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Linux 4.1.16
[linux/fpc-iii.git] / drivers / tty / serial / msm_serial.c
blobb73889c8ed4b91242be90295d225aaa93b0adaa2
1 /*
2 * Driver for msm7k serial device and console
3 *
4 * Copyright (C) 2007 Google, Inc.
5 * Author: Robert Love <rlove@google.com>
6 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
7 *
8 * This software is licensed under the terms of the GNU General Public
9 * License version 2, as published by the Free Software Foundation, and
10 * may be copied, distributed, and modified under those terms.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18 #if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
19 # define SUPPORT_SYSRQ
20 #endif
21
22 #include <linux/atomic.h>
23 #include <linux/hrtimer.h>
24 #include <linux/module.h>
25 #include <linux/io.h>
26 #include <linux/ioport.h>
27 #include <linux/irq.h>
28 #include <linux/init.h>
29 #include <linux/console.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial_core.h>
33 #include <linux/serial.h>
34 #include <linux/clk.h>
35 #include <linux/platform_device.h>
36 #include <linux/delay.h>
37 #include <linux/of.h>
38 #include <linux/of_device.h>
39
40 #include "msm_serial.h"
41
42 enum {
43 UARTDM_1P1 = 1,
44 UARTDM_1P2,
45 UARTDM_1P3,
46 UARTDM_1P4,
47 };
48
49 struct msm_port {
50 struct uart_port uart;
51 char name[16];
52 struct clk *clk;
53 struct clk *pclk;
54 unsigned int imr;
55 int is_uartdm;
56 unsigned int old_snap_state;
57 bool break_detected;
58 };
59
60 static inline void wait_for_xmitr(struct uart_port *port)
61 {
62 while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) {
63 if (msm_read(port, UART_ISR) & UART_ISR_TX_READY)
64 break;
65 udelay(1);
66 }
67 msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR);
68 }
69
70 static void msm_stop_tx(struct uart_port *port)
71 {
72 struct msm_port *msm_port = UART_TO_MSM(port);
73
74 msm_port->imr &= ~UART_IMR_TXLEV;
75 msm_write(port, msm_port->imr, UART_IMR);
76 }
77
78 static void msm_start_tx(struct uart_port *port)
79 {
80 struct msm_port *msm_port = UART_TO_MSM(port);
81
82 msm_port->imr |= UART_IMR_TXLEV;
83 msm_write(port, msm_port->imr, UART_IMR);
84 }
85
86 static void msm_stop_rx(struct uart_port *port)
87 {
88 struct msm_port *msm_port = UART_TO_MSM(port);
89
90 msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
91 msm_write(port, msm_port->imr, UART_IMR);
92 }
93
94 static void msm_enable_ms(struct uart_port *port)
95 {
96 struct msm_port *msm_port = UART_TO_MSM(port);
97
98 msm_port->imr |= UART_IMR_DELTA_CTS;
99 msm_write(port, msm_port->imr, UART_IMR);
100 }
101
102 static void handle_rx_dm(struct uart_port *port, unsigned int misr)
103 {
104 struct tty_port *tport = &port->state->port;
105 unsigned int sr;
106 int count = 0;
107 struct msm_port *msm_port = UART_TO_MSM(port);
108
109 if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
110 port->icount.overrun++;
111 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
112 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
113 }
114
115 if (misr & UART_IMR_RXSTALE) {
116 count = msm_read(port, UARTDM_RX_TOTAL_SNAP) -
117 msm_port->old_snap_state;
118 msm_port->old_snap_state = 0;
119 } else {
120 count = 4 * (msm_read(port, UART_RFWR));
121 msm_port->old_snap_state += count;
122 }
123
124 /* TODO: Precise error reporting */
125
126 port->icount.rx += count;
127
128 while (count > 0) {
129 unsigned char buf[4];
130 int sysrq, r_count, i;
131
132 sr = msm_read(port, UART_SR);
133 if ((sr & UART_SR_RX_READY) == 0) {
134 msm_port->old_snap_state -= count;
135 break;
136 }
137
138 ioread32_rep(port->membase + UARTDM_RF, buf, 1);
139 r_count = min_t(int, count, sizeof(buf));
140
141 for (i = 0; i < r_count; i++) {
142 char flag = TTY_NORMAL;
143
144 if (msm_port->break_detected && buf[i] == 0) {
145 port->icount.brk++;
146 flag = TTY_BREAK;
147 msm_port->break_detected = false;
148 if (uart_handle_break(port))
149 continue;
150 }
151
152 if (!(port->read_status_mask & UART_SR_RX_BREAK))
153 flag = TTY_NORMAL;
154
155 spin_unlock(&port->lock);
156 sysrq = uart_handle_sysrq_char(port, buf[i]);
157 spin_lock(&port->lock);
158 if (!sysrq)
159 tty_insert_flip_char(tport, buf[i], flag);
160 }
161 count -= r_count;
162 }
163
164 spin_unlock(&port->lock);
165 tty_flip_buffer_push(tport);
166 spin_lock(&port->lock);
167
168 if (misr & (UART_IMR_RXSTALE))
169 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
170 msm_write(port, 0xFFFFFF, UARTDM_DMRX);
171 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
172 }
173
174 static void handle_rx(struct uart_port *port)
175 {
176 struct tty_port *tport = &port->state->port;
177 unsigned int sr;
178
179 /*
180 * Handle overrun. My understanding of the hardware is that overrun
181 * is not tied to the RX buffer, so we handle the case out of band.
