		return 1;
 786
 787	/* Cast for ARM damage */
 788	return !!__raw_readb((void __iomem *)(uintptr_t)s->cfg->port_reg);
 789}
 790
 791/* ********************************************************************** *
 792 *                   the interrupt related routines                       *
 793 * ********************************************************************** */
 794
 795static void sci_transmit_chars(struct uart_port *port)
 796{
 797	struct circ_buf *xmit = &port->state->xmit;
 798	unsigned int stopped = uart_tx_stopped(port);
 799	unsigned short status;
 800	unsigned short ctrl;
 801	int count;
 802
 803	status = serial_port_in(port, SCxSR);
 804	if (!(status & SCxSR_TDxE(port))) {
 805		ctrl = serial_port_in(port, SCSCR);
 806		if (uart_circ_empty(xmit))
 807			ctrl &= ~SCSCR_TIE;
 808		else
 809			ctrl |= SCSCR_TIE;
 810		serial_port_out(port, SCSCR, ctrl);
 811		return;
 812	}
 813
 814	count = sci_txroom(port);
 815
 816	do {
 817		unsigned char c;
 818
 819		if (port->x_char) {
 820			c = port->x_char;
 821			port->x_char = 0;
 822		} else if (!uart_circ_empty(xmit) && !stopped) {
 823			c = xmit->buf[xmit->tail];
 824			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 825		} else {
 826			break;
 827		}
 828
 829		serial_port_out(port, SCxTDR, c);
 830
 831		port->icount.tx++;
 832	} while (--count > 0);
 833
 834	sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 835
 836	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 837		uart_write_wakeup(port);
 838	if (uart_circ_empty(xmit)) {
 839		sci_stop_tx(port);
 840	} else {
 841		ctrl = serial_port_in(port, SCSCR);
 842
 843		if (port->type != PORT_SCI) {
 844			serial_port_in(port, SCxSR); /* Dummy read */
 845			sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 846		}
 847
 848		ctrl |= SCSCR_TIE;
 849		serial_port_out(port, SCSCR, ctrl);
 850	}
 851}
 852
 853/* On SH3, SCIF may read end-of-break as a space->mark char */
 854#define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
 855
 856static void sci_receive_chars(struct uart_port *port)
 857{
 858	struct sci_port *sci_port = to_sci_port(port);
 859	struct tty_port *tport = &port->state->port;
 860	int i, count, copied = 0;
 861	unsigned short status;
 862	unsigned char flag;
 863
 864	status = serial_port_in(port, SCxSR);
 865	if (!(status & SCxSR_RDxF(port)))
 866		return;
 867
 868	while (1) {
 869		/* Don't copy more bytes than there is room for in the buffer */
 870		count = tty_buffer_request_room(tport, sci_rxfill(port));
 871
 872		/* If for any reason we can't copy more data, we're done! */
 873		if (count == 0)
 874			break;
 875
 876		if (port->type == PORT_SCI) {
 877			char c = serial_port_in(port, SCxRDR);
 878			if (uart_handle_sysrq_char(port, c) ||
 879			    sci_port->break_flag)
 880				count = 0;
 881			else
 882				tty_insert_flip_char(tport, c, TTY_NORMAL);
 883		} else {
 884			for (i = 0; i < count; i++) {
 885				char c = serial_port_in(port, SCxRDR);
 886
 887				status = serial_port_in(port, SCxSR);
 888#if defined(CONFIG_CPU_SH3)
 889				/* Skip "chars" during break */
 890				if (sci_port->break_flag) {
 891					if ((c == 0) &&
 892					    (status & SCxSR_FER(port))) {
 893						count--; i--;
 894						continue;
 895					}
 896
 897					/* Nonzero => end-of-break */
 898					dev_dbg(port->dev, "debounce<%02x>\n", c);
 899					sci_port->break_flag = 0;
 900
 901					if (STEPFN(c)) {
 902						count--; i--;
 903						continue;
 904					}
 905				}
 906#endif /* CONFIG_CPU_SH3 */
 907				if (uart_handle_sysrq_char(port, c)) {
 908					count--; i--;
 909					continue;
 910				}
 911
 912				/* Store data and status */
 913				if (status & SCxSR_FER(port)) {
 914					flag = TTY_FRAME;
 915					port->icount.frame++;
 916					dev_notice(port->dev, "frame error\n");
 917				} else if (status & SCxSR_PER(port)) {
 918					flag = TTY_PARITY;
 919					port->icount.parity++;
 920					dev_notice(port->dev, "parity error\n");
 921				} else
 922					flag = TTY_NORMAL;
 923
 924				tty_insert_flip_char(tport, c, flag);
 925			}
 926		}
 927
 928		serial_port_in(port, SCxSR); /* dummy read */
 929		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 930
 931		copied += count;
 932		port->icount.rx += count;
 933	}
 934
 935	if (copied) {
 936		/* Tell the rest of the system the news. New characters! */
 937		tty_flip_buffer_push(tport);
 938	} else {
 939		serial_port_in(port, SCxSR); /* dummy read */
 940		sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 941	}
 942}
 943
 944#define SCI_BREAK_JIFFIES (HZ/20)
 945
 946/*
 947 * The sci generates interrupts during the break,
 948 * 1 per millisecond or so during the break period, for 9600 baud.
 949 * So dont bother disabling interrupts.
 950 * But dont want more than 1 break event.
 951 * Use a kernel timer to periodically poll the rx line until
 952 * the break is finished.
 953 */
 954static inline void sci_schedule_break_timer(struct sci_port *port)
 955{
 956	mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES);
 957}
 958
 959/* Ensure that two consecutive samples find the break over. */
 960static void sci_break_timer(unsigned long data)
 961{
 962	struct sci_port *port = (struct sci_port *)data;
 963
 
 
 964	if (sci_rxd_in(&port->port) == 0) {
 965		port->break_flag = 1;
 966		sci_schedule_break_timer(port);
 967	} else if (port->break_flag == 1) {
 968		/* break is over. */
 969		port->break_flag = 2;
 970		sci_schedule_break_timer(port);
 971	} else
 972		port->break_flag = 0;
 
 
 973}
 974
 975static int sci_handle_errors(struct uart_port *port)
 976{
 977	int copied = 0;
 978	unsigned short status = serial_port_in(port, SCxSR);
 979	struct tty_port *tport = &port->state->port;
 980	struct sci_port *s = to_sci_port(port);
 981
 982	/* Handle overruns */
 983	if (status & s->overrun_mask) {
 984		port->icount.overrun++;
 
 
 
 
 
 985
 986		/* overrun error */
 987		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 988			copied++;
 989
 990		dev_notice(port->dev, "overrun error\n");
 991	}
 992
 993	if (status & SCxSR_FER(port)) {
 994		if (sci_rxd_in(port) == 0) {
 995			/* Notify of BREAK */
 996			struct sci_port *sci_port = to_sci_port(port);
 997
 998			if (!sci_port->break_flag) {
 999				port->icount.brk++;
1000
1001				sci_port->break_flag = 1;
1002				sci_schedule_break_timer(sci_port);
1003
1004				/* Do sysrq handling. */
1005				if (uart_handle_break(port))
1006					return 0;
1007
1008				dev_dbg(port->dev, "BREAK detected\n");
1009
1010				if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1011					copied++;
1012			}
1013
1014		} else {
1015			/* frame error */
1016			port->icount.frame++;
1017
1018			if (tty_insert_flip_char(tport, 0, TTY_FRAME))
1019				copied++;
1020
1021			dev_notice(port->dev, "frame error\n");
1022		}
1023	}
1024
1025	if (status & SCxSR_PER(port)) {
1026		/* parity error */
1027		port->icount.parity++;
1028
1029		if (tty_insert_flip_char(tport, 0, TTY_PARITY))
1030			copied++;
1031
1032		dev_notice(port->dev, "parity error\n");
1033	}
1034
1035	if (copied)
1036		tty_flip_buffer_push(tport);
1037
1038	return copied;
1039}
1040
1041static int sci_handle_fifo_overrun(struct uart_port *port)
1042{
1043	struct tty_port *tport = &port->state->port;
1044	struct sci_port *s = to_sci_port(port);
1045	const struct plat_sci_reg *reg;
1046	int copied = 0;
1047	u16 status;
1048
1049	reg = sci_getreg(port, s->overrun_reg);
1050	if (!reg->size)
1051		return 0;
1052
1053	status = serial_port_in(port, s->overrun_reg);
1054	if (status & s->overrun_mask) {
1055		status &= ~s->overrun_mask;
1056		serial_port_out(port, s->overrun_reg, status);
1057
1058		port->icount.overrun++;
 
