1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Driver for Motorola/Freescale IMX serial ports
   4 *
   5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   6 *
   7 * Author: Sascha Hauer <sascha@saschahauer.de>
   8 * Copyright (C) 2004 Pengutronix
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   9 */
  10
  11#if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  12#define SUPPORT_SYSRQ
  13#endif
  14
  15#include <linux/module.h>
  16#include <linux/ioport.h>
  17#include <linux/init.h>
  18#include <linux/console.h>
  19#include <linux/sysrq.h>
  20#include <linux/platform_device.h>
  21#include <linux/tty.h>
  22#include <linux/tty_flip.h>
  23#include <linux/serial_core.h>
  24#include <linux/serial.h>
  25#include <linux/clk.h>
  26#include <linux/delay.h>
  27#include <linux/rational.h>
  28#include <linux/slab.h>
  29#include <linux/of.h>
  30#include <linux/of_device.h>
  31#include <linux/io.h>
  32#include <linux/dma-mapping.h>
  33
  34#include <asm/irq.h>
  35#include <linux/platform_data/serial-imx.h>
  36#include <linux/platform_data/dma-imx.h>
  37
  38#include "serial_mctrl_gpio.h"
  39
  40/* Register definitions */
  41#define URXD0 0x0  /* Receiver Register */
  42#define URTX0 0x40 /* Transmitter Register */
  43#define UCR1  0x80 /* Control Register 1 */
  44#define UCR2  0x84 /* Control Register 2 */
  45#define UCR3  0x88 /* Control Register 3 */
  46#define UCR4  0x8c /* Control Register 4 */
  47#define UFCR  0x90 /* FIFO Control Register */
  48#define USR1  0x94 /* Status Register 1 */
  49#define USR2  0x98 /* Status Register 2 */
  50#define UESC  0x9c /* Escape Character Register */
  51#define UTIM  0xa0 /* Escape Timer Register */
  52#define UBIR  0xa4 /* BRM Incremental Register */
  53#define UBMR  0xa8 /* BRM Modulator Register */
  54#define UBRC  0xac /* Baud Rate Count Register */
  55#define IMX21_ONEMS 0xb0 /* One Millisecond register */
  56#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
  57#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
  58
  59/* UART Control Register Bit Fields.*/
  60#define URXD_DUMMY_READ (1<<16)
  61#define URXD_CHARRDY	(1<<15)
  62#define URXD_ERR	(1<<14)
  63#define URXD_OVRRUN	(1<<13)
  64#define URXD_FRMERR	(1<<12)
  65#define URXD_BRK	(1<<11)
  66#define URXD_PRERR	(1<<10)
  67#define URXD_RX_DATA	(0xFF<<0)
  68#define UCR1_ADEN	(1<<15) /* Auto detect interrupt */
  69#define UCR1_ADBR	(1<<14) /* Auto detect baud rate */
  70#define UCR1_TRDYEN	(1<<13) /* Transmitter ready interrupt enable */
  71#define UCR1_IDEN	(1<<12) /* Idle condition interrupt */
  72#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
  73#define UCR1_RRDYEN	(1<<9)	/* Recv ready interrupt enable */
  74#define UCR1_RXDMAEN	(1<<8)	/* Recv ready DMA enable */
  75#define UCR1_IREN	(1<<7)	/* Infrared interface enable */
  76#define UCR1_TXMPTYEN	(1<<6)	/* Transimitter empty interrupt enable */
  77#define UCR1_RTSDEN	(1<<5)	/* RTS delta interrupt enable */
  78#define UCR1_SNDBRK	(1<<4)	/* Send break */
  79#define UCR1_TXDMAEN	(1<<3)	/* Transmitter ready DMA enable */
  80#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
  81#define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
  82#define UCR1_DOZE	(1<<1)	/* Doze */
  83#define UCR1_UARTEN	(1<<0)	/* UART enabled */
  84#define UCR2_ESCI	(1<<15)	/* Escape seq interrupt enable */
  85#define UCR2_IRTS	(1<<14)	/* Ignore RTS pin */
  86#define UCR2_CTSC	(1<<13)	/* CTS pin control */
  87#define UCR2_CTS	(1<<12)	/* Clear to send */
  88#define UCR2_ESCEN	(1<<11)	/* Escape enable */
  89#define UCR2_PREN	(1<<8)	/* Parity enable */
  90#define UCR2_PROE	(1<<7)	/* Parity odd/even */
  91#define UCR2_STPB	(1<<6)	/* Stop */
  92#define UCR2_WS		(1<<5)	/* Word size */
  93#define UCR2_RTSEN	(1<<4)	/* Request to send interrupt enable */
  94#define UCR2_ATEN	(1<<3)	/* Aging Timer Enable */
  95#define UCR2_TXEN	(1<<2)	/* Transmitter enabled */
  96#define UCR2_RXEN	(1<<1)	/* Receiver enabled */
  97#define UCR2_SRST	(1<<0)	/* SW reset */
  98#define UCR3_DTREN	(1<<13) /* DTR interrupt enable */
  99#define UCR3_PARERREN	(1<<12) /* Parity enable */
 100#define UCR3_FRAERREN	(1<<11) /* Frame error interrupt enable */
 101#define UCR3_DSR	(1<<10) /* Data set ready */
 102#define UCR3_DCD	(1<<9)	/* Data carrier detect */
 103#define UCR3_RI		(1<<8)	/* Ring indicator */
 104#define UCR3_ADNIMP	(1<<7)	/* Autobaud Detection Not Improved */
 105#define UCR3_RXDSEN	(1<<6)	/* Receive status interrupt enable */
 106#define UCR3_AIRINTEN	(1<<5)	/* Async IR wake interrupt enable */
 107#define UCR3_AWAKEN	(1<<4)	/* Async wake interrupt enable */
 108#define UCR3_DTRDEN	(1<<3)	/* Data Terminal Ready Delta Enable. */
 109#define IMX21_UCR3_RXDMUXSEL	(1<<2)	/* RXD Muxed Input Select */
 110#define UCR3_INVT	(1<<1)	/* Inverted Infrared transmission */
 111#define UCR3_BPEN	(1<<0)	/* Preset registers enable */
 112#define UCR4_CTSTL_SHF	10	/* CTS trigger level shift */
 113#define UCR4_CTSTL_MASK	0x3F	/* CTS trigger is 6 bits wide */
 114#define UCR4_INVR	(1<<9)	/* Inverted infrared reception */
 115#define UCR4_ENIRI	(1<<8)	/* Serial infrared interrupt enable */
 116#define UCR4_WKEN	(1<<7)	/* Wake interrupt enable */
 117#define UCR4_REF16	(1<<6)	/* Ref freq 16 MHz */
 118#define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
 119#define UCR4_IRSC	(1<<5)	/* IR special case */
 120#define UCR4_TCEN	(1<<3)	/* Transmit complete interrupt enable */
 121#define UCR4_BKEN	(1<<2)	/* Break condition interrupt enable */
 122#define UCR4_OREN	(1<<1)	/* Receiver overrun interrupt enable */
 123#define UCR4_DREN	(1<<0)	/* Recv data ready interrupt enable */
 124#define UFCR_RXTL_SHF	0	/* Receiver trigger level shift */
 125#define UFCR_DCEDTE	(1<<6)	/* DCE/DTE mode select */
 126#define UFCR_RFDIV	(7<<7)	/* Reference freq divider mask */
 127#define UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
 128#define UFCR_TXTL_SHF	10	/* Transmitter trigger level shift */
 129#define USR1_PARITYERR	(1<<15) /* Parity error interrupt flag */
 130#define USR1_RTSS	(1<<14) /* RTS pin status */
 131#define USR1_TRDY	(1<<13) /* Transmitter ready interrupt/dma flag */
 132#define USR1_RTSD	(1<<12) /* RTS delta */
 133#define USR1_ESCF	(1<<11) /* Escape seq interrupt flag */
 134#define USR1_FRAMERR	(1<<10) /* Frame error interrupt flag */
 135#define USR1_RRDY	(1<<9)	 /* Receiver ready interrupt/dma flag */
 136#define USR1_AGTIM	(1<<8)	 /* Ageing timer interrupt flag */
 137#define USR1_DTRD	(1<<7)	 /* DTR Delta */
 138#define USR1_RXDS	 (1<<6)	 /* Receiver idle interrupt flag */
 139#define USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
 140#define USR1_AWAKE	 (1<<4)	 /* Aysnc wake interrupt flag */
 141#define USR2_ADET	 (1<<15) /* Auto baud rate detect complete */
 142#define USR2_TXFE	 (1<<14) /* Transmit buffer FIFO empty */
 143#define USR2_DTRF	 (1<<13) /* DTR edge interrupt flag */
 144#define USR2_IDLE	 (1<<12) /* Idle condition */
 145#define USR2_RIDELT	 (1<<10) /* Ring Interrupt Delta */
 146#define USR2_RIIN	 (1<<9)	 /* Ring Indicator Input */
 147#define USR2_IRINT	 (1<<8)	 /* Serial infrared interrupt flag */
 148#define USR2_WAKE	 (1<<7)	 /* Wake */
 149#define USR2_DCDIN	 (1<<5)	 /* Data Carrier Detect Input */
 150#define USR2_RTSF	 (1<<4)	 /* RTS edge interrupt flag */
 151#define USR2_TXDC	 (1<<3)	 /* Transmitter complete */
 152#define USR2_BRCD	 (1<<2)	 /* Break condition */
 153#define USR2_ORE	(1<<1)	 /* Overrun error */
 154#define USR2_RDR	(1<<0)	 /* Recv data ready */
 155#define UTS_FRCPERR	(1<<13) /* Force parity error */
 156#define UTS_LOOP	(1<<12)	 /* Loop tx and rx */
 157#define UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
 158#define UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
 159#define UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
 160#define UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
 161#define UTS_SOFTRST	 (1<<0)	 /* Software reset */
 162
 163/* We've been assigned a range on the "Low-density serial ports" major */
 164#define SERIAL_IMX_MAJOR	207
 165#define MINOR_START		16
 166#define DEV_NAME		"ttymxc"
 167
 168/*
 169 * This determines how often we check the modem status signals
 170 * for any change.  They generally aren't connected to an IRQ
 171 * so we have to poll them.  We also check immediately before
 172 * filling the TX fifo incase CTS has been dropped.
 173 */
 174#define MCTRL_TIMEOUT	(250*HZ/1000)
 175
 176#define DRIVER_NAME "IMX-uart"
 177
 178#define UART_NR 8
 179
 180/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
 181enum imx_uart_type {
 182	IMX1_UART,
 183	IMX21_UART,
 184	IMX53_UART,
 185	IMX6Q_UART,
 186};
 187
 188/* device type dependent stuff */
 189struct imx_uart_data {
 190	unsigned uts_reg;
 191	enum imx_uart_type devtype;
 192};
 193
 194struct imx_port {
 195	struct uart_port	port;
 196	struct timer_list	timer;
 197	unsigned int		old_status;
 
 198	unsigned int		have_rtscts:1;
 199	unsigned int		have_rtsgpio:1;
 200	unsigned int		dte_mode:1;
 
 
 