182 */
183 if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
184 port->icount.overrun++;
185 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
186 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
187 }
188
189 /* and now the main RX loop */
190 while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
191 unsigned int c;
192 char flag = TTY_NORMAL;
193 int sysrq;
194
195 c = msm_read(port, UART_RF);
196
197 if (sr & UART_SR_RX_BREAK) {
198 port->icount.brk++;
199 if (uart_handle_break(port))
200 continue;
201 } else if (sr & UART_SR_PAR_FRAME_ERR) {
202 port->icount.frame++;
203 } else {
204 port->icount.rx++;
205 }
206
207 /* Mask conditions we're ignorning. */
208 sr &= port->read_status_mask;
209
210 if (sr & UART_SR_RX_BREAK)
211 flag = TTY_BREAK;
212 else if (sr & UART_SR_PAR_FRAME_ERR)
213 flag = TTY_FRAME;
214
215 spin_unlock(&port->lock);
216 sysrq = uart_handle_sysrq_char(port, c);
217 spin_lock(&port->lock);
218 if (!sysrq)
219 tty_insert_flip_char(tport, c, flag);
220 }
221
222 spin_unlock(&port->lock);
223 tty_flip_buffer_push(tport);
224 spin_lock(&port->lock);
225 }
226
227 static void reset_dm_count(struct uart_port *port, int count)
228 {
229 wait_for_xmitr(port);
230 msm_write(port, count, UARTDM_NCF_TX);
231 msm_read(port, UARTDM_NCF_TX);
232 }
233
234 static void handle_tx(struct uart_port *port)
235 {
236 struct circ_buf *xmit = &port->state->xmit;
237 struct msm_port *msm_port = UART_TO_MSM(port);
238 unsigned int tx_count, num_chars;
239 unsigned int tf_pointer = 0;
240 void __iomem *tf;
241
242 if (msm_port->is_uartdm)
243 tf = port->membase + UARTDM_TF;
244 else
245 tf = port->membase + UART_TF;
246
247 tx_count = uart_circ_chars_pending(xmit);
248 tx_count = min3(tx_count, (unsigned int)UART_XMIT_SIZE - xmit->tail,
249 port->fifosize);
250
251 if (port->x_char) {
252 if (msm_port->is_uartdm)
253 reset_dm_count(port, tx_count + 1);
254
255 iowrite8_rep(tf, &port->x_char, 1);
256 port->icount.tx++;
257 port->x_char = 0;
258 } else if (tx_count && msm_port->is_uartdm) {
259 reset_dm_count(port, tx_count);
260 }
261
262 while (tf_pointer < tx_count) {
263 int i;
264 char buf[4] = { 0 };
265
266 if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
267 break;
268
269 if (msm_port->is_uartdm)
270 num_chars = min(tx_count - tf_pointer,
271 (unsigned int)sizeof(buf));
272 else
273 num_chars = 1;
274
275 for (i = 0; i < num_chars; i++) {
276 buf[i] = xmit->buf[xmit->tail + i];
277 port->icount.tx++;
278 }
279
280 iowrite32_rep(tf, buf, 1);
281 xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
282 tf_pointer += num_chars;
283 }
284
285 /* disable tx interrupts if nothing more to send */
286 if (uart_circ_empty(xmit))
287 msm_stop_tx(port);
288
289 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
290 uart_write_wakeup(port);
291 }
292
293 static void handle_delta_cts(struct uart_port *port)
294 {
295 msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
296 port->icount.cts++;
297 wake_up_interruptible(&port->state->port.delta_msr_wait);
298 }
299
300 static irqreturn_t msm_irq(int irq, void *dev_id)
301 {
302 struct uart_port *port = dev_id;
303 struct msm_port *msm_port = UART_TO_MSM(port);
304 unsigned int misr;
305
306 spin_lock(&port->lock);
307 misr = msm_read(port, UART_MISR);
308 msm_write(port, 0, UART_IMR); /* disable interrupt */
309
310 if (misr & UART_IMR_RXBREAK_START) {
311 msm_port->break_detected = true;
312 msm_write(port, UART_CR_CMD_RESET_RXBREAK_START, UART_CR);
313 }
314
315 if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) {
