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[mirror_ubuntu-bionic-kernel.git] / drivers / tty / serial / st-asc.c
1 /*
2 * st-asc.c: ST Asynchronous serial controller (ASC) driver
3 *
4 * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 */
12
13 #if defined(CONFIG_SERIAL_ST_ASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
14 #define SUPPORT_SYSRQ
15 #endif
16
17 #include <linux/module.h>
18 #include <linux/serial.h>
19 #include <linux/console.h>
20 #include <linux/sysrq.h>
21 #include <linux/platform_device.h>
22 #include <linux/io.h>
23 #include <linux/irq.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/delay.h>
27 #include <linux/spinlock.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/of.h>
30 #include <linux/of_platform.h>
31 #include <linux/serial_core.h>
32 #include <linux/clk.h>
33
34 #define DRIVER_NAME "st-asc"
35 #define ASC_SERIAL_NAME "ttyAS"
36 #define ASC_FIFO_SIZE 16
37 #define ASC_MAX_PORTS 8
38
39 struct asc_port {
40 struct uart_port port;
41 struct clk *clk;
42 unsigned int hw_flow_control:1;
43 unsigned int force_m1:1;
44 };
45
46 static struct asc_port asc_ports[ASC_MAX_PORTS];
47 static struct uart_driver asc_uart_driver;
48
49 /*---- UART Register definitions ------------------------------*/
50
51 /* Register offsets */
52
53 #define ASC_BAUDRATE 0x00
54 #define ASC_TXBUF 0x04
55 #define ASC_RXBUF 0x08
56 #define ASC_CTL 0x0C
57 #define ASC_INTEN 0x10
58 #define ASC_STA 0x14
59 #define ASC_GUARDTIME 0x18
60 #define ASC_TIMEOUT 0x1C
61 #define ASC_TXRESET 0x20
62 #define ASC_RXRESET 0x24
63 #define ASC_RETRIES 0x28
64
65 /* ASC_RXBUF */
66 #define ASC_RXBUF_PE 0x100
67 #define ASC_RXBUF_FE 0x200
68 /**
69 * Some of status comes from higher bits of the character and some come from
70 * the status register. Combining both of them in to single status using dummy
71 * bits.
72 */
73 #define ASC_RXBUF_DUMMY_RX 0x10000
74 #define ASC_RXBUF_DUMMY_BE 0x20000
75 #define ASC_RXBUF_DUMMY_OE 0x40000
76
77 /* ASC_CTL */
78
79 #define ASC_CTL_MODE_MSK 0x0007
80 #define ASC_CTL_MODE_8BIT 0x0001
81 #define ASC_CTL_MODE_7BIT_PAR 0x0003
82 #define ASC_CTL_MODE_9BIT 0x0004
83 #define ASC_CTL_MODE_8BIT_WKUP 0x0005
84 #define ASC_CTL_MODE_8BIT_PAR 0x0007
85 #define ASC_CTL_STOP_MSK 0x0018
86 #define ASC_CTL_STOP_HALFBIT 0x0000
87 #define ASC_CTL_STOP_1BIT 0x0008
88 #define ASC_CTL_STOP_1_HALFBIT 0x0010
89 #define ASC_CTL_STOP_2BIT 0x0018
90 #define ASC_CTL_PARITYODD 0x0020
91 #define ASC_CTL_LOOPBACK 0x0040
92 #define ASC_CTL_RUN 0x0080
93 #define ASC_CTL_RXENABLE 0x0100
94 #define ASC_CTL_SCENABLE 0x0200
95 #define ASC_CTL_FIFOENABLE 0x0400
96 #define ASC_CTL_CTSENABLE 0x0800
97 #define ASC_CTL_BAUDMODE 0x1000
98
99 /* ASC_GUARDTIME */
100
101 #define ASC_GUARDTIME_MSK 0x00FF
102
103 /* ASC_INTEN */
104
105 #define ASC_INTEN_RBE 0x0001
106 #define ASC_INTEN_TE 0x0002
107 #define ASC_INTEN_THE 0x0004
108 #define ASC_INTEN_PE 0x0008
109 #define ASC_INTEN_FE 0x0010
110 #define ASC_INTEN_OE 0x0020
111 #define ASC_INTEN_TNE 0x0040
112 #define ASC_INTEN_TOI 0x0080
113 #define ASC_INTEN_RHF 0x0100
114
115 /* ASC_RETRIES */
116
117 #define ASC_RETRIES_MSK 0x00FF
118
119 /* ASC_RXBUF */
120
121 #define ASC_RXBUF_MSK 0x03FF
122
123 /* ASC_STA */
124
125 #define ASC_STA_RBF 0x0001
126 #define ASC_STA_TE 0x0002
127 #define ASC_STA_THE 0x0004
128 #define ASC_STA_PE 0x0008
