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Merge tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
[mirror_ubuntu-artful-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 #ifdef readl_relaxed
155 return readl_relaxed(port->membase + offset);
156 #else
157 return readl(port->membase + offset);
158 #endif
159 }
160
161 static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
162 {
163 #ifdef writel_relaxed
164 writel_relaxed(value, port->membase + offset);
165 #else
166 writel(value, port->membase + offset);
167 #endif
168 }
169
170 /*
171 * Some simple utility functions to enable and disable interrupts.
172 * Note that these need to be called with interrupts disabled.
173 */
174 static inline void asc_disable_tx_interrupts(struct uart_port *port)
175 {
176 u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE;
177 asc_out(port, ASC_INTEN, intenable);
178 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
179 }
180
181 static inline void asc_enable_tx_interrupts(struct uart_port *port)
182 {
183 u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE;
184 asc_out(port, ASC_INTEN, intenable);
185 }
186
187 static inline void asc_disable_rx_interrupts(struct uart_port *port)
188 {
189 u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE;
190 asc_out(port, ASC_INTEN, intenable);
191 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
192 }
193
194 static inline void asc_enable_rx_interrupts(struct uart_port *port)
195 {
196 u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE;
197 asc_out(port, ASC_INTEN, intenable);
198 }
199
200 static inline u32 asc_txfifo_is_empty(struct uart_port *port)
201 {
202 return asc_in(port, ASC_STA) & ASC_STA_TE;
203 }
204
205 static inline u32 asc_txfifo_is_half_empty(struct uart_port *port)
206 {
207 return asc_in(port, ASC_STA) & ASC_STA_THE;
208 }
209
210 static inline const char *asc_port_name(struct uart_port *port)
211 {
212 return to_platform_device(port->dev)->name;
213 }
214
215 /*----------------------------------------------------------------------*/
216
217 /*
218 * This section contains code to support the use of the ASC as a
219 * generic serial port.
220 */
221
222 static inline unsigned asc_hw_txroom(struct uart_port *port)
223 {
224 u32 status = asc_in(port, ASC_STA);
225
226 if (status & ASC_STA_THE)
227 return port->fifosize / 2;
228 else if (!(status & ASC_STA_TF))
229 return 1;
230
231 return 0;
232 }
233
234 /*
235 * Start transmitting chars.
236 * This is called from both interrupt and task level.
237 * Either way interrupts are disabled.
238 */
239 static void asc_transmit_chars(struct uart_port *port)
240 {
241 struct circ_buf *xmit = &port->state->xmit;
242 int txroom;
243 unsigned char c;
244
245 txroom = asc_hw_txroom(port);
246
247 if ((txroom != 0) && port->x_char) {
248 c = port->x_char;
249 port->x_char = 0;
250 asc_out(port, ASC_TXBUF, c);
251 port->icount.tx++;
252 txroom = asc_hw_txroom(port);
253 }
254
255 if (uart_tx_stopped(port)) {
256 /*
257 * We should try and stop the hardware here, but I
258 * don't think the ASC has any way to do that.
259 */
260 asc_disable_tx_interrupts(port);
261 return;
262 }
263
264 if (uart_circ_empty(xmit)) {
265 asc_disable_tx_interrupts(port);
266 return;
267 }
268
269 if (txroom == 0)
270 return;
271
272 do {
273 c = xmit->buf[xmit->tail];
274 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
275 asc_out(port, ASC_TXBUF, c);
276 port->icount.tx++;
277 txroom--;
278 } while ((txroom > 0) && (!uart_circ_empty(xmit)));
279
280 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
281 uart_write_wakeup(port);
282
283 if (uart_circ_empty(xmit))
284 asc_disable_tx_interrupts(port);
285 }
286
287 static void asc_receive_chars(struct uart_port *port)
288 {
289 struct tty_port *tport = &port->state->port;
290 unsigned long status;
291 unsigned long c = 0;
292 char flag;
293
294 if (port->irq_wake)
295 pm_wakeup_event(tport->tty->dev, 0);
296
297 while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) {
298 c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX;
299 flag = TTY_NORMAL;
300 port->icount.rx++;
301
302 if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) ||
303 status & ASC_STA_OE) {
304
305 if (c & ASC_RXBUF_FE) {
306 if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) {
307 port->icount.brk++;
308 if (uart_handle_break(port))
309 continue;
310 c |= ASC_RXBUF_DUMMY_BE;
311 } else {
312 port->icount.frame++;
313 }
314 } else if (c & ASC_RXBUF_PE) {
315 port->icount.parity++;
316 }
317 /*
318 * Reading any data from the RX FIFO clears the
319 * overflow error condition.