316 if (msm_port->is_uartdm)
317 handle_rx_dm(port, misr);
318 else
319 handle_rx(port);
320 }
321 if (misr & UART_IMR_TXLEV)
322 handle_tx(port);
323 if (misr & UART_IMR_DELTA_CTS)
324 handle_delta_cts(port);
325
326 msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
327 spin_unlock(&port->lock);
328
329 return IRQ_HANDLED;
330 }
331
332 static unsigned int msm_tx_empty(struct uart_port *port)
333 {
334 return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
335 }
336
337 static unsigned int msm_get_mctrl(struct uart_port *port)
338 {
339 return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
340 }
341
342 static void msm_reset(struct uart_port *port)
343 {
344 struct msm_port *msm_port = UART_TO_MSM(port);
345
346 /* reset everything */
347 msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
348 msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
349 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
350 msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
351 msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
352 msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
353
354 /* Disable DM modes */
355 if (msm_port->is_uartdm)
356 msm_write(port, 0, UARTDM_DMEN);
357 }
358
359 static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
360 {
361 unsigned int mr;
362
363 mr = msm_read(port, UART_MR1);
364
365 if (!(mctrl & TIOCM_RTS)) {
366 mr &= ~UART_MR1_RX_RDY_CTL;
367 msm_write(port, mr, UART_MR1);
368 msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
369 } else {
370 mr |= UART_MR1_RX_RDY_CTL;
371 msm_write(port, mr, UART_MR1);
372 }
373 }
374
375 static void msm_break_ctl(struct uart_port *port, int break_ctl)
376 {
377 if (break_ctl)
378 msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
379 else
380 msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
381 }
382
383 struct msm_baud_map {
384 u16 divisor;
385 u8 code;
386 u8 rxstale;
387 };
388
389 static const struct msm_baud_map *
390 msm_find_best_baud(struct uart_port *port, unsigned int baud)
391 {
392 unsigned int i, divisor;
393 const struct msm_baud_map *entry;
394 static const struct msm_baud_map table[] = {
395 { 1536, 0x00, 1 },
396 { 768, 0x11, 1 },
397 { 384, 0x22, 1 },
398 { 192, 0x33, 1 },
399 { 96, 0x44, 1 },
400 { 48, 0x55, 1 },
401 { 32, 0x66, 1 },
402 { 24, 0x77, 1 },
403 { 16, 0x88, 1 },
404 { 12, 0x99, 6 },
405 { 8, 0xaa, 6 },
406 { 6, 0xbb, 6 },
407 { 4, 0xcc, 6 },
408 { 3, 0xdd, 8 },
409 { 2, 0xee, 16 },
410 { 1, 0xff, 31 },
411 };
412
413 divisor = uart_get_divisor(port, baud);
414
415 for (i = 0, entry = table; i < ARRAY_SIZE(table); i++, entry++)
416 if (entry->divisor <= divisor)
417 break;
418
419 return entry; /* Default to smallest divider */
420 }
421
422 static int msm_set_baud_rate(struct uart_port *port, unsigned int baud)
423 {
424 unsigned int rxstale, watermark;
425 struct msm_port *msm_port = UART_TO_MSM(port);
426 const struct msm_baud_map *entry;
427
428 entry = msm_find_best_baud(port, baud);
429
430 msm_write(port, entry->code, UART_CSR);
431
432 /* RX stale watermark */
433 rxstale = entry->rxstale;
434 watermark = UART_IPR_STALE_LSB & rxstale;
435 watermark |= UART_IPR_RXSTALE_LAST;
436 watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2);
437 msm_write(port, watermark, UART_IPR);
438
439 /* set RX watermark */
440 watermark = (port->fifosize * 3) / 4;
441 msm_write(port, watermark, UART_RFWR);
442
443 /* set TX watermark */
444 msm_write(port, 10, UART_TFWR);
445
446 msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
447 msm_reset(port);
448
449 /* Enable RX and TX */