129 #define ASC_STA_FE 0x0010
130 #define ASC_STA_OE 0x0020
131 #define ASC_STA_TNE 0x0040
132 #define ASC_STA_TOI 0x0080
133 #define ASC_STA_RHF 0x0100
134 #define ASC_STA_TF 0x0200
135 #define ASC_STA_NKD 0x0400
136
137 /* ASC_TIMEOUT */
138
139 #define ASC_TIMEOUT_MSK 0x00FF
140
141 /* ASC_TXBUF */
142
143 #define ASC_TXBUF_MSK 0x01FF
144
145 /*---- Inline function definitions ---------------------------*/
146
147 static inline struct asc_port *to_asc_port(struct uart_port *port)
148 {
149 return container_of(port, struct asc_port, port);
150 }
151
152 static inline u32 asc_in(struct uart_port *port, u32 offset)
153 {
154 return readl(port->membase + offset);
155 }
156
157 static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
158 {
159 writel(value, port->membase + offset);
160 }
161
162 /*
163 * Some simple utility functions to enable and disable interrupts.
164 * Note that these need to be called with interrupts disabled.
165 */
166 static inline void asc_disable_tx_interrupts(struct uart_port *port)
167 {
168 u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE;
169 asc_out(port, ASC_INTEN, intenable);
170 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
171 }
172
173 static inline void asc_enable_tx_interrupts(struct uart_port *port)
174 {
175 u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE;
176 asc_out(port, ASC_INTEN, intenable);
177 }
178
179 static inline void asc_disable_rx_interrupts(struct uart_port *port)
180 {
181 u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE;
182 asc_out(port, ASC_INTEN, intenable);
183 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
184 }
185
186 static inline void asc_enable_rx_interrupts(struct uart_port *port)
187 {
188 u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE;
189 asc_out(port, ASC_INTEN, intenable);
190 }
191
192 static inline u32 asc_txfifo_is_empty(struct uart_port *port)
193 {
194 return asc_in(port, ASC_STA) & ASC_STA_TE;
195 }
196
197 static inline u32 asc_txfifo_is_half_empty(struct uart_port *port)
198 {
199 return asc_in(port, ASC_STA) & ASC_STA_THE;
200 }
201
202 static inline const char *asc_port_name(struct uart_port *port)
203 {
204 return to_platform_device(port->dev)->name;
205 }
206
207 /*----------------------------------------------------------------------*/
208
209 /*
210 * This section contains code to support the use of the ASC as a
211 * generic serial port.
212 */
213
214 static inline unsigned asc_hw_txroom(struct uart_port *port)
215 {
216 u32 status = asc_in(port, ASC_STA);
217
218 if (status & ASC_STA_THE)
219 return port->fifosize / 2;
220 else if (!(status & ASC_STA_TF))
221 return 1;
222
223 return 0;
224 }
225
226 /*
227 * Start transmitting chars.
228 * This is called from both interrupt and task level.
229 * Either way interrupts are disabled.
230 */
231 static void asc_transmit_chars(struct uart_port *port)
232 {
233 struct circ_buf *xmit = &port->state->xmit;
234 int txroom;
235 unsigned char c;
236
237 txroom = asc_hw_txroom(port);
238
239 if ((txroom != 0) && port->x_char) {
240 c = port->x_char;
241 port->x_char = 0;
242 asc_out(port, ASC_TXBUF, c);
243 port->icount.tx++;
244 txroom = asc_hw_txroom(port);
245 }
246
247 if (uart_tx_stopped(port)) {
248 /*
249 * We should try and stop the hardware here, but I
250 * don't think the ASC has any way to do that.
