Linux 3.12.39
[linux/fpc-iii.git] / drivers / tty / serial / imx.c
blob042aa077b5b3e166a8453ac0684da1dd024f6785
1 /*
2 * Driver for Motorola IMX serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Author: Sascha Hauer <sascha@saschahauer.de>
7 * Copyright (C) 2004 Pengutronix
9 * Copyright (C) 2009 emlix GmbH
10 * Author: Fabian Godehardt (added IrDA support for iMX)
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 * [29-Mar-2005] Mike Lee
27 * Added hardware handshake
30 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
31 #define SUPPORT_SYSRQ
32 #endif
34 #include <linux/module.h>
35 #include <linux/ioport.h>
36 #include <linux/init.h>
37 #include <linux/console.h>
38 #include <linux/sysrq.h>
39 #include <linux/platform_device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/serial.h>
44 #include <linux/clk.h>
45 #include <linux/delay.h>
46 #include <linux/rational.h>
47 #include <linux/slab.h>
48 #include <linux/of.h>
49 #include <linux/of_device.h>
50 #include <linux/io.h>
51 #include <linux/dma-mapping.h>
53 #include <asm/irq.h>
54 #include <linux/platform_data/serial-imx.h>
55 #include <linux/platform_data/dma-imx.h>
57 /* Register definitions */
58 #define URXD0 0x0 /* Receiver Register */
59 #define URTX0 0x40 /* Transmitter Register */
60 #define UCR1 0x80 /* Control Register 1 */
61 #define UCR2 0x84 /* Control Register 2 */
62 #define UCR3 0x88 /* Control Register 3 */
63 #define UCR4 0x8c /* Control Register 4 */
64 #define UFCR 0x90 /* FIFO Control Register */
65 #define USR1 0x94 /* Status Register 1 */
66 #define USR2 0x98 /* Status Register 2 */
67 #define UESC 0x9c /* Escape Character Register */
68 #define UTIM 0xa0 /* Escape Timer Register */
69 #define UBIR 0xa4 /* BRM Incremental Register */
70 #define UBMR 0xa8 /* BRM Modulator Register */
71 #define UBRC 0xac /* Baud Rate Count Register */
72 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
73 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
74 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
76 /* UART Control Register Bit Fields.*/
77 #define URXD_CHARRDY (1<<15)
78 #define URXD_ERR (1<<14)
79 #define URXD_OVRRUN (1<<13)
80 #define URXD_FRMERR (1<<12)
81 #define URXD_BRK (1<<11)
82 #define URXD_PRERR (1<<10)
83 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
84 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
85 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
86 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
87 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
88 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
89 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
90 #define UCR1_IREN (1<<7) /* Infrared interface enable */
91 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
92 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
93 #define UCR1_SNDBRK (1<<4) /* Send break */
94 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
95 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
96 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
97 #define UCR1_DOZE (1<<1) /* Doze */
98 #define UCR1_UARTEN (1<<0) /* UART enabled */
99 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
100 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
101 #define UCR2_CTSC (1<<13) /* CTS pin control */
102 #define UCR2_CTS (1<<12) /* Clear to send */
103 #define UCR2_ESCEN (1<<11) /* Escape enable */
104 #define UCR2_PREN (1<<8) /* Parity enable */
105 #define UCR2_PROE (1<<7) /* Parity odd/even */
106 #define UCR2_STPB (1<<6) /* Stop */
107 #define UCR2_WS (1<<5) /* Word size */
108 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
109 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
110 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
111 #define UCR2_RXEN (1<<1) /* Receiver enabled */
112 #define UCR2_SRST (1<<0) /* SW reset */
113 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
114 #define UCR3_PARERREN (1<<12) /* Parity enable */
115 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
116 #define UCR3_DSR (1<<10) /* Data set ready */
117 #define UCR3_DCD (1<<9) /* Data carrier detect */
118 #define UCR3_RI (1<<8) /* Ring indicator */
119 #define UCR3_TIMEOUTEN (1<<7) /* Timeout interrupt enable */
120 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
121 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
122 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
123 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
124 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
125 #define UCR3_BPEN (1<<0) /* Preset registers enable */
126 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
127 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
128 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
129 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
130 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
131 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
132 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
133 #define UCR4_IRSC (1<<5) /* IR special case */
134 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
135 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
136 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
137 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
138 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
139 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
140 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
141 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
142 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
143 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
144 #define USR1_RTSS (1<<14) /* RTS pin status */
145 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
146 #define USR1_RTSD (1<<12) /* RTS delta */
147 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
148 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
149 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
150 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
151 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
152 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
153 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
154 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
155 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
156 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
157 #define USR2_IDLE (1<<12) /* Idle condition */
158 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
159 #define USR2_WAKE (1<<7) /* Wake */
160 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
161 #define USR2_TXDC (1<<3) /* Transmitter complete */
162 #define USR2_BRCD (1<<2) /* Break condition */
163 #define USR2_ORE (1<<1) /* Overrun error */
164 #define USR2_RDR (1<<0) /* Recv data ready */
165 #define UTS_FRCPERR (1<<13) /* Force parity error */
166 #define UTS_LOOP (1<<12) /* Loop tx and rx */
167 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
168 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
169 #define UTS_TXFULL (1<<4) /* TxFIFO full */
170 #define UTS_RXFULL (1<<3) /* RxFIFO full */
171 #define UTS_SOFTRST (1<<0) /* Software reset */
173 /* We've been assigned a range on the "Low-density serial ports" major */
174 #define SERIAL_IMX_MAJOR 207
175 #define MINOR_START 16
176 #define DEV_NAME "ttymxc"
179 * This determines how often we check the modem status signals
180 * for any change. They generally aren't connected to an IRQ
181 * so we have to poll them. We also check immediately before
182 * filling the TX fifo incase CTS has been dropped.