450 msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR);
451
452 /* turn on RX and CTS interrupts */
453 msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
454 UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START;
455
456 msm_write(port, msm_port->imr, UART_IMR);
457
458 if (msm_port->is_uartdm) {
459 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
460 msm_write(port, 0xFFFFFF, UARTDM_DMRX);
461 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR);
462 }
463
464 return baud;
465 }
466
467 static void msm_init_clock(struct uart_port *port)
468 {
469 struct msm_port *msm_port = UART_TO_MSM(port);
470
471 clk_prepare_enable(msm_port->clk);
472 clk_prepare_enable(msm_port->pclk);
473 msm_serial_set_mnd_regs(port);
474 }
475
476 static int msm_startup(struct uart_port *port)
477 {
478 struct msm_port *msm_port = UART_TO_MSM(port);
479 unsigned int data, rfr_level;
480 int ret;
481
482 snprintf(msm_port->name, sizeof(msm_port->name),
483 "msm_serial%d", port->line);
484
485 ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH,
486 msm_port->name, port);
487 if (unlikely(ret))
488 return ret;
489
490 msm_init_clock(port);
491
492 if (likely(port->fifosize > 12))
493 rfr_level = port->fifosize - 12;
494 else
495 rfr_level = port->fifosize;
496
497 /* set automatic RFR level */
498 data = msm_read(port, UART_MR1);
499 data &= ~UART_MR1_AUTO_RFR_LEVEL1;
500 data &= ~UART_MR1_AUTO_RFR_LEVEL0;
501 data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2);
502 data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
503 msm_write(port, data, UART_MR1);
504 return 0;
505 }
506
507 static void msm_shutdown(struct uart_port *port)
508 {
509 struct msm_port *msm_port = UART_TO_MSM(port);
510
511 msm_port->imr = 0;
512 msm_write(port, 0, UART_IMR); /* disable interrupts */
513
514 clk_disable_unprepare(msm_port->clk);
515
516 free_irq(port->irq, port);
517 }
518
519 static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
520 struct ktermios *old)
521 {
522 unsigned long flags;
523 unsigned int baud, mr;
524
525 spin_lock_irqsave(&port->lock, flags);
526
527 /* calculate and set baud rate */
528 baud = uart_get_baud_rate(port, termios, old, 300, 115200);
529 baud = msm_set_baud_rate(port, baud);
530 if (tty_termios_baud_rate(termios))
531 tty_termios_encode_baud_rate(termios, baud, baud);
532
533 /* calculate parity */
534 mr = msm_read(port, UART_MR2);
535 mr &= ~UART_MR2_PARITY_MODE;
536 if (termios->c_cflag & PARENB) {
537 if (termios->c_cflag & PARODD)
538 mr |= UART_MR2_PARITY_MODE_ODD;
539 else if (termios->c_cflag & CMSPAR)
540 mr |= UART_MR2_PARITY_MODE_SPACE;
541 else
542 mr |= UART_MR2_PARITY_MODE_EVEN;
543 }
544
545 /* calculate bits per char */
546 mr &= ~UART_MR2_BITS_PER_CHAR;
547 switch (termios->c_cflag & CSIZE) {
548 case CS5:
549 mr |= UART_MR2_BITS_PER_CHAR_5;
550 break;
551 case CS6:
552 mr |= UART_MR2_BITS_PER_CHAR_6;
553 break;
554 case CS7:
555 mr |= UART_MR2_BITS_PER_CHAR_7;
556 break;
557 case CS8:
558 default:
559 mr |= UART_MR2_BITS_PER_CHAR_8;
560 break;
561 }
562
563 /* calculate stop bits */
564 mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
565 if (termios->c_cflag & CSTOPB)
566 mr |= UART_MR2_STOP_BIT_LEN_TWO;
567 else
568 mr |= UART_MR2_STOP_BIT_LEN_ONE;
569
570 /* set parity, bits per char, and stop bit */
571 msm_write(port, mr, UART_MR2);
572
573 /* calculate and set hardware flow control */
574 mr = msm_read(port, UART_MR1);
575 mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
576 if (termios->c_cflag & CRTSCTS) {