 
 201	struct clk		*clk_ipg;
 202	struct clk		*clk_per;
 203	const struct imx_uart_data *devdata;
 204
 205	struct mctrl_gpios *gpios;
 206
 207	/* shadow registers */
 208	unsigned int ucr1;
 209	unsigned int ucr2;
 210	unsigned int ucr3;
 211	unsigned int ucr4;
 212	unsigned int ufcr;
 213
 214	/* DMA fields */
 
 215	unsigned int		dma_is_enabled:1;
 216	unsigned int		dma_is_rxing:1;
 217	unsigned int		dma_is_txing:1;
 218	struct dma_chan		*dma_chan_rx, *dma_chan_tx;
 219	struct scatterlist	rx_sgl, tx_sgl[2];
 220	void			*rx_buf;
 221	struct circ_buf		rx_ring;
 222	unsigned int		rx_periods;
 223	dma_cookie_t		rx_cookie;
 224	unsigned int		tx_bytes;
 225	unsigned int		dma_tx_nents;
 226	unsigned int            saved_reg[10];
 227	bool			context_saved;
 228};
 229
 230struct imx_port_ucrs {
 231	unsigned int	ucr1;
 232	unsigned int	ucr2;
 233	unsigned int	ucr3;
 234};
 235
 
 
 
 
 
 
 236static struct imx_uart_data imx_uart_devdata[] = {
 237	[IMX1_UART] = {
 238		.uts_reg = IMX1_UTS,
 239		.devtype = IMX1_UART,
 240	},
 241	[IMX21_UART] = {
 242		.uts_reg = IMX21_UTS,
 243		.devtype = IMX21_UART,
 244	},
 245	[IMX53_UART] = {
 246		.uts_reg = IMX21_UTS,
 247		.devtype = IMX53_UART,
 248	},
 249	[IMX6Q_UART] = {
 250		.uts_reg = IMX21_UTS,
 251		.devtype = IMX6Q_UART,
 252	},
 253};
 254
 255static const struct platform_device_id imx_uart_devtype[] = {
 256	{
 257		.name = "imx1-uart",
 258		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
 259	}, {
 260		.name = "imx21-uart",
 261		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
 262	}, {
 263		.name = "imx53-uart",
 264		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
 265	}, {
 266		.name = "imx6q-uart",
 267		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
 268	}, {
 269		/* sentinel */
 270	}
 271};
 272MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
 273
 274static const struct of_device_id imx_uart_dt_ids[] = {
 275	{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
 276	{ .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
 277	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
 278	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
 279	{ /* sentinel */ }
 280};
 281MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
 282
 283static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
 284{
 285	switch (offset) {
 286	case UCR1:
 287		sport->ucr1 = val;
 288		break;
 289	case UCR2:
 290		sport->ucr2 = val;
 291		break;
 292	case UCR3:
 293		sport->ucr3 = val;
 294		break;
 295	case UCR4:
 296		sport->ucr4 = val;
 297		break;
 298	case UFCR:
 299		sport->ufcr = val;
 300		break;
 301	default:
 302		break;
 303	}
 304	writel(val, sport->port.membase + offset);
 305}
 306
 307static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
 308{
 309	switch (offset) {
 310	case UCR1:
 311		return sport->ucr1;
 312		break;
 313	case UCR2:
 314		/*
 315		 * UCR2_SRST is the only bit in the cached registers that might
 316		 * differ from the value that was last written. As it only
 317		 * clears after being set, reread conditionally.
 318		 */
 319		if (!(sport->ucr2 & UCR2_SRST))
 320			sport->ucr2 = readl(sport->port.membase + offset);
 321		return sport->ucr2;
 322		break;
 323	case UCR3:
 324		return sport->ucr3;
 325		break;
 326	case UCR4:
 327		return sport->ucr4;
 328		break;
 329	case UFCR:
 330		return sport->ufcr;
 331		break;
 332	default:
 333		return readl(sport->port.membase + offset);
 334	}
 335}
 336
 337static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
 338{
 339	return sport->devdata->uts_reg;
 340}
 341
 342static inline int imx_uart_is_imx1(struct imx_port *sport)
 343{
 344	return sport->devdata->devtype == IMX1_UART;
 345}
 346
 347static inline int imx_uart_is_imx21(struct imx_port *sport)
 348{
 349	return sport->devdata->devtype == IMX21_UART;
 350}
 351
 352static inline int imx_uart_is_imx53(struct imx_port *sport)
 353{
 354	return sport->devdata->devtype == IMX53_UART;
 355}
 356
 357static inline int imx_uart_is_imx6q(struct imx_port *sport)
 358{
 359	return sport->devdata->devtype == IMX6Q_UART;
 360}
 361/*
 362 * Save and restore functions for UCR1, UCR2 and UCR3 registers
 363 */
 364#if defined(CONFIG_SERIAL_IMX_CONSOLE)
 365static void imx_uart_ucrs_save(struct imx_port *sport,
 366			       struct imx_port_ucrs *ucr)
 367{
 368	/* save control registers */
 369	ucr->ucr1 = imx_uart_readl(sport, UCR1);
 370	ucr->ucr2 = imx_uart_readl(sport, UCR2);
 371	ucr->ucr3 = imx_uart_readl(sport, UCR3);
 372}
 373
 374static void imx_uart_ucrs_restore(struct imx_port *sport,
 375				  struct imx_port_ucrs *ucr)
 376{
 377	/* restore control registers */
 378	imx_uart_writel(sport, ucr->ucr1, UCR1);
 379	imx_uart_writel(sport, ucr->ucr2, UCR2);
 380	imx_uart_writel(sport, ucr->ucr3, UCR3);
 381}
 382#endif
 383
 384static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
 
 
 
 385{
 386	*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
 387
 388	sport->port.mctrl |= TIOCM_RTS;
 389	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 390}
 391
 392static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
 393{
 394	*ucr2 &= ~UCR2_CTSC;
 395	*ucr2 |= UCR2_CTS;
 396
 397	sport->port.mctrl &= ~TIOCM_RTS;
 398	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 399}
 400
 401static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
 402{
 403	*ucr2 |= UCR2_CTSC;
 
 
 
 
 
 
 
 404}
 405
 406/* called with port.lock taken and irqs off */
 407static void imx_uart_start_rx(struct uart_port *port)
 
 
 
 408{
 409	struct imx_port *sport = (struct imx_port *)port;
 410	unsigned int ucr1, ucr2;
 411
 412	ucr1 = imx_uart_readl(sport, UCR1);
 413	ucr2 = imx_uart_readl(sport, UCR2);
 414
 415	ucr2 |= UCR2_RXEN;
 
 
 
 416
 417	if (sport->dma_is_enabled) {
 418		ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
 419	} else {
 420		ucr1 |= UCR1_RRDYEN;
 421		ucr2 |= UCR2_ATEN;
 422	}
 423
 424	/* Write UCR2 first as it includes RXEN */
 425	imx_uart_writel(sport, ucr2, UCR2);
 426	imx_uart_writel(sport, ucr1, UCR1);
 427}
 428
 429/* called with port.lock taken and irqs off */
 430static void imx_uart_stop_tx(struct uart_port *port)
 
 
 431{
 432	struct imx_port *sport = (struct imx_port *)port;
 433	u32 ucr1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 434
 435	/*
 436	 * We are maybe in the SMP context, so if the DMA TX thread is running
 437	 * on other cpu, we have to wait for it to finish.
 438	 */
 439	if (sport->dma_is_txing)
 440		return;
 441
 442	ucr1 = imx_uart_readl(sport, UCR1);
 443	imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
 444
 445	/* in rs485 mode disable transmitter if shifter is empty */
 446	if (port->rs485.flags & SER_RS485_ENABLED &&
 447	    imx_uart_readl(sport, USR2) & USR2_TXDC) {
 448		u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
 449		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
 450			imx_uart_rts_active(sport, &ucr2);
 451		else
 452			imx_uart_rts_inactive(sport, &ucr2);
 453		imx_uart_writel(sport, ucr2, UCR2);
 454
 455		imx_uart_start_rx(port);
 456
 457		ucr4 = imx_uart_readl(sport, UCR4);
 458		ucr4 &= ~UCR4_TCEN;
 459		imx_uart_writel(sport, ucr4, UCR4);
 460	}
 461}
 462
 463/* called with port.lock taken and irqs off */
 464static void imx_uart_stop_rx(struct uart_port *port)
 
 
 465{
 466	struct imx_port *sport = (struct imx_port *)port;
 467	u32 ucr1, ucr2;
 468
 469	ucr1 = imx_uart_readl(sport, UCR1);
 470	ucr2 = imx_uart_readl(sport, UCR2);
 471
 472	if (sport->dma_is_enabled) {
 473		ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
 474	} else {
 475		ucr1 &= ~UCR1_RRDYEN;
 476		ucr2 &= ~UCR2_ATEN;
 477	}
 478	imx_uart_writel(sport, ucr1, UCR1);
 479
 480	ucr2 &= ~UCR2_RXEN;
 481	imx_uart_writel(sport, ucr2, UCR2);
 482}
 483
 484/* called with port.lock taken and irqs off */
 485static void imx_uart_enable_ms(struct uart_port *port)
 
 
 486{
 487	struct imx_port *sport = (struct imx_port *)port;
 488
 489	mod_timer(&sport->timer, jiffies);
 490
 491	mctrl_gpio_enable_ms(sport->gpios);
 492}
 493
 494static void imx_uart_dma_tx(struct imx_port *sport);
 495
 496/* called with port.lock taken and irqs off */
 497static inline void imx_uart_transmit_buffer(struct imx_port *sport)
 498{
 499	struct circ_buf *xmit = &sport->port.state->xmit;
 500
 501	if (sport->port.x_char) {
 502		/* Send next char */
 503		imx_uart_writel(sport, sport->port.x_char, URTX0);
 504		sport->port.icount.tx++;
 505		sport->port.x_char = 0;
 506		return;
 507	}
 508
 509	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
 510		imx_uart_stop_tx(&sport->port);
 511		return;
 512	}
 513
 514	if (sport->dma_is_enabled) {
 515		u32 ucr1;
 516		/*
 517		 * We've just sent a X-char Ensure the TX DMA is enabled
 518		 * and the TX IRQ is disabled.
 519		 **/
 520		ucr1 = imx_uart_readl(sport, UCR1);
 521		ucr1 &= ~UCR1_TXMPTYEN;
 522		if (sport->dma_is_txing) {
 523			ucr1 |= UCR1_TXDMAEN;
 524			imx_uart_writel(sport, ucr1, UCR1);
 525		} else {
 526			imx_uart_writel(sport, ucr1, UCR1);
 527			imx_uart_dma_tx(sport);
 528		}
 529
 530		return;
 531	}
 532
 533	while (!uart_circ_empty(xmit) &&
 534	       !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
 
