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v6.2
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 *  Driver for AMBA serial ports
  4 *
  5 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
  6 *
  7 *  Copyright 1999 ARM Limited
  8 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
  9 *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 10 * This is a generic driver for ARM AMBA-type serial ports.  They
 11 * have a lot of 16550-like features, but are not register compatible.
 12 * Note that although they do have CTS, DCD and DSR inputs, they do
 13 * not have an RI input, nor do they have DTR or RTS outputs.  If
 14 * required, these have to be supplied via some other means (eg, GPIO)
 15 * and hooked into this driver.
 16 */
 17
 
 
 
 
 18#include <linux/module.h>
 19#include <linux/ioport.h>
 20#include <linux/init.h>
 21#include <linux/console.h>
 22#include <linux/sysrq.h>
 23#include <linux/device.h>
 24#include <linux/tty.h>
 25#include <linux/tty_flip.h>
 26#include <linux/serial_core.h>
 27#include <linux/serial.h>
 28#include <linux/amba/bus.h>
 29#include <linux/amba/serial.h>
 30#include <linux/clk.h>
 31#include <linux/slab.h>
 32#include <linux/io.h>
 33
 34#define UART_NR		8
 35
 36#define SERIAL_AMBA_MAJOR	204
 37#define SERIAL_AMBA_MINOR	16
 38#define SERIAL_AMBA_NR		UART_NR
 39
 40#define AMBA_ISR_PASS_LIMIT	256
 41
 42#define UART_RX_DATA(s)		(((s) & UART01x_FR_RXFE) == 0)
 43#define UART_TX_READY(s)	(((s) & UART01x_FR_TXFF) == 0)
 44
 45#define UART_DUMMY_RSR_RX	256
 46#define UART_PORT_SIZE		64
 47
 48/*
 49 * We wrap our port structure around the generic uart_port.
 50 */
 51struct uart_amba_port {
 52	struct uart_port	port;
 53	struct clk		*clk;
 54	struct amba_device	*dev;
 55	struct amba_pl010_data	*data;
 56	unsigned int		old_status;
 57};
 58
 59static void pl010_stop_tx(struct uart_port *port)
 60{
 61	struct uart_amba_port *uap =
 62		container_of(port, struct uart_amba_port, port);
 63	unsigned int cr;
 64
 65	cr = readb(uap->port.membase + UART010_CR);
 66	cr &= ~UART010_CR_TIE;
 67	writel(cr, uap->port.membase + UART010_CR);
 68}
 69
 70static void pl010_start_tx(struct uart_port *port)
 71{
 72	struct uart_amba_port *uap =
 73		container_of(port, struct uart_amba_port, port);
 74	unsigned int cr;
 75
 76	cr = readb(uap->port.membase + UART010_CR);
 77	cr |= UART010_CR_TIE;
 78	writel(cr, uap->port.membase + UART010_CR);
 79}
 80
 81static void pl010_stop_rx(struct uart_port *port)
 82{
 83	struct uart_amba_port *uap =
 84		container_of(port, struct uart_amba_port, port);
 85	unsigned int cr;
 86
 87	cr = readb(uap->port.membase + UART010_CR);
 88	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
 89	writel(cr, uap->port.membase + UART010_CR);
 90}
 91
 92static void pl010_disable_ms(struct uart_port *port)
 93{
 94	struct uart_amba_port *uap = (struct uart_amba_port *)port;
 95	unsigned int cr;
 96
 97	cr = readb(uap->port.membase + UART010_CR);
 98	cr &= ~UART010_CR_MSIE;
 99	writel(cr, uap->port.membase + UART010_CR);
100}
101
102static void pl010_enable_ms(struct uart_port *port)
103{
104	struct uart_amba_port *uap =
105		container_of(port, struct uart_amba_port, port);
106	unsigned int cr;
107
108	cr = readb(uap->port.membase + UART010_CR);
109	cr |= UART010_CR_MSIE;
110	writel(cr, uap->port.membase + UART010_CR);
111}
112
113static void pl010_rx_chars(struct uart_port *port)
114{
115	unsigned int status, ch, flag, rsr, max_count = 256;
116
117	status = readb(port->membase + UART01x_FR);
118	while (UART_RX_DATA(status) && max_count--) {
119		ch = readb(port->membase + UART01x_DR);
120		flag = TTY_NORMAL;
121
122		port->icount.rx++;
123
124		/*
125		 * Note that the error handling code is
126		 * out of the main execution path
127		 */
128		rsr = readb(port->membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
129		if (unlikely(rsr & UART01x_RSR_ANY)) {
130			writel(0, port->membase + UART01x_ECR);
131
132			if (rsr & UART01x_RSR_BE) {
133				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
134				port->icount.brk++;
135				if (uart_handle_break(port))
136					goto ignore_char;
137			} else if (rsr & UART01x_RSR_PE)
138				port->icount.parity++;
139			else if (rsr & UART01x_RSR_FE)
140				port->icount.frame++;
141			if (rsr & UART01x_RSR_OE)
142				port->icount.overrun++;
143
144			rsr &= port->read_status_mask;
145
146			if (rsr & UART01x_RSR_BE)
147				flag = TTY_BREAK;
148			else if (rsr & UART01x_RSR_PE)
149				flag = TTY_PARITY;
150			else if (rsr & UART01x_RSR_FE)
151				flag = TTY_FRAME;
152		}
153
154		if (uart_handle_sysrq_char(port, ch))
155			goto ignore_char;
156
157		uart_insert_char(port, rsr, UART01x_RSR_OE, ch, flag);
158
159	ignore_char:
160		status = readb(port->membase + UART01x_FR);
161	}
162	tty_flip_buffer_push(&port->state->port);
 