251 */
252 asc_disable_tx_interrupts(port);
253 return;
254 }
255
256 if (uart_circ_empty(xmit)) {
257 asc_disable_tx_interrupts(port);
258 return;
259 }
260
261 if (txroom == 0)
262 return;
263
264 do {
265 c = xmit->buf[xmit->tail];
266 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
267 asc_out(port, ASC_TXBUF, c);
268 port->icount.tx++;
269 txroom--;
270 } while ((txroom > 0) && (!uart_circ_empty(xmit)));
271
272 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
273 uart_write_wakeup(port);
274
275 if (uart_circ_empty(xmit))
276 asc_disable_tx_interrupts(port);
277 }
278
279 static void asc_receive_chars(struct uart_port *port)
280 {
281 struct tty_port *tport = &port->state->port;
282 unsigned long status;
283 unsigned long c = 0;
284 char flag;
285
286 if (port->irq_wake)
287 pm_wakeup_event(tport->tty->dev, 0);
288
289 while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) {
290 c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX;
291 flag = TTY_NORMAL;
292 port->icount.rx++;
293
294 if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) ||
295 status & ASC_STA_OE) {
296
297 if (c & ASC_RXBUF_FE) {
298 if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) {
299 port->icount.brk++;
300 if (uart_handle_break(port))
301 continue;
302 c |= ASC_RXBUF_DUMMY_BE;
303 } else {
304 port->icount.frame++;
305 }
306 } else if (c & ASC_RXBUF_PE) {
307 port->icount.parity++;
308 }
309 /*
310 * Reading any data from the RX FIFO clears the
311 * overflow error condition.
312 */
313 if (status & ASC_STA_OE) {
314 port->icount.overrun++;
315 c |= ASC_RXBUF_DUMMY_OE;
316 }
317
318 c &= port->read_status_mask;
319
320 if (c & ASC_RXBUF_DUMMY_BE)
321 flag = TTY_BREAK;
322 else if (c & ASC_RXBUF_PE)
323 flag = TTY_PARITY;
324 else if (c & ASC_RXBUF_FE)
325 flag = TTY_FRAME;
326 }
327
328 if (uart_handle_sysrq_char(port, c & 0xff))
329 continue;
330
331 uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag);
332 }
333
334 /* Tell the rest of the system the news. New characters! */
335 tty_flip_buffer_push(tport);
336 }
337
338 static irqreturn_t asc_interrupt(int irq, void *ptr)
339 {
340 struct uart_port *port = ptr;
341 u32 status;
342
343 spin_lock(&port->lock);
344
345 status = asc_in(port, ASC_STA);
346
347 if (status & ASC_STA_RBF) {
348 /* Receive FIFO not empty */
349 asc_receive_chars(port);
350 }
351
352 if ((status & ASC_STA_THE) &&
353 (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) {
354 /* Transmitter FIFO at least half empty */
355 asc_transmit_chars(port);
356 }
357
358 spin_unlock(&port->lock);
359
360 return IRQ_HANDLED;
361 }
362
363 /*----------------------------------------------------------------------*/
364
365 /*
366 * UART Functions
367 */
368
369 static unsigned int asc_tx_empty(struct uart_port *port)
370 {
371 return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
372 }
373
374 static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
375 {
376 /*
377 * This routine is used for seting signals of: DTR, DCD, CTS/RTS
378 * We use ASC's hardware for CTS/RTS, so don't need any for that.
379 * Some boards have DTR and DCD implemented using PIO pins,
380 * code to do this should be hooked in here.
