xref: /openbmc/linux/drivers/tty/serial/amba-pl010.c (revision 95e9fd10)
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 
50 #include <asm/io.h>
51 
52 #define UART_NR		8
53 
54 #define SERIAL_AMBA_MAJOR	204
55 #define SERIAL_AMBA_MINOR	16
56 #define SERIAL_AMBA_NR		UART_NR
57 
58 #define AMBA_ISR_PASS_LIMIT	256
59 
60 #define UART_RX_DATA(s)		(((s) & UART01x_FR_RXFE) == 0)
61 #define UART_TX_READY(s)	(((s) & UART01x_FR_TXFF) == 0)
62 
63 #define UART_DUMMY_RSR_RX	256
64 #define UART_PORT_SIZE		64
65 
66 /*
67  * We wrap our port structure around the generic uart_port.
68  */
69 struct uart_amba_port {
70 	struct uart_port	port;
71 	struct clk		*clk;
72 	struct amba_device	*dev;
73 	struct amba_pl010_data	*data;
74 	unsigned int		old_status;
75 };
76 
77 static void pl010_stop_tx(struct uart_port *port)
78 {
79 	struct uart_amba_port *uap = (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 
87 static void pl010_start_tx(struct uart_port *port)
88 {
89 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
90 	unsigned int cr;
91 
92 	cr = readb(uap->port.membase + UART010_CR);
93 	cr |= UART010_CR_TIE;
94 	writel(cr, uap->port.membase + UART010_CR);
95 }
96 
97 static void pl010_stop_rx(struct uart_port *port)
98 {
99 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
100 	unsigned int cr;
101 
102 	cr = readb(uap->port.membase + UART010_CR);
103 	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
104 	writel(cr, uap->port.membase + UART010_CR);
105 }
106 
107 static void pl010_enable_ms(struct uart_port *port)
108 {
109 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
110 	unsigned int cr;
111 
112 	cr = readb(uap->port.membase + UART010_CR);
113 	cr |= UART010_CR_MSIE;
114 	writel(cr, uap->port.membase + UART010_CR);
115 }
116 
117 static void pl010_rx_chars(struct uart_amba_port *uap)
118 {
119 	struct tty_struct *tty = uap->port.state->port.tty;
120 	unsigned int status, ch, flag, rsr, max_count = 256;
121 
122 	status = readb(uap->port.membase + UART01x_FR);
123 	while (UART_RX_DATA(status) && max_count--) {
124 		ch = readb(uap->port.membase + UART01x_DR);
125 		flag = TTY_NORMAL;
126 
127 		uap->port.icount.rx++;
128 
129 		/*
130 		 * Note that the error handling code is
131 		 * out of the main execution path
132 		 */
133 		rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
134 		if (unlikely(rsr & UART01x_RSR_ANY)) {
135 			writel(0, uap->port.membase + UART01x_ECR);
136 
137 			if (rsr & UART01x_RSR_BE) {
138 				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
139 				uap->port.icount.brk++;
140 				if (uart_handle_break(&uap->port))
141 					goto ignore_char;
142 			} else if (rsr & UART01x_RSR_PE)
143 				uap->port.icount.parity++;
144 			else if (rsr & UART01x_RSR_FE)
145 				uap->port.icount.frame++;
146 			if (rsr & UART01x_RSR_OE)
147 				uap->port.icount.overrun++;
148 
149 			rsr &= uap->port.read_status_mask;
150 
151 			if (rsr & UART01x_RSR_BE)
152 				flag = TTY_BREAK;
153 			else if (rsr & UART01x_RSR_PE)
154 				flag = TTY_PARITY;
155 			else if (rsr & UART01x_RSR_FE)
156 				flag = TTY_FRAME;
157 		}
158 
159 		if (uart_handle_sysrq_char(&uap->port, ch))
160 			goto ignore_char;
161 
162 		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
163 
164 	ignore_char:
165 		status = readb(uap->port.membase + UART01x_FR);
166 	}
167 	spin_unlock(&uap->port.lock);
168 	tty_flip_buffer_push(tty);
169 	spin_lock(&uap->port.lock);
170 }
171 
172 static void pl010_tx_chars(struct uart_amba_port *uap)
173 {
174 	struct circ_buf *xmit = &uap->port.state->xmit;
175 	int count;
176 
177 	if (uap->port.x_char) {
178 		writel(uap->port.x_char, uap->port.membase + UART01x_DR);
179 		uap->port.icount.tx++;
180 		uap->port.x_char = 0;
181 		return;
182 	}
183 	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
184 		pl010_stop_tx(&uap->port);
185 		return;
186 	}
187 
188 	count = uap->port.fifosize >> 1;
189 	do {
190 		writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
191 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
192 		uap->port.icount.tx++;
193 		if (uart_circ_empty(xmit))
194 			break;
195 	} while (--count > 0);
196 
197 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
198 		uart_write_wakeup(&uap->port);
199 
200 	if (uart_circ_empty(xmit))
201 		pl010_stop_tx(&uap->port);
202 }
203 
204 static void pl010_modem_status(struct uart_amba_port *uap)
205 {
206 	unsigned int status, delta;
207 
208 	writel(0, uap->port.membase + UART010_ICR);
209 
210 	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
211 
212 	delta = status ^ uap->old_status;
213 	uap->old_status = status;
214 
215 	if (!delta)
216 		return;
217 
218 	if (delta & UART01x_FR_DCD)
219 		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
220 
221 	if (delta & UART01x_FR_DSR)
222 		uap->port.icount.dsr++;
223 
224 	if (delta & UART01x_FR_CTS)
225 		uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
