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serial: mxs-auart: Remove unneeded zeroing of 'ret'
[linux-2.6/btrfs-unstable.git] / drivers / tty / serial / mxs-auart.c
blobd1298b6cc68e4e6f1f610959f57f94cf350650fd
1 /*
2 * Freescale STMP37XX/STMP378X Application UART driver
3 *
4 * Author: dmitry pervushin <dimka@embeddedalley.com>
5 *
6 * Copyright 2008-2010 Freescale Semiconductor, Inc.
7 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
8 *
9 * The code contained herein is licensed under the GNU General Public
10 * License. You may obtain a copy of the GNU General Public License
11 * Version 2 or later at the following locations:
12 *
13 * http://www.opensource.org/licenses/gpl-license.html
14 * http://www.gnu.org/copyleft/gpl.html
15 */
16
17 #if defined(CONFIG_SERIAL_MXS_AUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
18 #define SUPPORT_SYSRQ
19 #endif
20
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/console.h>
25 #include <linux/interrupt.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/wait.h>
29 #include <linux/tty.h>
30 #include <linux/tty_driver.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial.h>
33 #include <linux/serial_core.h>
34 #include <linux/platform_device.h>
35 #include <linux/device.h>
36 #include <linux/clk.h>
37 #include <linux/delay.h>
38 #include <linux/io.h>
39 #include <linux/of_device.h>
40 #include <linux/dma-mapping.h>
41 #include <linux/dmaengine.h>
42
43 #include <asm/cacheflush.h>
44
45 #include <linux/gpio.h>
46 #include <linux/gpio/consumer.h>
47 #include <linux/err.h>
48 #include <linux/irq.h>
49 #include "serial_mctrl_gpio.h"
50
51 #define MXS_AUART_PORTS 5
52 #define MXS_AUART_FIFO_SIZE 16
53
54 #define AUART_CTRL0 0x00000000
55 #define AUART_CTRL0_SET 0x00000004
56 #define AUART_CTRL0_CLR 0x00000008
57 #define AUART_CTRL0_TOG 0x0000000c
58 #define AUART_CTRL1 0x00000010
59 #define AUART_CTRL1_SET 0x00000014
60 #define AUART_CTRL1_CLR 0x00000018
61 #define AUART_CTRL1_TOG 0x0000001c
62 #define AUART_CTRL2 0x00000020
63 #define AUART_CTRL2_SET 0x00000024
64 #define AUART_CTRL2_CLR 0x00000028
65 #define AUART_CTRL2_TOG 0x0000002c
66 #define AUART_LINECTRL 0x00000030
67 #define AUART_LINECTRL_SET 0x00000034
68 #define AUART_LINECTRL_CLR 0x00000038
69 #define AUART_LINECTRL_TOG 0x0000003c
70 #define AUART_LINECTRL2 0x00000040
71 #define AUART_LINECTRL2_SET 0x00000044
72 #define AUART_LINECTRL2_CLR 0x00000048
73 #define AUART_LINECTRL2_TOG 0x0000004c
74 #define AUART_INTR 0x00000050
75 #define AUART_INTR_SET 0x00000054
76 #define AUART_INTR_CLR 0x00000058
77 #define AUART_INTR_TOG 0x0000005c
78 #define AUART_DATA 0x00000060
79 #define AUART_STAT 0x00000070
80 #define AUART_DEBUG 0x00000080
81 #define AUART_VERSION 0x00000090
82 #define AUART_AUTOBAUD 0x000000a0
83
84 #define AUART_CTRL0_SFTRST (1 << 31)
85 #define AUART_CTRL0_CLKGATE (1 << 30)
86 #define AUART_CTRL0_RXTO_ENABLE (1 << 27)
87 #define AUART_CTRL0_RXTIMEOUT(v) (((v) & 0x7ff) << 16)
88 #define AUART_CTRL0_XFER_COUNT(v) ((v) & 0xffff)
89
90 #define AUART_CTRL1_XFER_COUNT(v) ((v) & 0xffff)
91
92 #define AUART_CTRL2_DMAONERR (1 << 26)
93 #define AUART_CTRL2_TXDMAE (1 << 25)
94 #define AUART_CTRL2_RXDMAE (1 << 24)
95
96 #define AUART_CTRL2_CTSEN (1 << 15)
97 #define AUART_CTRL2_RTSEN (1 << 14)
98 #define AUART_CTRL2_RTS (1 << 11)
99 #define AUART_CTRL2_RXE (1 << 9)
100 #define AUART_CTRL2_TXE (1 << 8)
101 #define AUART_CTRL2_UARTEN (1 << 0)
102
103 #define AUART_LINECTRL_BAUD_DIVINT_SHIFT 16
104 #define AUART_LINECTRL_BAUD_DIVINT_MASK 0xffff0000
105 #define AUART_LINECTRL_BAUD_DIVINT(v) (((v) & 0xffff) << 16)
106 #define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT 8
107 #define AUART_LINECTRL_BAUD_DIVFRAC_MASK 0x00003f00
108 #define AUART_LINECTRL_BAUD_DIVFRAC(v) (((v) & 0x3f) << 8)
109 #define AUART_LINECTRL_WLEN_MASK 0x00000060
110 #define AUART_LINECTRL_WLEN(v) (((v) & 0x3) << 5)
111 #define AUART_LINECTRL_FEN (1 << 4)
112 #define AUART_LINECTRL_STP2 (1 << 3)
113 #define AUART_LINECTRL_EPS (1 << 2)
114 #define AUART_LINECTRL_PEN (1 << 1)
115 #define AUART_LINECTRL_BRK (1 << 0)
116
117 #define AUART_INTR_RTIEN (1 << 22)
118 #define AUART_INTR_TXIEN (1 << 21)
119 #define AUART_INTR_RXIEN (1 << 20)
120 #define AUART_INTR_CTSMIEN (1 << 17)
121 #define AUART_INTR_RTIS (1 << 6)
122 #define AUART_INTR_TXIS (1 << 5)
123 #define AUART_INTR_RXIS (1 << 4)
124 #define AUART_INTR_CTSMIS (1 << 1)
125
126 #define AUART_STAT_BUSY (1 << 29)
127 #define AUART_STAT_CTS (1 << 28)
128 #define AUART_STAT_TXFE (1 << 27)
129 #define AUART_STAT_TXFF (1 << 25)
130 #define AUART_STAT_RXFE (1 << 24)
131 #define AUART_STAT_OERR (1 << 19)
132 #define AUART_STAT_BERR (1 << 18)
133 #define AUART_STAT_PERR (1 << 17)
134 #define AUART_STAT_FERR (1 << 16)
135 #define AUART_STAT_RXCOUNT_MASK 0xffff
136