 
163}
164
165static void pl010_tx_chars(struct uart_port *port)
166{
167	u8 ch;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
168
169	uart_port_tx_limited(port, ch, port->fifosize >> 1,
170		true,
171		writel(ch, port->membase + UART01x_DR),
172		({}));
173}
174
175static void pl010_modem_status(struct uart_amba_port *uap)
176{
177	struct uart_port *port = &uap->port;
178	unsigned int status, delta;
179
180	writel(0, port->membase + UART010_ICR);
181
182	status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
183
184	delta = status ^ uap->old_status;
185	uap->old_status = status;
186
187	if (!delta)
188		return;
189
190	if (delta & UART01x_FR_DCD)
191		uart_handle_dcd_change(port, status & UART01x_FR_DCD);
192
193	if (delta & UART01x_FR_DSR)
194		port->icount.dsr++;
195
196	if (delta & UART01x_FR_CTS)
197		uart_handle_cts_change(port, status & UART01x_FR_CTS);
198
199	wake_up_interruptible(&port->state->port.delta_msr_wait);
200}
201
202static irqreturn_t pl010_int(int irq, void *dev_id)
203{
204	struct uart_amba_port *uap = dev_id;
205	struct uart_port *port = &uap->port;
206	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
207	int handled = 0;
208
209	spin_lock(&port->lock);
210
211	status = readb(port->membase + UART010_IIR);
212	if (status) {
213		do {
214			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
215				pl010_rx_chars(port);
216			if (status & UART010_IIR_MIS)
217				pl010_modem_status(uap);
218			if (status & UART010_IIR_TIS)
219				pl010_tx_chars(port);
220
221			if (pass_counter-- == 0)
222				break;
223
224			status = readb(port->membase + UART010_IIR);
225		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
226				   UART010_IIR_TIS));
227		handled = 1;
228	}
229
230	spin_unlock(&port->lock);
231
232	return IRQ_RETVAL(handled);
233}
234
235static unsigned int pl010_tx_empty(struct uart_port *port)
236{
237	unsigned int status = readb(port->membase + UART01x_FR);
238
 
239	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
240}
241
242static unsigned int pl010_get_mctrl(struct uart_port *port)
243{
 
 
244	unsigned int result = 0;
245	unsigned int status;
246
247	status = readb(port->membase + UART01x_FR);
248	if (status & UART01x_FR_DCD)
249		result |= TIOCM_CAR;
250	if (status & UART01x_FR_DSR)
251		result |= TIOCM_DSR;
252	if (status & UART01x_FR_CTS)
253		result |= TIOCM_CTS;
254
255	return result;
256}
257
258static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
259{
260	struct uart_amba_port *uap =
261		container_of(port, struct uart_amba_port, port);
262
263	if (uap->data)
264		uap->data->set_mctrl(uap->dev, port->membase, mctrl);
265}
266
267static void pl010_break_ctl(struct uart_port *port, int break_state)
268{
 
 
269	unsigned long flags;
270	unsigned int lcr_h;
271
272	spin_lock_irqsave(&port->lock, flags);
273	lcr_h = readb(port->membase + UART010_LCRH);
274	if (break_state == -1)
275		lcr_h |= UART01x_LCRH_BRK;
276	else
277		lcr_h &= ~UART01x_LCRH_BRK;
278	writel(lcr_h, port->membase + UART010_LCRH);
279	spin_unlock_irqrestore(&port->lock, flags);
280}
281
282static int pl010_startup(struct uart_port *port)
283{
284	struct uart_amba_port *uap =
285		container_of(port, struct uart_amba_port, port);
286	int retval;
287
288	/*
289	 * Try to enable the clock producer.
290	 */
291	retval = clk_prepare_enable(uap->clk);
292	if (retval)
293		goto out;
294
295	port->uartclk = clk_get_rate(uap->clk);
296
297	/*
298	 * Allocate the IRQ
299	 */
300	retval = request_irq(port->irq, pl010_int, 0, "uart-pl010", uap);
301	if (retval)
302		goto clk_dis;
303
304	/*
305	 * initialise the old status of the modem signals
306	 */
307	uap->old_status = readb(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
308
309	/*
310	 * Finally, enable interrupts
311	 */
312	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
313	       port->membase + UART010_CR);
314
315	return 0;
316
317 clk_dis:
318	clk_disable_unprepare(uap->clk);
319 out:
320	return retval;
321}
322
323static void pl010_shutdown(struct uart_port *port)
324{
325	struct uart_amba_port *uap =
326		container_of(port, struct uart_amba_port, port);
327
328	/*
329	 * Free the interrupt
330	 */
331	free_irq(port->irq, uap);
332
333	/*
334	 * disable all interrupts, disable the port
335	 */
336	writel(0, port->membase + UART010_CR);
337
338	/* disable break condition and fifos */
339	writel(readb(port->membase + UART010_LCRH) &
340		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
341	       port->membase + UART010_LCRH);
342
343	/*
344	 * Shut down the clock producer
345	 */
346	clk_disable_unprepare(uap->clk);
347}
348
349static void
350pl010_set_termios(struct uart_port *port, struct ktermios *termios,
351		  const struct ktermios *old)
352{
 
 
353	unsigned int lcr_h, old_cr;
354	unsigned long flags;
355	unsigned int baud, quot;
356
357	/*
358	 * Ask the core to calculate the divisor for us.
359	 */
360	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
361	quot = uart_get_divisor(port, baud);
362
363	switch (termios->c_cflag & CSIZE) {
364	case CS5:
365		lcr_h = UART01x_LCRH_WLEN_5;
366		break;
367	case CS6:
368		lcr_h = UART01x_LCRH_WLEN_6;
369		break;
370	case CS7:
371		lcr_h = UART01x_LCRH_WLEN_7;
372		break;
373	default: // CS8
374		lcr_h = UART01x_LCRH_WLEN_8;
375		break;
376	}
377	if (termios->c_cflag & CSTOPB)
378		lcr_h |= UART01x_LCRH_STP2;
379	if (termios->c_cflag & PARENB) {
380		lcr_h |= UART01x_LCRH_PEN;
381		if (!(termios->c_cflag & PARODD))
382			lcr_h |= UART01x_LCRH_EPS;
383	}
384	if (port->fifosize > 1)
385		lcr_h |= UART01x_LCRH_FEN;
386
387	spin_lock_irqsave(&port->lock, flags);
388
389	/*
390	 * Update the per-port timeout.
391	 */
392	uart_update_timeout(port, termios->c_cflag, baud);
393
394	port->read_status_mask = UART01x_RSR_OE;
395	if (termios->c_iflag & INPCK)
396		port->read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
397	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
398		port->read_status_mask |= UART01x_RSR_BE;
399
400	/*
401	 * Characters to ignore
402	 */
403	port->ignore_status_mask = 0;
404	if (termios->c_iflag & IGNPAR)
405		port->ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
406	if (termios->c_iflag & IGNBRK) {
407		port->ignore_status_mask |= UART01x_RSR_BE;
408		/*
409		 * If we're ignoring parity and break indicators,
410		 * ignore overruns too (for real raw support).
411		 */
412		if (termios->c_iflag & IGNPAR)
413			port->ignore_status_mask |= UART01x_RSR_OE;
414	}
415
416	/*
417	 * Ignore all characters if CREAD is not set.
418	 */
419	if ((termios->c_cflag & CREAD) == 0)
420		port->ignore_status_mask |= UART_DUMMY_RSR_RX;
421
422	old_cr = readb(port->membase + UART010_CR) & ~UART010_CR_MSIE;
 