1059
1060		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
1061		tty_flip_buffer_push(tport);
1062
1063		dev_dbg(port->dev, "overrun error\n");
1064		copied++;
1065	}
1066
1067	return copied;
1068}
1069
1070static int sci_handle_breaks(struct uart_port *port)
1071{
1072	int copied = 0;
1073	unsigned short status = serial_port_in(port, SCxSR);
1074	struct tty_port *tport = &port->state->port;
1075	struct sci_port *s = to_sci_port(port);
1076
1077	if (uart_handle_break(port))
1078		return 0;
1079
1080	if (!s->break_flag && status & SCxSR_BRK(port)) {
1081#if defined(CONFIG_CPU_SH3)
1082		/* Debounce break */
1083		s->break_flag = 1;
1084#endif
1085
1086		port->icount.brk++;
1087
1088		/* Notify of BREAK */
1089		if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1090			copied++;
1091
1092		dev_dbg(port->dev, "BREAK detected\n");
1093	}
1094
1095	if (copied)
1096		tty_flip_buffer_push(tport);
1097
1098	copied += sci_handle_fifo_overrun(port);
1099
1100	return copied;
1101}
1102
1103#ifdef CONFIG_SERIAL_SH_SCI_DMA
1104static void sci_dma_tx_complete(void *arg)
1105{
1106	struct sci_port *s = arg;
1107	struct uart_port *port = &s->port;
1108	struct circ_buf *xmit = &port->state->xmit;
1109	unsigned long flags;
1110
1111	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1112
1113	spin_lock_irqsave(&port->lock, flags);
1114
1115	xmit->tail += s->tx_dma_len;
1116	xmit->tail &= UART_XMIT_SIZE - 1;
1117
1118	port->icount.tx += s->tx_dma_len;
1119
1120	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1121		uart_write_wakeup(port);
1122
1123	if (!uart_circ_empty(xmit)) {
1124		s->cookie_tx = 0;
1125		schedule_work(&s->work_tx);
1126	} else {
1127		s->cookie_tx = -EINVAL;
1128		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1129			u16 ctrl = serial_port_in(port, SCSCR);
1130			serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1131		}
1132	}
1133
1134	spin_unlock_irqrestore(&port->lock, flags);
1135}
1136
1137/* Locking: called with port lock held */
1138static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1139{
1140	struct uart_port *port = &s->port;
1141	struct tty_port *tport = &port->state->port;
1142	int copied;
1143
1144	copied = tty_insert_flip_string(tport, buf, count);
1145	if (copied < count)
1146		port->icount.buf_overrun++;
1147
1148	port->icount.rx += copied;
1149
1150	return copied;
1151}
1152
1153static int sci_dma_rx_find_active(struct sci_port *s)
1154{
1155	unsigned int i;
1156
1157	for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1158		if (s->active_rx == s->cookie_rx[i])
1159			return i;
1160
1161	return -1;
1162}
1163
1164static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
1165{
1166	struct dma_chan *chan = s->chan_rx;
1167	struct uart_port *port = &s->port;
1168	unsigned long flags;
1169
1170	spin_lock_irqsave(&port->lock, flags);
1171	s->chan_rx = NULL;
1172	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
1173	spin_unlock_irqrestore(&port->lock, flags);
1174	dmaengine_terminate_all(chan);
1175	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1176			  sg_dma_address(&s->sg_rx[0]));
1177	dma_release_channel(chan);
1178	if (enable_pio)
1179		sci_start_rx(port);
1180}
1181
1182static void sci_dma_rx_complete(void *arg)
1183{
1184	struct sci_port *s = arg;
1185	struct dma_chan *chan = s->chan_rx;
1186	struct uart_port *port = &s->port;
1187	struct dma_async_tx_descriptor *desc;
1188	unsigned long flags;
1189	int active, count = 0;
1190
1191	dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1192		s->active_rx);
1193
1194	spin_lock_irqsave(&port->lock, flags);
1195
1196	active = sci_dma_rx_find_active(s);
1197	if (active >= 0)
1198		count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1199
1200	mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1201
1202	if (count)
1203		tty_flip_buffer_push(&port->state->port);
1204
1205	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1206				       DMA_DEV_TO_MEM,
1207				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1208	if (!desc)
1209		goto fail;
1210
1211	desc->callback = sci_dma_rx_complete;
1212	desc->callback_param = s;
1213	s->cookie_rx[active] = dmaengine_submit(desc);
1214	if (dma_submit_error(s->cookie_rx[active]))
1215		goto fail;
1216
1217	s->active_rx = s->cookie_rx[!active];
1218
1219	dma_async_issue_pending(chan);
1220
1221	spin_unlock_irqrestore(&port->lock, flags);
1222	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1223		__func__, s->cookie_rx[active], active, s->active_rx);
1224	return;
1225
1226fail:
1227	spin_unlock_irqrestore(&port->lock, flags);
1228	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1229	sci_rx_dma_release(s, true);
1230}
1231
1232static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)
1233{
1234	struct dma_chan *chan = s->chan_tx;
1235	struct uart_port *port = &s->port;
1236	unsigned long flags;
1237
1238	spin_lock_irqsave(&port->lock, flags);
1239	s->chan_tx = NULL;
1240	s->cookie_tx = -EINVAL;
1241	spin_unlock_irqrestore(&port->lock, flags);
1242	dmaengine_terminate_all(chan);
1243	dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1244			 DMA_TO_DEVICE);
1245	dma_release_channel(chan);
1246	if (enable_pio)
1247		sci_start_tx(port);
1248}
1249
1250static void sci_submit_rx(struct sci_port *s)
1251{
1252	struct dma_chan *chan = s->chan_rx;
1253	int i;
1254
1255	for (i = 0; i < 2; i++) {
1256		struct scatterlist *sg = &s->sg_rx[i];
1257		struct dma_async_tx_descriptor *desc;
1258
1259		desc = dmaengine_prep_slave_sg(chan,
1260			sg, 1, DMA_DEV_TO_MEM,
1261			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1262		if (!desc)
1263			goto fail;
1264
1265		desc->callback = sci_dma_rx_complete;
1266		desc->callback_param = s;
1267		s->cookie_rx[i] = dmaengine_submit(desc);
1268		if (dma_submit_error(s->cookie_rx[i]))
1269			goto fail;
1270
1271	}
1272
1273	s->active_rx = s->cookie_rx[0];
1274
1275	dma_async_issue_pending(chan);
1276	return;
1277
1278fail:
1279	if (i)
1280		dmaengine_terminate_all(chan);
1281	for (i = 0; i < 2; i++)
1282		s->cookie_rx[i] = -EINVAL;
1283	s->active_rx = -EINVAL;
1284	sci_rx_dma_release(s, true);
1285}
1286
1287static void work_fn_tx(struct work_struct *work)
1288{
1289	struct sci_port *s = container_of(work, struct sci_port, work_tx);
1290	struct dma_async_tx_descriptor *desc;
1291	struct dma_chan *chan = s->chan_tx;
1292	struct uart_port *port = &s->port;
1293	struct circ_buf *xmit = &port->state->xmit;
1294	dma_addr_t buf;
1295
1296	/*
1297	 * DMA is idle now.
1298	 * Port xmit buffer is already mapped, and it is one page... Just adjust
1299	 * offsets and lengths. Since it is a circular buffer, we have to
1300	 * transmit till the end, and then the rest. Take the port lock to get a
1301	 * consistent xmit buffer state.
1302	 */
1303	spin_lock_irq(&port->lock);
1304	buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
1305	s->tx_dma_len = min_t(unsigned int,
1306		CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
1307		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
1308	spin_unlock_irq(&port->lock);
1309
1310	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1311					   DMA_MEM_TO_DEV,
1312					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1313	if (!desc) {
1314		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1315		/* switch to PIO */
1316		sci_tx_dma_release(s, true);
1317		return;
1318	}
1319
1320	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1321				   DMA_TO_DEVICE);
1322
1323	spin_lock_irq(&port->lock);
1324	desc->callback = sci_dma_tx_complete;
1325	desc->callback_param = s;
1326	spin_unlock_irq(&port->lock);
1327	s->cookie_tx = dmaengine_submit(desc);
1328	if (dma_submit_error(s->cookie_tx)) {
1329		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1330		/* switch to PIO */
1331		sci_tx_dma_release(s, true);
1332		return;
1333	}
1334
1335	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1336		__func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
1337
1338	dma_async_issue_pending(chan);
1339}
1340
1341static void rx_timer_fn(unsigned long arg)
1342{
1343	struct sci_port *s = (struct sci_port *)arg;
1344	struct dma_chan *chan = s->chan_rx;
1345	struct uart_port *port = &s->port;
1346	struct dma_tx_state state;
1347	enum dma_status status;
1348	unsigned long flags;
1349	unsigned int read;
1350	int active, count;
1351	u16 scr;
1352
1353	dev_dbg(port->dev, "DMA Rx timed out\n");
1354
1355	spin_lock_irqsave(&port->lock, flags);
1356
1357	active = sci_dma_rx_find_active(s);
1358	if (active < 0) {
1359		spin_unlock_irqrestore(&port->lock, flags);
1360		return;
1361	}
1362
1363	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1364	if (status == DMA_COMPLETE) {
1365		spin_unlock_irqrestore(&port->lock, flags);
1366		dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1367			s->active_rx, active);
1368
1369		/* Let packet complete handler take care of the packet */
1370		return;
1371	}
1372
1373	dmaengine_pause(chan);
1374
1375	/*
1376	 * sometimes DMA transfer doesn't stop even if it is stopped and
1377	 * data keeps on coming until transaction is complete so check
1378	 * for DMA_COMPLETE again
1379	 * Let packet complete handler take care of the packet
1380	 */
1381	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1382	if (status == DMA_COMPLETE) {
1383		spin_unlock_irqrestore(&port->lock, flags);
1384		dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1385		return;
1386	}
1387
1388	/* Handle incomplete DMA receive */
1389	dmaengine_terminate_all(s->chan_rx);
1390	read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1391
1392	if (read) {
1393		count = sci_dma_rx_push(s, s->rx_buf[active], read);
1394		if (count)
1395			tty_flip_buffer_push(&port->state->port);
1396	}
1397
1398	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1399		sci_submit_rx(s);
1400
1401	/* Direct new serial port interrupts back to CPU */
1402	scr = serial_port_in(port, SCSCR);
1403	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1404		scr &= ~SCSCR_RDRQE;
1405		enable_irq(s->irqs[SCIx_RXI_IRQ]);
1406	}
1407	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1408
1409	spin_unlock_irqrestore(&port->lock, flags);
1410}
1411
1412static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1413					     enum dma_transfer_direction dir,
1414					     unsigned int id)
1415{
1416	dma_cap_mask_t mask;
1417	struct dma_chan *chan;
1418	struct dma_slave_config cfg;
1419	int ret;
1420
1421	dma_cap_zero(mask);
1422	dma_cap_set(DMA_SLAVE, mask);
1423
1424	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1425					(void *)(unsigned long)id, port->dev,
1426					dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1427	if (!chan) {
1428		dev_warn(port->dev,
1429			 "dma_request_slave_channel_compat failed\n");
1430		return NULL;
1431	}
1432
1433	memset(&cfg, 0, sizeof(cfg));
1434	cfg.direction = dir;
1435	if (dir == DMA_MEM_TO_DEV) {
1436		cfg.dst_addr = port->mapbase +
1437			(sci_getreg(port, SCxTDR)->offset << port->regshift);
1438		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1439	} else {
1440		cfg.src_addr = port->mapbase +
1441			(sci_getreg(port, SCxRDR)->offset << port->regshift);
1442		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1443	}
1444
1445	ret = dmaengine_slave_config(chan, &cfg);
1446	if (ret) {
1447		dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1448		dma_release_channel(chan);
1449		return NULL;
1450	}
1451
1452	return chan;
1453}
1454
1455static void sci_request_dma(struct uart_port *port)
1456{
1457	struct sci_port *s = to_sci_port(port);
1458	struct dma_chan *chan;
1459
1460	dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1461
1462	if (!port->dev->of_node &&
1463	    (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0))
1464		return;
1465
1466	s->cookie_tx = -EINVAL;
1467	chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV, s->cfg->dma_slave_tx);
1468	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1469	if (chan) {
1470		s->chan_tx = chan;
1471		/* UART circular tx buffer is an aligned page. */
1472		s->tx_dma_addr = dma_map_single(chan->device->dev,
1473						port->state->xmit.buf,
1474						UART_XMIT_SIZE,
1475						DMA_TO_DEVICE);
1476		if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1477			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1478			dma_release_channel(chan);
1479			s->chan_tx = NULL;
1480		} else {
1481			dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1482				__func__, UART_XMIT_SIZE,
1483				port->state->xmit.buf, &s->tx_dma_addr);
1484		}
1485
1486		INIT_WORK(&s->work_tx, work_fn_tx);
1487	}
1488
1489	chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM, s->cfg->dma_slave_rx);
1490	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1491	if (chan) {
1492		unsigned int i;
1493		dma_addr_t dma;
1494		void *buf;
1495
1496		s->chan_rx = chan;
1497
1498		s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1499		buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1500					 &dma, GFP_KERNEL);
1501		if (!buf) {
1502			dev_warn(port->dev,
1503				 "Failed to allocate Rx dma buffer, using PIO\n");
1504			dma_release_channel(chan);
1505			s->chan_rx = NULL;
1506			return;
1507		}
1508
1509		for (i = 0; i < 2; i++) {
1510			struct scatterlist *sg = &s->sg_rx[i];
1511
1512			sg_init_table(sg, 1);
1513			s->rx_buf[i] = buf;
1514			sg_dma_address(sg) = dma;
1515			sg_dma_len(sg) = s->buf_len_rx;
1516
1517			buf += s->buf_len_rx;
1518			dma += s->buf_len_rx;
1519		}
1520
1521		setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);
1522
1523		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1524			sci_submit_rx(s);
1525	}
1526}
1527
1528static void sci_free_dma(struct uart_port *port)
1529{
1530	struct sci_port *s = to_sci_port(port);
1531
1532	if (s->chan_tx)
1533		sci_tx_dma_release(s, false);
1534	if (s->chan_rx)
1535		sci_rx_dma_release(s, false);
1536}
1537#else
1538static inline void sci_request_dma(struct uart_port *port)
1539{
1540}
1541
1542static inline void sci_free_dma(struct uart_port *port)
1543{
1544}
1545#endif
1546
1547static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1548{
1549#ifdef CONFIG_SERIAL_SH_SCI_DMA
1550	struct uart_port *port = ptr;
1551	struct sci_port *s = to_sci_port(port);
1552
1553	if (s->chan_rx) {
1554		u16 scr = serial_port_in(port, SCSCR);
1555		u16 ssr = serial_port_in(port, SCxSR);
1556
1557		/* Disable future Rx interrupts */
1558		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1559			disable_irq_nosync(irq);
1560			scr |= SCSCR_RDRQE;
1561		} else {
1562			scr &= ~SCSCR_RIE;
1563			sci_submit_rx(s);
1564		}
1565		serial_port_out(port, SCSCR, scr);
1566		/* Clear current interrupt */
1567		serial_port_out(port, SCxSR,
1568				ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1569		dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
1570			jiffies, s->rx_timeout);
1571		mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
1572
1573		return IRQ_HANDLED;
1574	}
1575#endif
1576
1577	/* I think sci_receive_chars has to be called irrespective
1578	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
1579	 * to be disabled?
1580	 */
1581	sci_receive_chars(ptr);
1582
1583	return IRQ_HANDLED;
1584}
1585
1586static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1587{
1588	struct uart_port *port = ptr;
1589	unsigned long flags;
1590
1591	spin_lock_irqsave(&port->lock, flags);
1592	sci_transmit_chars(port);
1593	spin_unlock_irqrestore(&port->lock, flags);
1594
1595	return IRQ_HANDLED;
1596}
1597
1598static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1599{
1600	struct uart_port *port = ptr;
1601	struct sci_port *s = to_sci_port(port);
1602
1603	/* Handle errors */
1604	if (port->type == PORT_SCI) {
1605		if (sci_handle_errors(port)) {
1606			/* discard character in rx buffer */
1607			serial_port_in(port, SCxSR);
1608			sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1609		}
1610	} else {
1611		sci_handle_fifo_overrun(port);
1612		if (!s->chan_rx)
1613			sci_receive_chars(ptr);
1614	}
1615
1616	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1617
1618	/* Kick the transmission */
1619	if (!s->chan_tx)
1620		sci_tx_interrupt(irq, ptr);
1621
1622	return IRQ_HANDLED;
1623}
1624
1625static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1626{
1627	struct uart_port *port = ptr;
1628
1629	/* Handle BREAKs */
1630	sci_handle_breaks(port);
1631	sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1632
1633	return IRQ_HANDLED;
1634}
1635
 