577 mr |= UART_MR1_CTS_CTL;
578 mr |= UART_MR1_RX_RDY_CTL;
579 }
580 msm_write(port, mr, UART_MR1);
581
582 /* Configure status bits to ignore based on termio flags. */
583 port->read_status_mask = 0;
584 if (termios->c_iflag & INPCK)
585 port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
586 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
587 port->read_status_mask |= UART_SR_RX_BREAK;
588
589 uart_update_timeout(port, termios->c_cflag, baud);
590
591 spin_unlock_irqrestore(&port->lock, flags);
592 }
593
594 static const char *msm_type(struct uart_port *port)
595 {
596 return "MSM";
597 }
598
599 static void msm_release_port(struct uart_port *port)
600 {
601 struct platform_device *pdev = to_platform_device(port->dev);
602 struct resource *uart_resource;
603 resource_size_t size;
604
605 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
606 if (unlikely(!uart_resource))
607 return;
608 size = resource_size(uart_resource);
609
610 release_mem_region(port->mapbase, size);
611 iounmap(port->membase);
612 port->membase = NULL;
613 }
614
615 static int msm_request_port(struct uart_port *port)
616 {
617 struct platform_device *pdev = to_platform_device(port->dev);
618 struct resource *uart_resource;
619 resource_size_t size;
620 int ret;
621
622 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
623 if (unlikely(!uart_resource))
624 return -ENXIO;
625
626 size = resource_size(uart_resource);
627
628 if (!request_mem_region(port->mapbase, size, "msm_serial"))
629 return -EBUSY;
630
631 port->membase = ioremap(port->mapbase, size);
632 if (!port->membase) {
633 ret = -EBUSY;
634 goto fail_release_port;
635 }
636
637 return 0;
638
639 fail_release_port:
640 release_mem_region(port->mapbase, size);
641 return ret;
642 }
643
644 static void msm_config_port(struct uart_port *port, int flags)
645 {
646 int ret;
647
648 if (flags & UART_CONFIG_TYPE) {
649 port->type = PORT_MSM;
650 ret = msm_request_port(port);
651 if (ret)
652 return;
653 }
654 }
655
656 static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
657 {
658 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
659 return -EINVAL;
660 if (unlikely(port->irq != ser->irq))
661 return -EINVAL;
662 return 0;
663 }
664
665 static void msm_power(struct uart_port *port, unsigned int state,
666 unsigned int oldstate)
667 {
668 struct msm_port *msm_port = UART_TO_MSM(port);
669
670 switch (state) {
671 case 0:
672 clk_prepare_enable(msm_port->clk);
673 clk_prepare_enable(msm_port->pclk);
674 break;
675 case 3:
676 clk_disable_unprepare(msm_port->clk);
677 clk_disable_unprepare(msm_port->pclk);
678 break;
679 default:
680 pr_err("msm_serial: Unknown PM state %d\n", state);
681 }
682 }
683
684 #ifdef CONFIG_CONSOLE_POLL
685 static int msm_poll_get_char_single(struct uart_port *port)
686 {
687 struct msm_port *msm_port = UART_TO_MSM(port);
688 unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF;
689
690 if (!(msm_read(port, UART_SR) & UART_SR_RX_READY))
691 return NO_POLL_CHAR;
692
693 return msm_read(port, rf_reg) & 0xff;
694 }
695
696 static int msm_poll_get_char_dm(struct uart_port *port)
697 {
698 int c;
699 static u32 slop;
700 static int count;
701 unsigned char *sp = (unsigned char *)&slop;
702
703 /* Check if a previous read had more than one char */
704 if (count) {
705 c = sp[sizeof(slop) - count];
706 count--;
707 /* Or if FIFO is empty */
708 } else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) {
709 /*
710 * If RX packing buffer has less than a word, force stale to
711 * push contents into RX FIFO
712 */
713 count = msm_read(port, UARTDM_RXFS);