423
424	if (UART_ENABLE_MS(port, termios->c_cflag))
425		old_cr |= UART010_CR_MSIE;
426
 
 
427	/* Set baud rate */
428	quot -= 1;
429	writel((quot & 0xf00) >> 8, port->membase + UART010_LCRM);
430	writel(quot & 0xff, port->membase + UART010_LCRL);
431
432	/*
433	 * ----------v----------v----------v----------v-----
434	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
435	 * ----------^----------^----------^----------^-----
436	 */
437	writel(lcr_h, port->membase + UART010_LCRH);
438	writel(old_cr, port->membase + UART010_CR);
439
440	spin_unlock_irqrestore(&port->lock, flags);
441}
442
443static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
444{
445	if (termios->c_line == N_PPS) {
446		port->flags |= UPF_HARDPPS_CD;
447		spin_lock_irq(&port->lock);
448		pl010_enable_ms(port);
449		spin_unlock_irq(&port->lock);
450	} else {
451		port->flags &= ~UPF_HARDPPS_CD;
452		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
453			spin_lock_irq(&port->lock);
454			pl010_disable_ms(port);
455			spin_unlock_irq(&port->lock);
456		}
457	}
458}
459
460static const char *pl010_type(struct uart_port *port)
461{
462	return port->type == PORT_AMBA ? "AMBA" : NULL;
463}
464
465/*
466 * Release the memory region(s) being used by 'port'
467 */
468static void pl010_release_port(struct uart_port *port)
469{
470	release_mem_region(port->mapbase, UART_PORT_SIZE);
471}
472
473/*
474 * Request the memory region(s) being used by 'port'
475 */
476static int pl010_request_port(struct uart_port *port)
477{
478	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
479			!= NULL ? 0 : -EBUSY;
480}
481
482/*
483 * Configure/autoconfigure the port.
484 */
485static void pl010_config_port(struct uart_port *port, int flags)
486{
487	if (flags & UART_CONFIG_TYPE) {
488		port->type = PORT_AMBA;
489		pl010_request_port(port);
490	}
491}
492
493/*
494 * verify the new serial_struct (for TIOCSSERIAL).
495 */
496static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
497{
498	int ret = 0;
499	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
500		ret = -EINVAL;
501	if (ser->irq < 0 || ser->irq >= nr_irqs)
502		ret = -EINVAL;
503	if (ser->baud_base < 9600)
504		ret = -EINVAL;
505	return ret;
506}
507
508static const struct uart_ops amba_pl010_pops = {
509	.tx_empty	= pl010_tx_empty,
510	.set_mctrl	= pl010_set_mctrl,
511	.get_mctrl	= pl010_get_mctrl,
512	.stop_tx	= pl010_stop_tx,
513	.start_tx	= pl010_start_tx,
514	.stop_rx	= pl010_stop_rx,
515	.enable_ms	= pl010_enable_ms,
516	.break_ctl	= pl010_break_ctl,
517	.startup	= pl010_startup,
518	.shutdown	= pl010_shutdown,
519	.set_termios	= pl010_set_termios,
520	.set_ldisc	= pl010_set_ldisc,
521	.type		= pl010_type,
522	.release_port	= pl010_release_port,
523	.request_port	= pl010_request_port,
524	.config_port	= pl010_config_port,
525	.verify_port	= pl010_verify_port,
526};
527
528static struct uart_amba_port *amba_ports[UART_NR];
529
530#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
531
532static void pl010_console_putchar(struct uart_port *port, unsigned char ch)
533{
 