 
 
 
 
 
 
 
 
 
 
 
1636static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1637{
1638	unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1639	struct uart_port *port = ptr;
1640	struct sci_port *s = to_sci_port(port);
1641	irqreturn_t ret = IRQ_NONE;
1642
1643	ssr_status = serial_port_in(port, SCxSR);
1644	scr_status = serial_port_in(port, SCSCR);
1645	if (s->overrun_reg == SCxSR)
1646		orer_status = ssr_status;
1647	else {
1648		if (sci_getreg(port, s->overrun_reg)->size)
1649			orer_status = serial_port_in(port, s->overrun_reg);
1650	}
1651
1652	err_enabled = scr_status & port_rx_irq_mask(port);
1653
1654	/* Tx Interrupt */
1655	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1656	    !s->chan_tx)
1657		ret = sci_tx_interrupt(irq, ptr);
1658
1659	/*
1660	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1661	 * DR flags
1662	 */
1663	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1664	    (scr_status & SCSCR_RIE))
1665		ret = sci_rx_interrupt(irq, ptr);
1666
1667	/* Error Interrupt */
1668	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1669		ret = sci_er_interrupt(irq, ptr);
1670
1671	/* Break Interrupt */
1672	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1673		ret = sci_br_interrupt(irq, ptr);
1674
1675	/* Overrun Interrupt */
1676	if (orer_status & s->overrun_mask) {
1677		sci_handle_fifo_overrun(port);
1678		ret = IRQ_HANDLED;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1679	}
1680
1681	return ret;
1682}
1683
1684static const struct sci_irq_desc {
1685	const char	*desc;
1686	irq_handler_t	handler;
1687} sci_irq_desc[] = {
1688	/*
1689	 * Split out handlers, the default case.
1690	 */
1691	[SCIx_ERI_IRQ] = {
1692		.desc = "rx err",
1693		.handler = sci_er_interrupt,
1694	},
1695
1696	[SCIx_RXI_IRQ] = {
1697		.desc = "rx full",
1698		.handler = sci_rx_interrupt,
1699	},
1700
1701	[SCIx_TXI_IRQ] = {
1702		.desc = "tx empty",
1703		.handler = sci_tx_interrupt,
1704	},
1705
1706	[SCIx_BRI_IRQ] = {
1707		.desc = "break",
1708		.handler = sci_br_interrupt,
1709	},
1710
1711	/*
1712	 * Special muxed handler.
1713	 */
1714	[SCIx_MUX_IRQ] = {
1715		.desc = "mux",
1716		.handler = sci_mpxed_interrupt,
1717	},
1718};
1719
1720static int sci_request_irq(struct sci_port *port)
1721{
1722	struct uart_port *up = &port->port;
1723	int i, j, ret = 0;
1724
1725	for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1726		const struct sci_irq_desc *desc;
1727		int irq;
1728
1729		if (SCIx_IRQ_IS_MUXED(port)) {
1730			i = SCIx_MUX_IRQ;
1731			irq = up->irq;
1732		} else {
1733			irq = port->irqs[i];
1734
1735			/*
1736			 * Certain port types won't support all of the
1737			 * available interrupt sources.
1738			 */
1739			if (unlikely(irq < 0))
1740				continue;
1741		}
1742
1743		desc = sci_irq_desc + i;
1744		port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1745					    dev_name(up->dev), desc->desc);
1746		if (!port->irqstr[j])
 
