st-asc.c revision daea65a7be76953bb80d13d0ac43e7441fd42cdf 
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
39struct 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
46static struct asc_port asc_ports[ASC_MAX_PORTS];
47static 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
147static inline struct asc_port *to_asc_port(struct uart_port *port)
148{
149	return container_of(port, struct asc_port, port);
150}
151
152static 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
161static 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 */
174static 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
181static 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
187static 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
194static 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
200static inline u32 asc_txfifo_is_empty(struct uart_port *port)
201{
202	return asc_in(port, ASC_STA) & ASC_STA_TE;
203}
204
205static inline u32 asc_txfifo_is_half_empty(struct uart_port *port)
206{
207	return asc_in(port, ASC_STA) & ASC_STA_THE;
208}
209
210static 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
222static 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 */
239static 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
287static 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
346static 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
377static unsigned int asc_tx_empty(struct uart_port *port)
378{
379	return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
380}
381
382static 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
392static 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. */
402static 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 */
411static void asc_stop_tx(struct uart_port *port)
412{
413	asc_disable_tx_interrupts(port);
414}
415
416/* Receive stop */
417static void asc_stop_rx(struct uart_port *port)
418{
419	asc_disable_rx_interrupts(port);
420}
421
422/* Handle breaks - ignored by us */
423static 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 */
431static int asc_startup(struct uart_port *port)
432{
433	if (request_irq(port->irq, asc_interrupt, IRQF_NO_SUSPEND,
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
445static 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
452static 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
478static 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
586static const char *asc_type(struct uart_port *port)
587{
588	return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
589}
590
591static void asc_release_port(struct uart_port *port)
592{
593}
594
595static 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 */
604static void asc_config_port(struct uart_port *port, int flags)
605{
606	if ((flags & UART_CONFIG_TYPE))
607		port->type = PORT_ASC;
608}
609
610static int
611asc_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
623static 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
631static 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
642static 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
665static 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
699static 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
723static struct of_device_id asc_match[] = {
724	{ .compatible = "st,asc", },
725	{},
726};
727
728MODULE_DEVICE_TABLE(of, asc_match);
729#endif
730
731static 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
753static 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
761static 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
769static 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
782static 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
798static 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
834static 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
862static 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
878static 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
888static const struct dev_pm_ops asc_serial_pm_ops = {
889	SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
890};
891
892static 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		.owner	= THIS_MODULE,
899		.of_match_table = of_match_ptr(asc_match),
900	},
901};
902
903static int __init asc_init(void)
904{
905	int ret;
906	static char banner[] __initdata =
907		KERN_INFO "STMicroelectronics ASC driver initialized\n";
908
909	printk(banner);
910
911	ret = uart_register_driver(&asc_uart_driver);
912	if (ret)
913		return ret;
914
915	ret = platform_driver_register(&asc_serial_driver);
916	if (ret)
917		uart_unregister_driver(&asc_uart_driver);
918
919	return ret;
920}
921
922static void __exit asc_exit(void)
923{
924	platform_driver_unregister(&asc_serial_driver);
925	uart_unregister_driver(&asc_uart_driver);
926}
927
928module_init(asc_init);
929module_exit(asc_exit);
930
931MODULE_ALIAS("platform:" DRIVER_NAME);
932MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
933MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
934MODULE_LICENSE("GPL");
935