137 static struct uart_driver auart_driver;
138
139 enum mxs_auart_type {
140 IMX23_AUART,
141 IMX28_AUART,
142 };
143
144 struct mxs_auart_port {
145 struct uart_port port;
146
147 #define MXS_AUART_DMA_ENABLED 0x2
148 #define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */
149 #define MXS_AUART_DMA_RX_READY 3 /* bit 3 */
150 #define MXS_AUART_RTSCTS 4 /* bit 4 */
151 unsigned long flags;
152 unsigned int mctrl_prev;
153 enum mxs_auart_type devtype;
154
155 struct clk *clk;
156 struct device *dev;
157
158 /* for DMA */
159 struct scatterlist tx_sgl;
160 struct dma_chan *tx_dma_chan;
161 void *tx_dma_buf;
162
163 struct scatterlist rx_sgl;
164 struct dma_chan *rx_dma_chan;
165 void *rx_dma_buf;
166
167 struct mctrl_gpios *gpios;
168 int gpio_irq[UART_GPIO_MAX];
169 bool ms_irq_enabled;
170 };
171
172 static struct platform_device_id mxs_auart_devtype[] = {
173 { .name = "mxs-auart-imx23", .driver_data = IMX23_AUART },
174 { .name = "mxs-auart-imx28", .driver_data = IMX28_AUART },
175 { /* sentinel */ }
176 };
177 MODULE_DEVICE_TABLE(platform, mxs_auart_devtype);
178
179 static struct of_device_id mxs_auart_dt_ids[] = {
180 {
181 .compatible = "fsl,imx28-auart",
182 .data = &mxs_auart_devtype[IMX28_AUART]
183 }, {
184 .compatible = "fsl,imx23-auart",
185 .data = &mxs_auart_devtype[IMX23_AUART]
186 }, { /* sentinel */ }
187 };
188 MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids);
189
190 static inline int is_imx28_auart(struct mxs_auart_port *s)
191 {
192 return s->devtype == IMX28_AUART;
193 }
194
195 static inline bool auart_dma_enabled(struct mxs_auart_port *s)
196 {
197 return s->flags & MXS_AUART_DMA_ENABLED;
198 }
199
200 static void mxs_auart_stop_tx(struct uart_port *u);
201
202 #define to_auart_port(u) container_of(u, struct mxs_auart_port, port)
203
204 static void mxs_auart_tx_chars(struct mxs_auart_port *s);
205
206 static void dma_tx_callback(void *param)
207 {
208 struct mxs_auart_port *s = param;
209 struct circ_buf *xmit = &s->port.state->xmit;
210
211 dma_unmap_sg(s->dev, &s->tx_sgl, 1, DMA_TO_DEVICE);
212
213 /* clear the bit used to serialize the DMA tx. */
214 clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
215 smp_mb__after_atomic();
216
217 /* wake up the possible processes. */
218 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
219 uart_write_wakeup(&s->port);
220
221 mxs_auart_tx_chars(s);
222 }
223
224 static int mxs_auart_dma_tx(struct mxs_auart_port *s, int size)
225 {
226 struct dma_async_tx_descriptor *desc;
227 struct scatterlist *sgl = &s->tx_sgl;
228 struct dma_chan *channel = s->tx_dma_chan;
229 u32 pio;
230
231 /* [1] : send PIO. Note, the first pio word is CTRL1. */
232 pio = AUART_CTRL1_XFER_COUNT(size);
233 desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)&pio,
234 1, DMA_TRANS_NONE, 0);
235 if (!desc) {
236 dev_err(s->dev, "step 1 error\n");
237 return -EINVAL;
238 }
239
240 /* [2] : set DMA buffer. */
241 sg_init_one(sgl, s->tx_dma_buf, size);
242 dma_map_sg(s->dev, sgl, 1, DMA_TO_DEVICE);
243 desc = dmaengine_prep_slave_sg(channel, sgl,
244 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
245 if (!desc) {
246 dev_err(s->dev, "step 2 error\n");
247 return -EINVAL;
248 }
249
250 /* [3] : submit the DMA */
251 desc->callback = dma_tx_callback;
252 desc->callback_param = s;
253 dmaengine_submit(desc);
254 dma_async_issue_pending(channel);
255 return 0;
256 }
257
258 static void mxs_auart_tx_chars(struct mxs_auart_port *s)
259 {
260 struct circ_buf *xmit = &s->port.state->xmit;
261
262 if (auart_dma_enabled(s)) {
263 u32 i = 0;
264 int size;
265 void *buffer = s->tx_dma_buf;
266
267 if (test_and_set_bit(MXS_AUART_DMA_TX_SYNC, &s->flags))
268 return;
269
270 while (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
271 size = min_t(u32, UART_XMIT_SIZE - i,
272 CIRC_CNT_TO_END(xmit->head,
273 xmit->tail,
274 UART_XMIT_SIZE));
275 memcpy(buffer + i, xmit->buf + xmit->tail, size);
276 xmit->tail = (xmit->tail + size) & (UART_XMIT_SIZE - 1);
277
278 i += size;
279 if (i >= UART_XMIT_SIZE)
280 break;
281 }
282
283 if (uart_tx_stopped(&s->port))
284 mxs_auart_stop_tx(&s->port);
285
286 if (i) {
287 mxs_auart_dma_tx(s, i);
288 } else {
289 clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
290 smp_mb__after_atomic();
291 }
292 return;
293 }
294
295
296 while (!(readl(s->port.membase + AUART_STAT) &
297 AUART_STAT_TXFF)) {
298 if (s->port.x_char) {
299 s->port.icount.tx++;
300 writel(s->port.x_char,
301 s->port.membase + AUART_DATA);
302 s->port.x_char = 0;
303 continue;
304 }
305 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
306 s->port.icount.tx++;
307 writel(xmit->buf[xmit->tail],
308 s->port.membase + AUART_DATA);
309 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
310 } else
311 break;
312 }
313 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