184 #define MCTRL_TIMEOUT (250*HZ/1000)
186 #define DRIVER_NAME "IMX-uart"
188 #define UART_NR 8
190 /* i.mx21 type uart runs on all i.mx except i.mx1 */
191 enum imx_uart_type {
192 IMX1_UART,
193 IMX21_UART,
194 IMX6Q_UART,
197 /* device type dependent stuff */
198 struct imx_uart_data {
199 unsigned uts_reg;
200 enum imx_uart_type devtype;
203 struct imx_port {
204 struct uart_port port;
205 struct timer_list timer;
206 unsigned int old_status;
207 int txirq, rxirq, rtsirq;
208 unsigned int have_rtscts:1;
209 unsigned int dte_mode:1;
210 unsigned int use_irda:1;
211 unsigned int irda_inv_rx:1;
212 unsigned int irda_inv_tx:1;
213 unsigned short trcv_delay; /* transceiver delay */
214 struct clk *clk_ipg;
215 struct clk *clk_per;
216 const struct imx_uart_data *devdata;
218 /* DMA fields */
219 unsigned int dma_is_inited:1;
220 unsigned int dma_is_enabled:1;
221 unsigned int dma_is_rxing:1;
222 unsigned int dma_is_txing:1;
223 struct dma_chan *dma_chan_rx, *dma_chan_tx;
224 struct scatterlist rx_sgl, tx_sgl[2];
225 void *rx_buf;
226 unsigned int rx_bytes, tx_bytes;
227 struct work_struct tsk_dma_rx, tsk_dma_tx;
228 unsigned int dma_tx_nents;
229 wait_queue_head_t dma_wait;
232 struct imx_port_ucrs {
233 unsigned int ucr1;
234 unsigned int ucr2;
235 unsigned int ucr3;
238 #ifdef CONFIG_IRDA
239 #define USE_IRDA(sport) ((sport)->use_irda)
240 #else
241 #define USE_IRDA(sport) (0)
242 #endif
244 static struct imx_uart_data imx_uart_devdata[] = {
245 [IMX1_UART] = {
246 .uts_reg = IMX1_UTS,
247 .devtype = IMX1_UART,
249 [IMX21_UART] = {
250 .uts_reg = IMX21_UTS,
251 .devtype = IMX21_UART,
253 [IMX6Q_UART] = {
254 .uts_reg = IMX21_UTS,
255 .devtype = IMX6Q_UART,
259 static struct platform_device_id imx_uart_devtype[] = {
261 .name = "imx1-uart",
262 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
263 }, {
264 .name = "imx21-uart",
265 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
266 }, {
267 .name = "imx6q-uart",
268 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
269 }, {
270 /* sentinel */
273 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
275 static struct of_device_id imx_uart_dt_ids[] = {
276 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_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 */ }
281 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
283 static inline unsigned uts_reg(struct imx_port *sport)
285 return sport->devdata->uts_reg;
288 static inline int is_imx1_uart(struct imx_port *sport)
290 return sport->devdata->devtype == IMX1_UART;
293 static inline int is_imx21_uart(struct imx_port *sport)
295 return sport->devdata->devtype == IMX21_UART;
298 static inline int is_imx6q_uart(struct imx_port *sport)
300 return sport->devdata->devtype == IMX6Q_UART;
303 * Save and restore functions for UCR1, UCR2 and UCR3 registers
305 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
306 static void imx_port_ucrs_save(struct uart_port *port,
307 struct imx_port_ucrs *ucr)
309 /* save control registers */
310 ucr->ucr1 = readl(port->membase + UCR1);
311 ucr->ucr2 = readl(port->membase + UCR2);
312 ucr->ucr3 = readl(port->membase + UCR3);
315 static void imx_port_ucrs_restore(struct uart_port *port,
316 struct imx_port_ucrs *ucr)
318 /* restore control registers */
319 writel(ucr->ucr1, port->membase + UCR1);
320 writel(ucr->ucr2, port->membase + UCR2);
321 writel(ucr->ucr3, port->membase + UCR3);
323 #endif
326 * Handle any change of modem status signal since we were last called.
328 static void imx_mctrl_check(struct imx_port *sport)
330 unsigned int status, changed;
332 status = sport->port.ops->get_mctrl(&sport->port);
333 changed = status ^ sport->old_status;
335 if (changed == 0)
336 return;
338 sport->old_status = status;
340 if (changed & TIOCM_RI)
341 sport->port.icount.rng++;
342 if (changed & TIOCM_DSR)
343 sport->port.icount.dsr++;
344 if (changed & TIOCM_CAR)
345 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
346 if (changed & TIOCM_CTS)
347 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
349 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
353 * This is our per-port timeout handler, for checking the
354 * modem status signals.
356 static void imx_timeout(unsigned long data)
358 struct imx_port *sport = (struct imx_port *)data;
359 unsigned long flags;
361 if (sport->port.state) {
362 spin_lock_irqsave(&sport->port.lock, flags);
363 imx_mctrl_check(sport);
364 spin_unlock_irqrestore(&sport->port.lock, flags);
366 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
371 * interrupts disabled on entry
373 static void imx_stop_tx(struct uart_port *port)
375 struct imx_port *sport = (struct imx_port *)port;
376 unsigned long temp;
378 if (USE_IRDA(sport)) {
379 /* half duplex - wait for end of transmission */
380 int n = 256;
381 while ((--n > 0) &&
382 !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
383 udelay(5);
384 barrier();
387 * irda transceiver - wait a bit more to avoid
388 * cutoff, hardware dependent
390 udelay(sport->trcv_delay);
393 * half duplex - reactivate receive mode,
394 * flush receive pipe echo crap
396 if (readl(sport->port.membase + USR2) & USR2_TXDC) {
397 temp = readl(sport->port.membase + UCR1);
398 temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
399 writel(temp, sport->port.membase + UCR1);
401 temp = readl(sport->port.membase + UCR4);
402 temp &= ~(UCR4_TCEN);
403 writel(temp, sport->port.membase + UCR4);
405 while (readl(sport->port.membase + URXD0) &
406 URXD_CHARRDY)
407 barrier();
409 temp = readl(sport->port.membase + UCR1);
410 temp |= UCR1_RRDYEN;
411 writel(temp, sport->port.membase + UCR1);
413 temp = readl(sport->port.membase + UCR4);
414 temp |= UCR4_DREN;
415 writel(temp, sport->port.membase + UCR4);
417 return;
421 * We are maybe in the SMP context, so if the DMA TX thread is running
422 * on other cpu, we have to wait for it to finish.
424 if (sport->dma_is_enabled && sport->dma_is_txing)
425 return;
427 temp = readl(sport->port.membase + UCR1);
428 writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
432 * interrupts disabled on entry
434 static void imx_stop_rx(struct uart_port *port)
436 struct imx_port *sport = (struct imx_port *)port;
437 unsigned long temp;
440 * We are maybe in the SMP context, so if the DMA TX thread is running
441 * on other cpu, we have to wait for it to finish.
443 if (sport->dma_is_enabled && sport->dma_is_rxing)
444 return;
446 temp = readl(sport->port.membase + UCR2);
447 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
451 * Set the modem control timer to fire immediately.