 535		/* send xmit->buf[xmit->tail]
 536		 * out the port here */
 537		imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
 538		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 539		sport->port.icount.tx++;
 540	}
 541
 542	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 543		uart_write_wakeup(&sport->port);
 544
 545	if (uart_circ_empty(xmit))
 546		imx_uart_stop_tx(&sport->port);
 547}
 548
 549static void imx_uart_dma_tx_callback(void *data)
 550{
 551	struct imx_port *sport = data;
 552	struct scatterlist *sgl = &sport->tx_sgl[0];
 553	struct circ_buf *xmit = &sport->port.state->xmit;
 554	unsigned long flags;
 555	u32 ucr1;
 556
 557	spin_lock_irqsave(&sport->port.lock, flags);
 558
 559	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 560
 561	ucr1 = imx_uart_readl(sport, UCR1);
 562	ucr1 &= ~UCR1_TXDMAEN;
 563	imx_uart_writel(sport, ucr1, UCR1);
 564
 565	/* update the stat */
 
 566	xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
 567	sport->port.icount.tx += sport->tx_bytes;
 
 568
 569	dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
 570
 571	sport->dma_is_txing = 0;
 572
 573	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 574		uart_write_wakeup(&sport->port);
 575
 576	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
 577		imx_uart_dma_tx(sport);
 578	else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
 579		u32 ucr4 = imx_uart_readl(sport, UCR4);
 580		ucr4 |= UCR4_TCEN;
 581		imx_uart_writel(sport, ucr4, UCR4);
 582	}
 583
 584	spin_unlock_irqrestore(&sport->port.lock, flags);
 585}
 586
 587/* called with port.lock taken and irqs off */
 588static void imx_uart_dma_tx(struct imx_port *sport)
 589{
 590	struct circ_buf *xmit = &sport->port.state->xmit;
 591	struct scatterlist *sgl = sport->tx_sgl;
 592	struct dma_async_tx_descriptor *desc;
 593	struct dma_chan	*chan = sport->dma_chan_tx;
 594	struct device *dev = sport->port.dev;
 595	u32 ucr1, ucr4;
 596	int ret;
 597
 598	if (sport->dma_is_txing)
 
 599		return;
 600
 601	ucr4 = imx_uart_readl(sport, UCR4);
 602	ucr4 &= ~UCR4_TCEN;
 603	imx_uart_writel(sport, ucr4, UCR4);
 604
 605	sport->tx_bytes = uart_circ_chars_pending(xmit);
 606
 607	if (xmit->tail < xmit->head) {
 608		sport->dma_tx_nents = 1;
 609		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
 610	} else {
 611		sport->dma_tx_nents = 2;
 612		sg_init_table(sgl, 2);
 613		sg_set_buf(sgl, xmit->buf + xmit->tail,
 614				UART_XMIT_SIZE - xmit->tail);
 615		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
 
 
 
 616	}
 617
 618	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 619	if (ret == 0) {
 620		dev_err(dev, "DMA mapping error for TX.\n");
 621		return;
 622	}
 623	desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
 624					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 625	if (!desc) {
 626		dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
 627			     DMA_TO_DEVICE);
 628		dev_err(dev, "We cannot prepare for the TX slave dma!\n");
 629		return;
 630	}
 631	desc->callback = imx_uart_dma_tx_callback;
 632	desc->callback_param = sport;
 633
 634	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
 635			uart_circ_chars_pending(xmit));
 636
 637	ucr1 = imx_uart_readl(sport, UCR1);
 638	ucr1 |= UCR1_TXDMAEN;
 639	imx_uart_writel(sport, ucr1, UCR1);
 640
 641	/* fire it */
 642	sport->dma_is_txing = 1;
 643	dmaengine_submit(desc);
 644	dma_async_issue_pending(chan);
 645	return;
 646}
 647
 648/* called with port.lock taken and irqs off */
 649static void imx_uart_start_tx(struct uart_port *port)
 
 
 650{
 651	struct imx_port *sport = (struct imx_port *)port;
 652	u32 ucr1;
 653
 654	if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
 655		return;
 656
 657	if (port->rs485.flags & SER_RS485_ENABLED) {
 658		u32 ucr2;
 
 
 
 659
 660		ucr2 = imx_uart_readl(sport, UCR2);
 661		if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
 662			imx_uart_rts_active(sport, &ucr2);
 663		else
 664			imx_uart_rts_inactive(sport, &ucr2);
 665		imx_uart_writel(sport, ucr2, UCR2);
 
 666
 667		if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
 668			imx_uart_stop_rx(port);
 
 669
 670		/*
 671		 * Enable transmitter and shifter empty irq only if DMA is off.
 672		 * In the DMA case this is done in the tx-callback.
 673		 */
 674		if (!sport->dma_is_enabled) {
 675			u32 ucr4 = imx_uart_readl(sport, UCR4);
 676			ucr4 |= UCR4_TCEN;
 677			imx_uart_writel(sport, ucr4, UCR4);
 678		}
 679	}
 680
 681	if (!sport->dma_is_enabled) {
 682		ucr1 = imx_uart_readl(sport, UCR1);
 683		imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
 
 
 
 
 
 684	}
 685
 686	if (sport->dma_is_enabled) {
 687		if (sport->port.x_char) {
 688			/* We have X-char to send, so enable TX IRQ and
 689			 * disable TX DMA to let TX interrupt to send X-char */
 690			ucr1 = imx_uart_readl(sport, UCR1);
 691			ucr1 &= ~UCR1_TXDMAEN;
 692			ucr1 |= UCR1_TXMPTYEN;
 693			imx_uart_writel(sport, ucr1, UCR1);
 694			return;
 695		}
 696
 697		if (!uart_circ_empty(&port->state->xmit) &&
 698		    !uart_tx_stopped(port))
 699			imx_uart_dma_tx(sport);
 700		return;
 701	}
 
 
 
 702}
 703
 704static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
 705{
 706	struct imx_port *sport = dev_id;
 707	u32 usr1;
 708	unsigned long flags;
 709
 710	spin_lock_irqsave(&sport->port.lock, flags);
 711
 712	imx_uart_writel(sport, USR1_RTSD, USR1);
 713	usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
 714	uart_handle_cts_change(&sport->port, !!usr1);
 715	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 716
 717	spin_unlock_irqrestore(&sport->port.lock, flags);
 718	return IRQ_HANDLED;
 719}
 720
 721static irqreturn_t imx_uart_txint(int irq, void *dev_id)
 722{
 723	struct imx_port *sport = dev_id;
 
 724	unsigned long flags;
 725
 726	spin_lock_irqsave(&sport->port.lock, flags);
 727	imx_uart_transmit_buffer(sport);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 728	spin_unlock_irqrestore(&sport->port.lock, flags);
 729	return IRQ_HANDLED;
 730}
 731
 732static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
 733{
 734	struct imx_port *sport = dev_id;
 735	unsigned int rx, flg, ignored = 0;
 736	struct tty_port *port = &sport->port.state->port;
 737	unsigned long flags;
 738
 739	spin_lock_irqsave(&sport->port.lock, flags);
 740
 741	while (imx_uart_readl(sport, USR2) & USR2_RDR) {
 742		u32 usr2;
 743
 744		flg = TTY_NORMAL;
 745		sport->port.icount.rx++;
 746
 747		rx = imx_uart_readl(sport, URXD0);
 748
 749		usr2 = imx_uart_readl(sport, USR2);
 750		if (usr2 & USR2_BRCD) {
 751			imx_uart_writel(sport, USR2_BRCD, USR2);
 752			if (uart_handle_break(&sport->port))
 753				continue;
 754		}
 755
 756		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 757			continue;
 758
 759		if (unlikely(rx & URXD_ERR)) {
 760			if (rx & URXD_BRK)
 761				sport->port.icount.brk++;
 762			else if (rx & URXD_PRERR)
 763				sport->port.icount.parity++;
 764			else if (rx & URXD_FRMERR)
 765				sport->port.icount.frame++;
 766			if (rx & URXD_OVRRUN)
 767				sport->port.icount.overrun++;
 768
 769			if (rx & sport->port.ignore_status_mask) {
 770				if (++ignored > 100)
 771					goto out;
 772				continue;
 773			}
 774
 775			rx &= (sport->port.read_status_mask | 0xFF);
 776
 777			if (rx & URXD_BRK)
 778				flg = TTY_BREAK;
 779			else if (rx & URXD_PRERR)
 780				flg = TTY_PARITY;
 781			else if (rx & URXD_FRMERR)
 782				flg = TTY_FRAME;
 783			if (rx & URXD_OVRRUN)
 784				flg = TTY_OVERRUN;
 785
 786#ifdef SUPPORT_SYSRQ
 787			sport->port.sysrq = 0;
 788#endif
 789		}
 790
 791		if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
 792			goto out;
 793
 794		if (tty_insert_flip_char(port, rx, flg) == 0)
 795			sport->port.icount.buf_overrun++;
 796	}
 797
 798out:
 799	spin_unlock_irqrestore(&sport->port.lock, flags);
 800	tty_flip_buffer_push(port);
 801	return IRQ_HANDLED;
 802}
 803
 804static void imx_uart_clear_rx_errors(struct imx_port *sport);
 805
 806/*
 807 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
 808 */
 809static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
 810{
 811	unsigned int tmp = TIOCM_DSR;
 812	unsigned usr1 = imx_uart_readl(sport, USR1);
 813	unsigned usr2 = imx_uart_readl(sport, USR2);
 814
 815	if (usr1 & USR1_RTSS)
 816		tmp |= TIOCM_CTS;
 817
 818	/* in DCE mode DCDIN is always 0 */
 819	if (!(usr2 & USR2_DCDIN))
 820		tmp |= TIOCM_CAR;
 821
 822	if (sport->dte_mode)
 823		if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
 824			tmp |= TIOCM_RI;
 825
 826	return tmp;
 827}
 828
 829/*
 830 * Handle any change of modem status signal since we were last called.
 
 831 */
 832static void imx_uart_mctrl_check(struct imx_port *sport)
 833{
 834	unsigned int status, changed;
 835
 836	status = imx_uart_get_hwmctrl(sport);
 837	changed = status ^ sport->old_status;
 
 838
 839	if (changed == 0)
 840		return;
 841
 842	sport->old_status = status;
 843
 844	if (changed & TIOCM_RI && status & TIOCM_RI)
 845		sport->port.icount.rng++;
 846	if (changed & TIOCM_DSR)
 847		sport->port.icount.dsr++;
 848	if (changed & TIOCM_CAR)
 849		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
 850	if (changed & TIOCM_CTS)
 851		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
 852
 853	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 
 