320 */
321 if (status & ASC_STA_OE) {
322 port->icount.overrun++;
323 c |= ASC_RXBUF_DUMMY_OE;
324 }
325
326 c &= port->read_status_mask;
327
328 if (c & ASC_RXBUF_DUMMY_BE)
329 flag = TTY_BREAK;
330 else if (c & ASC_RXBUF_PE)
331 flag = TTY_PARITY;
332 else if (c & ASC_RXBUF_FE)
333 flag = TTY_FRAME;
334 }
335
336 if (uart_handle_sysrq_char(port, c & 0xff))
337 continue;
338
339 uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag);
340 }
341
342 /* Tell the rest of the system the news. New characters! */
343 tty_flip_buffer_push(tport);
344 }
345
346 static irqreturn_t asc_interrupt(int irq, void *ptr)
347 {
348 struct uart_port *port = ptr;
349 u32 status;
350
351 spin_lock(&port->lock);
352
353 status = asc_in(port, ASC_STA);
354
355 if (status & ASC_STA_RBF) {
356 /* Receive FIFO not empty */
357 asc_receive_chars(port);
358 }
359
360 if ((status & ASC_STA_THE) &&
361 (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) {
362 /* Transmitter FIFO at least half empty */
363 asc_transmit_chars(port);
364 }
365
366 spin_unlock(&port->lock);
367
368 return IRQ_HANDLED;
369 }
370
371 /*----------------------------------------------------------------------*/
372
373 /*
374 * UART Functions
375 */
376
377 static unsigned int asc_tx_empty(struct uart_port *port)
378 {
379 return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
380 }
381
382 static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
383 {
384 /*
385 * This routine is used for seting signals of: DTR, DCD, CTS/RTS
386 * We use ASC's hardware for CTS/RTS, so don't need any for that.
387 * Some boards have DTR and DCD implemented using PIO pins,
388 * code to do this should be hooked in here.
389 */
390 }
391
392 static unsigned int asc_get_mctrl(struct uart_port *port)
393 {
394 /*
395 * This routine is used for geting signals of: DTR, DCD, DSR, RI,
396 * and CTS/RTS
397 */
398 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
399 }
400
401 /* There are probably characters waiting to be transmitted. */
402 static void asc_start_tx(struct uart_port *port)
403 {
404 struct circ_buf *xmit = &port->state->xmit;
405
406 if (!uart_circ_empty(xmit))
407 asc_enable_tx_interrupts(port);
408 }
409
410 /* Transmit stop */
411 static void asc_stop_tx(struct uart_port *port)
412 {
413 asc_disable_tx_interrupts(port);
414 }
415
416 /* Receive stop */
417 static void asc_stop_rx(struct uart_port *port)
418 {
419 asc_disable_rx_interrupts(port);
420 }
421
422 /* Handle breaks - ignored by us */
423 static void asc_break_ctl(struct uart_port *port, int break_state)
424 {
425 /* Nothing here yet .. */
426 }
427
428 /*
429 * Enable port for reception.
430 */
431 static int asc_startup(struct uart_port *port)
432 {
433 if (request_irq(port->irq, asc_interrupt, 0,
434 asc_port_name(port), port)) {
435 dev_err(port->dev, "cannot allocate irq.\n");
436 return -ENODEV;
437 }
438
439 asc_transmit_chars(port);
440 asc_enable_rx_interrupts(port);
441
442 return 0;
443 }
444
445 static void asc_shutdown(struct uart_port *port)
446 {
447 asc_disable_tx_interrupts(port);
448 asc_disable_rx_interrupts(port);
449 free_irq(port->irq, port);
450 }
451
452 static void asc_pm(struct uart_port *port, unsigned int state,
453 unsigned int oldstate)
454 {
455 struct asc_port *ascport = to_asc_port(port);
456 unsigned long flags = 0;
457 u32 ctl;
458
459 switch (state) {
460 case UART_PM_STATE_ON:
461 clk_prepare_enable(ascport->clk);
462 break;
463 case UART_PM_STATE_OFF:
464 /*
465 * Disable the ASC baud rate generator, which is as close as
466 * we can come to turning it off. Note this is not called with
467 * the port spinlock held.