314 uart_write_wakeup(&s->port);
315
316 if (uart_circ_empty(&(s->port.state->xmit)))
317 writel(AUART_INTR_TXIEN,
318 s->port.membase + AUART_INTR_CLR);
319 else
320 writel(AUART_INTR_TXIEN,
321 s->port.membase + AUART_INTR_SET);
322
323 if (uart_tx_stopped(&s->port))
324 mxs_auart_stop_tx(&s->port);
325 }
326
327 static void mxs_auart_rx_char(struct mxs_auart_port *s)
328 {
329 int flag;
330 u32 stat;
331 u8 c;
332
333 c = readl(s->port.membase + AUART_DATA);
334 stat = readl(s->port.membase + AUART_STAT);
335
336 flag = TTY_NORMAL;
337 s->port.icount.rx++;
338
339 if (stat & AUART_STAT_BERR) {
340 s->port.icount.brk++;
341 if (uart_handle_break(&s->port))
342 goto out;
343 } else if (stat & AUART_STAT_PERR) {
344 s->port.icount.parity++;
345 } else if (stat & AUART_STAT_FERR) {
346 s->port.icount.frame++;
347 }
348
349 /*
350 * Mask off conditions which should be ingored.
351 */
352 stat &= s->port.read_status_mask;
353
354 if (stat & AUART_STAT_BERR) {
355 flag = TTY_BREAK;
356 } else if (stat & AUART_STAT_PERR)
357 flag = TTY_PARITY;
358 else if (stat & AUART_STAT_FERR)
359 flag = TTY_FRAME;
360
361 if (stat & AUART_STAT_OERR)
362 s->port.icount.overrun++;
363
364 if (uart_handle_sysrq_char(&s->port, c))
365 goto out;
366
367 uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag);
368 out:
369 writel(stat, s->port.membase + AUART_STAT);
370 }
371
372 static void mxs_auart_rx_chars(struct mxs_auart_port *s)
373 {
374 u32 stat = 0;
375
376 for (;;) {
377 stat = readl(s->port.membase + AUART_STAT);
378 if (stat & AUART_STAT_RXFE)
379 break;
380 mxs_auart_rx_char(s);
381 }
382
383 writel(stat, s->port.membase + AUART_STAT);
384 tty_flip_buffer_push(&s->port.state->port);
385 }
386
387 static int mxs_auart_request_port(struct uart_port *u)
388 {
389 return 0;
390 }
391
392 static int mxs_auart_verify_port(struct uart_port *u,
393 struct serial_struct *ser)
394 {
395 if (u->type != PORT_UNKNOWN && u->type != PORT_IMX)
396 return -EINVAL;
397 return 0;
398 }
399
400 static void mxs_auart_config_port(struct uart_port *u, int flags)
401 {
402 }
403
404 static const char *mxs_auart_type(struct uart_port *u)
405 {
406 struct mxs_auart_port *s = to_auart_port(u);
407
408 return dev_name(s->dev);
409 }
410
411 static void mxs_auart_release_port(struct uart_port *u)
412 {
413 }
414
415 static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
416 {
417 struct mxs_auart_port *s = to_auart_port(u);
418
419 u32 ctrl = readl(u->membase + AUART_CTRL2);
420
421 ctrl &= ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS);
422 if (mctrl & TIOCM_RTS) {
423 if (uart_cts_enabled(u))
424 ctrl |= AUART_CTRL2_RTSEN;
425 else
426 ctrl |= AUART_CTRL2_RTS;
427 }
428
429 writel(ctrl, u->membase + AUART_CTRL2);
430
431 mctrl_gpio_set(s->gpios, mctrl);
432 }
433
434 #define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
435 static u32 mxs_auart_modem_status(struct mxs_auart_port *s, u32 mctrl)
436 {
437 u32 mctrl_diff;
438
439 mctrl_diff = mctrl ^ s->mctrl_prev;
440 s->mctrl_prev = mctrl;
441 if (mctrl_diff & MCTRL_ANY_DELTA && s->ms_irq_enabled &&
442 s->port.state != NULL) {
443 if (mctrl_diff & TIOCM_RI)
444 s->port.icount.rng++;
445 if (mctrl_diff & TIOCM_DSR)
446 s->port.icount.dsr++;
447 if (mctrl_diff & TIOCM_CD)
448 uart_handle_dcd_change(&s->port, mctrl & TIOCM_CD);
449 if (mctrl_diff & TIOCM_CTS)
450 uart_handle_cts_change(&s->port, mctrl & TIOCM_CTS);
451
452 wake_up_interruptible(&s->port.state->port.delta_msr_wait);
453 }
454 return mctrl;
455 }
456
457 static u32 mxs_auart_get_mctrl(struct uart_port *u)
458 {
459 struct mxs_auart_port *s = to_auart_port(u);
460 u32 stat = readl(u->membase + AUART_STAT);
461 u32 mctrl = 0;
462
463 if (stat & AUART_STAT_CTS)
464 mctrl |= TIOCM_CTS;
465
466 return mctrl_gpio_get(s->gpios, &mctrl);
467 }
468
469 /*
470 * Enable modem status interrupts
471 */
472 static void mxs_auart_enable_ms(struct uart_port *port)
473 {
474 struct mxs_auart_port *s = to_auart_port(port);
475
476 /*
477 * Interrupt should not be enabled twice
478 */
479 if (s->ms_irq_enabled)
480 return;
481
482 s->ms_irq_enabled = true;
483
484 if (s->gpio_irq[UART_GPIO_CTS] >= 0)
485 enable_irq(s->gpio_irq[UART_GPIO_CTS]);
486 /* TODO: enable AUART_INTR_CTSMIEN otherwise */
487
488 if (s->gpio_irq[UART_GPIO_DSR] >= 0)
489 enable_irq(s->gpio_irq[UART_GPIO_DSR]);
490
491 if (s->gpio_irq[UART_GPIO_RI] >= 0)
492 enable_irq(s->gpio_irq[UART_GPIO_RI]);
493
494 if (s->gpio_irq[UART_GPIO_DCD] >= 0)
495 enable_irq(s->gpio_irq[UART_GPIO_DCD]);
496 }
497
498 /*
499 * Disable modem status interrupts
500 */
501 static void mxs_auart_disable_ms(struct uart_port *port)
502 {
503 struct mxs_auart_port *s = to_auart_port(port);
504
505 /*
506 * Interrupt should not be disabled twice
507 */
508 if (!s->ms_irq_enabled)