 854}
 855
 856static irqreturn_t imx_uart_int(int irq, void *dev_id)
 857{
 858	struct imx_port *sport = dev_id;
 859	unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
 860	irqreturn_t ret = IRQ_NONE;
 861
 862	usr1 = imx_uart_readl(sport, USR1);
 863	usr2 = imx_uart_readl(sport, USR2);
 864	ucr1 = imx_uart_readl(sport, UCR1);
 865	ucr2 = imx_uart_readl(sport, UCR2);
 866	ucr3 = imx_uart_readl(sport, UCR3);
 867	ucr4 = imx_uart_readl(sport, UCR4);
 868
 869	/*
 870	 * Even if a condition is true that can trigger an irq only handle it if
 871	 * the respective irq source is enabled. This prevents some undesired
 872	 * actions, for example if a character that sits in the RX FIFO and that
 873	 * should be fetched via DMA is tried to be fetched using PIO. Or the
 874	 * receiver is currently off and so reading from URXD0 results in an
 875	 * exception. So just mask the (raw) status bits for disabled irqs.
 876	 */
 877	if ((ucr1 & UCR1_RRDYEN) == 0)
 878		usr1 &= ~USR1_RRDY;
 879	if ((ucr2 & UCR2_ATEN) == 0)
 880		usr1 &= ~USR1_AGTIM;
 881	if ((ucr1 & UCR1_TXMPTYEN) == 0)
 882		usr1 &= ~USR1_TRDY;
 883	if ((ucr4 & UCR4_TCEN) == 0)
 884		usr2 &= ~USR2_TXDC;
 885	if ((ucr3 & UCR3_DTRDEN) == 0)
 886		usr1 &= ~USR1_DTRD;
 887	if ((ucr1 & UCR1_RTSDEN) == 0)
 888		usr1 &= ~USR1_RTSD;
 889	if ((ucr3 & UCR3_AWAKEN) == 0)
 890		usr1 &= ~USR1_AWAKE;
 891	if ((ucr4 & UCR4_OREN) == 0)
 892		usr2 &= ~USR2_ORE;
 893
 894	if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
 895		imx_uart_rxint(irq, dev_id);
 896		ret = IRQ_HANDLED;
 897	}
 898
 899	if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
 900		imx_uart_txint(irq, dev_id);
 901		ret = IRQ_HANDLED;
 902	}
 903
 904	if (usr1 & USR1_DTRD) {
 905		unsigned long flags;
 
 906
 907		imx_uart_writel(sport, USR1_DTRD, USR1);
 
 908
 909		spin_lock_irqsave(&sport->port.lock, flags);
 910		imx_uart_mctrl_check(sport);
 911		spin_unlock_irqrestore(&sport->port.lock, flags);
 912
 913		ret = IRQ_HANDLED;
 914	}
 915
 916	if (usr1 & USR1_RTSD) {
 917		imx_uart_rtsint(irq, dev_id);
 918		ret = IRQ_HANDLED;
 919	}
 920
 921	if (usr1 & USR1_AWAKE) {
 922		imx_uart_writel(sport, USR1_AWAKE, USR1);
 923		ret = IRQ_HANDLED;
 924	}
 925
 926	if (usr2 & USR2_ORE) {
 
 
 927		sport->port.icount.overrun++;
 928		imx_uart_writel(sport, USR2_ORE, USR2);
 929		ret = IRQ_HANDLED;
 930	}
 931
 932	return ret;
 933}
 934
 935/*
 936 * Return TIOCSER_TEMT when transmitter is not busy.
 937 */
 938static unsigned int imx_uart_tx_empty(struct uart_port *port)
 939{
 940	struct imx_port *sport = (struct imx_port *)port;
 941	unsigned int ret;
 942
 943	ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
 944
 945	/* If the TX DMA is working, return 0. */
 946	if (sport->dma_is_txing)
 947		ret = 0;
 948
 949	return ret;
 950}
 951
 952/* called with port.lock taken and irqs off */
 953static unsigned int imx_uart_get_mctrl(struct uart_port *port)
 
 
 954{
 955	struct imx_port *sport = (struct imx_port *)port;
 956	unsigned int ret = imx_uart_get_hwmctrl(sport);
 957
 958	mctrl_gpio_get(sport->gpios, &ret);
 
 959
 960	return ret;
 
 
 
 
 
 
 961}
 962
 963/* called with port.lock taken and irqs off */
 964static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 965{
 966	struct imx_port *sport = (struct imx_port *)port;
 967	u32 ucr3, uts;
 968
 969	if (!(port->rs485.flags & SER_RS485_ENABLED)) {
 970		u32 ucr2;
 971
 972		ucr2 = imx_uart_readl(sport, UCR2);
 973		ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
 974		if (mctrl & TIOCM_RTS)
 975			ucr2 |= UCR2_CTS | UCR2_CTSC;
 976		imx_uart_writel(sport, ucr2, UCR2);
 977	}
 978
 979	ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
 980	if (!(mctrl & TIOCM_DTR))
 981		ucr3 |= UCR3_DSR;
 982	imx_uart_writel(sport, ucr3, UCR3);
 983
 984	uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
 985	if (mctrl & TIOCM_LOOP)
 986		uts |= UTS_LOOP;
 987	imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
 988
 989	mctrl_gpio_set(sport->gpios, mctrl);
 990}
 991
 992/*
 993 * Interrupts always disabled.
 994 */
 995static void imx_uart_break_ctl(struct uart_port *port, int break_state)
 996{
 997	struct imx_port *sport = (struct imx_port *)port;
 998	unsigned long flags;
 999	u32 ucr1;
1000
1001	spin_lock_irqsave(&sport->port.lock, flags);
1002
1003	ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1004
1005	if (break_state != 0)
1006		ucr1 |= UCR1_SNDBRK;
1007
1008	imx_uart_writel(sport, ucr1, UCR1);
1009
1010	spin_unlock_irqrestore(&sport->port.lock, flags);
1011}
1012
1013/*
1014 * This is our per-port timeout handler, for checking the
1015 * modem status signals.
1016 */
1017static void imx_uart_timeout(struct timer_list *t)
1018{
1019	struct imx_port *sport = from_timer(sport, t, timer);
1020	unsigned long flags;
1021
1022	if (sport->port.state) {
1023		spin_lock_irqsave(&sport->port.lock, flags);
1024		imx_uart_mctrl_check(sport);
1025		spin_unlock_irqrestore(&sport->port.lock, flags);
1026
1027		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1028	}
 
 
 
1029}
1030
1031#define RX_BUF_SIZE	(PAGE_SIZE)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1032
1033/*
1034 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1035 *   [1] the RX DMA buffer is full.
1036 *   [2] the aging timer expires
 
1037 *
1038 * Condition [2] is triggered when a character has been sitting in the FIFO
1039 * for at least 8 byte durations.
 
1040 */
1041static void imx_uart_dma_rx_callback(void *data)
1042{
1043	struct imx_port *sport = data;
1044	struct dma_chan	*chan = sport->dma_chan_rx;
1045	struct scatterlist *sgl = &sport->rx_sgl;
1046	struct tty_port *port = &sport->port.state->port;
1047	struct dma_tx_state state;
1048	struct circ_buf *rx_ring = &sport->rx_ring;
1049	enum dma_status status;
1050	unsigned int w_bytes = 0;
1051	unsigned int r_bytes;
1052	unsigned int bd_size;
1053
1054	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
1055
1056	if (status == DMA_ERROR) {
1057		imx_uart_clear_rx_errors(sport);
1058		return;
1059	}
1060
1061	if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1062
1063		/*
1064		 * The state-residue variable represents the empty space
1065		 * relative to the entire buffer. Taking this in consideration
1066		 * the head is always calculated base on the buffer total
1067		 * length - DMA transaction residue. The UART script from the
1068		 * SDMA firmware will jump to the next buffer descriptor,
1069		 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1070		 * Taking this in consideration the tail is always at the
1071		 * beginning of the buffer descriptor that contains the head.
1072		 */
1073
1074		/* Calculate the head */
1075		rx_ring->head = sg_dma_len(sgl) - state.residue;
1076
1077		/* Calculate the tail. */
1078		bd_size = sg_dma_len(sgl) / sport->rx_periods;
1079		rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1080
1081		if (rx_ring->head <= sg_dma_len(sgl) &&
1082		    rx_ring->head > rx_ring->tail) {
1083
1084			/* Move data from tail to head */
1085			r_bytes = rx_ring->head - rx_ring->tail;
1086
1087			/* CPU claims ownership of RX DMA buffer */
1088			dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1089				DMA_FROM_DEVICE);
1090
1091			w_bytes = tty_insert_flip_string(port,
1092				sport->rx_buf + rx_ring->tail, r_bytes);
1093
1094			/* UART retrieves ownership of RX DMA buffer */
1095			dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1096				DMA_FROM_DEVICE);
1097
1098			if (w_bytes != r_bytes)
1099				sport->port.icount.buf_overrun++;
1100
1101			sport->port.icount.rx += w_bytes;
1102		} else	{
1103			WARN_ON(rx_ring->head > sg_dma_len(sgl));
1104			WARN_ON(rx_ring->head <= rx_ring->tail);
1105		}
1106	}
1107
1108	if (w_bytes) {
 
1109		tty_flip_buffer_push(port);
1110		dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1111	}
1112}
1113
1114/* RX DMA buffer periods */
1115#define RX_DMA_PERIODS 4
 
 
1116
1117static int imx_uart_start_rx_dma(struct imx_port *sport)
1118{
1119	struct scatterlist *sgl = &sport->rx_sgl;
1120	struct dma_chan	*chan = sport->dma_chan_rx;
1121	struct device *dev = sport->port.dev;
1122	struct dma_async_tx_descriptor *desc;
1123	int ret;
1124
1125	sport->rx_ring.head = 0;
1126	sport->rx_ring.tail = 0;
1127	sport->rx_periods = RX_DMA_PERIODS;
1128
1129	sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1130	ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1131	if (ret == 0) {
1132		dev_err(dev, "DMA mapping error for RX.\n");
1133		return -EINVAL;
1134	}
1135
1136	desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1137		sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1138		DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1139
1140	if (!desc) {
1141		dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1142		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1143		return -EINVAL;
1144	}
1145	desc->callback = imx_uart_dma_rx_callback;
1146	desc->callback_param = sport;
1147
1148	dev_dbg(dev, "RX: prepare for the DMA.\n");
1149	sport->dma_is_rxing = 1;
1150	sport->rx_cookie = dmaengine_submit(desc);
1151	dma_async_issue_pending(chan);
1152	return 0;
1153}
1154
1155static void imx_uart_clear_rx_errors(struct imx_port *sport)
1156{
1157	struct tty_port *port = &sport->port.state->port;
1158	u32 usr1, usr2;
1159
1160	usr1 = imx_uart_readl(sport, USR1);
1161	usr2 = imx_uart_readl(sport, USR2);
1162
1163	if (usr2 & USR2_BRCD) {
1164		sport->port.icount.brk++;
1165		imx_uart_writel(sport, USR2_BRCD, USR2);
1166		uart_handle_break(&sport->port);
1167		if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1168			sport->port.icount.buf_overrun++;
1169		tty_flip_buffer_push(port);
1170	} else {
1171		dev_err(sport->port.dev, "DMA transaction error.\n");
1172		if (usr1 & USR1_FRAMERR) {
1173			sport->port.icount.frame++;
1174			imx_uart_writel(sport, USR1_FRAMERR, USR1);
1175		} else if (usr1 & USR1_PARITYERR) {
1176			sport->port.icount.parity++;
1177			imx_uart_writel(sport, USR1_PARITYERR, USR1);
1178		}
1179	}
1180
1181	if (usr2 & USR2_ORE) {
1182		sport->port.icount.overrun++;
1183		imx_uart_writel(sport, USR2_ORE, USR2);
1184	}
1185
1186}
1187
1188#define TXTL_DEFAULT 2 /* reset default */
1189#define RXTL_DEFAULT 1 /* reset default */
1190#define TXTL_DMA 8 /* DMA burst setting */
1191#define RXTL_DMA 9 /* DMA burst setting */
1192
1193static void imx_uart_setup_ufcr(struct imx_port *sport,
1194				unsigned char txwl, unsigned char rxwl)
1195{
1196	unsigned int val;
1197
1198	/* set receiver / transmitter trigger level */
1199	val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1200	val |= txwl << UFCR_TXTL_SHF | rxwl;
1201	imx_uart_writel(sport, val, UFCR);
1202}
1203
1204static void imx_uart_dma_exit(struct imx_port *sport)
1205{
1206	if (sport->dma_chan_rx) {
1207		dmaengine_terminate_sync(sport->dma_chan_rx);
1208		dma_release_channel(sport->dma_chan_rx);
1209		sport->dma_chan_rx = NULL;
1210		sport->rx_cookie = -EINVAL;
1211		kfree(sport->rx_buf);
1212		sport->rx_buf = NULL;
1213	}
1214
1215	if (sport->dma_chan_tx) {
1216		dmaengine_terminate_sync(sport->dma_chan_tx);
1217		dma_release_channel(sport->dma_chan_tx);
1218		sport->dma_chan_tx = NULL;
1219	}
 