 
1747			goto out_nomem;
 
1748
1749		ret = request_irq(irq, desc->handler, up->irqflags,
1750				  port->irqstr[j], port);
1751		if (unlikely(ret)) {
1752			dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1753			goto out_noirq;
1754		}
1755	}
1756
1757	return 0;
1758
1759out_noirq:
1760	while (--i >= 0)
1761		free_irq(port->irqs[i], port);
1762
1763out_nomem:
1764	while (--j >= 0)
1765		kfree(port->irqstr[j]);
1766
1767	return ret;
1768}
1769
1770static void sci_free_irq(struct sci_port *port)
1771{
1772	int i;
1773
1774	/*
1775	 * Intentionally in reverse order so we iterate over the muxed
1776	 * IRQ first.
1777	 */
1778	for (i = 0; i < SCIx_NR_IRQS; i++) {
1779		int irq = port->irqs[i];
1780
1781		/*
1782		 * Certain port types won't support all of the available
1783		 * interrupt sources.
1784		 */
1785		if (unlikely(irq < 0))
1786			continue;
1787
1788		free_irq(port->irqs[i], port);
1789		kfree(port->irqstr[i]);
1790
1791		if (SCIx_IRQ_IS_MUXED(port)) {
1792			/* If there's only one IRQ, we're done. */
1793			return;
1794		}
1795	}
1796}
1797
1798static unsigned int sci_tx_empty(struct uart_port *port)
1799{
1800	unsigned short status = serial_port_in(port, SCxSR);
1801	unsigned short in_tx_fifo = sci_txfill(port);
1802
1803	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1804}
1805
1806static void sci_set_rts(struct uart_port *port, bool state)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1807{
1808	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1809		u16 data = serial_port_in(port, SCPDR);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1810
1811		/* Active low */
1812		if (state)
1813			data &= ~SCPDR_RTSD;
1814		else
1815			data |= SCPDR_RTSD;
1816		serial_port_out(port, SCPDR, data);
1817
1818		/* RTS# is output */
1819		serial_port_out(port, SCPCR,
1820				serial_port_in(port, SCPCR) | SCPCR_RTSC);
1821	} else if (sci_getreg(port, SCSPTR)->size) {
1822		u16 ctrl = serial_port_in(port, SCSPTR);
1823
1824		/* Active low */
1825		if (state)
1826			ctrl &= ~SCSPTR_RTSDT;
1827		else
1828			ctrl |= SCSPTR_RTSDT;
1829		serial_port_out(port, SCSPTR, ctrl);
1830	}
 
 
1831}
1832
1833static bool sci_get_cts(struct uart_port *port)
 
 
1834{
1835	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1836		/* Active low */
1837		return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
1838	} else if (sci_getreg(port, SCSPTR)->size) {
1839		/* Active low */
1840		return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
 
 
 
 
 
 
1841	}
1842
1843	return true;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1844}
1845
1846/*
1847 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
1848 * CTS/RTS is supported in hardware by at least one port and controlled
1849 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
1850 * handled via the ->init_pins() op, which is a bit of a one-way street,
1851 * lacking any ability to defer pin control -- this will later be
1852 * converted over to the GPIO framework).
1853 *
1854 * Other modes (such as loopback) are supported generically on certain
1855 * port types, but not others. For these it's sufficient to test for the
1856 * existence of the support register and simply ignore the port type.
1857 */
1858static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
1859{
1860	struct sci_port *s = to_sci_port(port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1861
1862	if (mctrl & TIOCM_LOOP) {
1863		const struct plat_sci_reg *reg;
 
 
 
 
1864
1865		/*
1866		 * Standard loopback mode for SCFCR ports.
1867		 */
1868		reg = sci_getreg(port, SCFCR);
1869		if (reg->size)
1870			serial_port_out(port, SCFCR,
1871					serial_port_in(port, SCFCR) |
1872					SCFCR_LOOP);
1873	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1874
1875	mctrl_gpio_set(s->gpios, mctrl);
 
 
1876
1877	if (!(s->cfg->capabilities & SCIx_HAVE_RTSCTS))
 
 
 
 
 
 
 
 
 
 
 
1878		return;
 
 
 
1879
1880	if (!(mctrl & TIOCM_RTS)) {
1881		/* Disable Auto RTS */
1882		serial_port_out(port, SCFCR,
1883				serial_port_in(port, SCFCR) & ~SCFCR_MCE);
1884
1885		/* Clear RTS */
1886		sci_set_rts(port, 0);
1887	} else if (s->autorts) {
1888		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1889			/* Enable RTS# pin function */
1890			serial_port_out(port, SCPCR,
1891				serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
1892		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1893
1894		/* Enable Auto RTS */
1895		serial_port_out(port, SCFCR,
1896				serial_port_in(port, SCFCR) | SCFCR_MCE);
1897	} else {
1898		/* Set RTS */
1899		sci_set_rts(port, 1);
 
 
 
 
 
1900	}
 
 
 
 
 
1901}
 
1902
1903static unsigned int sci_get_mctrl(struct uart_port *port)
1904{
1905	struct sci_port *s = to_sci_port(port);
1906	struct mctrl_gpios *gpios = s->gpios;
1907	unsigned int mctrl = 0;
 
 
 
 
 
 
 
 
 
 
1908
1909	mctrl_gpio_get(gpios, &mctrl);
 
 
 
1910
1911	/*
1912	 * CTS/RTS is handled in hardware when supported, while nothing
1913	 * else is wired up.
1914	 */
1915	if (s->autorts) {
1916		if (sci_get_cts(port))
1917			mctrl |= TIOCM_CTS;
1918	} else if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS))) {
1919		mctrl |= TIOCM_CTS;
1920	}
1921	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)))
1922		mctrl |= TIOCM_DSR;
1923	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)))
1924		mctrl |= TIOCM_CAR;
 
1925
1926	return mctrl;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1927}
1928
1929static void sci_enable_ms(struct uart_port *port)
1930{
1931	mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
1932}
1933
1934static void sci_break_ctl(struct uart_port *port, int break_state)
1935{
1936	unsigned short scscr, scsptr;
 
 
 
 
 
 
 
 
 
1937
1938	/* check wheter the port has SCSPTR */
1939	if (!sci_getreg(port, SCSPTR)->size) {
1940		/*
1941		 * Not supported by hardware. Most parts couple break and rx
1942		 * interrupts together, with break detection always enabled.
1943		 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1944		return;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1945	}
1946
1947	scsptr = serial_port_in(port, SCSPTR);
1948	scscr = serial_port_in(port, SCSCR);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1949
1950	if (break_state == -1) {
1951		scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
1952		scscr &= ~SCSCR_TE;
1953	} else {
1954		scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
1955		scscr |= SCSCR_TE;
 
 
 
 
 
 
 
1956	}
 
 
 
 
 
 
 
 
1957
1958	serial_port_out(port, SCSPTR, scsptr);
1959	serial_port_out(port, SCSCR, scscr);
 
 
 
 
 
 
1960}
1961
 
 
 
 
 
1962static int sci_startup(struct uart_port *port)
1963{
1964	struct sci_port *s = to_sci_port(port);
1965	int ret;
1966
1967	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1968
 
 
1969	ret = sci_request_irq(s);
1970	if (unlikely(ret < 0))
1971		return ret;
1972
1973	sci_request_dma(port);
1974
 
 
 