509 return;
510
511 s->ms_irq_enabled = false;
512
513 if (s->gpio_irq[UART_GPIO_CTS] >= 0)
514 disable_irq(s->gpio_irq[UART_GPIO_CTS]);
515 /* TODO: disable AUART_INTR_CTSMIEN otherwise */
516
517 if (s->gpio_irq[UART_GPIO_DSR] >= 0)
518 disable_irq(s->gpio_irq[UART_GPIO_DSR]);
519
520 if (s->gpio_irq[UART_GPIO_RI] >= 0)
521 disable_irq(s->gpio_irq[UART_GPIO_RI]);
522
523 if (s->gpio_irq[UART_GPIO_DCD] >= 0)
524 disable_irq(s->gpio_irq[UART_GPIO_DCD]);
525 }
526
527 static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);
528 static void dma_rx_callback(void *arg)
529 {
530 struct mxs_auart_port *s = (struct mxs_auart_port *) arg;
531 struct tty_port *port = &s->port.state->port;
532 int count;
533 u32 stat;
534
535 dma_unmap_sg(s->dev, &s->rx_sgl, 1, DMA_FROM_DEVICE);
536
537 stat = readl(s->port.membase + AUART_STAT);
538 stat &= ~(AUART_STAT_OERR | AUART_STAT_BERR |
539 AUART_STAT_PERR | AUART_STAT_FERR);
540
541 count = stat & AUART_STAT_RXCOUNT_MASK;
542 tty_insert_flip_string(port, s->rx_dma_buf, count);
543
544 writel(stat, s->port.membase + AUART_STAT);
545 tty_flip_buffer_push(port);
546
547 /* start the next DMA for RX. */
548 mxs_auart_dma_prep_rx(s);
549 }
550
551 static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s)
552 {
553 struct dma_async_tx_descriptor *desc;
554 struct scatterlist *sgl = &s->rx_sgl;
555 struct dma_chan *channel = s->rx_dma_chan;
556 u32 pio[1];
557
558 /* [1] : send PIO */
559 pio[0] = AUART_CTRL0_RXTO_ENABLE
560 | AUART_CTRL0_RXTIMEOUT(0x80)
561 | AUART_CTRL0_XFER_COUNT(UART_XMIT_SIZE);
562 desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
563 1, DMA_TRANS_NONE, 0);
564 if (!desc) {
565 dev_err(s->dev, "step 1 error\n");
566 return -EINVAL;
567 }
568
569 /* [2] : send DMA request */
570 sg_init_one(sgl, s->rx_dma_buf, UART_XMIT_SIZE);
571 dma_map_sg(s->dev, sgl, 1, DMA_FROM_DEVICE);
572 desc = dmaengine_prep_slave_sg(channel, sgl, 1, DMA_DEV_TO_MEM,
573 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
574 if (!desc) {
575 dev_err(s->dev, "step 2 error\n");
576 return -1;
577 }
578
579 /* [3] : submit the DMA, but do not issue it. */
580 desc->callback = dma_rx_callback;
581 desc->callback_param = s;
582 dmaengine_submit(desc);
583 dma_async_issue_pending(channel);
584 return 0;
585 }
586
587 static void mxs_auart_dma_exit_channel(struct mxs_auart_port *s)
588 {
589 if (s->tx_dma_chan) {
590 dma_release_channel(s->tx_dma_chan);
591 s->tx_dma_chan = NULL;
592 }
593 if (s->rx_dma_chan) {
594 dma_release_channel(s->rx_dma_chan);
595 s->rx_dma_chan = NULL;
596 }
597
598 kfree(s->tx_dma_buf);
599 kfree(s->rx_dma_buf);
600 s->tx_dma_buf = NULL;
601 s->rx_dma_buf = NULL;
602 }
603
604 static void mxs_auart_dma_exit(struct mxs_auart_port *s)
605 {
606
607 writel(AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE | AUART_CTRL2_DMAONERR,
608 s->port.membase + AUART_CTRL2_CLR);
609
610 mxs_auart_dma_exit_channel(s);
611 s->flags &= ~MXS_AUART_DMA_ENABLED;
612 clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags);
613 clear_bit(MXS_AUART_DMA_RX_READY, &s->flags);
614 }
615
616 static int mxs_auart_dma_init(struct mxs_auart_port *s)
617 {
618 if (auart_dma_enabled(s))
619 return 0;
620
621 /* init for RX */
622 s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx");
623 if (!s->rx_dma_chan)
624 goto err_out;
625 s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
626 if (!s->rx_dma_buf)
627 goto err_out;
628
629 /* init for TX */
630 s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx");
631 if (!s->tx_dma_chan)
632 goto err_out;
633 s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
634 if (!s->tx_dma_buf)
635 goto err_out;
636
637 /* set the flags */
638 s->flags |= MXS_AUART_DMA_ENABLED;
639 dev_dbg(s->dev, "enabled the DMA support.");
640
641 /* The DMA buffer is now the FIFO the TTY subsystem can use */
642 s->port.fifosize = UART_XMIT_SIZE;
643
644 return 0;
645
646 err_out:
647 mxs_auart_dma_exit_channel(s);
648 return -EINVAL;
649
650 }
651
652 #define RTS_AT_AUART() IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios, \
653 UART_GPIO_RTS))
654 #define CTS_AT_AUART() IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios, \
655 UART_GPIO_CTS))
656 static void mxs_auart_settermios(struct uart_port *u,
657 struct ktermios *termios,
658 struct ktermios *old)
659 {
660 struct mxs_auart_port *s = to_auart_port(u);
661 u32 bm, ctrl, ctrl2, div;
662 unsigned int cflag, baud;
663
664 cflag = termios->c_cflag;
665
666 ctrl = AUART_LINECTRL_FEN;
667 ctrl2 = readl(u->membase + AUART_CTRL2);
668
669 /* byte size */
670 switch (cflag & CSIZE) {
671 case CS5:
672 bm = 0;
673 break;
674 case CS6:
675 bm = 1;
676 break;
677 case CS7:
678 bm = 2;
679 break;
680 case CS8:
681 bm = 3;
682 break;
683 default:
684 return;
685 }
686