 
534	unsigned int status;
535
536	do {
537		status = readb(port->membase + UART01x_FR);
538		barrier();
539	} while (!UART_TX_READY(status));
540	writel(ch, port->membase + UART01x_DR);
541}
542
543static void
544pl010_console_write(struct console *co, const char *s, unsigned int count)
545{
546	struct uart_amba_port *uap = amba_ports[co->index];
547	struct uart_port *port = &uap->port;
548	unsigned int status, old_cr;
549
550	clk_enable(uap->clk);
551
552	/*
553	 *	First save the CR then disable the interrupts
554	 */
555	old_cr = readb(port->membase + UART010_CR);
556	writel(UART01x_CR_UARTEN, port->membase + UART010_CR);
557
558	uart_console_write(port, s, count, pl010_console_putchar);
559
560	/*
561	 *	Finally, wait for transmitter to become empty
562	 *	and restore the TCR
563	 */
564	do {
565		status = readb(port->membase + UART01x_FR);
566		barrier();
567	} while (status & UART01x_FR_BUSY);
568	writel(old_cr, port->membase + UART010_CR);
569
570	clk_disable(uap->clk);
571}
572
573static void __init
574pl010_console_get_options(struct uart_amba_port *uap, int *baud,
575			     int *parity, int *bits)
576{
577	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
578		unsigned int lcr_h, quot;
579		lcr_h = readb(uap->port.membase + UART010_LCRH);
580
581		*parity = 'n';
582		if (lcr_h & UART01x_LCRH_PEN) {
583			if (lcr_h & UART01x_LCRH_EPS)
584				*parity = 'e';
585			else
586				*parity = 'o';
587		}
588
589		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
590			*bits = 7;
591		else
592			*bits = 8;
593
594		quot = readb(uap->port.membase + UART010_LCRL) |
595		       readb(uap->port.membase + UART010_LCRM) << 8;
596		*baud = uap->port.uartclk / (16 * (quot + 1));
597	}
598}
599
600static int __init pl010_console_setup(struct console *co, char *options)
601{
602	struct uart_amba_port *uap;
603	int baud = 38400;
604	int bits = 8;
605	int parity = 'n';
606	int flow = 'n';
607	int ret;
608
609	/*
610	 * Check whether an invalid uart number has been specified, and
611	 * if so, search for the first available port that does have
612	 * console support.
613	 */
614	if (co->index >= UART_NR)
615		co->index = 0;
616	uap = amba_ports[co->index];
617	if (!uap)
618		return -ENODEV;
619
620	ret = clk_prepare(uap->clk);
621	if (ret)
622		return ret;
623
624	uap->port.uartclk = clk_get_rate(uap->clk);
625
626	if (options)
627		uart_parse_options(options, &baud, &parity, &bits, &flow);
628	else
629		pl010_console_get_options(uap, &baud, &parity, &bits);
630
631	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
632}
633
634static struct uart_driver amba_reg;
635static struct console amba_console = {
636	.name		= "ttyAM",
637	.write		= pl010_console_write,
638	.device		= uart_console_device,
639	.setup		= pl010_console_setup,
640	.flags		= CON_PRINTBUFFER,
641	.index		= -1,
642	.data		= &amba_reg,
643};
644
645#define AMBA_CONSOLE	&amba_console
646#else
647#define AMBA_CONSOLE	NULL
648#endif
649
650static DEFINE_MUTEX(amba_reg_lock);
651static struct uart_driver amba_reg = {
652	.owner			= THIS_MODULE,
653	.driver_name		= "ttyAM",
654	.dev_name		= "ttyAM",
655	.major			= SERIAL_AMBA_MAJOR,
656	.minor			= SERIAL_AMBA_MINOR,
657	.nr			= UART_NR,
658	.cons			= AMBA_CONSOLE,
659};
660
661static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
662{
663	struct uart_amba_port *uap;
664	void __iomem *base;
665	int i, ret;
666
667	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
668		if (amba_ports[i] == NULL)
669			break;
670
671	if (i == ARRAY_SIZE(amba_ports))
672		return -EBUSY;
673
674	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
675			   GFP_KERNEL);
676	if (!uap)
677		return -ENOMEM;
678
679	base = devm_ioremap(&dev->dev, dev->res.start,
680			    resource_size(&dev->res));
681	if (!base)
682		return -ENOMEM;
683
684	uap->clk = devm_clk_get(&dev->dev, NULL);
685	if (IS_ERR(uap->clk))
686		return PTR_ERR(uap->clk);
687
688	uap->port.dev = &dev->dev;
689	uap->port.mapbase = dev->res.start;
690	uap->port.membase = base;
691	uap->port.iotype = UPIO_MEM;
692	uap->port.irq = dev->irq[0];
693	uap->port.fifosize = 16;
694	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
695	uap->port.ops = &amba_pl010_pops;
696	uap->port.flags = UPF_BOOT_AUTOCONF;
697	uap->port.line = i;
698	uap->dev = dev;
699	uap->data = dev_get_platdata(&dev->dev);
700
701	amba_ports[i] = uap;
702
703	amba_set_drvdata(dev, uap);
704
705	mutex_lock(&amba_reg_lock);
706	if (!amba_reg.state) {
707		ret = uart_register_driver(&amba_reg);
708		if (ret < 0) {
709			mutex_unlock(&amba_reg_lock);
710			dev_err(uap->port.dev,
711				"Failed to register AMBA-PL010 driver\n");
712			return ret;
713		}
714	}
715	mutex_unlock(&amba_reg_lock);
716
717	ret = uart_add_one_port(&amba_reg, &uap->port);
718	if (ret)
719		amba_ports[i] = NULL;
720
721	return ret;
722}
723
724static void pl010_remove(struct amba_device *dev)
725{
726	struct uart_amba_port *uap = amba_get_drvdata(dev);
727	int i;
728	bool busy = false;
729
730	uart_remove_one_port(&amba_reg, &uap->port);
731
732	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
733		if (amba_ports[i] == uap)
734			amba_ports[i] = NULL;
735		else if (amba_ports[i])
736			busy = true;
737
738	if (!busy)
739		uart_unregister_driver(&amba_reg);
740}
741
742#ifdef CONFIG_PM_SLEEP
743static int pl010_suspend(struct device *dev)
744{
745	struct uart_amba_port *uap = dev_get_drvdata(dev);
746
747	if (uap)
748		uart_suspend_port(&amba_reg, &uap->port);
749
750	return 0;
751}
752
753static int pl010_resume(struct device *dev)
754{
755	struct uart_amba_port *uap = dev_get_drvdata(dev);
756
757	if (uap)
758		uart_resume_port(&amba_reg, &uap->port);
759
760	return 0;
761}
762#endif
763
764static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
765
766static const struct amba_id pl010_ids[] = {
767	{
768		.id	= 0x00041010,
769		.mask	= 0x000fffff,
770	},
771	{ 0, 0 },
772};
773
774MODULE_DEVICE_TABLE(amba, pl010_ids);
775
776static struct amba_driver pl010_driver = {
777	.drv = {
778		.name	= "uart-pl010",
779		.pm	= &pl010_dev_pm_ops,
780	},
781	.id_table	= pl010_ids,
782	.probe		= pl010_probe,
783	.remove		= pl010_remove,
784};
785
786static int __init pl010_init(void)
787{
 
 
788	printk(KERN_INFO "Serial: AMBA driver\n");
789
790	return  amba_driver_register(&pl010_driver);
 
 
 
 
 
 
791}
792
793static void __exit pl010_exit(void)
794{
795	amba_driver_unregister(&pl010_driver);
 
796}
797
798module_init(pl010_init);
799module_exit(pl010_exit);
800
801MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
802MODULE_DESCRIPTION("ARM AMBA serial port driver");
803MODULE_LICENSE("GPL");
v4.6
 