468 */
469 spin_lock_irqsave(&port->lock, flags);
470 ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
471 asc_out(port, ASC_CTL, ctl);
472 spin_unlock_irqrestore(&port->lock, flags);
473 clk_disable_unprepare(ascport->clk);
474 break;
475 }
476 }
477
478 static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
479 struct ktermios *old)
480 {
481 struct asc_port *ascport = to_asc_port(port);
482 unsigned int baud;
483 u32 ctrl_val;
484 tcflag_t cflag;
485 unsigned long flags;
486
487 /* Update termios to reflect hardware capabilities */
488 termios->c_cflag &= ~(CMSPAR |
489 (ascport->hw_flow_control ? 0 : CRTSCTS));
490
491 port->uartclk = clk_get_rate(ascport->clk);
492
493 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
494 cflag = termios->c_cflag;
495
496 spin_lock_irqsave(&port->lock, flags);
497
498 /* read control register */
499 ctrl_val = asc_in(port, ASC_CTL);
500
501 /* stop serial port and reset value */
502 asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN));
503 ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE;
504
505 /* reset fifo rx & tx */
506 asc_out(port, ASC_TXRESET, 1);
507 asc_out(port, ASC_RXRESET, 1);
508
509 /* set character length */
510 if ((cflag & CSIZE) == CS7) {
511 ctrl_val |= ASC_CTL_MODE_7BIT_PAR;
512 } else {
513 ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR :
514 ASC_CTL_MODE_8BIT;
515 }
516
517 /* set stop bit */
518 ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;
519
520 /* odd parity */
521 if (cflag & PARODD)
522 ctrl_val |= ASC_CTL_PARITYODD;
523
524 /* hardware flow control */
525 if ((cflag & CRTSCTS))
526 ctrl_val |= ASC_CTL_CTSENABLE;
527
528 if ((baud < 19200) && !ascport->force_m1) {
529 asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));
530 } else {
531 /*
532 * MODE 1: recommended for high bit rates (above 19.2K)
533 *
534 * baudrate * 16 * 2^16
535 * ASCBaudRate = ------------------------
536 * inputclock
537 *
538 * To keep maths inside 64bits, we divide inputclock by 16.
539 */
540 u64 dividend = (u64)baud * (1 << 16);
541
542 do_div(dividend, port->uartclk / 16);
543 asc_out(port, ASC_BAUDRATE, dividend);
544 ctrl_val |= ASC_CTL_BAUDMODE;
545 }
546
547 uart_update_timeout(port, cflag, baud);
548
549 ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE;
550 if (termios->c_iflag & INPCK)
551 ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
552 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
553 ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE;
554
555 /*
556 * Characters to ignore
557 */
558 ascport->port.ignore_status_mask = 0;
559 if (termios->c_iflag & IGNPAR)
560 ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
561 if (termios->c_iflag & IGNBRK) {
562 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE;
563 /*
564 * If we're ignoring parity and break indicators,
565 * ignore overruns too (for real raw support).
566 */
567 if (termios->c_iflag & IGNPAR)
568 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE;
569 }
570
571 /*
572 * Ignore all characters if CREAD is not set.
573 */
574 if (!(termios->c_cflag & CREAD))
575 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX;
576
577 /* Set the timeout */
578 asc_out(port, ASC_TIMEOUT, 20);
579
580 /* write final value and enable port */
581 asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
582
583 spin_unlock_irqrestore(&port->lock, flags);
584 }
585
586 static const char *asc_type(struct uart_port *port)
587 {
588 return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
589 }
590
591 static void asc_release_port(struct uart_port *port)
592 {
593 }
594
595 static int asc_request_port(struct uart_port *port)
596 {
597 return 0;
598 }
599
600 /*
601 * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set
602 * Set type field if successful
603 */
604 static void asc_config_port(struct uart_port *port, int flags)
605 {
606 if ((flags & UART_CONFIG_TYPE))
607 port->type = PORT_ASC;
608 }
609
610 static int
611 asc_verify_port(struct uart_port *port, struct serial_struct *ser)
612 {
613 /* No user changeable parameters */
614 return -EINVAL;
615 }
616
617 #ifdef CONFIG_CONSOLE_POLL
618 /*
619 * Console polling routines for writing and reading from the uart while
620 * in an interrupt or debug context (i.e. kgdb).