1975	return 0;
1976}
1977
1978static void sci_shutdown(struct uart_port *port)
1979{
1980	struct sci_port *s = to_sci_port(port);
1981	unsigned long flags;
1982	u16 scr;
1983
1984	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1985
1986	s->autorts = false;
1987	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
1988
1989	spin_lock_irqsave(&port->lock, flags);
1990	sci_stop_rx(port);
1991	sci_stop_tx(port);
1992	/* Stop RX and TX, disable related interrupts, keep clock source */
1993	scr = serial_port_in(port, SCSCR);
1994	serial_port_out(port, SCSCR, scr & (SCSCR_CKE1 | SCSCR_CKE0));
1995	spin_unlock_irqrestore(&port->lock, flags);
1996
1997#ifdef CONFIG_SERIAL_SH_SCI_DMA
1998	if (s->chan_rx) {
1999		dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2000			port->line);
2001		del_timer_sync(&s->rx_timer);
2002	}
2003#endif
2004
2005	sci_free_dma(port);
2006	sci_free_irq(s);
2007}
2008
2009static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2010			unsigned int *srr)
2011{
2012	unsigned long freq = s->clk_rates[SCI_SCK];
2013	int err, min_err = INT_MAX;
2014	unsigned int sr;
2015
2016	if (s->port.type != PORT_HSCIF)
2017		freq *= 2;
2018
2019	for_each_sr(sr, s) {
2020		err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2021		if (abs(err) >= abs(min_err))
2022			continue;
2023
2024		min_err = err;
2025		*srr = sr - 1;
2026
2027		if (!err)
2028			break;
2029	}
2030
2031	dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2032		*srr + 1);
2033	return min_err;
2034}
2035
2036static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2037			unsigned long freq, unsigned int *dlr,
2038			unsigned int *srr)
2039{
2040	int err, min_err = INT_MAX;
2041	unsigned int sr, dl;
2042
2043	if (s->port.type != PORT_HSCIF)
2044		freq *= 2;
2045
2046	for_each_sr(sr, s) {
2047		dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2048		dl = clamp(dl, 1U, 65535U);
2049
2050		err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2051		if (abs(err) >= abs(min_err))
2052			continue;
2053
2054		min_err = err;
2055		*dlr = dl;
2056		*srr = sr - 1;
2057
2058		if (!err)
2059			break;
2060	}
2061
2062	dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2063		min_err, *dlr, *srr + 1);
2064	return min_err;
2065}
2066
2067/* calculate sample rate, BRR, and clock select */
2068static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2069			  unsigned int *brr, unsigned int *srr,
2070			  unsigned int *cks)
2071{
2072	unsigned long freq = s->clk_rates[SCI_FCK];
2073	unsigned int sr, br, prediv, scrate, c;
2074	int err, min_err = INT_MAX;
2075
2076	if (s->port.type != PORT_HSCIF)
2077		freq *= 2;
2078
2079	/*
2080	 * Find the combination of sample rate and clock select with the
2081	 * smallest deviation from the desired baud rate.
2082	 * Prefer high sample rates to maximise the receive margin.
2083	 *
2084	 * M: Receive margin (%)
2085	 * N: Ratio of bit rate to clock (N = sampling rate)
2086	 * D: Clock duty (D = 0 to 1.0)
2087	 * L: Frame length (L = 9 to 12)
2088	 * F: Absolute value of clock frequency deviation
2089	 *
2090	 *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2091	 *      (|D - 0.5| / N * (1 + F))|
2092	 *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2093	 */
2094	for_each_sr(sr, s) {
2095		for (c = 0; c <= 3; c++) {
2096			/* integerized formulas from HSCIF documentation */
2097			prediv = sr * (1 << (2 * c + 1));
2098
2099			/*
2100			 * We need to calculate:
2101			 *
2102			 *     br = freq / (prediv * bps) clamped to [1..256]
2103			 *     err = freq / (br * prediv) - bps
2104			 *
2105			 * Watch out for overflow when calculating the desired
2106			 * sampling clock rate!
2107			 */
2108			if (bps > UINT_MAX / prediv)
2109				break;
2110
2111			scrate = prediv * bps;
2112			br = DIV_ROUND_CLOSEST(freq, scrate);
2113			br = clamp(br, 1U, 256U);
2114
2115			err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2116			if (abs(err) >= abs(min_err))
2117				continue;
2118
2119			min_err = err;
2120			*brr = br - 1;
2121			*srr = sr - 1;
2122			*cks = c;
2123
2124			if (!err)
2125				goto found;
2126		}
2127	}
2128
2129found:
2130	dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2131		min_err, *brr, *srr + 1, *cks);
2132	return min_err;
2133}
2134
2135static void sci_reset(struct uart_port *port)
2136{
2137	const struct plat_sci_reg *reg;
2138	unsigned int status;
2139
2140	do {
2141		status = serial_port_in(port, SCxSR);
2142	} while (!(status & SCxSR_TEND(port)));
2143
2144	serial_port_out(port, SCSCR, 0x00);	/* TE=0, RE=0, CKE1=0 */
2145
2146	reg = sci_getreg(port, SCFCR);
2147	if (reg->size)
2148		serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2149
2150	sci_clear_SCxSR(port,
2151			SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2152			SCxSR_BREAK_CLEAR(port));
2153	if (sci_getreg(port, SCLSR)->size) {
2154		status = serial_port_in(port, SCLSR);
2155		status &= ~(SCLSR_TO | SCLSR_ORER);
2156		serial_port_out(port, SCLSR, status);
2157	}
2158}
2159
2160static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2161			    struct ktermios *old)
2162{
2163	unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i;
2164	unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2165	unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2166	struct sci_port *s = to_sci_port(port);
2167	const struct plat_sci_reg *reg;
2168	int min_err = INT_MAX, err;
2169	unsigned long max_freq = 0;
2170	int best_clk = -1;
2171
2172	if ((termios->c_cflag & CSIZE) == CS7)
2173		smr_val |= SCSMR_CHR;
2174	if (termios->c_cflag & PARENB)
2175		smr_val |= SCSMR_PE;
2176	if (termios->c_cflag & PARODD)
2177		smr_val |= SCSMR_PE | SCSMR_ODD;
2178	if (termios->c_cflag & CSTOPB)
2179		smr_val |= SCSMR_STOP;
2180
2181	/*
2182	 * earlyprintk comes here early on with port->uartclk set to zero.
2183	 * the clock framework is not up and running at this point so here
2184	 * we assume that 115200 is the maximum baud rate. please note that
2185	 * the baud rate is not programmed during earlyprintk - it is assumed
2186	 * that the previous boot loader has enabled required clocks and
2187	 * setup the baud rate generator hardware for us already.
2188	 */
2189	if (!port->uartclk) {
2190		baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2191		goto done;
2192	}
2193
2194	for (i = 0; i < SCI_NUM_CLKS; i++)
2195		max_freq = max(max_freq, s->clk_rates[i]);
2196
2197	baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2198	if (!baud)
2199		goto done;
2200
2201	/*
2202	 * There can be multiple sources for the sampling clock.  Find the one
2203	 * that gives us the smallest deviation from the desired baud rate.
2204	 */
2205
2206	/* Optional Undivided External Clock */
2207	if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2208	    port->type != PORT_SCIFB) {
2209		err = sci_sck_calc(s, baud, &srr1);
2210		if (abs(err) < abs(min_err)) {
2211			best_clk = SCI_SCK;
2212			scr_val = SCSCR_CKE1;
2213			sccks = SCCKS_CKS;
2214			min_err = err;
2215			srr = srr1;
2216			if (!err)
2217				goto done;
2218		}
2219	}
2220
2221	/* Optional BRG Frequency Divided External Clock */
2222	if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2223		err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2224				   &srr1);
2225		if (abs(err) < abs(min_err)) {
2226			best_clk = SCI_SCIF_CLK;
2227			scr_val = SCSCR_CKE1;
2228			sccks = 0;
2229			min_err = err;
2230			dl = dl1;
2231			srr = srr1;
2232			if (!err)
2233				goto done;
2234		}
2235	}
2236
2237	/* Optional BRG Frequency Divided Internal Clock */
2238	if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2239		err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2240				   &srr1);
2241		if (abs(err) < abs(min_err)) {
2242			best_clk = SCI_BRG_INT;
2243			scr_val = SCSCR_CKE1;
2244			sccks = SCCKS_XIN;
2245			min_err = err;
2246			dl = dl1;
2247			srr = srr1;
2248			if (!min_err)
2249				goto done;
2250		}
2251	}
2252
2253	/* Divided Functional Clock using standard Bit Rate Register */
2254	err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2255	if (abs(err) < abs(min_err)) {
2256		best_clk = SCI_FCK;
2257		scr_val = 0;
2258		min_err = err;
2259		brr = brr1;
2260		srr = srr1;
2261		cks = cks1;
2262	}
2263
2264done:
2265	if (best_clk >= 0)
2266		dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2267			s->clks[best_clk], baud, min_err);
2268
2269	sci_port_enable(s);
 
 
 
 
 
 
 
2270
2271	/*
2272	 * Program the optional External Baud Rate Generator (BRG) first.
2273	 * It controls the mux to select (H)SCK or frequency divided clock.
2274	 */
2275	if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2276		serial_port_out(port, SCDL, dl);
2277		serial_port_out(port, SCCKS, sccks);
2278	}
2279
2280	sci_reset(port);
2281
2282	uart_update_timeout(port, termios->c_cflag, baud);
 
2283
2284	if (best_clk >= 0) {
2285		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2286			switch (srr + 1) {
2287			case 5:  smr_val |= SCSMR_SRC_5;  break;
2288			case 7:  smr_val |= SCSMR_SRC_7;  break;
2289			case 11: smr_val |= SCSMR_SRC_11; break;
2290			case 13: smr_val |= SCSMR_SRC_13; break;
2291			case 16: smr_val |= SCSMR_SRC_16; break;
2292			case 17: smr_val |= SCSMR_SRC_17; break;
2293			case 19: smr_val |= SCSMR_SRC_19; break;
2294			case 27: smr_val |= SCSMR_SRC_27; break;
2295			}
2296		smr_val |= cks;
2297		dev_dbg(port->dev,
2298			 "SCR 0x%x SMR 0x%x BRR %u CKS 0x%x DL %u SRR %u\n",
2299			 scr_val, smr_val, brr, sccks, dl, srr);
2300		serial_port_out(port, SCSCR, scr_val);
2301		serial_port_out(port, SCSMR, smr_val);
2302		serial_port_out(port, SCBRR, brr);
2303		if (sci_getreg(port, HSSRR)->size)
2304			serial_port_out(port, HSSRR, srr | HSCIF_SRE);
2305
2306		/* Wait one bit interval */
2307		udelay((1000000 + (baud - 1)) / baud);
2308	} else {
2309		/* Don't touch the bit rate configuration */
2310		scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2311		smr_val |= serial_port_in(port, SCSMR) &
2312			   (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2313		dev_dbg(port->dev, "SCR 0x%x SMR 0x%x\n", scr_val, smr_val);
2314		serial_port_out(port, SCSCR, scr_val);
2315		serial_port_out(port, SCSMR, smr_val);
2316	}
2317
2318	sci_init_pins(port, termios->c_cflag);
 