453 static void imx_enable_ms(struct uart_port *port)
455 struct imx_port *sport = (struct imx_port *)port;
457 mod_timer(&sport->timer, jiffies);
460 static inline void imx_transmit_buffer(struct imx_port *sport)
462 struct circ_buf *xmit = &sport->port.state->xmit;
464 while (!uart_circ_empty(xmit) &&
465 !(readl(sport->port.membase + uts_reg(sport))
466 & UTS_TXFULL)) {
467 /* send xmit->buf[xmit->tail]
468 * out the port here */
469 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
470 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
471 sport->port.icount.tx++;
474 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
475 uart_write_wakeup(&sport->port);
477 if (uart_circ_empty(xmit))
478 imx_stop_tx(&sport->port);
481 static void dma_tx_callback(void *data)
483 struct imx_port *sport = data;
484 struct scatterlist *sgl = &sport->tx_sgl[0];
485 struct circ_buf *xmit = &sport->port.state->xmit;
486 unsigned long flags;
488 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
490 sport->dma_is_txing = 0;
492 /* update the stat */
493 spin_lock_irqsave(&sport->port.lock, flags);
494 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
495 sport->port.icount.tx += sport->tx_bytes;
496 spin_unlock_irqrestore(&sport->port.lock, flags);
498 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
500 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
501 uart_write_wakeup(&sport->port);
503 if (waitqueue_active(&sport->dma_wait)) {
504 wake_up(&sport->dma_wait);
505 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
506 return;
509 schedule_work(&sport->tsk_dma_tx);
512 static void dma_tx_work(struct work_struct *w)
514 struct imx_port *sport = container_of(w, struct imx_port, tsk_dma_tx);
515 struct circ_buf *xmit = &sport->port.state->xmit;
516 struct scatterlist *sgl = sport->tx_sgl;
517 struct dma_async_tx_descriptor *desc;
518 struct dma_chan *chan = sport->dma_chan_tx;
519 struct device *dev = sport->port.dev;
520 enum dma_status status;
521 unsigned long flags;
522 int ret;
524 status = chan->device->device_tx_status(chan, (dma_cookie_t)0, NULL);
525 if (DMA_IN_PROGRESS == status)
526 return;
528 spin_lock_irqsave(&sport->port.lock, flags);
529 sport->tx_bytes = uart_circ_chars_pending(xmit);
530 if (sport->tx_bytes == 0) {
531 spin_unlock_irqrestore(&sport->port.lock, flags);
532 return;
535 if (xmit->tail > xmit->head) {
536 sport->dma_tx_nents = 2;
537 sg_init_table(sgl, 2);
538 sg_set_buf(sgl, xmit->buf + xmit->tail,
539 UART_XMIT_SIZE - xmit->tail);
540 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
541 } else {
542 sport->dma_tx_nents = 1;
543 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
545 spin_unlock_irqrestore(&sport->port.lock, flags);
547 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
548 if (ret == 0) {
549 dev_err(dev, "DMA mapping error for TX.\n");
550 return;
552 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
553 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
554 if (!desc) {
555 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
556 return;
558 desc->callback = dma_tx_callback;
559 desc->callback_param = sport;
561 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
562 uart_circ_chars_pending(xmit));
563 /* fire it */
564 sport->dma_is_txing = 1;
565 dmaengine_submit(desc);
566 dma_async_issue_pending(chan);
567 return;
571 * interrupts disabled on entry
573 static void imx_start_tx(struct uart_port *port)
575 struct imx_port *sport = (struct imx_port *)port;
576 unsigned long temp;
578 if (USE_IRDA(sport)) {
579 /* half duplex in IrDA mode; have to disable receive mode */
580 temp = readl(sport->port.membase + UCR4);
581 temp &= ~(UCR4_DREN);
582 writel(temp, sport->port.membase + UCR4);
584 temp = readl(sport->port.membase + UCR1);
585 temp &= ~(UCR1_RRDYEN);
586 writel(temp, sport->port.membase + UCR1);
588 /* Clear any pending ORE flag before enabling interrupt */
589 temp = readl(sport->port.membase + USR2);
590 writel(temp | USR2_ORE, sport->port.membase + USR2);
592 temp = readl(sport->port.membase + UCR4);
593 temp |= UCR4_OREN;
594 writel(temp, sport->port.membase + UCR4);
596 if (!sport->dma_is_enabled) {
597 temp = readl(sport->port.membase + UCR1);
598 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
601 if (USE_IRDA(sport)) {
602 temp = readl(sport->port.membase + UCR1);
603 temp |= UCR1_TRDYEN;
604 writel(temp, sport->port.membase + UCR1);
606 temp = readl(sport->port.membase + UCR4);
607 temp |= UCR4_TCEN;
608 writel(temp, sport->port.membase + UCR4);
611 if (sport->dma_is_enabled) {
613 * We may in the interrupt context, so arise a work_struct to
614 * do the real job.
616 schedule_work(&sport->tsk_dma_tx);
617 return;
620 if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
621 imx_transmit_buffer(sport);
624 static irqreturn_t imx_rtsint(int irq, void *dev_id)
626 struct imx_port *sport = dev_id;
627 unsigned int val;
628 unsigned long flags;
630 spin_lock_irqsave(&sport->port.lock, flags);
632 writel(USR1_RTSD, sport->port.membase + USR1);
633 val = readl(sport->port.membase + USR1) & USR1_RTSS;
634 uart_handle_cts_change(&sport->port, !!val);
635 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
637 spin_unlock_irqrestore(&sport->port.lock, flags);
638 return IRQ_HANDLED;
641 static irqreturn_t imx_txint(int irq, void *dev_id)
643 struct imx_port *sport = dev_id;
644 struct circ_buf *xmit = &sport->port.state->xmit;
645 unsigned long flags;
647 spin_lock_irqsave(&sport->port.lock, flags);
648 if (sport->port.x_char) {
649 /* Send next char */
650 writel(sport->port.x_char, sport->port.membase + URTX0);
651 goto out;
654 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
655 imx_stop_tx(&sport->port);
656 goto out;
659 imx_transmit_buffer(sport);
661 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
662 uart_write_wakeup(&sport->port);
664 out:
665 spin_unlock_irqrestore(&sport->port.lock, flags);
666 return IRQ_HANDLED;
669 static irqreturn_t imx_rxint(int irq, void *dev_id)
671 struct imx_port *sport = dev_id;
672 unsigned int rx, flg, ignored = 0;
673 struct tty_port *port = &sport->port.state->port;
674 unsigned long flags, temp;
676 spin_lock_irqsave(&sport->port.lock, flags);
678 while (readl(sport->port.membase + USR2) & USR2_RDR) {
679 flg = TTY_NORMAL;
680 sport->port.icount.rx++;
682 rx = readl(sport->port.membase + URXD0);
684 temp = readl(sport->port.membase + USR2);
685 if (temp & USR2_BRCD) {
686 writel(USR2_BRCD, sport->port.membase + USR2);
687 if (uart_handle_break(&sport->port))
688 continue;
691 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
692 continue;
694 if (unlikely(rx & URXD_ERR)) {
695 if (rx & URXD_BRK)
696 sport->port.icount.brk++;
697 else if (rx & URXD_PRERR)
698 sport->port.icount.parity++;
699 else if (rx & URXD_FRMERR)
700 sport->port.icount.frame++;
701 if (rx & URXD_OVRRUN)
702 sport->port.icount.overrun++;
704 if (rx & sport->port.ignore_status_mask) {
705 if (++ignored > 100)
706 goto out;
707 continue;
710 rx &= sport->port.read_status_mask;
712 if (rx & URXD_BRK)
713 flg = TTY_BREAK;
714 else if (rx & URXD_PRERR)
715 flg = TTY_PARITY;
716 else if (rx & URXD_FRMERR)
717 flg = TTY_FRAME;
718 if (rx & URXD_OVRRUN)
719 flg = TTY_OVERRUN;
721 #ifdef SUPPORT_SYSRQ
722 sport->port.sysrq = 0;
723 #endif
726 tty_insert_flip_char(port, rx, flg);
729 out:
730 spin_unlock_irqrestore(&sport->port.lock, flags);
731 tty_flip_buffer_push(port);
732 return IRQ_HANDLED;
736 * If the RXFIFO is filled with some data, and then we
737 * arise a DMA operation to receive them.
739 static void imx_dma_rxint(struct imx_port *sport)
741 unsigned long temp;
743 temp = readl(sport->port.membase + USR2);
744 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
745 sport->dma_is_rxing = 1;
747 /* disable the `Recerver Ready Interrrupt` */
748 temp = readl(sport->port.membase + UCR1);
749 temp &= ~(UCR1_RRDYEN);
750 writel(temp, sport->port.membase + UCR1);
752 /* tell the DMA to receive the data. */
753 schedule_work(&sport->tsk_dma_rx);
757 static irqreturn_t imx_int(int irq, void *dev_id)
759 struct imx_port *sport = dev_id;
760 unsigned int sts;
761 unsigned int sts2;
763 sts = readl(sport->port.membase + USR1);
765 if (sts & USR1_RRDY) {
766 if (sport->dma_is_enabled)
767 imx_dma_rxint(sport);
768 else
769 imx_rxint(irq, dev_id);
772 if (sts & USR1_TRDY &&
773 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
774 imx_txint(irq, dev_id);
776 if (sts & USR1_RTSD)
777 imx_rtsint(irq, dev_id);
779 if (sts & USR1_AWAKE)
780 writel(USR1_AWAKE, sport->port.membase + USR1);
782 sts2 = readl(sport->port.membase + USR2);
783 if (sts2 & USR2_ORE) {
784 dev_err(sport->port.dev, "Rx FIFO overrun\n");
785 sport->port.icount.overrun++;
786 writel(sts2 | USR2_ORE, sport->port.membase + USR2);
789 return IRQ_HANDLED;
793 * Return TIOCSER_TEMT when transmitter is not busy.