381 */
382 }
383
384 static unsigned int asc_get_mctrl(struct uart_port *port)
385 {
386 /*
387 * This routine is used for geting signals of: DTR, DCD, DSR, RI,
388 * and CTS/RTS
389 */
390 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
391 }
392
393 /* There are probably characters waiting to be transmitted. */
394 static void asc_start_tx(struct uart_port *port)
395 {
396 struct circ_buf *xmit = &port->state->xmit;
397
398 if (!uart_circ_empty(xmit))
399 asc_enable_tx_interrupts(port);
400 }
401
402 /* Transmit stop */
403 static void asc_stop_tx(struct uart_port *port)
404 {
405 asc_disable_tx_interrupts(port);
406 }
407
408 /* Receive stop */
409 static void asc_stop_rx(struct uart_port *port)
410 {
411 asc_disable_rx_interrupts(port);
412 }
413
414 /* Force modem status interrupts on */
415 static void asc_enable_ms(struct uart_port *port)
416 {
417 /* Nothing here yet .. */
418 }
419
420 /* Handle breaks - ignored by us */
421 static void asc_break_ctl(struct uart_port *port, int break_state)
422 {
423 /* Nothing here yet .. */
424 }
425
426 /*
427 * Enable port for reception.
428 */
429 static int asc_startup(struct uart_port *port)
430 {
431 if (request_irq(port->irq, asc_interrupt, IRQF_NO_SUSPEND,
432 asc_port_name(port), port)) {
433 dev_err(port->dev, "cannot allocate irq.\n");
434 return -ENODEV;
435 }
436
437 asc_transmit_chars(port);
438 asc_enable_rx_interrupts(port);
439
440 return 0;
441 }
442
443 static void asc_shutdown(struct uart_port *port)
444 {
445 asc_disable_tx_interrupts(port);
446 asc_disable_rx_interrupts(port);
447 free_irq(port->irq, port);
448 }
449
450 static void asc_pm(struct uart_port *port, unsigned int state,
451 unsigned int oldstate)
452 {
453 struct asc_port *ascport = to_asc_port(port);
454 unsigned long flags = 0;
455 u32 ctl;
456
457 switch (state) {
458 case UART_PM_STATE_ON:
459 clk_prepare_enable(ascport->clk);
460 break;
461 case UART_PM_STATE_OFF:
462 /*
463 * Disable the ASC baud rate generator, which is as close as
464 * we can come to turning it off. Note this is not called with
465 * the port spinlock held.
466 */
467 spin_lock_irqsave(&port->lock, flags);
468 ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
469 asc_out(port, ASC_CTL, ctl);
470 spin_unlock_irqrestore(&port->lock, flags);
471 clk_disable_unprepare(ascport->clk);
472 break;
473 }
474 }
475
476 static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
477 struct ktermios *old)
478 {
479 struct asc_port *ascport = to_asc_port(port);
480 unsigned int baud;
481 u32 ctrl_val;
482 tcflag_t cflag;
483 unsigned long flags;
484
485 /* Update termios to reflect hardware capabilities */
486 termios->c_cflag &= ~(CMSPAR |
487 (ascport->hw_flow_control ? 0 : CRTSCTS));
488
489 port->uartclk = clk_get_rate(ascport->clk);
490
491 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
492 cflag = termios->c_cflag;
493
494 spin_lock_irqsave(&port->lock, flags);
495
496 /* read control register */
497 ctrl_val = asc_in(port, ASC_CTL);
498
499 /* stop serial port and reset value */
500 asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN));
501 ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE;
502
503 /* reset fifo rx & tx */
504 asc_out(port, ASC_TXRESET, 1);
505 asc_out(port, ASC_RXRESET, 1);
506
507 /* set character length */
508 if ((cflag & CSIZE) == CS7) {
509 ctrl_val |= ASC_CTL_MODE_7BIT_PAR;
510 } else {
511 ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR :
512 ASC_CTL_MODE_8BIT;
513 }
514
515 /* set stop bit */
516 ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;
517
518 /* odd parity */
519 if (cflag & PARODD)
520 ctrl_val |= ASC_CTL_PARITYODD;
521
522 /* hardware flow control */
523 if ((cflag & CRTSCTS))
524 ctrl_val |= ASC_CTL_CTSENABLE;
525
526 if ((baud < 19200) && !ascport->force_m1) {
527 asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));
528 } else {
529 /*
530 * MODE 1: recommended for high bit rates (above 19.2K)
531 *
532 * baudrate * 16 * 2^16
533 * ASCBaudRate = ------------------------
534 * inputclock
535 *
536 * However to keep the maths inside 32bits we divide top and
537 * bottom by 64. The +1 is to avoid a divide by zero if the
538 * input clock rate is something unexpected.