  1/*
  2 *  Driver for AMBA serial ports
  3 *
  4 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
  5 *
  6 *  Copyright 1999 ARM Limited
  7 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or
 12 * (at your option) any later version.
 13 *
 14 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 * GNU General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License
 20 * along with this program; if not, write to the Free Software
 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 22 *
 23 * This is a generic driver for ARM AMBA-type serial ports.  They
 24 * have a lot of 16550-like features, but are not register compatible.
 25 * Note that although they do have CTS, DCD and DSR inputs, they do
 26 * not have an RI input, nor do they have DTR or RTS outputs.  If
 27 * required, these have to be supplied via some other means (eg, GPIO)
 28 * and hooked into this driver.
 29 */
 30
 31#if defined(CONFIG_SERIAL_AMBA_PL010_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 32#define SUPPORT_SYSRQ
 33#endif
 34
 35#include <linux/module.h>
 36#include <linux/ioport.h>
 37#include <linux/init.h>
 38#include <linux/console.h>
 39#include <linux/sysrq.h>
 40#include <linux/device.h>
 41#include <linux/tty.h>
 42#include <linux/tty_flip.h>
 43#include <linux/serial_core.h>
 44#include <linux/serial.h>
 45#include <linux/amba/bus.h>
 46#include <linux/amba/serial.h>
 47#include <linux/clk.h>
 48#include <linux/slab.h>
 49#include <linux/io.h>
 50
 51#define UART_NR		8
 52
 53#define SERIAL_AMBA_MAJOR	204
 54#define SERIAL_AMBA_MINOR	16
 55#define SERIAL_AMBA_NR		UART_NR
 56
 57#define AMBA_ISR_PASS_LIMIT	256
 58
 59#define UART_RX_DATA(s)		(((s) & UART01x_FR_RXFE) == 0)
 60#define UART_TX_READY(s)	(((s) & UART01x_FR_TXFF) == 0)
 61
 62#define UART_DUMMY_RSR_RX	256
 63#define UART_PORT_SIZE		64
 64
 65/*
 66 * We wrap our port structure around the generic uart_port.
 67 */
 68struct uart_amba_port {
 69	struct uart_port	port;
 70	struct clk		*clk;
 71	struct amba_device	*dev;
 72	struct amba_pl010_data	*data;
 73	unsigned int		old_status;
 74};
 75
 76static void pl010_stop_tx(struct uart_port *port)
 77{
 78	struct uart_amba_port *uap =
 79		container_of(port, struct uart_amba_port, port);
 80	unsigned int cr;
 81
 82	cr = readb(uap->port.membase + UART010_CR);
 83	cr &= ~UART010_CR_TIE;
 84	writel(cr, uap->port.membase + UART010_CR);
 85}
 86
 87static void pl010_start_tx(struct uart_port *port)
 88{
 89	struct uart_amba_port *uap =
 90		container_of(port, struct uart_amba_port, port);
 91	unsigned int cr;
 92
 93	cr = readb(uap->port.membase + UART010_CR);
 94	cr |= UART010_CR_TIE;
 95	writel(cr, uap->port.membase + UART010_CR);
 96}
 97
 98static void pl010_stop_rx(struct uart_port *port)
 99{
100	struct uart_amba_port *uap =
101		container_of(port, struct uart_amba_port, port);
102	unsigned int cr;
103
104	cr = readb(uap->port.membase + UART010_CR);
105	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
106	writel(cr, uap->port.membase + UART010_CR);
107}
108
109static void pl010_disable_ms(struct uart_port *port)
110{
111	struct uart_amba_port *uap = (struct uart_amba_port *)port;
112	unsigned int cr;
113
114	cr = readb(uap->port.membase + UART010_CR);
115	cr &= ~UART010_CR_MSIE;
116	writel(cr, uap->port.membase + UART010_CR);
117}
118
119static void pl010_enable_ms(struct uart_port *port)
120{
121	struct uart_amba_port *uap =
122		container_of(port, struct uart_amba_port, port);
123	unsigned int cr;
124
125	cr = readb(uap->port.membase + UART010_CR);
126	cr |= UART010_CR_MSIE;
127	writel(cr, uap->port.membase + UART010_CR);
128}
129
130static void pl010_rx_chars(struct uart_amba_port *uap)
131{
132	unsigned int status, ch, flag, rsr, max_count = 256;
133
134	status = readb(uap->port.membase + UART01x_FR);
135	while (UART_RX_DATA(status) && max_count--) {
136		ch = readb(uap->port.membase + UART01x_DR);
137		flag = TTY_NORMAL;
138
139		uap->port.icount.rx++;
140
141		/*
142		 * Note that the error handling code is
143		 * out of the main execution path
144		 */
145		rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
146		if (unlikely(rsr & UART01x_RSR_ANY)) {
147			writel(0, uap->port.membase + UART01x_ECR);
148
149			if (rsr & UART01x_RSR_BE) {
150				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
151				uap->port.icount.brk++;
152				if (uart_handle_break(&uap->port))
153					goto ignore_char;
154			} else if (rsr & UART01x_RSR_PE)
155				uap->port.icount.parity++;
156			else if (rsr & UART01x_RSR_FE)
157				uap->port.icount.frame++;
158			if (rsr & UART01x_RSR_OE)
159				uap->port.icount.overrun++;
160
161			rsr &= uap->port.read_status_mask;
162
163			if (rsr & UART01x_RSR_BE)
164				flag = TTY_BREAK;
165			else if (rsr & UART01x_RSR_PE)
166				flag = TTY_PARITY;
167			else if (rsr & UART01x_RSR_FE)
168				flag = TTY_FRAME;
169		}
170
171		if (uart_handle_sysrq_char(&uap->port, ch))
172			goto ignore_char;
173
174		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
175
176	ignore_char:
177		status = readb(uap->port.membase + UART01x_FR);
178	}
179	spin_unlock(&uap->port.lock);
180	tty_flip_buffer_push(&uap->port.state->port);
181	spin_lock(&uap->port.lock);
182}
183
184static void pl010_tx_chars(struct uart_amba_port *uap)
185{
186	struct circ_buf *xmit = &uap->port.state->xmit;
187	int count;
188
189	if (uap->port.x_char) {
190		writel(uap->port.x_char, uap->port.membase + UART01x_DR);
191		uap->port.icount.tx++;
192		uap->port.x_char = 0;
193		return;
194	}
195	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
196		pl010_stop_tx(&uap->port);
197		return;
198	}
199
200	count = uap->port.fifosize >> 1;
201	do {
202		writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
203		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
204		uap->port.icount.tx++;
205		if (uart_circ_empty(xmit))
206			break;
207	} while (--count > 0);
208
209	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
210		uart_write_wakeup(&uap->port);
211
212	if (uart_circ_empty(xmit))
213		pl010_stop_tx(&uap->port);
 