795 static unsigned int imx_tx_empty(struct uart_port *port)
797 struct imx_port *sport = (struct imx_port *)port;
799 return (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
803 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
805 static unsigned int imx_get_mctrl(struct uart_port *port)
807 struct imx_port *sport = (struct imx_port *)port;
808 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
810 if (readl(sport->port.membase + USR1) & USR1_RTSS)
811 tmp |= TIOCM_CTS;
813 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
814 tmp |= TIOCM_RTS;
816 return tmp;
819 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
821 struct imx_port *sport = (struct imx_port *)port;
822 unsigned long temp;
824 temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
826 if (mctrl & TIOCM_RTS)
827 if (!sport->dma_is_enabled)
828 temp |= UCR2_CTS;
830 writel(temp, sport->port.membase + UCR2);
834 * Interrupts always disabled.
836 static void imx_break_ctl(struct uart_port *port, int break_state)
838 struct imx_port *sport = (struct imx_port *)port;
839 unsigned long flags, temp;
841 spin_lock_irqsave(&sport->port.lock, flags);
843 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
845 if (break_state != 0)
846 temp |= UCR1_SNDBRK;
848 writel(temp, sport->port.membase + UCR1);
850 spin_unlock_irqrestore(&sport->port.lock, flags);
853 #define TXTL 2 /* reset default */
854 #define RXTL 1 /* reset default */
856 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
858 unsigned int val;
860 /* set receiver / transmitter trigger level */
861 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
862 val |= TXTL << UFCR_TXTL_SHF | RXTL;
863 writel(val, sport->port.membase + UFCR);
864 return 0;
867 #define RX_BUF_SIZE (PAGE_SIZE)
868 static int start_rx_dma(struct imx_port *sport);
869 static void dma_rx_work(struct work_struct *w)
871 struct imx_port *sport = container_of(w, struct imx_port, tsk_dma_rx);
872 struct tty_port *port = &sport->port.state->port;
874 if (sport->rx_bytes) {
875 tty_insert_flip_string(port, sport->rx_buf, sport->rx_bytes);
876 tty_flip_buffer_push(port);
877 sport->rx_bytes = 0;
880 if (sport->dma_is_rxing)
881 start_rx_dma(sport);
884 static void imx_rx_dma_done(struct imx_port *sport)
886 unsigned long temp;
888 /* Enable this interrupt when the RXFIFO is empty. */
889 temp = readl(sport->port.membase + UCR1);
890 temp |= UCR1_RRDYEN;
891 writel(temp, sport->port.membase + UCR1);
893 sport->dma_is_rxing = 0;
895 /* Is the shutdown waiting for us? */
896 if (waitqueue_active(&sport->dma_wait))
897 wake_up(&sport->dma_wait);
901 * There are three kinds of RX DMA interrupts(such as in the MX6Q):
902 * [1] the RX DMA buffer is full.
903 * [2] the Aging timer expires(wait for 8 bytes long)
904 * [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
906 * The [2] is trigger when a character was been sitting in the FIFO
907 * meanwhile [3] can wait for 32 bytes long when the RX line is
908 * on IDLE state and RxFIFO is empty.
910 static void dma_rx_callback(void *data)
912 struct imx_port *sport = data;
913 struct dma_chan *chan = sport->dma_chan_rx;
914 struct scatterlist *sgl = &sport->rx_sgl;
915 struct dma_tx_state state;
916 enum dma_status status;
917 unsigned int count;
919 /* unmap it first */
920 dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
922 status = chan->device->device_tx_status(chan, (dma_cookie_t)0, &state);
923 count = RX_BUF_SIZE - state.residue;
924 dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
926 if (count) {
927 sport->rx_bytes = count;
928 schedule_work(&sport->tsk_dma_rx);
929 } else
930 imx_rx_dma_done(sport);
933 static int start_rx_dma(struct imx_port *sport)
935 struct scatterlist *sgl = &sport->rx_sgl;
936 struct dma_chan *chan = sport->dma_chan_rx;
937 struct device *dev = sport->port.dev;
938 struct dma_async_tx_descriptor *desc;
939 int ret;
941 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
942 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
943 if (ret == 0) {
944 dev_err(dev, "DMA mapping error for RX.\n");
945 return -EINVAL;
947 desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
948 DMA_PREP_INTERRUPT);
949 if (!desc) {
950 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
951 return -EINVAL;
953 desc->callback = dma_rx_callback;
954 desc->callback_param = sport;
956 dev_dbg(dev, "RX: prepare for the DMA.\n");
957 dmaengine_submit(desc);
958 dma_async_issue_pending(chan);
959 return 0;
962 static void imx_uart_dma_exit(struct imx_port *sport)
964 if (sport->dma_chan_rx) {
965 dma_release_channel(sport->dma_chan_rx);
966 sport->dma_chan_rx = NULL;
968 kfree(sport->rx_buf);
969 sport->rx_buf = NULL;
972 if (sport->dma_chan_tx) {
973 dma_release_channel(sport->dma_chan_tx);
974 sport->dma_chan_tx = NULL;
977 sport->dma_is_inited = 0;
980 static int imx_uart_dma_init(struct imx_port *sport)
982 struct dma_slave_config slave_config = {};
983 struct device *dev = sport->port.dev;
984 int ret;
986 /* Prepare for RX : */
987 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
988 if (!sport->dma_chan_rx) {
989 dev_dbg(dev, "cannot get the DMA channel.\n");
990 ret = -EINVAL;
991 goto err;
994 slave_config.direction = DMA_DEV_TO_MEM;
995 slave_config.src_addr = sport->port.mapbase + URXD0;
996 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
997 slave_config.src_maxburst = RXTL;
998 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
999 if (ret) {
1000 dev_err(dev, "error in RX dma configuration.\n");
1001 goto err;
1004 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1005 if (!sport->rx_buf) {
1006 dev_err(dev, "cannot alloc DMA buffer.\n");
1007 ret = -ENOMEM;
1008 goto err;
1010 sport->rx_bytes = 0;
1012 /* Prepare for TX : */
1013 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1014 if (!sport->dma_chan_tx) {
1015 dev_err(dev, "cannot get the TX DMA channel!\n");
1016 ret = -EINVAL;
1017 goto err;
1020 slave_config.direction = DMA_MEM_TO_DEV;
1021 slave_config.dst_addr = sport->port.mapbase + URTX0;
1022 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1023 slave_config.dst_maxburst = TXTL;
1024 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1025 if (ret) {
1026 dev_err(dev, "error in TX dma configuration.");
1027 goto err;
1030 sport->dma_is_inited = 1;
1032 return 0;
1033 err:
1034 imx_uart_dma_exit(sport);
1035 return ret;