539 */
540 u32 counter = (baud * 16384) / ((port->uartclk / 64) + 1);
541 asc_out(port, ASC_BAUDRATE, counter);
542 ctrl_val |= ASC_CTL_BAUDMODE;
543 }
544
545 uart_update_timeout(port, cflag, baud);
546
547 ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE;
548 if (termios->c_iflag & INPCK)
549 ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
550 if (termios->c_iflag & (BRKINT | PARMRK))
551 ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE;
552
553 /*
554 * Characters to ignore
555 */
556 ascport->port.ignore_status_mask = 0;
557 if (termios->c_iflag & IGNPAR)
558 ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
559 if (termios->c_iflag & IGNBRK) {
560 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE;
561 /*
562 * If we're ignoring parity and break indicators,
563 * ignore overruns too (for real raw support).
564 */
565 if (termios->c_iflag & IGNPAR)
566 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE;
567 }
568
569 /*
570 * Ignore all characters if CREAD is not set.
571 */
572 if (!(termios->c_cflag & CREAD))
573 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX;
574
575 /* Set the timeout */
576 asc_out(port, ASC_TIMEOUT, 20);
577
578 /* write final value and enable port */
579 asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
580
581 spin_unlock_irqrestore(&port->lock, flags);
582 }
583
584 static const char *asc_type(struct uart_port *port)
585 {
586 return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
587 }
588
589 static void asc_release_port(struct uart_port *port)
590 {
591 }
592
593 static int asc_request_port(struct uart_port *port)
594 {
595 return 0;
596 }
597
598 /*
599 * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set
600 * Set type field if successful
601 */
602 static void asc_config_port(struct uart_port *port, int flags)
603 {
604 if ((flags & UART_CONFIG_TYPE))
605 port->type = PORT_ASC;
606 }
607
608 static int
609 asc_verify_port(struct uart_port *port, struct serial_struct *ser)
610 {
611 /* No user changeable parameters */
612 return -EINVAL;
613 }
614
615 #ifdef CONFIG_CONSOLE_POLL
616 /*
617 * Console polling routines for writing and reading from the uart while
618 * in an interrupt or debug context (i.e. kgdb).
619 */
620
621 static int asc_get_poll_char(struct uart_port *port)
622 {
623 if (!(asc_in(port, ASC_STA) & ASC_STA_RBF))
624 return NO_POLL_CHAR;
625
626 return asc_in(port, ASC_RXBUF);
627 }
628
629 static void asc_put_poll_char(struct uart_port *port, unsigned char c)
630 {
631 while (!asc_txfifo_is_half_empty(port))
632 cpu_relax();
633 asc_out(port, ASC_TXBUF, c);
634 }
635
636 #endif /* CONFIG_CONSOLE_POLL */
637
638 /*---------------------------------------------------------------------*/
639
640 static struct uart_ops asc_uart_ops = {
641 .tx_empty = asc_tx_empty,
642 .set_mctrl = asc_set_mctrl,
643 .get_mctrl = asc_get_mctrl,
644 .start_tx = asc_start_tx,
645 .stop_tx = asc_stop_tx,
646 .stop_rx = asc_stop_rx,
647 .enable_ms = asc_enable_ms,
648 .break_ctl = asc_break_ctl,
649 .startup = asc_startup,
650 .shutdown = asc_shutdown,
651 .set_termios = asc_set_termios,
652 .type = asc_type,
653 .release_port = asc_release_port,
654 .request_port = asc_request_port,
655 .config_port = asc_config_port,
656 .verify_port = asc_verify_port,
657 .pm = asc_pm,
658 #ifdef CONFIG_CONSOLE_POLL
659 .poll_get_char = asc_get_poll_char,
660 .poll_put_char = asc_put_poll_char,
661 #endif /* CONFIG_CONSOLE_POLL */
662 };
663