 
214}
215
216static void pl010_modem_status(struct uart_amba_port *uap)
217{
 
218	unsigned int status, delta;
219
220	writel(0, uap->port.membase + UART010_ICR);
221
222	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
223
224	delta = status ^ uap->old_status;
225	uap->old_status = status;
226
227	if (!delta)
228		return;
229
230	if (delta & UART01x_FR_DCD)
231		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
232
233	if (delta & UART01x_FR_DSR)
234		uap->port.icount.dsr++;
235
236	if (delta & UART01x_FR_CTS)
237		uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
238
239	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
240}
241
242static irqreturn_t pl010_int(int irq, void *dev_id)
243{
244	struct uart_amba_port *uap = dev_id;
 
245	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
246	int handled = 0;
247
248	spin_lock(&uap->port.lock);
249
250	status = readb(uap->port.membase + UART010_IIR);
251	if (status) {
252		do {
253			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
254				pl010_rx_chars(uap);
255			if (status & UART010_IIR_MIS)
256				pl010_modem_status(uap);
257			if (status & UART010_IIR_TIS)
258				pl010_tx_chars(uap);
259
260			if (pass_counter-- == 0)
261				break;
262
263			status = readb(uap->port.membase + UART010_IIR);
264		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
265				   UART010_IIR_TIS));
266		handled = 1;
267	}
268
269	spin_unlock(&uap->port.lock);
270
271	return IRQ_RETVAL(handled);
272}
273
274static unsigned int pl010_tx_empty(struct uart_port *port)
275{
276	struct uart_amba_port *uap =
277		container_of(port, struct uart_amba_port, port);
278	unsigned int status = readb(uap->port.membase + UART01x_FR);
279	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
280}
281
282static unsigned int pl010_get_mctrl(struct uart_port *port)
283{
284	struct uart_amba_port *uap =
285		container_of(port, struct uart_amba_port, port);
286	unsigned int result = 0;
287	unsigned int status;
288
289	status = readb(uap->port.membase + UART01x_FR);
290	if (status & UART01x_FR_DCD)
291		result |= TIOCM_CAR;
292	if (status & UART01x_FR_DSR)
293		result |= TIOCM_DSR;
294	if (status & UART01x_FR_CTS)
295		result |= TIOCM_CTS;
296
297	return result;
298}
299
300static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
301{
302	struct uart_amba_port *uap =
303		container_of(port, struct uart_amba_port, port);
304
305	if (uap->data)
306		uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
307}
308
309static void pl010_break_ctl(struct uart_port *port, int break_state)
310{
311	struct uart_amba_port *uap =
312		container_of(port, struct uart_amba_port, port);
313	unsigned long flags;
314	unsigned int lcr_h;
315
316	spin_lock_irqsave(&uap->port.lock, flags);
317	lcr_h = readb(uap->port.membase + UART010_LCRH);
318	if (break_state == -1)
319		lcr_h |= UART01x_LCRH_BRK;
320	else
321		lcr_h &= ~UART01x_LCRH_BRK;
322	writel(lcr_h, uap->port.membase + UART010_LCRH);
323	spin_unlock_irqrestore(&uap->port.lock, flags);
324}
325
326static int pl010_startup(struct uart_port *port)
327{
328	struct uart_amba_port *uap =
329		container_of(port, struct uart_amba_port, port);
330	int retval;
331
332	/*
333	 * Try to enable the clock producer.
334	 */
335	retval = clk_prepare_enable(uap->clk);
336	if (retval)
337		goto out;
338
339	uap->port.uartclk = clk_get_rate(uap->clk);
340
341	/*
342	 * Allocate the IRQ
343	 */
344	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
345	if (retval)
346		goto clk_dis;
347
348	/*
349	 * initialise the old status of the modem signals
350	 */
351	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
352
353	/*
354	 * Finally, enable interrupts
355	 */
356	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
357	       uap->port.membase + UART010_CR);
358
359	return 0;
360
361 clk_dis:
362	clk_disable_unprepare(uap->clk);
363 out:
364	return retval;
365}
366
367static void pl010_shutdown(struct uart_port *port)
368{
369	struct uart_amba_port *uap =
370		container_of(port, struct uart_amba_port, port);
371
372	/*
373	 * Free the interrupt
374	 */
375	free_irq(uap->port.irq, uap);
376
377	/*
378	 * disable all interrupts, disable the port
379	 */
380	writel(0, uap->port.membase + UART010_CR);
381
382	/* disable break condition and fifos */
383	writel(readb(uap->port.membase + UART010_LCRH) &
384		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
385	       uap->port.membase + UART010_LCRH);
386
387	/*
388	 * Shut down the clock producer
389	 */
390	clk_disable_unprepare(uap->clk);
391}
392
393static void
394pl010_set_termios(struct uart_port *port, struct ktermios *termios,
395		     struct ktermios *old)
396{
397	struct uart_amba_port *uap =
398		container_of(port, struct uart_amba_port, port);
399	unsigned int lcr_h, old_cr;
400	unsigned long flags;
401	unsigned int baud, quot;
402
403	/*
404	 * Ask the core to calculate the divisor for us.
405	 */
406	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16); 
407	quot = uart_get_divisor(port, baud);
408
409	switch (termios->c_cflag & CSIZE) {
410	case CS5:
411		lcr_h = UART01x_LCRH_WLEN_5;
412		break;
413	case CS6:
414		lcr_h = UART01x_LCRH_WLEN_6;