714 count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK;
715 if (count) {
716 msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR);
717 slop = msm_read(port, UARTDM_RF);
718 c = sp[0];
719 count--;
720 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR);
721 msm_write(port, 0xFFFFFF, UARTDM_DMRX);
722 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE,
723 UART_CR);
724 } else {
725 c = NO_POLL_CHAR;
726 }
727 /* FIFO has a word */
728 } else {
729 slop = msm_read(port, UARTDM_RF);
730 c = sp[0];
731 count = sizeof(slop) - 1;
732 }
733
734 return c;
735 }
736
737 static int msm_poll_get_char(struct uart_port *port)
738 {
739 u32 imr;
740 int c;
741 struct msm_port *msm_port = UART_TO_MSM(port);
742
743 /* Disable all interrupts */
744 imr = msm_read(port, UART_IMR);
745 msm_write(port, 0, UART_IMR);
746
747 if (msm_port->is_uartdm)
748 c = msm_poll_get_char_dm(port);
749 else
750 c = msm_poll_get_char_single(port);
751
752 /* Enable interrupts */
753 msm_write(port, imr, UART_IMR);
754
755 return c;
756 }
757
758 static void msm_poll_put_char(struct uart_port *port, unsigned char c)
759 {
760 u32 imr;
761 struct msm_port *msm_port = UART_TO_MSM(port);
762
763 /* Disable all interrupts */
764 imr = msm_read(port, UART_IMR);
765 msm_write(port, 0, UART_IMR);
766
767 if (msm_port->is_uartdm)
768 reset_dm_count(port, 1);
769
770 /* Wait until FIFO is empty */
771 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
772 cpu_relax();
773
774 /* Write a character */
775 msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
776
777 /* Wait until FIFO is empty */
778 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
779 cpu_relax();
780
781 /* Enable interrupts */
782 msm_write(port, imr, UART_IMR);
783 }
784 #endif
785
786 static struct uart_ops msm_uart_pops = {
787 .tx_empty = msm_tx_empty,
788 .set_mctrl = msm_set_mctrl,
789 .get_mctrl = msm_get_mctrl,
790 .stop_tx = msm_stop_tx,
791 .start_tx = msm_start_tx,
792 .stop_rx = msm_stop_rx,
793 .enable_ms = msm_enable_ms,
794 .break_ctl = msm_break_ctl,
795 .startup = msm_startup,
796 .shutdown = msm_shutdown,
797 .set_termios = msm_set_termios,
798 .type = msm_type,
799 .release_port = msm_release_port,
800 .request_port = msm_request_port,
801 .config_port = msm_config_port,
802 .verify_port = msm_verify_port,
803 .pm = msm_power,
804 #ifdef CONFIG_CONSOLE_POLL
805 .poll_get_char = msm_poll_get_char,
806 .poll_put_char = msm_poll_put_char,
807 #endif
808 };
809
810 static struct msm_port msm_uart_ports[] = {
811 {
812 .uart = {
813 .iotype = UPIO_MEM,
814 .ops = &msm_uart_pops,
815 .flags = UPF_BOOT_AUTOCONF,
816 .fifosize = 64,
817 .line = 0,
818 },
819 },
820 {
821 .uart = {
822 .iotype = UPIO_MEM,
823 .ops = &msm_uart_pops,
824 .flags = UPF_BOOT_AUTOCONF,
825 .fifosize = 64,
826 .line = 1,
827 },
828 },
829 {
830 .uart = {
831 .iotype = UPIO_MEM,
832 .ops = &msm_uart_pops,
833 .flags = UPF_BOOT_AUTOCONF,
834 .fifosize = 64,
835 .line = 2,
836 },
837 },
838 };
839
840 #define UART_NR ARRAY_SIZE(msm_uart_ports)
841
842 static inline struct uart_port *get_port_from_line(unsigned int line)
843 {
844 return &msm_uart_ports[line].uart;
845 }
846
847 #ifdef CONFIG_SERIAL_MSM_CONSOLE
848 static void __msm_console_write(struct uart_port *port, const char *s,
849 unsigned int count, bool is_uartdm)
850 {
851 int i;
852 int num_newlines = 0;
853 bool replaced = false;
854 void __iomem *tf;
855
856 if (is_uartdm)
857 tf = port->membase + UARTDM_TF;
858 else
859 tf = port->membase + UART_TF;
860
861 /* Account for newlines that will get a carriage return added */