664 static int asc_init_port(struct asc_port *ascport,
665 struct platform_device *pdev)
666 {
667 struct uart_port *port = &ascport->port;
668 struct resource *res;
669
670 port->iotype = UPIO_MEM;
671 port->flags = UPF_BOOT_AUTOCONF;
672 port->ops = &asc_uart_ops;
673 port->fifosize = ASC_FIFO_SIZE;
674 port->dev = &pdev->dev;
675 port->irq = platform_get_irq(pdev, 0);
676
677 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
678 port->membase = devm_ioremap_resource(&pdev->dev, res);
679 if (IS_ERR(port->membase))
680 return PTR_ERR(port->membase);
681 port->mapbase = res->start;
682
683 spin_lock_init(&port->lock);
684
685 ascport->clk = devm_clk_get(&pdev->dev, NULL);
686
687 if (WARN_ON(IS_ERR(ascport->clk)))
688 return -EINVAL;
689 /* ensure that clk rate is correct by enabling the clk */
690 clk_prepare_enable(ascport->clk);
691 ascport->port.uartclk = clk_get_rate(ascport->clk);
692 WARN_ON(ascport->port.uartclk == 0);
693 clk_disable_unprepare(ascport->clk);
694
695 return 0;
696 }
697
698 static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
699 {
700 struct device_node *np = pdev->dev.of_node;
701 int id;
702
703 if (!np)
704 return NULL;
705
706 id = of_alias_get_id(np, ASC_SERIAL_NAME);
707
708 if (id < 0)
709 id = 0;
710
711 if (WARN_ON(id >= ASC_MAX_PORTS))
712 return NULL;
713
714 asc_ports[id].hw_flow_control = of_property_read_bool(np,
715 "st,hw-flow-control");
716 asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1");
717 asc_ports[id].port.line = id;
718 return &asc_ports[id];
719 }
720
721 #ifdef CONFIG_OF
722 static struct of_device_id asc_match[] = {
723 { .compatible = "st,asc", },
724 {},
725 };
726
727 MODULE_DEVICE_TABLE(of, asc_match);
728 #endif
729
730 static int asc_serial_probe(struct platform_device *pdev)
731 {
732 int ret;
733 struct asc_port *ascport;
734
735 ascport = asc_of_get_asc_port(pdev);
736 if (!ascport)
737 return -ENODEV;
738
739 ret = asc_init_port(ascport, pdev);
740 if (ret)
741 return ret;
742
743 ret = uart_add_one_port(&asc_uart_driver, &ascport->port);
744 if (ret)
745 return ret;
746
747 platform_set_drvdata(pdev, &ascport->port);
748
749 return 0;
750 }
751
752 static int asc_serial_remove(struct platform_device *pdev)
753 {
754 struct uart_port *port = platform_get_drvdata(pdev);
755
756 return uart_remove_one_port(&asc_uart_driver, port);
757 }
758
759 #ifdef CONFIG_PM_SLEEP
760 static int asc_serial_suspend(struct device *dev)
761 {
762 struct platform_device *pdev = to_platform_device(dev);
763 struct uart_port *port = platform_get_drvdata(pdev);
764
765 return uart_suspend_port(&asc_uart_driver, port);
766 }
767
768 static int asc_serial_resume(struct device *dev)
769 {
770 struct platform_device *pdev = to_platform_device(dev);
771 struct uart_port *port = platform_get_drvdata(pdev);
772
773 return uart_resume_port(&asc_uart_driver, port);
774 }
775
776 #endif /* CONFIG_PM_SLEEP */
777
778 /*----------------------------------------------------------------------*/
779
780 #ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
781 static void asc_console_putchar(struct uart_port *port, int ch)
782 {
783 unsigned int timeout = 1000000;
784
785 /* Wait for upto 1 second in case flow control is stopping us. */
786 while (--timeout && !asc_txfifo_is_half_empty(port))
787 udelay(1);
788
789 asc_out(port, ASC_TXBUF, ch);
790 }
791
792 /*
793 * Print a string to the serial port trying not to disturb
794 * any possible real use of the port...