687 ctrl |= AUART_LINECTRL_WLEN(bm);
688
689 /* parity */
690 if (cflag & PARENB) {
691 ctrl |= AUART_LINECTRL_PEN;
692 if ((cflag & PARODD) == 0)
693 ctrl |= AUART_LINECTRL_EPS;
694 }
695
696 u->read_status_mask = 0;
697
698 if (termios->c_iflag & INPCK)
699 u->read_status_mask |= AUART_STAT_PERR;
700 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
701 u->read_status_mask |= AUART_STAT_BERR;
702
703 /*
704 * Characters to ignore
705 */
706 u->ignore_status_mask = 0;
707 if (termios->c_iflag & IGNPAR)
708 u->ignore_status_mask |= AUART_STAT_PERR;
709 if (termios->c_iflag & IGNBRK) {
710 u->ignore_status_mask |= AUART_STAT_BERR;
711 /*
712 * If we're ignoring parity and break indicators,
713 * ignore overruns too (for real raw support).
714 */
715 if (termios->c_iflag & IGNPAR)
716 u->ignore_status_mask |= AUART_STAT_OERR;
717 }
718
719 /*
720 * ignore all characters if CREAD is not set
721 */
722 if (cflag & CREAD)
723 ctrl2 |= AUART_CTRL2_RXE;
724 else
725 ctrl2 &= ~AUART_CTRL2_RXE;
726
727 /* figure out the stop bits requested */
728 if (cflag & CSTOPB)
729 ctrl |= AUART_LINECTRL_STP2;
730
731 /* figure out the hardware flow control settings */
732 ctrl2 &= ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN);
733 if (cflag & CRTSCTS) {
734 /*
735 * The DMA has a bug(see errata:2836) in mx23.
736 * So we can not implement the DMA for auart in mx23,
737 * we can only implement the DMA support for auart
738 * in mx28.
739 */
740 if (is_imx28_auart(s)
741 && test_bit(MXS_AUART_RTSCTS, &s->flags)) {
742 if (!mxs_auart_dma_init(s))
743 /* enable DMA tranfer */
744 ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE
745 | AUART_CTRL2_DMAONERR;
746 }
747 /* Even if RTS is GPIO line RTSEN can be enabled because
748 * the pinctrl configuration decides about RTS pin function */
749 ctrl2 |= AUART_CTRL2_RTSEN;
750 if (CTS_AT_AUART())
751 ctrl2 |= AUART_CTRL2_CTSEN;
752 }
753
754 /* set baud rate */
755 baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk);
756 div = u->uartclk * 32 / baud;
757 ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F);
758 ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6);
759
760 writel(ctrl, u->membase + AUART_LINECTRL);
761 writel(ctrl2, u->membase + AUART_CTRL2);
762
763 uart_update_timeout(u, termios->c_cflag, baud);
764
765 /* prepare for the DMA RX. */
766 if (auart_dma_enabled(s) &&
767 !test_and_set_bit(MXS_AUART_DMA_RX_READY, &s->flags)) {
768 if (!mxs_auart_dma_prep_rx(s)) {
769 /* Disable the normal RX interrupt. */
770 writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN,
771 u->membase + AUART_INTR_CLR);
772 } else {
773 mxs_auart_dma_exit(s);
774 dev_err(s->dev, "We can not start up the DMA.\n");
775 }
776 }
777
778 /* CTS flow-control and modem-status interrupts */
779 if (UART_ENABLE_MS(u, termios->c_cflag))
780 mxs_auart_enable_ms(u);
781 else
782 mxs_auart_disable_ms(u);
783 }
784
785 static void mxs_auart_set_ldisc(struct uart_port *port,
786 struct ktermios *termios)
787 {
788 if (termios->c_line == N_PPS) {
789 port->flags |= UPF_HARDPPS_CD;
790 mxs_auart_enable_ms(port);
791 } else {
792 port->flags &= ~UPF_HARDPPS_CD;
793 }
794 }
795
796 static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
797 {
798 u32 istat;
799 struct mxs_auart_port *s = context;
800 u32 mctrl_temp = s->mctrl_prev;
801 u32 stat = readl(s->port.membase + AUART_STAT);
802
803 istat = readl(s->port.membase + AUART_INTR);
804
805 /* ack irq */
806 writel(istat & (AUART_INTR_RTIS
807 | AUART_INTR_TXIS
808 | AUART_INTR_RXIS
809 | AUART_INTR_CTSMIS),
810 s->port.membase + AUART_INTR_CLR);
811
812 /*
813 * Dealing with GPIO interrupt
814 */
815 if (irq == s->gpio_irq[UART_GPIO_CTS] ||
816 irq == s->gpio_irq[UART_GPIO_DCD] ||
817 irq == s->gpio_irq[UART_GPIO_DSR] ||
818 irq == s->gpio_irq[UART_GPIO_RI])
819 mxs_auart_modem_status(s,
820 mctrl_gpio_get(s->gpios, &mctrl_temp));
821
822 if (istat & AUART_INTR_CTSMIS) {
823 if (CTS_AT_AUART() && s->ms_irq_enabled)
824 uart_handle_cts_change(&s->port,
825 stat & AUART_STAT_CTS);
826 writel(AUART_INTR_CTSMIS,
827 s->port.membase + AUART_INTR_CLR);
828 istat &= ~AUART_INTR_CTSMIS;
829 }
830
831 if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) {
832 if (!auart_dma_enabled(s))
833 mxs_auart_rx_chars(s);
834 istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS);
835 }
836
837 if (istat & AUART_INTR_TXIS) {
838 mxs_auart_tx_chars(s);
839 istat &= ~AUART_INTR_TXIS;
840 }
841
842 return IRQ_HANDLED;
843 }
844
845 static void mxs_auart_reset(struct uart_port *u)
846 {
847 int i;
848 unsigned int reg;
849
850 writel(AUART_CTRL0_SFTRST, u->membase + AUART_CTRL0_CLR);
851
852 for (i = 0; i < 10000; i++) {
853 reg = readl(u->membase + AUART_CTRL0);
854 if (!(reg & AUART_CTRL0_SFTRST))
855 break;
856 udelay(3);
857 }