 
1220}
1221
1222static int imx_uart_dma_init(struct imx_port *sport)
1223{
1224	struct dma_slave_config slave_config = {};
1225	struct device *dev = sport->port.dev;
1226	int ret;
1227
1228	/* Prepare for RX : */
1229	sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1230	if (!sport->dma_chan_rx) {
1231		dev_dbg(dev, "cannot get the DMA channel.\n");
1232		ret = -EINVAL;
1233		goto err;
1234	}
1235
1236	slave_config.direction = DMA_DEV_TO_MEM;
1237	slave_config.src_addr = sport->port.mapbase + URXD0;
1238	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1239	/* one byte less than the watermark level to enable the aging timer */
1240	slave_config.src_maxburst = RXTL_DMA - 1;
1241	ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1242	if (ret) {
1243		dev_err(dev, "error in RX dma configuration.\n");
1244		goto err;
1245	}
1246
1247	sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1248	if (!sport->rx_buf) {
 
1249		ret = -ENOMEM;
1250		goto err;
1251	}
1252	sport->rx_ring.buf = sport->rx_buf;
1253
1254	/* Prepare for TX : */
1255	sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1256	if (!sport->dma_chan_tx) {
1257		dev_err(dev, "cannot get the TX DMA channel!\n");
1258		ret = -EINVAL;
1259		goto err;
1260	}
1261
1262	slave_config.direction = DMA_MEM_TO_DEV;
1263	slave_config.dst_addr = sport->port.mapbase + URTX0;
1264	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1265	slave_config.dst_maxburst = TXTL_DMA;
1266	ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1267	if (ret) {
1268		dev_err(dev, "error in TX dma configuration.");
1269		goto err;
1270	}
1271
 
 
1272	return 0;
1273err:
1274	imx_uart_dma_exit(sport);
1275	return ret;
1276}
1277
1278static void imx_uart_enable_dma(struct imx_port *sport)
1279{
1280	u32 ucr1;
1281
1282	imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1283
1284	/* set UCR1 */
1285	ucr1 = imx_uart_readl(sport, UCR1);
1286	ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1287	imx_uart_writel(sport, ucr1, UCR1);
 
 
 
 
 
 
 
1288
1289	sport->dma_is_enabled = 1;
1290}
1291
1292static void imx_uart_disable_dma(struct imx_port *sport)
1293{
1294	u32 ucr1, ucr2;
1295
1296	/* clear UCR1 */
1297	ucr1 = imx_uart_readl(sport, UCR1);
1298	ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1299	imx_uart_writel(sport, ucr1, UCR1);
1300
1301	/* clear UCR2 */
1302	ucr2 = imx_uart_readl(sport, UCR2);
1303	ucr2 &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
1304	imx_uart_writel(sport, ucr2, UCR2);
1305
1306	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
 
 
 
1307
1308	sport->dma_is_enabled = 0;
1309}
1310
1311/* half the RX buffer size */
1312#define CTSTL 16
1313
1314static int imx_uart_startup(struct uart_port *port)
1315{
1316	struct imx_port *sport = (struct imx_port *)port;
1317	int retval, i;
1318	unsigned long flags;
1319	int dma_is_inited = 0;
1320	u32 ucr1, ucr2, ucr4;
1321
1322	retval = clk_prepare_enable(sport->clk_per);
1323	if (retval)
1324		return retval;
1325	retval = clk_prepare_enable(sport->clk_ipg);
1326	if (retval) {
1327		clk_disable_unprepare(sport->clk_per);
1328		return retval;
1329	}
1330
1331	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1332
1333	/* disable the DREN bit (Data Ready interrupt enable) before
1334	 * requesting IRQs
1335	 */
1336	ucr4 = imx_uart_readl(sport, UCR4);
1337
1338	/* set the trigger level for CTS */
1339	ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1340	ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1341
1342	imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
 
1343
1344	/* Can we enable the DMA support? */
1345	if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1346		dma_is_inited = 1;
1347
1348	spin_lock_irqsave(&sport->port.lock, flags);
1349	/* Reset fifo's and state machines */
1350	i = 100;
1351
1352	ucr2 = imx_uart_readl(sport, UCR2);
1353	ucr2 &= ~UCR2_SRST;
1354	imx_uart_writel(sport, ucr2, UCR2);
 
 
 
 
 
 
 
 
1355
1356	while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1357		udelay(1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1358
 
1359	/*
1360	 * Finally, clear and enable interrupts
1361	 */
1362	imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1363	imx_uart_writel(sport, USR2_ORE, USR2);
1364
1365	ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1366	ucr1 |= UCR1_UARTEN;
1367	if (sport->have_rtscts)
1368		ucr1 |= UCR1_RTSDEN;
1369
1370	imx_uart_writel(sport, ucr1, UCR1);
 
 
 
1371
1372	ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
1373	if (!sport->dma_is_enabled)
1374		ucr4 |= UCR4_OREN;
1375	imx_uart_writel(sport, ucr4, UCR4);
1376
1377	ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1378	ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1379	if (!sport->have_rtscts)
1380		ucr2 |= UCR2_IRTS;
1381	/*
1382	 * make sure the edge sensitive RTS-irq is disabled,
1383	 * we're using RTSD instead.
1384	 */
1385	if (!imx_uart_is_imx1(sport))
1386		ucr2 &= ~UCR2_RTSEN;
1387	imx_uart_writel(sport, ucr2, UCR2);
1388
1389	if (!imx_uart_is_imx1(sport)) {
1390		u32 ucr3;
1391
1392		ucr3 = imx_uart_readl(sport, UCR3);
 
 
 
 
1393
1394		ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
 
 
 
 
1395
1396		if (sport->dte_mode)
1397			/* disable broken interrupts */
1398			ucr3 &= ~(UCR3_RI | UCR3_DCD);
 
 
 
 
1399
1400		imx_uart_writel(sport, ucr3, UCR3);
 
 
 
 
 
1401	}
1402
1403	/*
1404	 * Enable modem status interrupts
1405	 */
1406	imx_uart_enable_ms(&sport->port);
 
1407
1408	if (dma_is_inited) {
1409		imx_uart_enable_dma(sport);
1410		imx_uart_start_rx_dma(sport);
1411	} else {
1412		ucr1 = imx_uart_readl(sport, UCR1);
1413		ucr1 |= UCR1_RRDYEN;
1414		imx_uart_writel(sport, ucr1, UCR1);
1415
1416		ucr2 = imx_uart_readl(sport, UCR2);
1417		ucr2 |= UCR2_ATEN;
1418		imx_uart_writel(sport, ucr2, UCR2);
1419	}
1420
1421	spin_unlock_irqrestore(&sport->port.lock, flags);
1422
1423	return 0;
 
 
 
 
 
 
 
 
 
1424}
1425
1426static void imx_uart_shutdown(struct uart_port *port)
1427{
1428	struct imx_port *sport = (struct imx_port *)port;
 
1429	unsigned long flags;
1430	u32 ucr1, ucr2;
1431
1432	if (sport->dma_is_enabled) {
1433		sport->dma_is_rxing = 0;
1434		sport->dma_is_txing = 0;
1435		dmaengine_terminate_sync(sport->dma_chan_tx);
1436		dmaengine_terminate_sync(sport->dma_chan_rx);
1437
1438		spin_lock_irqsave(&sport->port.lock, flags);
1439		imx_uart_stop_tx(port);
1440		imx_uart_stop_rx(port);
1441		imx_uart_disable_dma(sport);
1442		spin_unlock_irqrestore(&sport->port.lock, flags);
1443		imx_uart_dma_exit(sport);
1444	}
1445
1446	mctrl_gpio_disable_ms(sport->gpios);
1447
1448	spin_lock_irqsave(&sport->port.lock, flags);
1449	ucr2 = imx_uart_readl(sport, UCR2);
1450	ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1451	imx_uart_writel(sport, ucr2, UCR2);
1452	spin_unlock_irqrestore(&sport->port.lock, flags);
1453
 
 
 
 
 
 
 
1454	/*
1455	 * Stop our timer.
1456	 */
1457	del_timer_sync(&sport->timer);
1458
1459	/*
 
 
 
 
 
 
 
 
 
 
 
1460	 * Disable all interrupts, port and break condition.
1461	 */
1462
1463	spin_lock_irqsave(&sport->port.lock, flags);
1464	ucr1 = imx_uart_readl(sport, UCR1);
1465	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
 
 
1466
1467	imx_uart_writel(sport, ucr1, UCR1);
1468	spin_unlock_irqrestore(&sport->port.lock, flags);
1469
1470	clk_disable_unprepare(sport->clk_per);
1471	clk_disable_unprepare(sport->clk_ipg);
1472}
1473
1474/* called with port.lock taken and irqs off */
1475static void imx_uart_flush_buffer(struct uart_port *port)
1476{
1477	struct imx_port *sport = (struct imx_port *)port;
1478	struct scatterlist *sgl = &sport->tx_sgl[0];
1479	u32 ucr2;
1480	int i = 100, ubir, ubmr, uts;
1481
1482	if (!sport->dma_chan_tx)
1483		return;
1484
1485	sport->tx_bytes = 0;
1486	dmaengine_terminate_all(sport->dma_chan_tx);
1487	if (sport->dma_is_txing) {
1488		u32 ucr1;
1489
1490		dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1491			     DMA_TO_DEVICE);
1492		ucr1 = imx_uart_readl(sport, UCR1);
1493		ucr1 &= ~UCR1_TXDMAEN;
1494		imx_uart_writel(sport, ucr1, UCR1);
1495		sport->dma_is_txing = 0;
1496	}
1497
1498	/*
1499	 * According to the Reference Manual description of the UART SRST bit:
1500	 *
1501	 * "Reset the transmit and receive state machines,
1502	 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1503	 * and UTS[6-3]".
1504	 *
1505	 * We don't need to restore the old values from USR1, USR2, URXD and
1506	 * UTXD. UBRC is read only, so only save/restore the other three
1507	 * registers.
1508	 */
1509	ubir = imx_uart_readl(sport, UBIR);
1510	ubmr = imx_uart_readl(sport, UBMR);
1511	uts = imx_uart_readl(sport, IMX21_UTS);
1512
1513	ucr2 = imx_uart_readl(sport, UCR2);
1514	ucr2 &= ~UCR2_SRST;
1515	imx_uart_writel(sport, ucr2, UCR2);
1516
1517	while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1518		udelay(1);
1519
1520	/* Restore the registers */
1521	imx_uart_writel(sport, ubir, UBIR);
1522	imx_uart_writel(sport, ubmr, UBMR);
1523	imx_uart_writel(sport, uts, IMX21_UTS);
1524}
1525
1526static void
1527imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1528		     struct ktermios *old)
1529{
1530	struct imx_port *sport = (struct imx_port *)port;
1531	unsigned long flags;
1532	u32 ucr2, old_ucr1, old_ucr2, ufcr;
1533	unsigned int baud, quot;
1534	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1535	unsigned long div;
1536	unsigned long num, denom;
1537	uint64_t tdiv64;
1538
1539	/*
 