1038 static void imx_enable_dma(struct imx_port *sport)
1040 unsigned long temp;
1041 struct tty_port *port = &sport->port.state->port;
1043 port->low_latency = 1;
1044 INIT_WORK(&sport->tsk_dma_tx, dma_tx_work);
1045 INIT_WORK(&sport->tsk_dma_rx, dma_rx_work);
1046 init_waitqueue_head(&sport->dma_wait);
1048 /* set UCR1 */
1049 temp = readl(sport->port.membase + UCR1);
1050 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1051 /* wait for 32 idle frames for IDDMA interrupt */
1052 UCR1_ICD_REG(3);
1053 writel(temp, sport->port.membase + UCR1);
1055 /* set UCR4 */
1056 temp = readl(sport->port.membase + UCR4);
1057 temp |= UCR4_IDDMAEN;
1058 writel(temp, sport->port.membase + UCR4);
1060 sport->dma_is_enabled = 1;
1063 static void imx_disable_dma(struct imx_port *sport)
1065 unsigned long temp;
1066 struct tty_port *port = &sport->port.state->port;
1068 /* clear UCR1 */
1069 temp = readl(sport->port.membase + UCR1);
1070 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1071 writel(temp, sport->port.membase + UCR1);
1073 /* clear UCR2 */
1074 temp = readl(sport->port.membase + UCR2);
1075 temp &= ~(UCR2_CTSC | UCR2_CTS);
1076 writel(temp, sport->port.membase + UCR2);
1078 /* clear UCR4 */
1079 temp = readl(sport->port.membase + UCR4);
1080 temp &= ~UCR4_IDDMAEN;
1081 writel(temp, sport->port.membase + UCR4);
1083 sport->dma_is_enabled = 0;
1084 port->low_latency = 0;
1087 /* half the RX buffer size */
1088 #define CTSTL 16
1090 static int imx_startup(struct uart_port *port)
1092 struct imx_port *sport = (struct imx_port *)port;
1093 int retval;
1094 unsigned long flags, temp;
1096 retval = clk_prepare_enable(sport->clk_per);
1097 if (retval)
1098 goto error_out1;
1099 retval = clk_prepare_enable(sport->clk_ipg);
1100 if (retval) {
1101 clk_disable_unprepare(sport->clk_per);
1102 goto error_out1;
1105 imx_setup_ufcr(sport, 0);
1107 /* disable the DREN bit (Data Ready interrupt enable) before
1108 * requesting IRQs
1110 temp = readl(sport->port.membase + UCR4);
1112 if (USE_IRDA(sport))
1113 temp |= UCR4_IRSC;
1115 /* set the trigger level for CTS */
1116 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1117 temp |= CTSTL << UCR4_CTSTL_SHF;
1119 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1121 if (USE_IRDA(sport)) {
1122 /* reset fifo's and state machines */
1123 int i = 100;
1124 temp = readl(sport->port.membase + UCR2);
1125 temp &= ~UCR2_SRST;
1126 writel(temp, sport->port.membase + UCR2);
1127 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
1128 (--i > 0)) {
1129 udelay(1);
1134 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1135 * chips only have one interrupt.
1137 if (sport->txirq > 0) {
1138 retval = request_irq(sport->rxirq, imx_rxint, 0,
1139 DRIVER_NAME, sport);
1140 if (retval)
1141 goto error_out1;
1143 retval = request_irq(sport->txirq, imx_txint, 0,
1144 DRIVER_NAME, sport);
1145 if (retval)
1146 goto error_out2;
1148 /* do not use RTS IRQ on IrDA */
1149 if (!USE_IRDA(sport)) {
1150 retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1151 DRIVER_NAME, sport);
1152 if (retval)
1153 goto error_out3;
1155 } else {
1156 retval = request_irq(sport->port.irq, imx_int, 0,
1157 DRIVER_NAME, sport);
1158 if (retval) {
1159 free_irq(sport->port.irq, sport);
1160 goto error_out1;
1164 spin_lock_irqsave(&sport->port.lock, flags);
1166 * Finally, clear and enable interrupts
1168 writel(USR1_RTSD, sport->port.membase + USR1);
1170 temp = readl(sport->port.membase + UCR1);
1171 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1173 if (USE_IRDA(sport)) {
1174 temp |= UCR1_IREN;
1175 temp &= ~(UCR1_RTSDEN);
1178 writel(temp, sport->port.membase + UCR1);
1180 temp = readl(sport->port.membase + UCR2);
1181 temp |= (UCR2_RXEN | UCR2_TXEN);
1182 if (!sport->have_rtscts)
1183 temp |= UCR2_IRTS;
1184 writel(temp, sport->port.membase + UCR2);
1186 if (USE_IRDA(sport)) {
1187 /* clear RX-FIFO */
1188 int i = 64;
1189 while ((--i > 0) &&
1190 (readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
1191 barrier();
1195 if (!is_imx1_uart(sport)) {
1196 temp = readl(sport->port.membase + UCR3);
1197 temp |= IMX21_UCR3_RXDMUXSEL;
1198 writel(temp, sport->port.membase + UCR3);
1201 if (USE_IRDA(sport)) {
1202 temp = readl(sport->port.membase + UCR4);
1203 if (sport->irda_inv_rx)
1204 temp |= UCR4_INVR;
1205 else
1206 temp &= ~(UCR4_INVR);
1207 writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1209 temp = readl(sport->port.membase + UCR3);
1210 if (sport->irda_inv_tx)
1211 temp |= UCR3_INVT;
1212 else
1213 temp &= ~(UCR3_INVT);
1214 writel(temp, sport->port.membase + UCR3);
1218 * Enable modem status interrupts
1220 imx_enable_ms(&sport->port);
1221 spin_unlock_irqrestore(&sport->port.lock, flags);
1223 if (USE_IRDA(sport)) {
1224 struct imxuart_platform_data *pdata;
1225 pdata = dev_get_platdata(sport->port.dev);
1226 sport->irda_inv_rx = pdata->irda_inv_rx;
1227 sport->irda_inv_tx = pdata->irda_inv_tx;
1228 sport->trcv_delay = pdata->transceiver_delay;
1229 if (pdata->irda_enable)
1230 pdata->irda_enable(1);
1233 return 0;
1235 error_out3:
1236 if (sport->txirq)
1237 free_irq(sport->txirq, sport);
1238 error_out2:
1239 if (sport->rxirq)
1240 free_irq(sport->rxirq, sport);
1241 error_out1:
1242 return retval;
1245 static void imx_shutdown(struct uart_port *port)
1247 struct imx_port *sport = (struct imx_port *)port;
1248 unsigned long temp;
1249 unsigned long flags;
1251 if (sport->dma_is_enabled) {
1252 /* We have to wait for the DMA to finish. */
1253 wait_event(sport->dma_wait,
1254 !sport->dma_is_rxing && !sport->dma_is_txing);
1255 imx_stop_rx(port);
1256 imx_disable_dma(sport);
1257 imx_uart_dma_exit(sport);
1260 spin_lock_irqsave(&sport->port.lock, flags);
1261 temp = readl(sport->port.membase + UCR2);
1262 temp &= ~(UCR2_TXEN);
1263 writel(temp, sport->port.membase + UCR2);
1264 spin_unlock_irqrestore(&sport->port.lock, flags);
1266 if (USE_IRDA(sport)) {
1267 struct imxuart_platform_data *pdata;
1268 pdata = dev_get_platdata(sport->port.dev);
1269 if (pdata->irda_enable)
1270 pdata->irda_enable(0);
1274 * Stop our timer.
1276 del_timer_sync(&sport->timer);
1279 * Free the interrupts
1281 if (sport->txirq > 0) {
1282 if (!USE_IRDA(sport))
1283 free_irq(sport->rtsirq, sport);
1284 free_irq(sport->txirq, sport);
1285 free_irq(sport->rxirq, sport);
1286 } else
1287 free_irq(sport->port.irq, sport);
1290 * Disable all interrupts, port and break condition.