2319
2320	port->status &= ~UPSTAT_AUTOCTS;
2321	s->autorts = false;
2322	reg = sci_getreg(port, SCFCR);
2323	if (reg->size) {
2324		unsigned short ctrl = serial_port_in(port, SCFCR);
2325
2326		if ((port->flags & UPF_HARD_FLOW) &&
2327		    (termios->c_cflag & CRTSCTS)) {
2328			/* There is no CTS interrupt to restart the hardware */
2329			port->status |= UPSTAT_AUTOCTS;
2330			/* MCE is enabled when RTS is raised */
2331			s->autorts = true;
2332		}
2333
2334		/*
2335		 * As we've done a sci_reset() above, ensure we don't
2336		 * interfere with the FIFOs while toggling MCE. As the
2337		 * reset values could still be set, simply mask them out.
2338		 */
2339		ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2340
2341		serial_port_out(port, SCFCR, ctrl);
2342	}
2343
2344	scr_val |= s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0);
2345	dev_dbg(port->dev, "SCSCR 0x%x\n", scr_val);
2346	serial_port_out(port, SCSCR, scr_val);
2347	if ((srr + 1 == 5) &&
2348	    (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2349		/*
2350		 * In asynchronous mode, when the sampling rate is 1/5, first
2351		 * received data may become invalid on some SCIFA and SCIFB.
2352		 * To avoid this problem wait more than 1 serial data time (1
2353		 * bit time x serial data number) after setting SCSCR.RE = 1.
2354		 */
2355		udelay(DIV_ROUND_UP(10 * 1000000, baud));
2356	}
2357
2358#ifdef CONFIG_SERIAL_SH_SCI_DMA
2359	/*
2360	 * Calculate delay for 2 DMA buffers (4 FIFO).
2361	 * See serial_core.c::uart_update_timeout().
2362	 * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2363	 * function calculates 1 jiffie for the data plus 5 jiffies for the
2364	 * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2365	 * buffers (4 FIFO sizes), but when performing a faster transfer, the
2366	 * value obtained by this formula is too small. Therefore, if the value
2367	 * is smaller than 20ms, use 20ms as the timeout value for DMA.
2368	 */
2369	if (s->chan_rx) {
2370		unsigned int bits;
2371
2372		/* byte size and parity */
2373		switch (termios->c_cflag & CSIZE) {
2374		case CS5:
2375			bits = 7;
2376			break;
2377		case CS6:
2378			bits = 8;
2379			break;
2380		case CS7:
2381			bits = 9;
2382			break;
2383		default:
2384			bits = 10;
2385			break;
2386		}
2387
2388		if (termios->c_cflag & CSTOPB)
2389			bits++;
2390		if (termios->c_cflag & PARENB)
2391			bits++;
2392		s->rx_timeout = DIV_ROUND_UP((s->buf_len_rx * 2 * bits * HZ) /
2393					     (baud / 10), 10);
2394		dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n",
2395			s->rx_timeout * 1000 / HZ, port->timeout);
2396		if (s->rx_timeout < msecs_to_jiffies(20))
2397			s->rx_timeout = msecs_to_jiffies(20);
2398	}
2399#endif
2400
2401	if ((termios->c_cflag & CREAD) != 0)
2402		sci_start_rx(port);
2403
2404	sci_port_disable(s);
2405
2406	if (UART_ENABLE_MS(port, termios->c_cflag))
2407		sci_enable_ms(port);
2408}
2409
2410static void sci_pm(struct uart_port *port, unsigned int state,
2411		   unsigned int oldstate)
2412{
2413	struct sci_port *sci_port = to_sci_port(port);
2414
2415	switch (state) {
2416	case UART_PM_STATE_OFF:
2417		sci_port_disable(sci_port);
2418		break;
2419	default:
2420		sci_port_enable(sci_port);
2421		break;
2422	}
2423}
2424
2425static const char *sci_type(struct uart_port *port)
2426{
2427	switch (port->type) {
2428	case PORT_IRDA:
2429		return "irda";
2430	case PORT_SCI:
2431		return "sci";
2432	case PORT_SCIF:
2433		return "scif";
2434	case PORT_SCIFA:
2435		return "scifa";
2436	case PORT_SCIFB:
2437		return "scifb";
2438	case PORT_HSCIF:
2439		return "hscif";
2440	}
2441
2442	return NULL;
2443}
2444
 
 
 
 
 
 
 
 
 
 
 
2445static int sci_remap_port(struct uart_port *port)
2446{
2447	struct sci_port *sport = to_sci_port(port);
2448
2449	/*
2450	 * Nothing to do if there's already an established membase.
2451	 */
2452	if (port->membase)
2453		return 0;
2454
2455	if (port->flags & UPF_IOREMAP) {
2456		port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2457		if (unlikely(!port->membase)) {
2458			dev_err(port->dev, "can't remap port#%d\n", port->line);
2459			return -ENXIO;
2460		}
2461	} else {
2462		/*
2463		 * For the simple (and majority of) cases where we don't
2464		 * need to do any remapping, just cast the cookie
2465		 * directly.
2466		 */
2467		port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2468	}
2469
2470	return 0;
2471}
2472
2473static void sci_release_port(struct uart_port *port)
2474{
2475	struct sci_port *sport = to_sci_port(port);
2476
2477	if (port->flags & UPF_IOREMAP) {
2478		iounmap(port->membase);
2479		port->membase = NULL;
2480	}
2481
2482	release_mem_region(port->mapbase, sport->reg_size);
2483}
2484
2485static int sci_request_port(struct uart_port *port)
2486{
 
2487	struct resource *res;
2488	struct sci_port *sport = to_sci_port(port);
2489	int ret;
2490
2491	res = request_mem_region(port->mapbase, sport->reg_size,
2492				 dev_name(port->dev));
2493	if (unlikely(res == NULL)) {
2494		dev_err(port->dev, "request_mem_region failed.");
2495		return -EBUSY;
2496	}
2497
2498	ret = sci_remap_port(port);
2499	if (unlikely(ret != 0)) {
2500		release_resource(res);
2501		return ret;
2502	}
2503
2504	return 0;
2505}
2506
2507static void sci_config_port(struct uart_port *port, int flags)
2508{
2509	if (flags & UART_CONFIG_TYPE) {
2510		struct sci_port *sport = to_sci_port(port);
2511
2512		port->type = sport->cfg->type;
2513		sci_request_port(port);
2514	}
2515}
2516
2517static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2518{
 
 
 
 
2519	if (ser->baud_base < 2400)
2520		/* No paper tape reader for Mitch.. */
2521		return -EINVAL;
2522
2523	return 0;
2524}
2525
2526static const struct uart_ops sci_uart_ops = {
2527	.tx_empty	= sci_tx_empty,
2528	.set_mctrl	= sci_set_mctrl,
2529	.get_mctrl	= sci_get_mctrl,
2530	.start_tx	= sci_start_tx,
2531	.stop_tx	= sci_stop_tx,
2532	.stop_rx	= sci_stop_rx,
2533	.enable_ms	= sci_enable_ms,
2534	.break_ctl	= sci_break_ctl,
2535	.startup	= sci_startup,
2536	.shutdown	= sci_shutdown,
2537	.set_termios	= sci_set_termios,
2538	.pm		= sci_pm,
2539	.type		= sci_type,
2540	.release_port	= sci_release_port,
2541	.request_port	= sci_request_port,
2542	.config_port	= sci_config_port,
2543	.verify_port	= sci_verify_port,
2544#ifdef CONFIG_CONSOLE_POLL
2545	.poll_get_char	= sci_poll_get_char,
2546	.poll_put_char	= sci_poll_put_char,
2547#endif
2548};
2549
2550static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2551{
2552	const char *clk_names[] = {
2553		[SCI_FCK] = "fck",
2554		[SCI_SCK] = "sck",
2555		[SCI_BRG_INT] = "brg_int",
2556		[SCI_SCIF_CLK] = "scif_clk",
2557	};
2558	struct clk *clk;
2559	unsigned int i;
2560
2561	if (sci_port->cfg->type == PORT_HSCIF)
2562		clk_names[SCI_SCK] = "hsck";
2563
2564	for (i = 0; i < SCI_NUM_CLKS; i++) {
2565		clk = devm_clk_get(dev, clk_names[i]);
2566		if (PTR_ERR(clk) == -EPROBE_DEFER)
2567			return -EPROBE_DEFER;
2568
2569		if (IS_ERR(clk) && i == SCI_FCK) {
2570			/*
2571			 * "fck" used to be called "sci_ick", and we need to
2572			 * maintain DT backward compatibility.
2573			 */
2574			clk = devm_clk_get(dev, "sci_ick");
2575			if (PTR_ERR(clk) == -EPROBE_DEFER)
2576				return -EPROBE_DEFER;
2577
2578			if (!IS_ERR(clk))
2579				goto found;
2580
2581			/*
2582			 * Not all SH platforms declare a clock lookup entry
2583			 * for SCI devices, in which case we need to get the
2584			 * global "peripheral_clk" clock.
2585			 */
2586			clk = devm_clk_get(dev, "peripheral_clk");
2587			if (!IS_ERR(clk))
2588				goto found;
2589
2590			dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2591				PTR_ERR(clk));
2592			return PTR_ERR(clk);
2593		}
2594
2595found:
2596		if (IS_ERR(clk))
2597			dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2598				PTR_ERR(clk));
2599		else
2600			dev_dbg(dev, "clk %s is %pC rate %pCr\n", clk_names[i],
2601				clk, clk);
2602		sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2603	}
2604	return 0;
2605}
2606
2607static int sci_init_single(struct platform_device *dev,
2608			   struct sci_port *sci_port, unsigned int index,
2609			   struct plat_sci_port *p, bool early)
2610{
2611	struct uart_port *port = &sci_port->port;
2612	const struct resource *res;
2613	unsigned int i;
2614	int ret;
2615
2616	sci_port->cfg	= p;
2617
2618	port->ops	= &sci_uart_ops;
2619	port->iotype	= UPIO_MEM;
2620	port->line	= index;
2621
2622	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2623	if (res == NULL)
2624		return -ENOMEM;
2625
2626	port->mapbase = res->start;
2627	sci_port->reg_size = resource_size(res);
2628
2629	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
2630		sci_port->irqs[i] = platform_get_irq(dev, i);
2631
2632	/* The SCI generates several interrupts. They can be muxed together or
2633	 * connected to different interrupt lines. In the muxed case only one
2634	 * interrupt resource is specified. In the non-muxed case three or four
2635	 * interrupt resources are specified, as the BRI interrupt is optional.
2636	 */
2637	if (sci_port->irqs[0] < 0)
2638		return -ENXIO;
2639
2640	if (sci_port->irqs[1] < 0) {
2641		sci_port->irqs[1] = sci_port->irqs[0];
2642		sci_port->irqs[2] = sci_port->irqs[0];
2643		sci_port->irqs[3] = sci_port->irqs[0];
2644	}
2645
2646	if (p->regtype == SCIx_PROBE_REGTYPE) {
2647		ret = sci_probe_regmap(p);
2648		if (unlikely(ret))
2649			return ret;
2650	}
2651
2652	switch (p->type) {
2653	case PORT_SCIFB:
2654		port->fifosize = 256;
2655		sci_port->overrun_reg = SCxSR;
2656		sci_port->overrun_mask = SCIFA_ORER;
2657		sci_port->sampling_rate_mask = SCI_SR_SCIFAB;
2658		break;
2659	case PORT_HSCIF:
2660		port->fifosize = 128;
2661		sci_port->overrun_reg = SCLSR;
2662		sci_port->overrun_mask = SCLSR_ORER;
2663		sci_port->sampling_rate_mask = SCI_SR_RANGE(8, 32);
2664		break;
2665	case PORT_SCIFA:
2666		port->fifosize = 64;
2667		sci_port->overrun_reg = SCxSR;
2668		sci_port->overrun_mask = SCIFA_ORER;
2669		sci_port->sampling_rate_mask = SCI_SR_SCIFAB;
2670		break;
2671	case PORT_SCIF:
2672		port->fifosize = 16;
2673		if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) {
2674			sci_port->overrun_reg = SCxSR;
2675			sci_port->overrun_mask = SCIFA_ORER;
2676			sci_port->sampling_rate_mask = SCI_SR(16);
2677		} else {
2678			sci_port->overrun_reg = SCLSR;
2679			sci_port->overrun_mask = SCLSR_ORER;
2680			sci_port->sampling_rate_mask = SCI_SR(32);
2681		}
2682		break;
2683	default:
2684		port->fifosize = 1;
2685		sci_port->overrun_reg = SCxSR;
2686		sci_port->overrun_mask = SCI_ORER;
2687		sci_port->sampling_rate_mask = SCI_SR(32);
2688		break;
2689	}
2690
2691	/* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2692	 * match the SoC datasheet, this should be investigated. Let platform
2693	 * data override the sampling rate for now.
2694	 */
2695	if (p->sampling_rate)
2696		sci_port->sampling_rate_mask = SCI_SR(p->sampling_rate);
2697
2698	if (!early) {
2699		ret = sci_init_clocks(sci_port, &dev->dev);
2700		if (ret < 0)
2701			return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2702
2703		port->dev = &dev->dev;
2704
 