862 for (i = 0; i < count; i++)
863 if (s[i] == '\n')
864 num_newlines++;
865 count += num_newlines;
866
867 spin_lock(&port->lock);
868 if (is_uartdm)
869 reset_dm_count(port, count);
870
871 i = 0;
872 while (i < count) {
873 int j;
874 unsigned int num_chars;
875 char buf[4] = { 0 };
876
877 if (is_uartdm)
878 num_chars = min(count - i, (unsigned int)sizeof(buf));
879 else
880 num_chars = 1;
881
882 for (j = 0; j < num_chars; j++) {
883 char c = *s;
884
885 if (c == '\n' && !replaced) {
886 buf[j] = '\r';
887 j++;
888 replaced = true;
889 }
890 if (j < num_chars) {
891 buf[j] = c;
892 s++;
893 replaced = false;
894 }
895 }
896
897 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
898 cpu_relax();
899
900 iowrite32_rep(tf, buf, 1);
901 i += num_chars;
902 }
903 spin_unlock(&port->lock);
904 }
905
906 static void msm_console_write(struct console *co, const char *s,
907 unsigned int count)
908 {
909 struct uart_port *port;
910 struct msm_port *msm_port;
911
912 BUG_ON(co->index < 0 || co->index >= UART_NR);
913
914 port = get_port_from_line(co->index);
915 msm_port = UART_TO_MSM(port);
916
917 __msm_console_write(port, s, count, msm_port->is_uartdm);
918 }
919
920 static int __init msm_console_setup(struct console *co, char *options)
921 {
922 struct uart_port *port;
923 int baud = 115200;
924 int bits = 8;
925 int parity = 'n';
926 int flow = 'n';
927
928 if (unlikely(co->index >= UART_NR || co->index < 0))
929 return -ENXIO;
930
931 port = get_port_from_line(co->index);
932
933 if (unlikely(!port->membase))
934 return -ENXIO;
935
936 msm_init_clock(port);
937
938 if (options)
939 uart_parse_options(options, &baud, &parity, &bits, &flow);
940
941 pr_info("msm_serial: console setup on port #%d\n", port->line);
942
943 return uart_set_options(port, co, baud, parity, bits, flow);
944 }
945
946 static void
947 msm_serial_early_write(struct console *con, const char *s, unsigned n)
948 {
949 struct earlycon_device *dev = con->data;
950
951 __msm_console_write(&dev->port, s, n, false);
952 }
953
954 static int __init
955 msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
956 {
957 if (!device->port.membase)
958 return -ENODEV;
959
960 device->con->write = msm_serial_early_write;
961 return 0;
962 }
963 EARLYCON_DECLARE(msm_serial, msm_serial_early_console_setup);
964 OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",
965 msm_serial_early_console_setup);
966
967 static void
968 msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)
969 {
970 struct earlycon_device *dev = con->data;
971
972 __msm_console_write(&dev->port, s, n, true);
973 }
974
975 static int __init
976 msm_serial_early_console_setup_dm(struct earlycon_device *device,
977 const char *opt)
978 {
979 if (!device->port.membase)
980 return -ENODEV;
981
982 device->con->write = msm_serial_early_write_dm;
983 return 0;
984 }
985 EARLYCON_DECLARE(msm_serial_dm, msm_serial_early_console_setup_dm);
986 OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",
987 msm_serial_early_console_setup_dm);
988
989 static struct uart_driver msm_uart_driver;
990
991 static struct console msm_console = {
992 .name = "ttyMSM",
993 .write = msm_console_write,
994 .device = uart_console_device,
995 .setup = msm_console_setup,
996 .flags = CON_PRINTBUFFER,
997 .index = -1,
998 .data = &msm_uart_driver,
999 };
1000
1001 #define MSM_CONSOLE (&msm_console)
1002
1003 #else
1004 #define MSM_CONSOLE NULL
1005 #endif
1006
1007 static struct uart_driver msm_uart_driver = {
1008 .owner = THIS_MODULE,
1009 .driver_name = "msm_serial",