415		break;
416	case CS7:
417		lcr_h = UART01x_LCRH_WLEN_7;
418		break;
419	default: // CS8
420		lcr_h = UART01x_LCRH_WLEN_8;
421		break;
422	}
423	if (termios->c_cflag & CSTOPB)
424		lcr_h |= UART01x_LCRH_STP2;
425	if (termios->c_cflag & PARENB) {
426		lcr_h |= UART01x_LCRH_PEN;
427		if (!(termios->c_cflag & PARODD))
428			lcr_h |= UART01x_LCRH_EPS;
429	}
430	if (uap->port.fifosize > 1)
431		lcr_h |= UART01x_LCRH_FEN;
432
433	spin_lock_irqsave(&uap->port.lock, flags);
434
435	/*
436	 * Update the per-port timeout.
437	 */
438	uart_update_timeout(port, termios->c_cflag, baud);
439
440	uap->port.read_status_mask = UART01x_RSR_OE;
441	if (termios->c_iflag & INPCK)
442		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
443	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
444		uap->port.read_status_mask |= UART01x_RSR_BE;
445
446	/*
447	 * Characters to ignore
448	 */
449	uap->port.ignore_status_mask = 0;
450	if (termios->c_iflag & IGNPAR)
451		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
452	if (termios->c_iflag & IGNBRK) {
453		uap->port.ignore_status_mask |= UART01x_RSR_BE;
454		/*
455		 * If we're ignoring parity and break indicators,
456		 * ignore overruns too (for real raw support).
457		 */
458		if (termios->c_iflag & IGNPAR)
459			uap->port.ignore_status_mask |= UART01x_RSR_OE;
460	}
461
462	/*
463	 * Ignore all characters if CREAD is not set.
464	 */
465	if ((termios->c_cflag & CREAD) == 0)
466		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
467
468	/* first, disable everything */
469	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
470
471	if (UART_ENABLE_MS(port, termios->c_cflag))
472		old_cr |= UART010_CR_MSIE;
473
474	writel(0, uap->port.membase + UART010_CR);
475
476	/* Set baud rate */
477	quot -= 1;
478	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
479	writel(quot & 0xff, uap->port.membase + UART010_LCRL);
480
481	/*
482	 * ----------v----------v----------v----------v-----
483	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
484	 * ----------^----------^----------^----------^-----
485	 */
486	writel(lcr_h, uap->port.membase + UART010_LCRH);
487	writel(old_cr, uap->port.membase + UART010_CR);
488
489	spin_unlock_irqrestore(&uap->port.lock, flags);
490}
491
492static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
493{
494	if (termios->c_line == N_PPS) {
495		port->flags |= UPF_HARDPPS_CD;
496		spin_lock_irq(&port->lock);
497		pl010_enable_ms(port);
498		spin_unlock_irq(&port->lock);
499	} else {
500		port->flags &= ~UPF_HARDPPS_CD;
501		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
502			spin_lock_irq(&port->lock);
503			pl010_disable_ms(port);
504			spin_unlock_irq(&port->lock);
505		}
506	}
507}
508
509static const char *pl010_type(struct uart_port *port)
510{
511	return port->type == PORT_AMBA ? "AMBA" : NULL;
512}
513
514/*
515 * Release the memory region(s) being used by 'port'
516 */
517static void pl010_release_port(struct uart_port *port)
518{
519	release_mem_region(port->mapbase, UART_PORT_SIZE);
520}
521
522/*
523 * Request the memory region(s) being used by 'port'
524 */
525static int pl010_request_port(struct uart_port *port)
526{
527	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
528			!= NULL ? 0 : -EBUSY;
529}
530
531/*
532 * Configure/autoconfigure the port.
533 */
534static void pl010_config_port(struct uart_port *port, int flags)
535{
536	if (flags & UART_CONFIG_TYPE) {
537		port->type = PORT_AMBA;
538		pl010_request_port(port);
539	}
540}
541
542/*
543 * verify the new serial_struct (for TIOCSSERIAL).
544 */
545static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
546{
547	int ret = 0;
548	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
549		ret = -EINVAL;
550	if (ser->irq < 0 || ser->irq >= nr_irqs)
551		ret = -EINVAL;
552	if (ser->baud_base < 9600)
553		ret = -EINVAL;
554	return ret;
555}
556
557static struct uart_ops amba_pl010_pops = {
558	.tx_empty	= pl010_tx_empty,
559	.set_mctrl	= pl010_set_mctrl,
560	.get_mctrl	= pl010_get_mctrl,
561	.stop_tx	= pl010_stop_tx,
562	.start_tx	= pl010_start_tx,
563	.stop_rx	= pl010_stop_rx,
564	.enable_ms	= pl010_enable_ms,
565	.break_ctl	= pl010_break_ctl,
566	.startup	= pl010_startup,
567	.shutdown	= pl010_shutdown,
568	.set_termios	= pl010_set_termios,
569	.set_ldisc	= pl010_set_ldisc,
570	.type		= pl010_type,
571	.release_port	= pl010_release_port,
572	.request_port	= pl010_request_port,
573	.config_port	= pl010_config_port,
574	.verify_port	= pl010_verify_port,
575};
576
577static struct uart_amba_port *amba_ports[UART_NR];
578
579#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
580
581static void pl010_console_putchar(struct uart_port *port, int ch)
582{
583	struct uart_amba_port *uap =
584		container_of(port, struct uart_amba_port, port);
585	unsigned int status;
586
587	do {
588		status = readb(uap->port.membase + UART01x_FR);
589		barrier();
590	} while (!UART_TX_READY(status));
591	writel(ch, uap->port.membase + UART01x_DR);
592}
593
594static void
595pl010_console_write(struct console *co, const char *s, unsigned int count)
596{
597	struct uart_amba_port *uap = amba_ports[co->index];
 