2705		pm_runtime_enable(&dev->dev);
2706	}
2707
2708	sci_port->break_timer.data = (unsigned long)sci_port;
2709	sci_port->break_timer.function = sci_break_timer;
2710	init_timer(&sci_port->break_timer);
2711
2712	/*
2713	 * Establish some sensible defaults for the error detection.
2714	 */
2715	if (p->type == PORT_SCI) {
2716		sci_port->error_mask = SCI_DEFAULT_ERROR_MASK;
2717		sci_port->error_clear = SCI_ERROR_CLEAR;
2718	} else {
2719		sci_port->error_mask = SCIF_DEFAULT_ERROR_MASK;
2720		sci_port->error_clear = SCIF_ERROR_CLEAR;
2721	}
2722
2723	/*
2724	 * Make the error mask inclusive of overrun detection, if
2725	 * supported.
2726	 */
2727	if (sci_port->overrun_reg == SCxSR) {
2728		sci_port->error_mask |= sci_port->overrun_mask;
2729		sci_port->error_clear &= ~sci_port->overrun_mask;
 
 
 
 
 
 
 
 
 
 
2730	}
2731
 
 
 
2732	port->type		= p->type;
2733	port->flags		= UPF_FIXED_PORT | p->flags;
2734	port->regshift		= p->regshift;
2735
2736	/*
2737	 * The UART port needs an IRQ value, so we peg this to the RX IRQ
2738	 * for the multi-IRQ ports, which is where we are primarily
2739	 * concerned with the shutdown path synchronization.
2740	 *
2741	 * For the muxed case there's nothing more to do.
2742	 */
2743	port->irq		= sci_port->irqs[SCIx_RXI_IRQ];
2744	port->irqflags		= 0;
2745
2746	port->serial_in		= sci_serial_in;
2747	port->serial_out	= sci_serial_out;
2748
2749	if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
2750		dev_dbg(port->dev, "DMA tx %d, rx %d\n",
2751			p->dma_slave_tx, p->dma_slave_rx);
2752
2753	return 0;
2754}
2755
2756static void sci_cleanup_single(struct sci_port *port)
2757{
2758	pm_runtime_disable(port->port.dev);
2759}
2760
2761#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
2762    defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
2763static void serial_console_putchar(struct uart_port *port, int ch)
2764{
2765	sci_poll_put_char(port, ch);
2766}
2767
2768/*
2769 *	Print a string to the serial port trying not to disturb
2770 *	any possible real use of the port...
2771 */
2772static void serial_console_write(struct console *co, const char *s,
2773				 unsigned count)
2774{
2775	struct sci_port *sci_port = &sci_ports[co->index];
2776	struct uart_port *port = &sci_port->port;
2777	unsigned short bits, ctrl, ctrl_temp;
2778	unsigned long flags;
2779	int locked = 1;
2780
2781	local_irq_save(flags);
2782#if defined(SUPPORT_SYSRQ)
2783	if (port->sysrq)
2784		locked = 0;
2785	else
2786#endif
2787	if (oops_in_progress)
2788		locked = spin_trylock(&port->lock);
2789	else
2790		spin_lock(&port->lock);
2791
2792	/* first save SCSCR then disable interrupts, keep clock source */
2793	ctrl = serial_port_in(port, SCSCR);
2794	ctrl_temp = (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
2795		    (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
2796	serial_port_out(port, SCSCR, ctrl_temp);
2797
2798	uart_console_write(port, s, count, serial_console_putchar);
2799
2800	/* wait until fifo is empty and last bit has been transmitted */
2801	bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
2802	while ((serial_port_in(port, SCxSR) & bits) != bits)
2803		cpu_relax();
2804
2805	/* restore the SCSCR */
2806	serial_port_out(port, SCSCR, ctrl);
2807
2808	if (locked)
2809		spin_unlock(&port->lock);
2810	local_irq_restore(flags);
2811}
2812
2813static int serial_console_setup(struct console *co, char *options)
2814{
2815	struct sci_port *sci_port;
2816	struct uart_port *port;
2817	int baud = 115200;
2818	int bits = 8;
2819	int parity = 'n';
2820	int flow = 'n';
2821	int ret;
2822
2823	/*
2824	 * Refuse to handle any bogus ports.
2825	 */
2826	if (co->index < 0 || co->index >= SCI_NPORTS)
2827		return -ENODEV;
2828
2829	sci_port = &sci_ports[co->index];
2830	port = &sci_port->port;
2831
2832	/*
2833	 * Refuse to handle uninitialized ports.
2834	 */
2835	if (!port->ops)
2836		return -ENODEV;
2837
2838	ret = sci_remap_port(port);
2839	if (unlikely(ret != 0))
2840		return ret;
2841
 
 
2842	if (options)
2843		uart_parse_options(options, &baud, &parity, &bits, &flow);
2844
 
 
2845	return uart_set_options(port, co, baud, parity, bits, flow);
2846}
2847
2848static struct console serial_console = {
2849	.name		= "ttySC",
2850	.device		= uart_console_device,
2851	.write		= serial_console_write,
2852	.setup		= serial_console_setup,
2853	.flags		= CON_PRINTBUFFER,
2854	.index		= -1,
2855	.data		= &sci_uart_driver,
2856};
2857
2858static struct console early_serial_console = {
2859	.name           = "early_ttySC",
2860	.write          = serial_console_write,
2861	.flags          = CON_PRINTBUFFER,
2862	.index		= -1,
2863};
2864
2865static char early_serial_buf[32];
2866
2867static int sci_probe_earlyprintk(struct platform_device *pdev)
2868{
2869	struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
2870
2871	if (early_serial_console.data)
2872		return -EEXIST;
2873
2874	early_serial_console.index = pdev->id;
2875
2876	sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
2877
2878	serial_console_setup(&early_serial_console, early_serial_buf);
2879
2880	if (!strstr(early_serial_buf, "keep"))
2881		early_serial_console.flags |= CON_BOOT;
2882
2883	register_console(&early_serial_console);
2884	return 0;
2885}
2886
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2887#define SCI_CONSOLE	(&serial_console)
2888
2889#else
2890static inline int sci_probe_earlyprintk(struct platform_device *pdev)
2891{
2892	return -EINVAL;
2893}
2894
2895#define SCI_CONSOLE	NULL
 