621 */
622
623 static int asc_get_poll_char(struct uart_port *port)
624 {
625 if (!(asc_in(port, ASC_STA) & ASC_STA_RBF))
626 return NO_POLL_CHAR;
627
628 return asc_in(port, ASC_RXBUF);
629 }
630
631 static void asc_put_poll_char(struct uart_port *port, unsigned char c)
632 {
633 while (!asc_txfifo_is_half_empty(port))
634 cpu_relax();
635 asc_out(port, ASC_TXBUF, c);
636 }
637
638 #endif /* CONFIG_CONSOLE_POLL */
639
640 /*---------------------------------------------------------------------*/
641
642 static const struct uart_ops asc_uart_ops = {
643 .tx_empty = asc_tx_empty,
644 .set_mctrl = asc_set_mctrl,
645 .get_mctrl = asc_get_mctrl,
646 .start_tx = asc_start_tx,
647 .stop_tx = asc_stop_tx,
648 .stop_rx = asc_stop_rx,
649 .break_ctl = asc_break_ctl,
650 .startup = asc_startup,
651 .shutdown = asc_shutdown,
652 .set_termios = asc_set_termios,
653 .type = asc_type,
654 .release_port = asc_release_port,
655 .request_port = asc_request_port,
656 .config_port = asc_config_port,
657 .verify_port = asc_verify_port,
658 .pm = asc_pm,
659 #ifdef CONFIG_CONSOLE_POLL
660 .poll_get_char = asc_get_poll_char,
661 .poll_put_char = asc_put_poll_char,
662 #endif /* CONFIG_CONSOLE_POLL */
663 };
664
665 static int asc_init_port(struct asc_port *ascport,
666 struct platform_device *pdev)
667 {
668 struct uart_port *port = &ascport->port;
669 struct resource *res;
670
671 port->iotype = UPIO_MEM;
672 port->flags = UPF_BOOT_AUTOCONF;
673 port->ops = &asc_uart_ops;
674 port->fifosize = ASC_FIFO_SIZE;
675 port->dev = &pdev->dev;
676 port->irq = platform_get_irq(pdev, 0);
677
678 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
679 port->membase = devm_ioremap_resource(&pdev->dev, res);
680 if (IS_ERR(port->membase))
681 return PTR_ERR(port->membase);
682 port->mapbase = res->start;
683
684 spin_lock_init(&port->lock);
685
686 ascport->clk = devm_clk_get(&pdev->dev, NULL);
687
688 if (WARN_ON(IS_ERR(ascport->clk)))
689 return -EINVAL;
690 /* ensure that clk rate is correct by enabling the clk */
691 clk_prepare_enable(ascport->clk);
692 ascport->port.uartclk = clk_get_rate(ascport->clk);
693 WARN_ON(ascport->port.uartclk == 0);
694 clk_disable_unprepare(ascport->clk);
695
696 return 0;
697 }
698
699 static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
700 {
701 struct device_node *np = pdev->dev.of_node;
702 int id;
703
704 if (!np)
705 return NULL;
706
707 id = of_alias_get_id(np, ASC_SERIAL_NAME);
708
709 if (id < 0)
710 id = 0;
711
712 if (WARN_ON(id >= ASC_MAX_PORTS))
713 return NULL;
714
715 asc_ports[id].hw_flow_control = of_property_read_bool(np,
716 "st,hw-flow-control");
717 asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1");
718 asc_ports[id].port.line = id;
719 return &asc_ports[id];
720 }
721
722 #ifdef CONFIG_OF
723 static const struct of_device_id asc_match[] = {
724 { .compatible = "st,asc", },
725 {},
726 };
727
728 MODULE_DEVICE_TABLE(of, asc_match);
729 #endif
730
731 static int asc_serial_probe(struct platform_device *pdev)
732 {
733 int ret;
734 struct asc_port *ascport;
735
736 ascport = asc_of_get_asc_port(pdev);
737 if (!ascport)
738 return -ENODEV;
739
740 ret = asc_init_port(ascport, pdev);
741 if (ret)
742 return ret;
743
744 ret = uart_add_one_port(&asc_uart_driver, &ascport->port);
745 if (ret)
746 return ret;
747
748 platform_set_drvdata(pdev, &ascport->port);
749
750 return 0;
751 }
752
753 static int asc_serial_remove(struct platform_device *pdev)
754 {
755 struct uart_port *port = platform_get_drvdata(pdev);
756
757 return uart_remove_one_port(&asc_uart_driver, port);
758 }
759
760 #ifdef CONFIG_PM_SLEEP
761 static int asc_serial_suspend(struct device *dev)
762 {
763 struct platform_device *pdev = to_platform_device(dev);
764 struct uart_port *port = platform_get_drvdata(pdev);
765
766 return uart_suspend_port(&asc_uart_driver, port);
767 }
768
769 static int asc_serial_resume(struct device *dev)
770 {
771 struct platform_device *pdev = to_platform_device(dev);
772 struct uart_port *port = platform_get_drvdata(pdev);
773
774 return uart_resume_port(&asc_uart_driver, port);
775 }
776
777 #endif /* CONFIG_PM_SLEEP */
778
779 /*----------------------------------------------------------------------*/
780
781 #ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
782 static void asc_console_putchar(struct uart_port *port, int ch)
783 {
784 unsigned int timeout = 1000000;
785
786 /* Wait for upto 1 second in case flow control is stopping us. */
787 while (--timeout && !asc_txfifo_is_half_empty(port))
788 udelay(1);
789
790 asc_out(port, ASC_TXBUF, ch);
791 }
792
793 /*
794 * Print a string to the serial port trying not to disturb
795 * any possible real use of the port...