1010 .dev_name = "ttyMSM",
1011 .nr = UART_NR,
1012 .cons = MSM_CONSOLE,
1013 };
1014
1015 static atomic_t msm_uart_next_id = ATOMIC_INIT(0);
1016
1017 static const struct of_device_id msm_uartdm_table[] = {
1018 { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 },
1019 { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 },
1020 { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 },
1021 { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 },
1022 { }
1023 };
1024
1025 static int msm_serial_probe(struct platform_device *pdev)
1026 {
1027 struct msm_port *msm_port;
1028 struct resource *resource;
1029 struct uart_port *port;
1030 const struct of_device_id *id;
1031 int irq, line;
1032
1033 if (pdev->dev.of_node)
1034 line = of_alias_get_id(pdev->dev.of_node, "serial");
1035 else
1036 line = pdev->id;
1037
1038 if (line < 0)
1039 line = atomic_inc_return(&msm_uart_next_id) - 1;
1040
1041 if (unlikely(line < 0 || line >= UART_NR))
1042 return -ENXIO;
1043
1044 dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line);
1045
1046 port = get_port_from_line(line);
1047 port->dev = &pdev->dev;
1048 msm_port = UART_TO_MSM(port);
1049
1050 id = of_match_device(msm_uartdm_table, &pdev->dev);
1051 if (id)
1052 msm_port->is_uartdm = (unsigned long)id->data;
1053 else
1054 msm_port->is_uartdm = 0;
1055
1056 msm_port->clk = devm_clk_get(&pdev->dev, "core");
1057 if (IS_ERR(msm_port->clk))
1058 return PTR_ERR(msm_port->clk);
1059
1060 if (msm_port->is_uartdm) {
1061 msm_port->pclk = devm_clk_get(&pdev->dev, "iface");
1062 if (IS_ERR(msm_port->pclk))
1063 return PTR_ERR(msm_port->pclk);
1064
1065 clk_set_rate(msm_port->clk, 1843200);
1066 }
1067
1068 port->uartclk = clk_get_rate(msm_port->clk);
1069 dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
1070
1071 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1072 if (unlikely(!resource))
1073 return -ENXIO;
1074 port->mapbase = resource->start;
1075
1076 irq = platform_get_irq(pdev, 0);
1077 if (unlikely(irq < 0))
1078 return -ENXIO;
1079 port->irq = irq;
1080
1081 platform_set_drvdata(pdev, port);
1082
1083 return uart_add_one_port(&msm_uart_driver, port);
1084 }
1085
1086 static int msm_serial_remove(struct platform_device *pdev)
1087 {
1088 struct uart_port *port = platform_get_drvdata(pdev);
1089
1090 uart_remove_one_port(&msm_uart_driver, port);
1091
1092 return 0;
1093 }
1094
1095 static const struct of_device_id msm_match_table[] = {
1096 { .compatible = "qcom,msm-uart" },
1097 { .compatible = "qcom,msm-uartdm" },
1098 {}
1099 };
1100
1101 static struct platform_driver msm_platform_driver = {
1102 .remove = msm_serial_remove,
1103 .probe = msm_serial_probe,
1104 .driver = {
1105 .name = "msm_serial",
1106 .of_match_table = msm_match_table,
1107 },
1108 };
1109
1110 static int __init msm_serial_init(void)
1111 {
1112 int ret;
1113
1114 ret = uart_register_driver(&msm_uart_driver);
1115 if (unlikely(ret))
1116 return ret;
1117
1118 ret = platform_driver_register(&msm_platform_driver);
1119 if (unlikely(ret))
1120 uart_unregister_driver(&msm_uart_driver);
1121
1122 pr_info("msm_serial: driver initialized\n");
1123
1124 return ret;
1125 }
1126
1127 static void __exit msm_serial_exit(void)
1128 {
1129 platform_driver_unregister(&msm_platform_driver);
1130 uart_unregister_driver(&msm_uart_driver);
1131 }
1132
1133 module_init(msm_serial_init);
1134 module_exit(msm_serial_exit);
1135
1136 MODULE_AUTHOR("Robert Love <rlove@google.com>");
1137 MODULE_DESCRIPTION("Driver for msm7x serial device");
1138 MODULE_LICENSE("GPL");
Linux with added FPC-III support