 
 
 
 
 
 
 
 
1540	 * We only support CS7 and CS8.
1541	 */
1542	while ((termios->c_cflag & CSIZE) != CS7 &&
1543	       (termios->c_cflag & CSIZE) != CS8) {
1544		termios->c_cflag &= ~CSIZE;
1545		termios->c_cflag |= old_csize;
1546		old_csize = CS8;
1547	}
1548
1549	if ((termios->c_cflag & CSIZE) == CS8)
1550		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1551	else
1552		ucr2 = UCR2_SRST | UCR2_IRTS;
1553
1554	if (termios->c_cflag & CRTSCTS) {
1555		if (sport->have_rtscts) {
1556			ucr2 &= ~UCR2_IRTS;
 
1557
1558			if (port->rs485.flags & SER_RS485_ENABLED) {
1559				/*
1560				 * RTS is mandatory for rs485 operation, so keep
1561				 * it under manual control and keep transmitter
1562				 * disabled.
1563				 */
1564				if (port->rs485.flags &
1565				    SER_RS485_RTS_AFTER_SEND)
1566					imx_uart_rts_active(sport, &ucr2);
1567				else
1568					imx_uart_rts_inactive(sport, &ucr2);
1569			} else {
1570				imx_uart_rts_auto(sport, &ucr2);
1571			}
1572		} else {
1573			termios->c_cflag &= ~CRTSCTS;
1574		}
1575	} else if (port->rs485.flags & SER_RS485_ENABLED) {
1576		/* disable transmitter */
1577		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1578			imx_uart_rts_active(sport, &ucr2);
1579		else
1580			imx_uart_rts_inactive(sport, &ucr2);
1581	}
1582
1583
1584	if (termios->c_cflag & CSTOPB)
1585		ucr2 |= UCR2_STPB;
1586	if (termios->c_cflag & PARENB) {
1587		ucr2 |= UCR2_PREN;
1588		if (termios->c_cflag & PARODD)
1589			ucr2 |= UCR2_PROE;
1590	}
1591
1592	del_timer_sync(&sport->timer);
1593
1594	/*
1595	 * Ask the core to calculate the divisor for us.
1596	 */
1597	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1598	quot = uart_get_divisor(port, baud);
1599
1600	spin_lock_irqsave(&sport->port.lock, flags);
1601
1602	sport->port.read_status_mask = 0;
1603	if (termios->c_iflag & INPCK)
1604		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1605	if (termios->c_iflag & (BRKINT | PARMRK))
1606		sport->port.read_status_mask |= URXD_BRK;
1607
1608	/*
1609	 * Characters to ignore
1610	 */
1611	sport->port.ignore_status_mask = 0;
1612	if (termios->c_iflag & IGNPAR)
1613		sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1614	if (termios->c_iflag & IGNBRK) {
1615		sport->port.ignore_status_mask |= URXD_BRK;
1616		/*
1617		 * If we're ignoring parity and break indicators,
1618		 * ignore overruns too (for real raw support).
1619		 */
1620		if (termios->c_iflag & IGNPAR)
1621			sport->port.ignore_status_mask |= URXD_OVRRUN;
1622	}
1623
1624	if ((termios->c_cflag & CREAD) == 0)
1625		sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1626
1627	/*
1628	 * Update the per-port timeout.
1629	 */
1630	uart_update_timeout(port, termios->c_cflag, baud);
1631
1632	/*
1633	 * disable interrupts and drain transmitter
1634	 */
1635	old_ucr1 = imx_uart_readl(sport, UCR1);
1636	imx_uart_writel(sport,
1637			old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1638			UCR1);
1639	old_ucr2 = imx_uart_readl(sport, UCR2);
1640	imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
1641
1642	while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
1643		barrier();
1644
1645	/* then, disable everything */
1646	imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
1647	old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
 
 
1648
1649	/* custom-baudrate handling */
1650	div = sport->port.uartclk / (baud * 16);
1651	if (baud == 38400 && quot != div)
1652		baud = sport->port.uartclk / (quot * 16);
1653
1654	div = sport->port.uartclk / (baud * 16);
1655	if (div > 7)
1656		div = 7;
1657	if (!div)
1658		div = 1;
 
 
 
 
 
 
 
 
 
 
 
 
1659
1660	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1661		1 << 16, 1 << 16, &num, &denom);
1662
1663	tdiv64 = sport->port.uartclk;
1664	tdiv64 *= num;
1665	do_div(tdiv64, denom * 16 * div);
1666	tty_termios_encode_baud_rate(termios,
1667				(speed_t)tdiv64, (speed_t)tdiv64);
1668
1669	num -= 1;
1670	denom -= 1;
1671
1672	ufcr = imx_uart_readl(sport, UFCR);
1673	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1674	imx_uart_writel(sport, ufcr, UFCR);
 
 
1675
1676	imx_uart_writel(sport, num, UBIR);
1677	imx_uart_writel(sport, denom, UBMR);
1678
1679	if (!imx_uart_is_imx1(sport))
1680		imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1681				IMX21_ONEMS);
1682
1683	imx_uart_writel(sport, old_ucr1, UCR1);
1684
1685	/* set the parity, stop bits and data size */
1686	imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
1687
1688	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1689		imx_uart_enable_ms(&sport->port);
1690
 
 
1691	spin_unlock_irqrestore(&sport->port.lock, flags);
1692}
1693
1694static const char *imx_uart_type(struct uart_port *port)
1695{
1696	struct imx_port *sport = (struct imx_port *)port;
1697
1698	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1699}
1700
1701/*
1702 * Configure/autoconfigure the port.
1703 */
1704static void imx_uart_config_port(struct uart_port *port, int flags)
1705{
1706	struct imx_port *sport = (struct imx_port *)port;
1707
1708	if (flags & UART_CONFIG_TYPE)
1709		sport->port.type = PORT_IMX;
1710}
1711
1712/*
1713 * Verify the new serial_struct (for TIOCSSERIAL).
1714 * The only change we allow are to the flags and type, and
1715 * even then only between PORT_IMX and PORT_UNKNOWN
1716 */
1717static int
1718imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1719{
1720	struct imx_port *sport = (struct imx_port *)port;
1721	int ret = 0;
1722
1723	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1724		ret = -EINVAL;
1725	if (sport->port.irq != ser->irq)
1726		ret = -EINVAL;
1727	if (ser->io_type != UPIO_MEM)
1728		ret = -EINVAL;
1729	if (sport->port.uartclk / 16 != ser->baud_base)
1730		ret = -EINVAL;
1731	if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1732		ret = -EINVAL;
1733	if (sport->port.iobase != ser->port)
1734		ret = -EINVAL;
1735	if (ser->hub6 != 0)
1736		ret = -EINVAL;
1737	return ret;
1738}
1739
1740#if defined(CONFIG_CONSOLE_POLL)
1741
1742static int imx_uart_poll_init(struct uart_port *port)
1743{
1744	struct imx_port *sport = (struct imx_port *)port;
1745	unsigned long flags;
1746	u32 ucr1, ucr2;
1747	int retval;
1748
1749	retval = clk_prepare_enable(sport->clk_ipg);
1750	if (retval)
1751		return retval;
1752	retval = clk_prepare_enable(sport->clk_per);
1753	if (retval)
1754		clk_disable_unprepare(sport->clk_ipg);
1755
1756	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1757
1758	spin_lock_irqsave(&sport->port.lock, flags);
1759
1760	/*
1761	 * Be careful about the order of enabling bits here. First enable the
1762	 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1763	 * This prevents that a character that already sits in the RX fifo is
1764	 * triggering an irq but the try to fetch it from there results in an
1765	 * exception because UARTEN or RXEN is still off.
1766	 */
1767	ucr1 = imx_uart_readl(sport, UCR1);
1768	ucr2 = imx_uart_readl(sport, UCR2);
1769
1770	if (imx_uart_is_imx1(sport))
1771		ucr1 |= IMX1_UCR1_UARTCLKEN;
1772
1773	ucr1 |= UCR1_UARTEN;
1774	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1775
1776	ucr2 |= UCR2_RXEN;
1777	ucr2 &= ~UCR2_ATEN;
 
 
 
 
1778
1779	imx_uart_writel(sport, ucr1, UCR1);
1780	imx_uart_writel(sport, ucr2, UCR2);
 
 
1781
1782	/* now enable irqs */
1783	imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1784	imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1785
1786	spin_unlock_irqrestore(&sport->port.lock, flags);
 
1787
1788	return 0;
1789}
1790
1791static int imx_uart_poll_get_char(struct uart_port *port)
1792{
1793	struct imx_port *sport = (struct imx_port *)port;
1794	if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1795		return NO_POLL_CHAR;
1796
1797	return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1798}
1799
1800static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1801{
1802	struct imx_port *sport = (struct imx_port *)port;
1803	unsigned int status;
 
 
1804
1805	/* drain */
1806	do {
1807		status = imx_uart_readl(sport, USR1);
1808	} while (~status & USR1_TRDY);
1809
1810	/* write */
1811	imx_uart_writel(sport, c, URTX0);
1812
1813	/* flush */
1814	do {
1815		status = imx_uart_readl(sport, USR2);
1816	} while (~status & USR2_TXDC);
1817}
1818#endif
1819
1820/* called with port.lock taken and irqs off or from .probe without locking */
1821static int imx_uart_rs485_config(struct uart_port *port,
1822				 struct serial_rs485 *rs485conf)
1823{
1824	struct imx_port *sport = (struct imx_port *)port;
1825	u32 ucr2;
1826
1827	/* unimplemented */
1828	rs485conf->delay_rts_before_send = 0;
1829	rs485conf->delay_rts_after_send = 0;
1830
1831	/* RTS is required to control the transmitter */
1832	if (!sport->have_rtscts && !sport->have_rtsgpio)
1833		rs485conf->flags &= ~SER_RS485_ENABLED;
1834
1835	if (rs485conf->flags & SER_RS485_ENABLED) {
1836		/* Enable receiver if low-active RTS signal is requested */
1837		if (sport->have_rtscts &&  !sport->have_rtsgpio &&
1838		    !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1839			rs485conf->flags |= SER_RS485_RX_DURING_TX;
1840
1841		/* disable transmitter */
1842		ucr2 = imx_uart_readl(sport, UCR2);
1843		if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1844			imx_uart_rts_active(sport, &ucr2);
1845		else
1846			imx_uart_rts_inactive(sport, &ucr2);
1847		imx_uart_writel(sport, ucr2, UCR2);
1848	}
1849
1850	/* Make sure Rx is enabled in case Tx is active with Rx disabled */
1851	if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1852	    rs485conf->flags & SER_RS485_RX_DURING_TX)
1853		imx_uart_start_rx(port);
1854
1855	port->rs485 = *rs485conf;
1856
1857	return 0;
 