1293 spin_lock_irqsave(&sport->port.lock, flags);
1294 temp = readl(sport->port.membase + UCR1);
1295 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1296 if (USE_IRDA(sport))
1297 temp &= ~(UCR1_IREN);
1299 writel(temp, sport->port.membase + UCR1);
1300 spin_unlock_irqrestore(&sport->port.lock, flags);
1302 clk_disable_unprepare(sport->clk_per);
1303 clk_disable_unprepare(sport->clk_ipg);
1306 static void
1307 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1308 struct ktermios *old)
1310 struct imx_port *sport = (struct imx_port *)port;
1311 unsigned long flags;
1312 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1313 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1314 unsigned int div, ufcr;
1315 unsigned long num, denom;
1316 uint64_t tdiv64;
1319 * If we don't support modem control lines, don't allow
1320 * these to be set.
1322 if (0) {
1323 termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1324 termios->c_cflag |= CLOCAL;
1328 * We only support CS7 and CS8.
1330 while ((termios->c_cflag & CSIZE) != CS7 &&
1331 (termios->c_cflag & CSIZE) != CS8) {
1332 termios->c_cflag &= ~CSIZE;
1333 termios->c_cflag |= old_csize;
1334 old_csize = CS8;
1337 if ((termios->c_cflag & CSIZE) == CS8)
1338 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1339 else
1340 ucr2 = UCR2_SRST | UCR2_IRTS;
1342 if (termios->c_cflag & CRTSCTS) {
1343 if (sport->have_rtscts) {
1344 ucr2 &= ~UCR2_IRTS;
1345 ucr2 |= UCR2_CTSC;
1347 /* Can we enable the DMA support? */
1348 if (is_imx6q_uart(sport) && !uart_console(port)
1349 && !sport->dma_is_inited)
1350 imx_uart_dma_init(sport);
1351 } else {
1352 termios->c_cflag &= ~CRTSCTS;
1356 if (termios->c_cflag & CSTOPB)
1357 ucr2 |= UCR2_STPB;
1358 if (termios->c_cflag & PARENB) {
1359 ucr2 |= UCR2_PREN;
1360 if (termios->c_cflag & PARODD)
1361 ucr2 |= UCR2_PROE;
1364 del_timer_sync(&sport->timer);
1367 * Ask the core to calculate the divisor for us.
1369 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1370 quot = uart_get_divisor(port, baud);
1372 spin_lock_irqsave(&sport->port.lock, flags);
1374 sport->port.read_status_mask = 0;
1375 if (termios->c_iflag & INPCK)
1376 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1377 if (termios->c_iflag & (BRKINT | PARMRK))
1378 sport->port.read_status_mask |= URXD_BRK;
1381 * Characters to ignore
1383 sport->port.ignore_status_mask = 0;
1384 if (termios->c_iflag & IGNPAR)
1385 sport->port.ignore_status_mask |= URXD_PRERR;
1386 if (termios->c_iflag & IGNBRK) {
1387 sport->port.ignore_status_mask |= URXD_BRK;
1389 * If we're ignoring parity and break indicators,
1390 * ignore overruns too (for real raw support).
1392 if (termios->c_iflag & IGNPAR)
1393 sport->port.ignore_status_mask |= URXD_OVRRUN;
1397 * Update the per-port timeout.
1399 uart_update_timeout(port, termios->c_cflag, baud);
1402 * disable interrupts and drain transmitter
1404 old_ucr1 = readl(sport->port.membase + UCR1);
1405 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1406 sport->port.membase + UCR1);
1408 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1409 barrier();
1411 /* then, disable everything */
1412 old_txrxen = readl(sport->port.membase + UCR2);
1413 writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1414 sport->port.membase + UCR2);
1415 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1417 if (USE_IRDA(sport)) {
1419 * use maximum available submodule frequency to
1420 * avoid missing short pulses due to low sampling rate
1422 div = 1;
1423 } else {
1424 /* custom-baudrate handling */
1425 div = sport->port.uartclk / (baud * 16);
1426 if (baud == 38400 && quot != div)
1427 baud = sport->port.uartclk / (quot * 16);
1429 div = sport->port.uartclk / (baud * 16);
1430 if (div > 7)
1431 div = 7;
1432 if (!div)
1433 div = 1;
1436 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1437 1 << 16, 1 << 16, &num, &denom);
1439 tdiv64 = sport->port.uartclk;
1440 tdiv64 *= num;
1441 do_div(tdiv64, denom * 16 * div);
1442 tty_termios_encode_baud_rate(termios,
1443 (speed_t)tdiv64, (speed_t)tdiv64);
1445 num -= 1;
1446 denom -= 1;
1448 ufcr = readl(sport->port.membase + UFCR);
1449 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1450 if (sport->dte_mode)
1451 ufcr |= UFCR_DCEDTE;
1452 writel(ufcr, sport->port.membase + UFCR);
1454 writel(num, sport->port.membase + UBIR);
1455 writel(denom, sport->port.membase + UBMR);
1457 if (!is_imx1_uart(sport))
1458 writel(sport->port.uartclk / div / 1000,
1459 sport->port.membase + IMX21_ONEMS);
1461 writel(old_ucr1, sport->port.membase + UCR1);
1463 /* set the parity, stop bits and data size */
1464 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1466 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1467 imx_enable_ms(&sport->port);
1469 if (sport->dma_is_inited && !sport->dma_is_enabled)
1470 imx_enable_dma(sport);
1471 spin_unlock_irqrestore(&sport->port.lock, flags);
1474 static const char *imx_type(struct uart_port *port)
1476 struct imx_port *sport = (struct imx_port *)port;
1478 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1482 * Release the memory region(s) being used by 'port'.
1484 static void imx_release_port(struct uart_port *port)
1486 struct platform_device *pdev = to_platform_device(port->dev);
1487 struct resource *mmres;
1489 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1490 release_mem_region(mmres->start, resource_size(mmres));
1494 * Request the memory region(s) being used by 'port'.
1496 static int imx_request_port(struct uart_port *port)
1498 struct platform_device *pdev = to_platform_device(port->dev);
1499 struct resource *mmres;
1500 void *ret;
1502 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1503 if (!mmres)
1504 return -ENODEV;
1506 ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
1508 return ret ? 0 : -EBUSY;
1512 * Configure/autoconfigure the port.
1514 static void imx_config_port(struct uart_port *port, int flags)
1516 struct imx_port *sport = (struct imx_port *)port;
1518 if (flags & UART_CONFIG_TYPE &&
1519 imx_request_port(&sport->port) == 0)
1520 sport->port.type = PORT_IMX;
1524 * Verify the new serial_struct (for TIOCSSERIAL).