796 */
797
798 static void asc_console_write(struct console *co, const char *s, unsigned count)
799 {
800 struct uart_port *port = &asc_ports[co->index].port;
801 unsigned long flags;
802 unsigned long timeout = 1000000;
803 int locked = 1;
804 u32 intenable;
805
806 local_irq_save(flags);
807 if (port->sysrq)
808 locked = 0; /* asc_interrupt has already claimed the lock */
809 else if (oops_in_progress)
810 locked = spin_trylock(&port->lock);
811 else
812 spin_lock(&port->lock);
813
814 /*
815 * Disable interrupts so we don't get the IRQ line bouncing
816 * up and down while interrupts are disabled.
817 */
818 intenable = asc_in(port, ASC_INTEN);
819 asc_out(port, ASC_INTEN, 0);
820 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
821
822 uart_console_write(port, s, count, asc_console_putchar);
823
824 while (--timeout && !asc_txfifo_is_empty(port))
825 udelay(1);
826
827 asc_out(port, ASC_INTEN, intenable);
828
829 if (locked)
830 spin_unlock(&port->lock);
831 local_irq_restore(flags);
832 }
833
834 static int asc_console_setup(struct console *co, char *options)
835 {
836 struct asc_port *ascport;
837 int baud = 9600;
838 int bits = 8;
839 int parity = 'n';
840 int flow = 'n';
841
842 if (co->index >= ASC_MAX_PORTS)
843 return -ENODEV;
844
845 ascport = &asc_ports[co->index];
846
847 /*
848 * This driver does not support early console initialization
849 * (use ARM early printk support instead), so we only expect
850 * this to be called during the uart port registration when the
851 * driver gets probed and the port should be mapped at that point.
852 */
853 if (ascport->port.mapbase == 0 || ascport->port.membase == NULL)
854 return -ENXIO;
855
856 if (options)
857 uart_parse_options(options, &baud, &parity, &bits, &flow);
858
859 return uart_set_options(&ascport->port, co, baud, parity, bits, flow);
860 }
861
862 static struct console asc_console = {
863 .name = ASC_SERIAL_NAME,
864 .device = uart_console_device,
865 .write = asc_console_write,
866 .setup = asc_console_setup,
867 .flags = CON_PRINTBUFFER,
868 .index = -1,
869 .data = &asc_uart_driver,
870 };
871
872 #define ASC_SERIAL_CONSOLE (&asc_console)
873
874 #else
875 #define ASC_SERIAL_CONSOLE NULL
876 #endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */
877
878 static struct uart_driver asc_uart_driver = {
879 .owner = THIS_MODULE,
880 .driver_name = DRIVER_NAME,
881 .dev_name = ASC_SERIAL_NAME,
882 .major = 0,
883 .minor = 0,
884 .nr = ASC_MAX_PORTS,
885 .cons = ASC_SERIAL_CONSOLE,
886 };
887
888 static const struct dev_pm_ops asc_serial_pm_ops = {
889 SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
890 };
891
892 static struct platform_driver asc_serial_driver = {
893 .probe = asc_serial_probe,
894 .remove = asc_serial_remove,
895 .driver = {
896 .name = DRIVER_NAME,
897 .pm = &asc_serial_pm_ops,
898 .of_match_table = of_match_ptr(asc_match),
899 },
900 };
901
902 static int __init asc_init(void)
903 {
904 int ret;
905 static char banner[] __initdata =
906 KERN_INFO "STMicroelectronics ASC driver initialized\n";
907
908 printk(banner);
909
910 ret = uart_register_driver(&asc_uart_driver);
911 if (ret)
912 return ret;
913
914 ret = platform_driver_register(&asc_serial_driver);
915 if (ret)
916 uart_unregister_driver(&asc_uart_driver);
917
918 return ret;
919 }
920
921 static void __exit asc_exit(void)
922 {
923 platform_driver_unregister(&asc_serial_driver);
924 uart_unregister_driver(&asc_uart_driver);
925 }
926
927 module_init(asc_init);
928 module_exit(asc_exit);
929
930 MODULE_ALIAS("platform:" DRIVER_NAME);
931 MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
932 MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
933 MODULE_LICENSE("GPL");
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