Version:  2.0.40 2.2.26 2.4.37 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0

Linux/drivers/tty/serial/msm_serial.c

  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");
1139 

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