1525 * The only change we allow are to the flags and type, and
1526 * even then only between PORT_IMX and PORT_UNKNOWN
1528 static int
1529 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1531 struct imx_port *sport = (struct imx_port *)port;
1532 int ret = 0;
1534 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1535 ret = -EINVAL;
1536 if (sport->port.irq != ser->irq)
1537 ret = -EINVAL;
1538 if (ser->io_type != UPIO_MEM)
1539 ret = -EINVAL;
1540 if (sport->port.uartclk / 16 != ser->baud_base)
1541 ret = -EINVAL;
1542 if ((void *)sport->port.mapbase != ser->iomem_base)
1543 ret = -EINVAL;
1544 if (sport->port.iobase != ser->port)
1545 ret = -EINVAL;
1546 if (ser->hub6 != 0)
1547 ret = -EINVAL;
1548 return ret;
1551 #if defined(CONFIG_CONSOLE_POLL)
1552 static int imx_poll_get_char(struct uart_port *port)
1554 struct imx_port_ucrs old_ucr;
1555 unsigned int status;
1556 unsigned char c;
1558 /* save control registers */
1559 imx_port_ucrs_save(port, &old_ucr);
1561 /* disable interrupts */
1562 writel(UCR1_UARTEN, port->membase + UCR1);
1563 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1564 port->membase + UCR2);
1565 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1566 port->membase + UCR3);
1568 /* poll */
1569 do {
1570 status = readl(port->membase + USR2);
1571 } while (~status & USR2_RDR);
1573 /* read */
1574 c = readl(port->membase + URXD0);
1576 /* restore control registers */
1577 imx_port_ucrs_restore(port, &old_ucr);
1579 return c;
1582 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1584 struct imx_port_ucrs old_ucr;
1585 unsigned int status;
1587 /* save control registers */
1588 imx_port_ucrs_save(port, &old_ucr);
1590 /* disable interrupts */
1591 writel(UCR1_UARTEN, port->membase + UCR1);
1592 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1593 port->membase + UCR2);
1594 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1595 port->membase + UCR3);
1597 /* drain */
1598 do {
1599 status = readl(port->membase + USR1);
1600 } while (~status & USR1_TRDY);
1602 /* write */
1603 writel(c, port->membase + URTX0);
1605 /* flush */
1606 do {
1607 status = readl(port->membase + USR2);
1608 } while (~status & USR2_TXDC);
1610 /* restore control registers */
1611 imx_port_ucrs_restore(port, &old_ucr);
1613 #endif
1615 static struct uart_ops imx_pops = {
1616 .tx_empty = imx_tx_empty,
1617 .set_mctrl = imx_set_mctrl,
1618 .get_mctrl = imx_get_mctrl,
1619 .stop_tx = imx_stop_tx,
1620 .start_tx = imx_start_tx,
1621 .stop_rx = imx_stop_rx,
1622 .enable_ms = imx_enable_ms,
1623 .break_ctl = imx_break_ctl,
1624 .startup = imx_startup,
1625 .shutdown = imx_shutdown,
1626 .set_termios = imx_set_termios,
1627 .type = imx_type,
1628 .release_port = imx_release_port,
1629 .request_port = imx_request_port,
1630 .config_port = imx_config_port,
1631 .verify_port = imx_verify_port,
1632 #if defined(CONFIG_CONSOLE_POLL)
1633 .poll_get_char = imx_poll_get_char,
1634 .poll_put_char = imx_poll_put_char,
1635 #endif
1638 static struct imx_port *imx_ports[UART_NR];
1640 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1641 static void imx_console_putchar(struct uart_port *port, int ch)
1643 struct imx_port *sport = (struct imx_port *)port;
1645 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1646 barrier();
1648 writel(ch, sport->port.membase + URTX0);
1652 * Interrupts are disabled on entering
1654 static void
1655 imx_console_write(struct console *co, const char *s, unsigned int count)
1657 struct imx_port *sport = imx_ports[co->index];
1658 struct imx_port_ucrs old_ucr;
1659 unsigned int ucr1;
1660 unsigned long flags = 0;
1661 int locked = 1;
1662 int retval;
1664 retval = clk_enable(sport->clk_per);
1665 if (retval)
1666 return;
1667 retval = clk_enable(sport->clk_ipg);
1668 if (retval) {
1669 clk_disable(sport->clk_per);
1670 return;
1673 if (sport->port.sysrq)
1674 locked = 0;
1675 else if (oops_in_progress)
1676 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1677 else
1678 spin_lock_irqsave(&sport->port.lock, flags);
1681 * First, save UCR1/2/3 and then disable interrupts
1683 imx_port_ucrs_save(&sport->port, &old_ucr);
1684 ucr1 = old_ucr.ucr1;
1686 if (is_imx1_uart(sport))
1687 ucr1 |= IMX1_UCR1_UARTCLKEN;
1688 ucr1 |= UCR1_UARTEN;
1689 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1691 writel(ucr1, sport->port.membase + UCR1);
1693 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1695 uart_console_write(&sport->port, s, count, imx_console_putchar);
1698 * Finally, wait for transmitter to become empty
1699 * and restore UCR1/2/3
1701 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1703 imx_port_ucrs_restore(&sport->port, &old_ucr);
1705 if (locked)
1706 spin_unlock_irqrestore(&sport->port.lock, flags);
1708 clk_disable(sport->clk_ipg);
1709 clk_disable(sport->clk_per);
1713 * If the port was already initialised (eg, by a boot loader),
1714 * try to determine the current setup.
1716 static void __init
1717 imx_console_get_options(struct imx_port *sport, int *baud,
1718 int *parity, int *bits)
1721 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1722 /* ok, the port was enabled */
1723 unsigned int ucr2, ubir, ubmr, uartclk;
1724 unsigned int baud_raw;
1725 unsigned int ucfr_rfdiv;
1727 ucr2 = readl(sport->port.membase + UCR2);
1729 *parity = 'n';
1730 if (ucr2 & UCR2_PREN) {
1731 if (ucr2 & UCR2_PROE)
1732 *parity = 'o';
1733 else
1734 *parity = 'e';
1737 if (ucr2 & UCR2_WS)
1738 *bits = 8;
1739 else
1740 *bits = 7;
1742 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1743 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1745 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1746 if (ucfr_rfdiv == 6)
1747 ucfr_rfdiv = 7;
1748 else
1749 ucfr_rfdiv = 6 - ucfr_rfdiv;
1751 uartclk = clk_get_rate(sport->clk_per);
1752 uartclk /= ucfr_rfdiv;
1754 { /*
1755 * The next code provides exact computation of
1756 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1757 * without need of float support or long long division,
1758 * which would be required to prevent 32bit arithmetic overflow
1760 unsigned int mul = ubir + 1;
1761 unsigned int div = 16 * (ubmr + 1);
1762 unsigned int rem = uartclk % div;
1764 baud_raw = (uartclk / div) * mul;
1765 baud_raw += (rem * mul + div / 2) / div;
1766 *baud = (baud_raw + 50) / 100 * 100;
1769 if (*baud != baud_raw)
1770 pr_info("Console IMX rounded baud rate from %d to %d\n",
1771 baud_raw, *baud);
1775 static int __init
1776 imx_console_setup(struct console *co, char *options)
1778 struct imx_port *sport;
1779 int baud = 9600;
1780 int bits = 8;
1781 int parity = 'n';
1782 int flow = 'n';
1783 int retval;
1786 * Check whether an invalid uart number has been specified, and
1787 * if so, search for the first available port that does have
1788 * console support.