598	unsigned int status, old_cr;
599
600	clk_enable(uap->clk);
601
602	/*
603	 *	First save the CR then disable the interrupts
604	 */
605	old_cr = readb(uap->port.membase + UART010_CR);
606	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
607
608	uart_console_write(&uap->port, s, count, pl010_console_putchar);
609
610	/*
611	 *	Finally, wait for transmitter to become empty
612	 *	and restore the TCR
613	 */
614	do {
615		status = readb(uap->port.membase + UART01x_FR);
616		barrier();
617	} while (status & UART01x_FR_BUSY);
618	writel(old_cr, uap->port.membase + UART010_CR);
619
620	clk_disable(uap->clk);
621}
622
623static void __init
624pl010_console_get_options(struct uart_amba_port *uap, int *baud,
625			     int *parity, int *bits)
626{
627	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
628		unsigned int lcr_h, quot;
629		lcr_h = readb(uap->port.membase + UART010_LCRH);
630
631		*parity = 'n';
632		if (lcr_h & UART01x_LCRH_PEN) {
633			if (lcr_h & UART01x_LCRH_EPS)
634				*parity = 'e';
635			else
636				*parity = 'o';
637		}
638
639		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
640			*bits = 7;
641		else
642			*bits = 8;
643
644		quot = readb(uap->port.membase + UART010_LCRL) |
645		       readb(uap->port.membase + UART010_LCRM) << 8;
646		*baud = uap->port.uartclk / (16 * (quot + 1));
647	}
648}
649
650static int __init pl010_console_setup(struct console *co, char *options)
651{
652	struct uart_amba_port *uap;
653	int baud = 38400;
654	int bits = 8;
655	int parity = 'n';
656	int flow = 'n';
657	int ret;
658
659	/*
660	 * Check whether an invalid uart number has been specified, and
661	 * if so, search for the first available port that does have
662	 * console support.
663	 */
664	if (co->index >= UART_NR)
665		co->index = 0;
666	uap = amba_ports[co->index];
667	if (!uap)
668		return -ENODEV;
669
670	ret = clk_prepare(uap->clk);
671	if (ret)
672		return ret;
673
674	uap->port.uartclk = clk_get_rate(uap->clk);
675
676	if (options)
677		uart_parse_options(options, &baud, &parity, &bits, &flow);
678	else
679		pl010_console_get_options(uap, &baud, &parity, &bits);
680
681	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
682}
683
684static struct uart_driver amba_reg;
685static struct console amba_console = {
686	.name		= "ttyAM",
687	.write		= pl010_console_write,
688	.device		= uart_console_device,
689	.setup		= pl010_console_setup,
690	.flags		= CON_PRINTBUFFER,
691	.index		= -1,
692	.data		= &amba_reg,
693};
694
695#define AMBA_CONSOLE	&amba_console
696#else
697#define AMBA_CONSOLE	NULL
698#endif
699
 
700static struct uart_driver amba_reg = {
701	.owner			= THIS_MODULE,
702	.driver_name		= "ttyAM",
703	.dev_name		= "ttyAM",
704	.major			= SERIAL_AMBA_MAJOR,
705	.minor			= SERIAL_AMBA_MINOR,
706	.nr			= UART_NR,
707	.cons			= AMBA_CONSOLE,
708};
709
710static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
711{
712	struct uart_amba_port *uap;
713	void __iomem *base;
714	int i, ret;
715
716	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
717		if (amba_ports[i] == NULL)
718			break;
719
720	if (i == ARRAY_SIZE(amba_ports))
721		return -EBUSY;
722
723	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
724			   GFP_KERNEL);
725	if (!uap)
726		return -ENOMEM;
727
728	base = devm_ioremap(&dev->dev, dev->res.start,
729			    resource_size(&dev->res));
730	if (!base)
731		return -ENOMEM;
732
733	uap->clk = devm_clk_get(&dev->dev, NULL);
734	if (IS_ERR(uap->clk))
735		return PTR_ERR(uap->clk);
736
737	uap->port.dev = &dev->dev;
738	uap->port.mapbase = dev->res.start;
739	uap->port.membase = base;
740	uap->port.iotype = UPIO_MEM;
741	uap->port.irq = dev->irq[0];
742	uap->port.fifosize = 16;
 
743	uap->port.ops = &amba_pl010_pops;
744	uap->port.flags = UPF_BOOT_AUTOCONF;
745	uap->port.line = i;
746	uap->dev = dev;
747	uap->data = dev_get_platdata(&dev->dev);
748
749	amba_ports[i] = uap;
750
751	amba_set_drvdata(dev, uap);
 
 
 
 
 
 
 
 
 
 
 
 
 
752	ret = uart_add_one_port(&amba_reg, &uap->port);
753	if (ret)
754		amba_ports[i] = NULL;
755
756	return ret;
757}
758
759static int pl010_remove(struct amba_device *dev)
760{
761	struct uart_amba_port *uap = amba_get_drvdata(dev);
762	int i;
 
763
764	uart_remove_one_port(&amba_reg, &uap->port);
765
766	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
767		if (amba_ports[i] == uap)
768			amba_ports[i] = NULL;
 
 
769
770	return 0;
 
771}
772
773#ifdef CONFIG_PM_SLEEP
774static int pl010_suspend(struct device *dev)
775{
776	struct uart_amba_port *uap = dev_get_drvdata(dev);
777
778	if (uap)
779		uart_suspend_port(&amba_reg, &uap->port);
780
781	return 0;
782}
783
784static int pl010_resume(struct device *dev)
785{
786	struct uart_amba_port *uap = dev_get_drvdata(dev);
787
788	if (uap)
789		uart_resume_port(&amba_reg, &uap->port);
790
791	return 0;
792}
793#endif
794
795static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
796
797static struct amba_id pl010_ids[] = {
798	{
799		.id	= 0x00041010,
800		.mask	= 0x000fffff,
801	},
802	{ 0, 0 },
803};
804
805MODULE_DEVICE_TABLE(amba, pl010_ids);
806
807static struct amba_driver pl010_driver = {
808	.drv = {
809		.name	= "uart-pl010",
810		.pm	= &pl010_dev_pm_ops,
811	},
812	.id_table	= pl010_ids,
813	.probe		= pl010_probe,
814	.remove		= pl010_remove,
815};
816
817static int __init pl010_init(void)
818{
819	int ret;
820
821	printk(KERN_INFO "Serial: AMBA driver\n");
822
823	ret = uart_register_driver(&amba_reg);
824	if (ret == 0) {
825		ret = amba_driver_register(&pl010_driver);
826		if (ret)
827			uart_unregister_driver(&amba_reg);
828	}
829	return ret;
830}
831
832static void __exit pl010_exit(void)
833{
834	amba_driver_unregister(&pl010_driver);
835	uart_unregister_driver(&amba_reg);
836}
837
838module_init(pl010_init);
839module_exit(pl010_exit);
840
841MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
842MODULE_DESCRIPTION("ARM AMBA serial port driver");
843MODULE_LICENSE("GPL");