 
2896
2897#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
2898
2899static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
 
2900
2901static struct uart_driver sci_uart_driver = {
2902	.owner		= THIS_MODULE,
2903	.driver_name	= "sci",
2904	.dev_name	= "ttySC",
2905	.major		= SCI_MAJOR,
2906	.minor		= SCI_MINOR_START,
2907	.nr		= SCI_NPORTS,
2908	.cons		= SCI_CONSOLE,
2909};
2910
2911static int sci_remove(struct platform_device *dev)
2912{
2913	struct sci_port *port = platform_get_drvdata(dev);
2914
 
 
 
2915	uart_remove_one_port(&sci_uart_driver, &port->port);
2916
2917	sci_cleanup_single(port);
 
2918
 
2919	return 0;
2920}
2921
2922
2923#define SCI_OF_DATA(type, regtype)	(void *)((type) << 16 | (regtype))
2924#define SCI_OF_TYPE(data)		((unsigned long)(data) >> 16)
2925#define SCI_OF_REGTYPE(data)		((unsigned long)(data) & 0xffff)
2926
2927static const struct of_device_id of_sci_match[] = {
2928	/* SoC-specific types */
2929	{
2930		.compatible = "renesas,scif-r7s72100",
2931		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
2932	},
2933	/* Family-specific types */
2934	{
2935		.compatible = "renesas,rcar-gen1-scif",
2936		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2937	}, {
2938		.compatible = "renesas,rcar-gen2-scif",
2939		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2940	}, {
2941		.compatible = "renesas,rcar-gen3-scif",
2942		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
2943	},
2944	/* Generic types */
2945	{
2946		.compatible = "renesas,scif",
2947		.data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
2948	}, {
2949		.compatible = "renesas,scifa",
2950		.data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
2951	}, {
2952		.compatible = "renesas,scifb",
2953		.data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
2954	}, {
2955		.compatible = "renesas,hscif",
2956		.data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
2957	}, {
2958		.compatible = "renesas,sci",
2959		.data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
2960	}, {
2961		/* Terminator */
2962	},
2963};
2964MODULE_DEVICE_TABLE(of, of_sci_match);
2965
2966static struct plat_sci_port *
2967sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id)
2968{
2969	struct device_node *np = pdev->dev.of_node;
2970	const struct of_device_id *match;
2971	struct plat_sci_port *p;
2972	int id;
2973
2974	if (!IS_ENABLED(CONFIG_OF) || !np)
2975		return NULL;
2976
2977	match = of_match_node(of_sci_match, np);
2978	if (!match)
2979		return NULL;
2980
2981	p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
2982	if (!p)
2983		return NULL;
2984
2985	/* Get the line number from the aliases node. */
2986	id = of_alias_get_id(np, "serial");
2987	if (id < 0) {
2988		dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
2989		return NULL;
2990	}
2991
2992	*dev_id = id;
2993
2994	p->flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
2995	p->type = SCI_OF_TYPE(match->data);
2996	p->regtype = SCI_OF_REGTYPE(match->data);
2997	p->scscr = SCSCR_RE | SCSCR_TE;
2998
2999	if (of_find_property(np, "uart-has-rtscts", NULL))
3000		p->capabilities |= SCIx_HAVE_RTSCTS;
3001
3002	return p;
3003}
3004
3005static int sci_probe_single(struct platform_device *dev,
3006				      unsigned int index,
3007				      struct plat_sci_port *p,
3008				      struct sci_port *sciport)
3009{
3010	int ret;
3011
3012	/* Sanity check */
3013	if (unlikely(index >= SCI_NPORTS)) {
3014		dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
 
3015			   index+1, SCI_NPORTS);
3016		dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3017		return -EINVAL;
 
3018	}
3019
3020	ret = sci_init_single(dev, sciport, index, p, false);
3021	if (ret)
3022		return ret;
3023
3024	sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3025	if (IS_ERR(sciport->gpios) && PTR_ERR(sciport->gpios) != -ENOSYS)
3026		return PTR_ERR(sciport->gpios);
3027
3028	if (p->capabilities & SCIx_HAVE_RTSCTS) {
3029		if (!IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3030							UART_GPIO_CTS)) ||
3031		    !IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(sciport->gpios,
3032							UART_GPIO_RTS))) {
3033			dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3034			return -EINVAL;
3035		}
3036		sciport->port.flags |= UPF_HARD_FLOW;
3037	}
3038
3039	ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3040	if (ret) {
3041		sci_cleanup_single(sciport);
3042		return ret;
3043	}
3044
3045	return 0;
3046}
3047
3048static int sci_probe(struct platform_device *dev)
3049{
3050	struct plat_sci_port *p;
3051	struct sci_port *sp;
3052	unsigned int dev_id;
3053	int ret;
3054
3055	/*
3056	 * If we've come here via earlyprintk initialization, head off to
3057	 * the special early probe. We don't have sufficient device state
3058	 * to make it beyond this yet.
3059	 */
3060	if (is_early_platform_device(dev))
3061		return sci_probe_earlyprintk(dev);
3062
3063	if (dev->dev.of_node) {
3064		p = sci_parse_dt(dev, &dev_id);
3065		if (p == NULL)
3066			return -EINVAL;
3067	} else {
3068		p = dev->dev.platform_data;
3069		if (p == NULL) {
3070			dev_err(&dev->dev, "no platform data supplied\n");
3071			return -EINVAL;
3072		}
3073
3074		dev_id = dev->id;
3075	}
 
3076
3077	sp = &sci_ports[dev_id];
3078	platform_set_drvdata(dev, sp);
3079
3080	ret = sci_probe_single(dev, dev_id, p, sp);
3081	if (ret)
3082		return ret;
 
3083
3084#ifdef CONFIG_SH_STANDARD_BIOS
3085	sh_bios_gdb_detach();
3086#endif
3087
3088	return 0;
 
 
 
 
3089}
3090
3091static __maybe_unused int sci_suspend(struct device *dev)
3092{
3093	struct sci_port *sport = dev_get_drvdata(dev);
3094
3095	if (sport)
3096		uart_suspend_port(&sci_uart_driver, &sport->port);
3097
3098	return 0;
3099}
3100
3101static __maybe_unused int sci_resume(struct device *dev)
3102{
3103	struct sci_port *sport = dev_get_drvdata(dev);
3104
3105	if (sport)
3106		uart_resume_port(&sci_uart_driver, &sport->port);
3107
3108	return 0;
3109}
3110
3111static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
 
 
 
 
 
3112
3113static struct platform_driver sci_driver = {
3114	.probe		= sci_probe,
3115	.remove		= sci_remove,
3116	.driver		= {
3117		.name	= "sh-sci",
 
3118		.pm	= &sci_dev_pm_ops,
3119		.of_match_table = of_match_ptr(of_sci_match),
3120	},
3121};
3122
3123static int __init sci_init(void)
3124{
3125	int ret;
3126
3127	pr_info("%s\n", banner);
3128
3129	ret = uart_register_driver(&sci_uart_driver);
3130	if (likely(ret == 0)) {
3131		ret = platform_driver_register(&sci_driver);
3132		if (unlikely(ret))
3133			uart_unregister_driver(&sci_uart_driver);
3134	}
3135
3136	return ret;
3137}
3138
3139static void __exit sci_exit(void)
3140{
3141	platform_driver_unregister(&sci_driver);
3142	uart_unregister_driver(&sci_uart_driver);
3143}
3144
3145#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3146early_platform_init_buffer("earlyprintk", &sci_driver,
3147			   early_serial_buf, ARRAY_SIZE(early_serial_buf));
3148#endif
3149#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3150static struct __init plat_sci_port port_cfg;
3151
3152static int __init early_console_setup(struct earlycon_device *device,
3153				      int type)
3154{
3155	if (!device->port.membase)
3156		return -ENODEV;
3157
3158	device->port.serial_in = sci_serial_in;
3159	device->port.serial_out	= sci_serial_out;
3160	device->port.type = type;
3161	memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3162	sci_ports[0].cfg = &port_cfg;
3163	sci_ports[0].cfg->type = type;
3164	sci_probe_regmap(sci_ports[0].cfg);
3165	port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR) |
3166			 SCSCR_RE | SCSCR_TE;
3167	sci_serial_out(&sci_ports[0].port, SCSCR, port_cfg.scscr);
3168
3169	device->con->write = serial_console_write;
3170	return 0;
3171}
3172static int __init sci_early_console_setup(struct earlycon_device *device,
3173					  const char *opt)
3174{
3175	return early_console_setup(device, PORT_SCI);
3176}
3177static int __init scif_early_console_setup(struct earlycon_device *device,
3178					  const char *opt)
3179{
3180	return early_console_setup(device, PORT_SCIF);
3181}
3182static int __init scifa_early_console_setup(struct earlycon_device *device,
3183					  const char *opt)
3184{
3185	return early_console_setup(device, PORT_SCIFA);
3186}
3187static int __init scifb_early_console_setup(struct earlycon_device *device,
3188					  const char *opt)
3189{
3190	return early_console_setup(device, PORT_SCIFB);
3191}
3192static int __init hscif_early_console_setup(struct earlycon_device *device,
3193					  const char *opt)
3194{
3195	return early_console_setup(device, PORT_HSCIF);
3196}
3197
3198OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3199OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3200OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3201OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3202OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3203#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3204
3205module_init(sci_init);
3206module_exit(sci_exit);
3207
3208MODULE_LICENSE("GPL");
3209MODULE_ALIAS("platform:sh-sci");
3210MODULE_AUTHOR("Paul Mundt");
3211MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");