1790 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1791 co->index = 0;
1792 sport = imx_ports[co->index];
1793 if (sport == NULL)
1794 return -ENODEV;
1796 /* For setting the registers, we only need to enable the ipg clock. */
1797 retval = clk_prepare_enable(sport->clk_ipg);
1798 if (retval)
1799 goto error_console;
1801 if (options)
1802 uart_parse_options(options, &baud, &parity, &bits, &flow);
1803 else
1804 imx_console_get_options(sport, &baud, &parity, &bits);
1806 imx_setup_ufcr(sport, 0);
1808 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1810 clk_disable(sport->clk_ipg);
1811 if (retval) {
1812 clk_unprepare(sport->clk_ipg);
1813 goto error_console;
1816 retval = clk_prepare(sport->clk_per);
1817 if (retval)
1818 clk_disable_unprepare(sport->clk_ipg);
1820 error_console:
1821 return retval;
1824 static struct uart_driver imx_reg;
1825 static struct console imx_console = {
1826 .name = DEV_NAME,
1827 .write = imx_console_write,
1828 .device = uart_console_device,
1829 .setup = imx_console_setup,
1830 .flags = CON_PRINTBUFFER,
1831 .index = -1,
1832 .data = &imx_reg,
1835 #define IMX_CONSOLE &imx_console
1836 #else
1837 #define IMX_CONSOLE NULL
1838 #endif
1840 static struct uart_driver imx_reg = {
1841 .owner = THIS_MODULE,
1842 .driver_name = DRIVER_NAME,
1843 .dev_name = DEV_NAME,
1844 .major = SERIAL_IMX_MAJOR,
1845 .minor = MINOR_START,
1846 .nr = ARRAY_SIZE(imx_ports),
1847 .cons = IMX_CONSOLE,
1850 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1852 struct imx_port *sport = platform_get_drvdata(dev);
1853 unsigned int val;
1855 /* enable wakeup from i.MX UART */
1856 val = readl(sport->port.membase + UCR3);
1857 val |= UCR3_AWAKEN;
1858 writel(val, sport->port.membase + UCR3);
1860 uart_suspend_port(&imx_reg, &sport->port);
1862 return 0;
1865 static int serial_imx_resume(struct platform_device *dev)
1867 struct imx_port *sport = platform_get_drvdata(dev);
1868 unsigned int val;
1870 /* disable wakeup from i.MX UART */
1871 val = readl(sport->port.membase + UCR3);
1872 val &= ~UCR3_AWAKEN;
1873 writel(val, sport->port.membase + UCR3);
1875 uart_resume_port(&imx_reg, &sport->port);
1877 return 0;
1880 #ifdef CONFIG_OF
1882 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1883 * could successfully get all information from dt or a negative errno.
1885 static int serial_imx_probe_dt(struct imx_port *sport,
1886 struct platform_device *pdev)
1888 struct device_node *np = pdev->dev.of_node;
1889 const struct of_device_id *of_id =
1890 of_match_device(imx_uart_dt_ids, &pdev->dev);
1891 int ret;
1893 if (!np)
1894 /* no device tree device */
1895 return 1;
1897 ret = of_alias_get_id(np, "serial");
1898 if (ret < 0) {
1899 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1900 return ret;
1902 sport->port.line = ret;
1904 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1905 sport->have_rtscts = 1;
1907 if (of_get_property(np, "fsl,irda-mode", NULL))
1908 sport->use_irda = 1;
1910 if (of_get_property(np, "fsl,dte-mode", NULL))
1911 sport->dte_mode = 1;
1913 sport->devdata = of_id->data;
1915 return 0;
1917 #else
1918 static inline int serial_imx_probe_dt(struct imx_port *sport,
1919 struct platform_device *pdev)
1921 return 1;
1923 #endif
1925 static void serial_imx_probe_pdata(struct imx_port *sport,
1926 struct platform_device *pdev)
1928 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1930 sport->port.line = pdev->id;
1931 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
1933 if (!pdata)
1934 return;
1936 if (pdata->flags & IMXUART_HAVE_RTSCTS)
1937 sport->have_rtscts = 1;
1939 if (pdata->flags & IMXUART_IRDA)
1940 sport->use_irda = 1;
1943 static int serial_imx_probe(struct platform_device *pdev)
1945 struct imx_port *sport;
1946 struct imxuart_platform_data *pdata;
1947 void __iomem *base;
1948 int ret = 0;
1949 struct resource *res;
1951 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1952 if (!sport)
1953 return -ENOMEM;
1955 ret = serial_imx_probe_dt(sport, pdev);
1956 if (ret > 0)
1957 serial_imx_probe_pdata(sport, pdev);
1958 else if (ret < 0)
1959 return ret;
1961 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1962 if (!res)
1963 return -ENODEV;
1965 base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE);
1966 if (!base)
1967 return -ENOMEM;
1969 sport->port.dev = &pdev->dev;
1970 sport->port.mapbase = res->start;
1971 sport->port.membase = base;
1972 sport->port.type = PORT_IMX,
1973 sport->port.iotype = UPIO_MEM;
1974 sport->port.irq = platform_get_irq(pdev, 0);
1975 sport->rxirq = platform_get_irq(pdev, 0);
1976 sport->txirq = platform_get_irq(pdev, 1);
1977 sport->rtsirq = platform_get_irq(pdev, 2);
1978 sport->port.fifosize = 32;
1979 sport->port.ops = &imx_pops;
1980 sport->port.flags = UPF_BOOT_AUTOCONF;
1981 init_timer(&sport->timer);
1982 sport->timer.function = imx_timeout;
1983 sport->timer.data = (unsigned long)sport;
1985 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1986 if (IS_ERR(sport->clk_ipg)) {
1987 ret = PTR_ERR(sport->clk_ipg);
1988 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1989 return ret;
1992 sport->clk_per = devm_clk_get(&pdev->dev, "per");
1993 if (IS_ERR(sport->clk_per)) {
1994 ret = PTR_ERR(sport->clk_per);
1995 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1996 return ret;
1999 sport->port.uartclk = clk_get_rate(sport->clk_per);
2001 imx_ports[sport->port.line] = sport;
2003 pdata = dev_get_platdata(&pdev->dev);
2004 if (pdata && pdata->init) {
2005 ret = pdata->init(pdev);
2006 if (ret)
2007 return ret;
2010 ret = uart_add_one_port(&imx_reg, &sport->port);
2011 if (ret)
2012 goto deinit;
2013 platform_set_drvdata(pdev, sport);
2015 return 0;
2016 deinit:
2017 if (pdata && pdata->exit)
2018 pdata->exit(pdev);
2019 return ret;
2022 static int serial_imx_remove(struct platform_device *pdev)
2024 struct imxuart_platform_data *pdata;
2025 struct imx_port *sport = platform_get_drvdata(pdev);
2027 pdata = dev_get_platdata(&pdev->dev);
2029 uart_remove_one_port(&imx_reg, &sport->port);
2031 if (pdata && pdata->exit)
2032 pdata->exit(pdev);
2034 return 0;
2037 static struct platform_driver serial_imx_driver = {
2038 .probe = serial_imx_probe,
2039 .remove = serial_imx_remove,
2041 .suspend = serial_imx_suspend,
2042 .resume = serial_imx_resume,
2043 .id_table = imx_uart_devtype,
2044 .driver = {
2045 .name = "imx-uart",
2046 .owner = THIS_MODULE,
2047 .of_match_table = imx_uart_dt_ids,
2051 static int __init imx_serial_init(void)
2053 int ret;
2055 pr_info("Serial: IMX driver\n");
2057 ret = uart_register_driver(&imx_reg);
2058 if (ret)
2059 return ret;
2061 ret = platform_driver_register(&serial_imx_driver);
2062 if (ret != 0)
2063 uart_unregister_driver(&imx_reg);
2065 return ret;
2068 static void __exit imx_serial_exit(void)
2070 platform_driver_unregister(&serial_imx_driver);
2071 uart_unregister_driver(&imx_reg);
2074 module_init(imx_serial_init);
2075 module_exit(imx_serial_exit);
2077 MODULE_AUTHOR("Sascha Hauer");
2078 MODULE_DESCRIPTION("IMX generic serial port driver");
2079 MODULE_LICENSE("GPL");
2080 MODULE_ALIAS("platform:imx-uart");