858 writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
859 }
860
861 static int mxs_auart_startup(struct uart_port *u)
862 {
863 int ret;
864 struct mxs_auart_port *s = to_auart_port(u);
865
866 ret = clk_prepare_enable(s->clk);
867 if (ret)
868 return ret;
869
870 writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
871
872 writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_SET);
873
874 writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
875 u->membase + AUART_INTR);
876
877 /* Reset FIFO size (it could have changed if DMA was enabled) */
878 u->fifosize = MXS_AUART_FIFO_SIZE;
879
880 /*
881 * Enable fifo so all four bytes of a DMA word are written to
882 * output (otherwise, only the LSB is written, ie. 1 in 4 bytes)
883 */
884 writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET);
885
886 /* get initial status of modem lines */
887 mctrl_gpio_get(s->gpios, &s->mctrl_prev);
888
889 s->ms_irq_enabled = false;
890 return 0;
891 }
892
893 static void mxs_auart_shutdown(struct uart_port *u)
894 {
895 struct mxs_auart_port *s = to_auart_port(u);
896
897 mxs_auart_disable_ms(u);
898
899 if (auart_dma_enabled(s))
900 mxs_auart_dma_exit(s);
901
902 writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR);
903
904 writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
905 u->membase + AUART_INTR_CLR);
906
907 writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET);
908
909 clk_disable_unprepare(s->clk);
910 }
911
912 static unsigned int mxs_auart_tx_empty(struct uart_port *u)
913 {
914 if ((readl(u->membase + AUART_STAT) &
915 (AUART_STAT_TXFE | AUART_STAT_BUSY)) == AUART_STAT_TXFE)
916 return TIOCSER_TEMT;
917
918 return 0;
919 }
920
921 static void mxs_auart_start_tx(struct uart_port *u)
922 {
923 struct mxs_auart_port *s = to_auart_port(u);
924
925 /* enable transmitter */
926 writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_SET);
927
928 mxs_auart_tx_chars(s);
929 }
930
931 static void mxs_auart_stop_tx(struct uart_port *u)
932 {
933 writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_CLR);
934 }
935
936 static void mxs_auart_stop_rx(struct uart_port *u)
937 {
938 writel(AUART_CTRL2_RXE, u->membase + AUART_CTRL2_CLR);
939 }
940
941 static void mxs_auart_break_ctl(struct uart_port *u, int ctl)
942 {
943 if (ctl)
944 writel(AUART_LINECTRL_BRK,
945 u->membase + AUART_LINECTRL_SET);
946 else
947 writel(AUART_LINECTRL_BRK,
948 u->membase + AUART_LINECTRL_CLR);
949 }
950
951 static struct uart_ops mxs_auart_ops = {
952 .tx_empty = mxs_auart_tx_empty,
953 .start_tx = mxs_auart_start_tx,
954 .stop_tx = mxs_auart_stop_tx,
955 .stop_rx = mxs_auart_stop_rx,
956 .enable_ms = mxs_auart_enable_ms,
957 .break_ctl = mxs_auart_break_ctl,
958 .set_mctrl = mxs_auart_set_mctrl,
959 .get_mctrl = mxs_auart_get_mctrl,
960 .startup = mxs_auart_startup,
961 .shutdown = mxs_auart_shutdown,
962 .set_termios = mxs_auart_settermios,
963 .set_ldisc = mxs_auart_set_ldisc,
964 .type = mxs_auart_type,
965 .release_port = mxs_auart_release_port,
966 .request_port = mxs_auart_request_port,
967 .config_port = mxs_auart_config_port,
968 .verify_port = mxs_auart_verify_port,
969 };
970
971 static struct mxs_auart_port *auart_port[MXS_AUART_PORTS];
972
973 #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
974 static void mxs_auart_console_putchar(struct uart_port *port, int ch)
975 {
976 unsigned int to = 1000;
977
978 while (readl(port->membase + AUART_STAT) & AUART_STAT_TXFF) {
979 if (!to--)
980 break;
981 udelay(1);
982 }
983
984 writel(ch, port->membase + AUART_DATA);
985 }
986
987 static void
988 auart_console_write(struct console *co, const char *str, unsigned int count)
989 {
990 struct mxs_auart_port *s;
991 struct uart_port *port;
992 unsigned int old_ctrl0, old_ctrl2;
993 unsigned int to = 20000;
994
995 if (co->index >= MXS_AUART_PORTS || co->index < 0)
996 return;
997
998 s = auart_port[co->index];
999 port = &s->port;
1000
1001 clk_enable(s->clk);
1002
1003 /* First save the CR then disable the interrupts */
1004 old_ctrl2 = readl(port->membase + AUART_CTRL2);
1005 old_ctrl0 = readl(port->membase + AUART_CTRL0);
1006
1007 writel(AUART_CTRL0_CLKGATE,
1008 port->membase + AUART_CTRL0_CLR);
1009 writel(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE,
1010 port->membase + AUART_CTRL2_SET);
1011
1012 uart_console_write(port, str, count, mxs_auart_console_putchar);
1013
1014 /* Finally, wait for transmitter to become empty ... */
1015 while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) {
1016 udelay(1);
1017 if (!to--)
1018 break;
1019 }
1020
1021 /*
1022 * ... and restore the TCR if we waited long enough for the transmitter
1023 * to be idle. This might keep the transmitter enabled although it is
1024 * unused, but that is better than to disable it while it is still
1025 * transmitting.