795 */
796
797 static void asc_console_write(struct console *co, const char *s, unsigned count)
798 {
799 struct uart_port *port = &asc_ports[co->index].port;
800 unsigned long flags;
801 unsigned long timeout = 1000000;
802 int locked = 1;
803 u32 intenable;
804
805 local_irq_save(flags);
806 if (port->sysrq)
807 locked = 0; /* asc_interrupt has already claimed the lock */
808 else if (oops_in_progress)
809 locked = spin_trylock(&port->lock);
810 else
811 spin_lock(&port->lock);
812
813 /*
814 * Disable interrupts so we don't get the IRQ line bouncing
815 * up and down while interrupts are disabled.
816 */
817 intenable = asc_in(port, ASC_INTEN);
818 asc_out(port, ASC_INTEN, 0);
819 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
820
821 uart_console_write(port, s, count, asc_console_putchar);
822
823 while (--timeout && !asc_txfifo_is_empty(port))
824 udelay(1);
825
826 asc_out(port, ASC_INTEN, intenable);
827
828 if (locked)
829 spin_unlock(&port->lock);
830 local_irq_restore(flags);
831 }
832
833 static int asc_console_setup(struct console *co, char *options)
834 {
835 struct asc_port *ascport;
836 int baud = 9600;
837 int bits = 8;
838 int parity = 'n';
839 int flow = 'n';
840
841 if (co->index >= ASC_MAX_PORTS)
842 return -ENODEV;
843
844 ascport = &asc_ports[co->index];
845
846 /*
847 * This driver does not support early console initialization
848 * (use ARM early printk support instead), so we only expect
849 * this to be called during the uart port registration when the
850 * driver gets probed and the port should be mapped at that point.
851 */
852 BUG_ON(ascport->port.mapbase == 0 || ascport->port.membase == NULL);
853
854 if (options)
855 uart_parse_options(options, &baud, &parity, &bits, &flow);
856
857 return uart_set_options(&ascport->port, co, baud, parity, bits, flow);
858 }
859
860 static struct console asc_console = {
861 .name = ASC_SERIAL_NAME,
862 .device = uart_console_device,
863 .write = asc_console_write,
864 .setup = asc_console_setup,
865 .flags = CON_PRINTBUFFER,
866 .index = -1,
867 .data = &asc_uart_driver,
868 };
869
870 #define ASC_SERIAL_CONSOLE (&asc_console)
871
872 #else
873 #define ASC_SERIAL_CONSOLE NULL
874 #endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */
875
876 static struct uart_driver asc_uart_driver = {
877 .owner = THIS_MODULE,
878 .driver_name = DRIVER_NAME,
879 .dev_name = ASC_SERIAL_NAME,
880 .major = 0,
881 .minor = 0,
882 .nr = ASC_MAX_PORTS,
883 .cons = ASC_SERIAL_CONSOLE,
884 };
885
886 static const struct dev_pm_ops asc_serial_pm_ops = {
887 SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
888 };
889
890 static struct platform_driver asc_serial_driver = {
891 .probe = asc_serial_probe,
892 .remove = asc_serial_remove,
893 .driver = {
894 .name = DRIVER_NAME,
895 .pm = &asc_serial_pm_ops,
896 .owner = THIS_MODULE,
897 .of_match_table = of_match_ptr(asc_match),
898 },
899 };
900
901 static int __init asc_init(void)
902 {
903 int ret;
904 static char banner[] __initdata =
905 KERN_INFO "STMicroelectronics ASC driver initialized\n";
906
907 printk(banner);
908
909 ret = uart_register_driver(&asc_uart_driver);
910 if (ret)
911 return ret;
912
913 ret = platform_driver_register(&asc_serial_driver);
914 if (ret)
915 uart_unregister_driver(&asc_uart_driver);
916
917 return ret;
918 }
919
920 static void __exit asc_exit(void)
921 {
922 platform_driver_unregister(&asc_serial_driver);
923 uart_unregister_driver(&asc_uart_driver);
924 }
925
926 module_init(asc_init);
927 module_exit(asc_exit);
928
929 MODULE_ALIAS("platform:" DRIVER_NAME);
930 MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
931 MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
932 MODULE_LICENSE("GPL");
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