1858}
 
1859
1860static const struct uart_ops imx_uart_pops = {
1861	.tx_empty	= imx_uart_tx_empty,
1862	.set_mctrl	= imx_uart_set_mctrl,
1863	.get_mctrl	= imx_uart_get_mctrl,
1864	.stop_tx	= imx_uart_stop_tx,
1865	.start_tx	= imx_uart_start_tx,
1866	.stop_rx	= imx_uart_stop_rx,
1867	.enable_ms	= imx_uart_enable_ms,
1868	.break_ctl	= imx_uart_break_ctl,
1869	.startup	= imx_uart_startup,
1870	.shutdown	= imx_uart_shutdown,
1871	.flush_buffer	= imx_uart_flush_buffer,
1872	.set_termios	= imx_uart_set_termios,
1873	.type		= imx_uart_type,
1874	.config_port	= imx_uart_config_port,
1875	.verify_port	= imx_uart_verify_port,
1876#if defined(CONFIG_CONSOLE_POLL)
1877	.poll_init      = imx_uart_poll_init,
1878	.poll_get_char  = imx_uart_poll_get_char,
1879	.poll_put_char  = imx_uart_poll_put_char,
1880#endif
1881};
1882
1883static struct imx_port *imx_uart_ports[UART_NR];
1884
1885#ifdef CONFIG_SERIAL_IMX_CONSOLE
1886static void imx_uart_console_putchar(struct uart_port *port, int ch)
1887{
1888	struct imx_port *sport = (struct imx_port *)port;
1889
1890	while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1891		barrier();
1892
1893	imx_uart_writel(sport, ch, URTX0);
1894}
1895
1896/*
1897 * Interrupts are disabled on entering
1898 */
1899static void
1900imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1901{
1902	struct imx_port *sport = imx_uart_ports[co->index];
1903	struct imx_port_ucrs old_ucr;
1904	unsigned int ucr1;
1905	unsigned long flags = 0;
1906	int locked = 1;
1907	int retval;
1908
1909	retval = clk_enable(sport->clk_per);
1910	if (retval)
1911		return;
1912	retval = clk_enable(sport->clk_ipg);
1913	if (retval) {
1914		clk_disable(sport->clk_per);
1915		return;
1916	}
1917
1918	if (sport->port.sysrq)
1919		locked = 0;
1920	else if (oops_in_progress)
1921		locked = spin_trylock_irqsave(&sport->port.lock, flags);
1922	else
1923		spin_lock_irqsave(&sport->port.lock, flags);
1924
1925	/*
1926	 *	First, save UCR1/2/3 and then disable interrupts
1927	 */
1928	imx_uart_ucrs_save(sport, &old_ucr);
1929	ucr1 = old_ucr.ucr1;
1930
1931	if (imx_uart_is_imx1(sport))
1932		ucr1 |= IMX1_UCR1_UARTCLKEN;
1933	ucr1 |= UCR1_UARTEN;
1934	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1935
1936	imx_uart_writel(sport, ucr1, UCR1);
1937
1938	imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
1939
1940	uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
1941
1942	/*
1943	 *	Finally, wait for transmitter to become empty
1944	 *	and restore UCR1/2/3
1945	 */
1946	while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
1947
1948	imx_uart_ucrs_restore(sport, &old_ucr);
1949
1950	if (locked)
1951		spin_unlock_irqrestore(&sport->port.lock, flags);
1952
1953	clk_disable(sport->clk_ipg);
1954	clk_disable(sport->clk_per);
1955}
1956
1957/*
1958 * If the port was already initialised (eg, by a boot loader),
1959 * try to determine the current setup.
1960 */
1961static void __init
1962imx_uart_console_get_options(struct imx_port *sport, int *baud,
1963			     int *parity, int *bits)
1964{
1965
1966	if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
1967		/* ok, the port was enabled */
1968		unsigned int ucr2, ubir, ubmr, uartclk;
1969		unsigned int baud_raw;
1970		unsigned int ucfr_rfdiv;
1971
1972		ucr2 = imx_uart_readl(sport, UCR2);
1973
1974		*parity = 'n';
1975		if (ucr2 & UCR2_PREN) {
1976			if (ucr2 & UCR2_PROE)
1977				*parity = 'o';
1978			else
1979				*parity = 'e';
1980		}
1981
1982		if (ucr2 & UCR2_WS)
1983			*bits = 8;
1984		else
1985			*bits = 7;
1986
1987		ubir = imx_uart_readl(sport, UBIR) & 0xffff;
1988		ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
1989
1990		ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
1991		if (ucfr_rfdiv == 6)
1992			ucfr_rfdiv = 7;
1993		else
1994			ucfr_rfdiv = 6 - ucfr_rfdiv;
1995
1996		uartclk = clk_get_rate(sport->clk_per);
1997		uartclk /= ucfr_rfdiv;
1998
1999		{	/*
2000			 * The next code provides exact computation of
2001			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2002			 * without need of float support or long long division,
2003			 * which would be required to prevent 32bit arithmetic overflow
2004			 */
2005			unsigned int mul = ubir + 1;
2006			unsigned int div = 16 * (ubmr + 1);
2007			unsigned int rem = uartclk % div;
2008
2009			baud_raw = (uartclk / div) * mul;
2010			baud_raw += (rem * mul + div / 2) / div;
2011			*baud = (baud_raw + 50) / 100 * 100;
2012		}
2013
2014		if (*baud != baud_raw)
2015			pr_info("Console IMX rounded baud rate from %d to %d\n",
2016				baud_raw, *baud);
2017	}
2018}
2019
2020static int __init
2021imx_uart_console_setup(struct console *co, char *options)
2022{
2023	struct imx_port *sport;
2024	int baud = 9600;
2025	int bits = 8;
2026	int parity = 'n';
2027	int flow = 'n';
2028	int retval;
2029
2030	/*
2031	 * Check whether an invalid uart number has been specified, and
2032	 * if so, search for the first available port that does have
2033	 * console support.
2034	 */
2035	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2036		co->index = 0;
2037	sport = imx_uart_ports[co->index];
2038	if (sport == NULL)
2039		return -ENODEV;
2040
2041	/* For setting the registers, we only need to enable the ipg clock. */
2042	retval = clk_prepare_enable(sport->clk_ipg);
2043	if (retval)
2044		goto error_console;
2045
2046	if (options)
2047		uart_parse_options(options, &baud, &parity, &bits, &flow);
2048	else
2049		imx_uart_console_get_options(sport, &baud, &parity, &bits);
2050
2051	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2052
2053	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2054
2055	clk_disable(sport->clk_ipg);
2056	if (retval) {
2057		clk_unprepare(sport->clk_ipg);
2058		goto error_console;
2059	}
2060
2061	retval = clk_prepare(sport->clk_per);
2062	if (retval)
2063		clk_disable_unprepare(sport->clk_ipg);
2064
2065error_console:
2066	return retval;
2067}
2068
2069static struct uart_driver imx_uart_uart_driver;
2070static struct console imx_uart_console = {
2071	.name		= DEV_NAME,
2072	.write		= imx_uart_console_write,
2073	.device		= uart_console_device,
2074	.setup		= imx_uart_console_setup,
2075	.flags		= CON_PRINTBUFFER,
2076	.index		= -1,
2077	.data		= &imx_uart_uart_driver,
2078};
2079
2080#define IMX_CONSOLE	&imx_uart_console
 
 
 
2081
2082#ifdef CONFIG_OF
2083static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
2084{
2085	struct imx_port *sport = (struct imx_port *)port;
 
 
 
 
 
2086
2087	while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
2088		cpu_relax();
 
 
2089
2090	imx_uart_writel(sport, ch, URTX0);
2091}
 
 
2092
2093static void imx_uart_console_early_write(struct console *con, const char *s,
2094					 unsigned count)
2095{
2096	struct earlycon_device *dev = con->data;
2097
2098	uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
2099}
2100
2101static int __init
2102imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2103{
2104	if (!dev->port.membase)
2105		return -ENODEV;
 
 
 
 
 
2106
2107	dev->con->write = imx_uart_console_early_write;
2108
2109	return 0;
2110}
2111OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2112OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2113#endif
2114
2115#else
2116#define IMX_CONSOLE	NULL
2117#endif
2118
2119static struct uart_driver imx_uart_uart_driver = {
2120	.owner          = THIS_MODULE,
2121	.driver_name    = DRIVER_NAME,
2122	.dev_name       = DEV_NAME,
2123	.major          = SERIAL_IMX_MAJOR,
2124	.minor          = MINOR_START,
2125	.nr             = ARRAY_SIZE(imx_uart_ports),
2126	.cons           = IMX_CONSOLE,
2127};
2128
2129#ifdef CONFIG_OF
2130/*
2131 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2132 * could successfully get all information from dt or a negative errno.
2133 */
2134static int imx_uart_probe_dt(struct imx_port *sport,
2135			     struct platform_device *pdev)
2136{
2137	struct device_node *np = pdev->dev.of_node;
 
 
2138	int ret;
2139
2140	sport->devdata = of_device_get_match_data(&pdev->dev);
2141	if (!sport->devdata)
2142		/* no device tree device */
2143		return 1;
2144
2145	ret = of_alias_get_id(np, "serial");
2146	if (ret < 0) {
2147		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2148		return ret;
2149	}
2150	sport->port.line = ret;
2151
2152	if (of_get_property(np, "uart-has-rtscts", NULL) ||
2153	    of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2154		sport->have_rtscts = 1;
2155
 
 
 
2156	if (of_get_property(np, "fsl,dte-mode", NULL))
2157		sport->dte_mode = 1;
2158
2159	if (of_get_property(np, "rts-gpios", NULL))
2160		sport->have_rtsgpio = 1;
2161
2162	return 0;
2163}
2164#else
2165static inline int imx_uart_probe_dt(struct imx_port *sport,
2166				    struct platform_device *pdev)
2167{
2168	return 1;
2169}
2170#endif
2171
2172static void imx_uart_probe_pdata(struct imx_port *sport,
2173				 struct platform_device *pdev)
2174{
2175	struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2176
2177	sport->port.line = pdev->id;
2178	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
2179
2180	if (!pdata)
2181		return;
2182
2183	if (pdata->flags & IMXUART_HAVE_RTSCTS)
2184		sport->have_rtscts = 1;
 
 
 