1026 */
1027 if (!(readl(port->membase + AUART_STAT) & AUART_STAT_BUSY)) {
1028 writel(old_ctrl0, port->membase + AUART_CTRL0);
1029 writel(old_ctrl2, port->membase + AUART_CTRL2);
1030 }
1031
1032 clk_disable(s->clk);
1033 }
1034
1035 static void __init
1036 auart_console_get_options(struct uart_port *port, int *baud,
1037 int *parity, int *bits)
1038 {
1039 unsigned int lcr_h, quot;
1040
1041 if (!(readl(port->membase + AUART_CTRL2) & AUART_CTRL2_UARTEN))
1042 return;
1043
1044 lcr_h = readl(port->membase + AUART_LINECTRL);
1045
1046 *parity = 'n';
1047 if (lcr_h & AUART_LINECTRL_PEN) {
1048 if (lcr_h & AUART_LINECTRL_EPS)
1049 *parity = 'e';
1050 else
1051 *parity = 'o';
1052 }
1053
1054 if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2))
1055 *bits = 7;
1056 else
1057 *bits = 8;
1058
1059 quot = ((readl(port->membase + AUART_LINECTRL)
1060 & AUART_LINECTRL_BAUD_DIVINT_MASK))
1061 >> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6);
1062 quot |= ((readl(port->membase + AUART_LINECTRL)
1063 & AUART_LINECTRL_BAUD_DIVFRAC_MASK))
1064 >> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT;
1065 if (quot == 0)
1066 quot = 1;
1067
1068 *baud = (port->uartclk << 2) / quot;
1069 }
1070
1071 static int __init
1072 auart_console_setup(struct console *co, char *options)
1073 {
1074 struct mxs_auart_port *s;
1075 int baud = 9600;
1076 int bits = 8;
1077 int parity = 'n';
1078 int flow = 'n';
1079 int ret;
1080
1081 /*
1082 * Check whether an invalid uart number has been specified, and
1083 * if so, search for the first available port that does have
1084 * console support.
1085 */
1086 if (co->index == -1 || co->index >= ARRAY_SIZE(auart_port))
1087 co->index = 0;
1088 s = auart_port[co->index];
1089 if (!s)
1090 return -ENODEV;
1091
1092 ret = clk_prepare_enable(s->clk);
1093 if (ret)
1094 return ret;
1095
1096 if (options)
1097 uart_parse_options(options, &baud, &parity, &bits, &flow);
1098 else
1099 auart_console_get_options(&s->port, &baud, &parity, &bits);
1100
1101 ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
1102
1103 clk_disable_unprepare(s->clk);
1104
1105 return ret;
1106 }
1107
1108 static struct console auart_console = {
1109 .name = "ttyAPP",
1110 .write = auart_console_write,
1111 .device = uart_console_device,
1112 .setup = auart_console_setup,
1113 .flags = CON_PRINTBUFFER,
1114 .index = -1,
1115 .data = &auart_driver,
1116 };
1117 #endif
1118
1119 static struct uart_driver auart_driver = {
1120 .owner = THIS_MODULE,
1121 .driver_name = "ttyAPP",
1122 .dev_name = "ttyAPP",
1123 .major = 0,
1124 .minor = 0,
1125 .nr = MXS_AUART_PORTS,
1126 #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
1127 .cons = &auart_console,
1128 #endif
1129 };
1130
1131 /*
1132 * This function returns 1 if pdev isn't a device instatiated by dt, 0 if it
1133 * could successfully get all information from dt or a negative errno.
1134 */
1135 static int serial_mxs_probe_dt(struct mxs_auart_port *s,
1136 struct platform_device *pdev)
1137 {
1138 struct device_node *np = pdev->dev.of_node;
1139 int ret;
1140
1141 if (!np)
1142 /* no device tree device */
1143 return 1;
1144
1145 ret = of_alias_get_id(np, "serial");
1146 if (ret < 0) {
1147 dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
1148 return ret;
1149 }
1150 s->port.line = ret;
1151
1152 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1153 set_bit(MXS_AUART_RTSCTS, &s->flags);
1154
1155 return 0;
1156 }
1157
1158 static bool mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev)
1159 {
1160 enum mctrl_gpio_idx i;
1161 struct gpio_desc *gpiod;
1162
1163 s->gpios = mctrl_gpio_init(dev, 0);
1164 if (IS_ERR_OR_NULL(s->gpios))
1165 return false;
1166
1167 /* Block (enabled before) DMA option if RTS or CTS is GPIO line */
1168 if (!RTS_AT_AUART() || !CTS_AT_AUART()) {
1169 if (test_bit(MXS_AUART_RTSCTS, &s->flags))
1170 dev_warn(dev,
1171 "DMA and flow control via gpio may cause some problems. DMA disabled!\n");
1172 clear_bit(MXS_AUART_RTSCTS, &s->flags);
1173 }
1174
1175 for (i = 0; i < UART_GPIO_MAX; i++) {
1176 gpiod = mctrl_gpio_to_gpiod(s->gpios, i);
1177 if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN))
1178 s->gpio_irq[i] = gpiod_to_irq(gpiod);
1179 else
1180 s->gpio_irq[i] = -EINVAL;
1181 }
1182
1183 return true;
1184 }
1185
1186 static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s)
1187 {
1188 enum mctrl_gpio_idx i;
1189
1190 for (i = 0; i < UART_GPIO_MAX; i++)
1191 if (s->gpio_irq[i] >= 0)
1192 free_irq(s->gpio_irq[i], s);
1193 }
1194
1195 static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s)
1196 {
1197 int *irq = s->gpio_irq;
1198 enum mctrl_gpio_idx i;
1199 int err = 0;
1200
1201 for (i = 0; (i < UART_GPIO_MAX) && !err; i++) {
1202 if (irq[i] < 0)
1203 continue;
1204
1205 irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
1206 err = request_irq(irq[i], mxs_auart_irq_handle,
1207 IRQ_TYPE_EDGE_BOTH, dev_name(s->dev), s);
1208 if (err)
1209 dev_err(s->dev, "%s - Can't get %d irq\n",
1210 __func__, irq[i]);
1211 }
1212
1213 /*
1214 * If something went wrong, rollback.
1215 */
1216 while (err && (--i >= 0))
1217 if (irq[i] >= 0)
1218 free_irq(irq[i], s);
1219
1220 return err;
1221 }
1222
1223 static int mxs_auart_probe(struct platform_device *pdev)
1224 {
1225 const struct of_device_id *of_id =
1226 of_match_device(mxs_auart_dt_ids, &pdev->dev);
1227 struct mxs_auart_port *s;
1228 u32 version;
1229 int ret, irq;
1230 struct resource *r;
1231
1232 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
1233 if (!s)
1234 return -ENOMEM;
1235
1236 ret = serial_mxs_probe_dt(s, pdev);
1237 if (ret > 0)
1238 s->port.line = pdev->id < 0 ? 0 : pdev->id;
1239 else if (ret < 0)
1240 return ret;
1241
1242 if (of_id) {
1243 pdev->id_entry = of_id->data;
1244 s->devtype = pdev->id_entry->driver_data;
1245 }
1246
1247 s->clk = devm_clk_get(&pdev->dev, NULL);
1248 if (IS_ERR(s->clk))
1249 return PTR_ERR(s->clk);
1250
1251 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1252 if (!r)
1253 return -ENXIO;
1254
1255
1256 s->port.mapbase = r->start;
1257 s->port.membase = ioremap(r->start, resource_size(r));
1258 s->port.ops = &mxs_auart_ops;
1259 s->port.iotype = UPIO_MEM;
1260 s->port.fifosize = MXS_AUART_FIFO_SIZE;
1261 s->port.uartclk = clk_get_rate(s->clk);
1262 s->port.type = PORT_IMX;
1263 s->port.dev = s->dev = &pdev->dev;
1264
1265 s->mctrl_prev = 0;
1266
1267 irq = platform_get_irq(pdev, 0);
1268 if (irq < 0)
1269 return irq;
1270
1271 s->port.irq = irq;
1272 ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0,
1273 dev_name(&pdev->dev), s);
1274 if (ret)
1275 return ret;
1276
1277 platform_set_drvdata(pdev, s);
1278
1279 if (!mxs_auart_init_gpios(s, &pdev->dev))
1280 dev_err(&pdev->dev,
1281 "Failed to initialize GPIOs. The serial port may not work as expected\n");
1282
1283 /*
1284 * Get the GPIO lines IRQ
1285 */
1286 ret = mxs_auart_request_gpio_irq(s);
1287 if (ret)
1288 return ret;
1289
1290 auart_port[s->port.line] = s;
1291
1292 mxs_auart_reset(&s->port);
1293
1294 ret = uart_add_one_port(&auart_driver, &s->port);
1295 if (ret)
1296 goto out_free_gpio_irq;
1297
1298 version = readl(s->port.membase + AUART_VERSION);
1299 dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n",
1300 (version >> 24) & 0xff,
1301 (version >> 16) & 0xff, version & 0xffff);
1302
1303 return 0;
1304
1305 out_free_gpio_irq:
1306 mxs_auart_free_gpio_irq(s);
1307 auart_port[pdev->id] = NULL;
1308 return ret;
1309 }
1310
1311 static int mxs_auart_remove(struct platform_device *pdev)
1312 {
1313 struct mxs_auart_port *s = platform_get_drvdata(pdev);
1314
1315 uart_remove_one_port(&auart_driver, &s->port);
1316 auart_port[pdev->id] = NULL;
1317 mxs_auart_free_gpio_irq(s);
1318
1319 return 0;
1320 }
1321
1322 static struct platform_driver mxs_auart_driver = {
1323 .probe = mxs_auart_probe,
1324 .remove = mxs_auart_remove,
1325 .driver = {
1326 .name = "mxs-auart",
1327 .of_match_table = mxs_auart_dt_ids,
1328 },
1329 };
1330
1331 static int __init mxs_auart_init(void)
1332 {
1333 int r;
1334
1335 r = uart_register_driver(&auart_driver);
1336 if (r)
1337 goto out;
1338
1339 r = platform_driver_register(&mxs_auart_driver);
1340 if (r)
1341 goto out_err;
1342
1343 return 0;
1344 out_err:
1345 uart_unregister_driver(&auart_driver);
1346 out:
1347 return r;
1348 }
1349
1350 static void __exit mxs_auart_exit(void)
1351 {
1352 platform_driver_unregister(&mxs_auart_driver);
1353 uart_unregister_driver(&auart_driver);
1354 }
1355
1356 module_init(mxs_auart_init);
1357 module_exit(mxs_auart_exit);
1358 MODULE_LICENSE("GPL");
1359 MODULE_DESCRIPTION("Freescale MXS application uart driver");
1360 MODULE_ALIAS("platform:mxs-auart");
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