2185}
2186
2187static int imx_uart_probe(struct platform_device *pdev)
2188{
2189	struct imx_port *sport;
2190	void __iomem *base;
2191	int ret = 0;
2192	u32 ucr1;
2193	struct resource *res;
2194	int txirq, rxirq, rtsirq;
2195
2196	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2197	if (!sport)
2198		return -ENOMEM;
2199
2200	ret = imx_uart_probe_dt(sport, pdev);
2201	if (ret > 0)
2202		imx_uart_probe_pdata(sport, pdev);
2203	else if (ret < 0)
2204		return ret;
2205
2206	if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2207		dev_err(&pdev->dev, "serial%d out of range\n",
2208			sport->port.line);
2209		return -EINVAL;
2210	}
2211
2212	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2213	base = devm_ioremap_resource(&pdev->dev, res);
2214	if (IS_ERR(base))
2215		return PTR_ERR(base);
2216
2217	rxirq = platform_get_irq(pdev, 0);
2218	txirq = platform_get_irq(pdev, 1);
2219	rtsirq = platform_get_irq(pdev, 2);
2220
2221	sport->port.dev = &pdev->dev;
2222	sport->port.mapbase = res->start;
2223	sport->port.membase = base;
2224	sport->port.type = PORT_IMX,
2225	sport->port.iotype = UPIO_MEM;
2226	sport->port.irq = rxirq;
 
 
 
2227	sport->port.fifosize = 32;
2228	sport->port.ops = &imx_uart_pops;
2229	sport->port.rs485_config = imx_uart_rs485_config;
2230	sport->port.flags = UPF_BOOT_AUTOCONF;
2231	timer_setup(&sport->timer, imx_uart_timeout, 0);
2232
2233	sport->gpios = mctrl_gpio_init(&sport->port, 0);
2234	if (IS_ERR(sport->gpios))
2235		return PTR_ERR(sport->gpios);
2236
2237	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2238	if (IS_ERR(sport->clk_ipg)) {
2239		ret = PTR_ERR(sport->clk_ipg);
2240		dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2241		return ret;
2242	}
2243
2244	sport->clk_per = devm_clk_get(&pdev->dev, "per");
2245	if (IS_ERR(sport->clk_per)) {
2246		ret = PTR_ERR(sport->clk_per);
2247		dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2248		return ret;
2249	}
2250
2251	sport->port.uartclk = clk_get_rate(sport->clk_per);
2252
2253	/* For register access, we only need to enable the ipg clock. */
2254	ret = clk_prepare_enable(sport->clk_ipg);
2255	if (ret) {
2256		dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2257		return ret;
2258	}
2259
2260	/* initialize shadow register values */
2261	sport->ucr1 = readl(sport->port.membase + UCR1);
2262	sport->ucr2 = readl(sport->port.membase + UCR2);
2263	sport->ucr3 = readl(sport->port.membase + UCR3);
2264	sport->ucr4 = readl(sport->port.membase + UCR4);
2265	sport->ufcr = readl(sport->port.membase + UFCR);
2266
2267	uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2268
2269	if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2270	    (!sport->have_rtscts && !sport->have_rtsgpio))
2271		dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2272
2273	/*
2274	 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2275	 * signal cannot be set low during transmission in case the
2276	 * receiver is off (limitation of the i.MX UART IP).
2277	 */
2278	if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2279	    sport->have_rtscts && !sport->have_rtsgpio &&
2280	    (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2281	     !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2282		dev_err(&pdev->dev,
2283			"low-active RTS not possible when receiver is off, enabling receiver\n");
2284
2285	imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2286
2287	/* Disable interrupts before requesting them */
2288	ucr1 = imx_uart_readl(sport, UCR1);
2289	ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2290		 UCR1_TXMPTYEN | UCR1_RTSDEN);
2291	imx_uart_writel(sport, ucr1, UCR1);
2292
2293	if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2294		/*
2295		 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2296		 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2297		 * and DCD (when they are outputs) or enables the respective
2298		 * irqs. So set this bit early, i.e. before requesting irqs.
2299		 */
2300		u32 ufcr = imx_uart_readl(sport, UFCR);
2301		if (!(ufcr & UFCR_DCEDTE))
2302			imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2303
2304		/*
2305		 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2306		 * enabled later because they cannot be cleared
2307		 * (confirmed on i.MX25) which makes them unusable.
2308		 */
2309		imx_uart_writel(sport,
2310				IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2311				UCR3);
2312
2313	} else {
2314		u32 ucr3 = UCR3_DSR;
2315		u32 ufcr = imx_uart_readl(sport, UFCR);
2316		if (ufcr & UFCR_DCEDTE)
2317			imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2318
2319		if (!imx_uart_is_imx1(sport))
2320			ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2321		imx_uart_writel(sport, ucr3, UCR3);
2322	}
2323
2324	clk_disable_unprepare(sport->clk_ipg);
2325
2326	/*
2327	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2328	 * chips only have one interrupt.
2329	 */
2330	if (txirq > 0) {
2331		ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2332				       dev_name(&pdev->dev), sport);
2333		if (ret) {
2334			dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2335				ret);
2336			return ret;
2337		}
2338
2339		ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2340				       dev_name(&pdev->dev), sport);
2341		if (ret) {
2342			dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2343				ret);
2344			return ret;
2345		}
2346	} else {
2347		ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2348				       dev_name(&pdev->dev), sport);
2349		if (ret) {
2350			dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2351			return ret;
2352		}
2353	}
2354
2355	imx_uart_ports[sport->port.line] = sport;
2356
2357	platform_set_drvdata(pdev, sport);
2358
2359	return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2360}
2361
2362static int imx_uart_remove(struct platform_device *pdev)
2363{
2364	struct imx_port *sport = platform_get_drvdata(pdev);
2365
2366	return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2367}
2368
2369static void imx_uart_restore_context(struct imx_port *sport)
2370{
2371	if (!sport->context_saved)
2372		return;
2373
2374	imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2375	imx_uart_writel(sport, sport->saved_reg[5], UESC);
2376	imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2377	imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2378	imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2379	imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2380	imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2381	imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2382	imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2383	imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2384	sport->context_saved = false;
2385}
2386
2387static void imx_uart_save_context(struct imx_port *sport)
2388{
2389	/* Save necessary regs */
2390	sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2391	sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2392	sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2393	sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2394	sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2395	sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2396	sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2397	sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2398	sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2399	sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2400	sport->context_saved = true;
2401}
2402
2403static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2404{
2405	u32 ucr3;
2406
2407	ucr3 = imx_uart_readl(sport, UCR3);
2408	if (on) {
2409		imx_uart_writel(sport, USR1_AWAKE, USR1);
2410		ucr3 |= UCR3_AWAKEN;
2411	} else {
2412		ucr3 &= ~UCR3_AWAKEN;
2413	}
2414	imx_uart_writel(sport, ucr3, UCR3);
2415
2416	if (sport->have_rtscts) {
2417		u32 ucr1 = imx_uart_readl(sport, UCR1);
2418		if (on)
2419			ucr1 |= UCR1_RTSDEN;
2420		else
2421			ucr1 &= ~UCR1_RTSDEN;
2422		imx_uart_writel(sport, ucr1, UCR1);
2423	}
2424}
2425
2426static int imx_uart_suspend_noirq(struct device *dev)
2427{
2428	struct platform_device *pdev = to_platform_device(dev);
2429	struct imx_port *sport = platform_get_drvdata(pdev);
2430
2431	imx_uart_save_context(sport);
2432
2433	clk_disable(sport->clk_ipg);
2434
2435	return 0;
2436}
2437
2438static int imx_uart_resume_noirq(struct device *dev)
2439{
2440	struct platform_device *pdev = to_platform_device(dev);
2441	struct imx_port *sport = platform_get_drvdata(pdev);
2442	int ret;
2443
2444	ret = clk_enable(sport->clk_ipg);
2445	if (ret)
2446		return ret;
2447
2448	imx_uart_restore_context(sport);
2449
2450	return 0;
2451}
2452
2453static int imx_uart_suspend(struct device *dev)
2454{
2455	struct platform_device *pdev = to_platform_device(dev);
2456	struct imx_port *sport = platform_get_drvdata(pdev);
2457	int ret;
2458
2459	uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2460	disable_irq(sport->port.irq);
2461
2462	ret = clk_prepare_enable(sport->clk_ipg);
2463	if (ret)
2464		return ret;
2465
2466	/* enable wakeup from i.MX UART */
2467	imx_uart_enable_wakeup(sport, true);
2468
2469	return 0;
2470}
2471
2472static int imx_uart_resume(struct device *dev)
2473{
2474	struct platform_device *pdev = to_platform_device(dev);
2475	struct imx_port *sport = platform_get_drvdata(pdev);
2476
2477	/* disable wakeup from i.MX UART */
2478	imx_uart_enable_wakeup(sport, false);
2479
2480	uart_resume_port(&imx_uart_uart_driver, &sport->port);
2481	enable_irq(sport->port.irq);
2482
2483	clk_disable_unprepare(sport->clk_ipg);
2484
2485	return 0;
2486}
2487
2488static int imx_uart_freeze(struct device *dev)
2489{
2490	struct platform_device *pdev = to_platform_device(dev);
2491	struct imx_port *sport = platform_get_drvdata(pdev);
2492
2493	uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2494
2495	return clk_prepare_enable(sport->clk_ipg);
2496}
2497
2498static int imx_uart_thaw(struct device *dev)
2499{
2500	struct platform_device *pdev = to_platform_device(dev);
2501	struct imx_port *sport = platform_get_drvdata(pdev);
2502
2503	uart_resume_port(&imx_uart_uart_driver, &sport->port);
2504
2505	clk_disable_unprepare(sport->clk_ipg);
2506
2507	return 0;
2508}
2509
2510static const struct dev_pm_ops imx_uart_pm_ops = {
2511	.suspend_noirq = imx_uart_suspend_noirq,
2512	.resume_noirq = imx_uart_resume_noirq,
2513	.freeze_noirq = imx_uart_suspend_noirq,
2514	.restore_noirq = imx_uart_resume_noirq,
2515	.suspend = imx_uart_suspend,
2516	.resume = imx_uart_resume,
2517	.freeze = imx_uart_freeze,
2518	.thaw = imx_uart_thaw,
2519	.restore = imx_uart_thaw,
2520};
2521
2522static struct platform_driver imx_uart_platform_driver = {
2523	.probe = imx_uart_probe,
2524	.remove = imx_uart_remove,
2525
2526	.id_table = imx_uart_devtype,
2527	.driver = {
2528		.name = "imx-uart",
2529		.of_match_table = imx_uart_dt_ids,
2530		.pm = &imx_uart_pm_ops,
2531	},
2532};
2533
2534static int __init imx_uart_init(void)
2535{
2536	int ret = uart_register_driver(&imx_uart_uart_driver);
 
 
2537
 
2538	if (ret)
2539		return ret;
2540
2541	ret = platform_driver_register(&imx_uart_platform_driver);
2542	if (ret != 0)
2543		uart_unregister_driver(&imx_uart_uart_driver);
2544
2545	return ret;
2546}
2547
2548static void __exit imx_uart_exit(void)
2549{
2550	platform_driver_unregister(&imx_uart_platform_driver);
2551	uart_unregister_driver(&imx_uart_uart_driver);
2552}
2553
2554module_init(imx_uart_init);
2555module_exit(imx_uart_exit);
2556
2557MODULE_AUTHOR("Sascha Hauer");
2558MODULE_DESCRIPTION("IMX generic serial port driver");
2559MODULE_LICENSE("GPL");
2560MODULE_ALIAS("platform:imx-uart");