226 
227 	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
228 }
229 
230 static irqreturn_t pl010_int(int irq, void *dev_id)
231 {
232 	struct uart_amba_port *uap = dev_id;
233 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
234 	int handled = 0;
235 
236 	spin_lock(&uap->port.lock);
237 
238 	status = readb(uap->port.membase + UART010_IIR);
239 	if (status) {
240 		do {
241 			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
242 				pl010_rx_chars(uap);
243 			if (status & UART010_IIR_MIS)
244 				pl010_modem_status(uap);
245 			if (status & UART010_IIR_TIS)
246 				pl010_tx_chars(uap);
247 
248 			if (pass_counter-- == 0)
249 				break;
250 
251 			status = readb(uap->port.membase + UART010_IIR);
252 		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
253 				   UART010_IIR_TIS));
254 		handled = 1;
255 	}
256 
257 	spin_unlock(&uap->port.lock);
258 
259 	return IRQ_RETVAL(handled);
260 }
261 
262 static unsigned int pl010_tx_empty(struct uart_port *port)
263 {
264 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
265 	unsigned int status = readb(uap->port.membase + UART01x_FR);
266 	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
267 }
268 
269 static unsigned int pl010_get_mctrl(struct uart_port *port)
270 {
271 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
272 	unsigned int result = 0;
273 	unsigned int status;
274 
275 	status = readb(uap->port.membase + UART01x_FR);
276 	if (status & UART01x_FR_DCD)
277 		result |= TIOCM_CAR;
278 	if (status & UART01x_FR_DSR)
279 		result |= TIOCM_DSR;
280 	if (status & UART01x_FR_CTS)
281 		result |= TIOCM_CTS;
282 
283 	return result;
284 }
285 
286 static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
287 {
288 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
289 
290 	if (uap->data)
291 		uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
292 }
293 
294 static void pl010_break_ctl(struct uart_port *port, int break_state)
295 {
296 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
297 	unsigned long flags;
298 	unsigned int lcr_h;
299 
300 	spin_lock_irqsave(&uap->port.lock, flags);
301 	lcr_h = readb(uap->port.membase + UART010_LCRH);
302 	if (break_state == -1)
303 		lcr_h |= UART01x_LCRH_BRK;
304 	else
305 		lcr_h &= ~UART01x_LCRH_BRK;
306 	writel(lcr_h, uap->port.membase + UART010_LCRH);
307 	spin_unlock_irqrestore(&uap->port.lock, flags);
308 }
309 
310 static int pl010_startup(struct uart_port *port)
311 {
312 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
313 	int retval;
314 
315 	retval = clk_prepare(uap->clk);
316 	if (retval)
317 		goto out;
318 
319 	/*
320 	 * Try to enable the clock producer.
321 	 */
322 	retval = clk_enable(uap->clk);
323 	if (retval)
324 		goto clk_unprep;
325 
326 	uap->port.uartclk = clk_get_rate(uap->clk);
327 
328 	/*
329 	 * Allocate the IRQ
330 	 */
331 	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
332 	if (retval)
333 		goto clk_dis;
334 
335 	/*
336 	 * initialise the old status of the modem signals
337 	 */
338 	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
339 
340 	/*
341 	 * Finally, enable interrupts
342 	 */
343 	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
344 	       uap->port.membase + UART010_CR);
345 
346 	return 0;
347 
348  clk_dis:
349 	clk_disable(uap->clk);
350  clk_unprep:
351 	clk_unprepare(uap->clk);
352  out:
353 	return retval;
354 }
355 
356 static void pl010_shutdown(struct uart_port *port)
357 {
358 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
359 
360 	/*
361 	 * Free the interrupt
362 	 */
363 	free_irq(uap->port.irq, uap);
364 
365 	/*
366 	 * disable all interrupts, disable the port
367 	 */
368 	writel(0, uap->port.membase + UART010_CR);
369 
370 	/* disable break condition and fifos */
371 	writel(readb(uap->port.membase + UART010_LCRH) &
372 		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
373 	       uap->port.membase + UART010_LCRH);
374 
375 	/*
376 	 * Shut down the clock producer
377 	 */
378 	clk_disable(uap->clk);
379 	clk_unprepare(uap->clk);
380 }
381 
382 static void
383 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
384 		     struct ktermios *old)
385 {
386 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
387 	unsigned int lcr_h, old_cr;
388 	unsigned long flags;
389 	unsigned int baud, quot;
390 
391 	/*
392 	 * Ask the core to calculate the divisor for us.
393 	 */
394 	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
395 	quot = uart_get_divisor(port, baud);
396 
397 	switch (termios->c_cflag & CSIZE) {
398 	case CS5:
399 		lcr_h = UART01x_LCRH_WLEN_5;
400 		break;
401 	case CS6:
402 		lcr_h = UART01x_LCRH_WLEN_6;
403 		break;
404 	case CS7:
405 		lcr_h = UART01x_LCRH_WLEN_7;
406 		break;
407 	default: // CS8
408 		lcr_h = UART01x_LCRH_WLEN_8;
409 		break;
410 	}
411 	if (termios->c_cflag & CSTOPB)
412 		lcr_h |= UART01x_LCRH_STP2;
413 	if (termios->c_cflag & PARENB) {
414 		lcr_h |= UART01x_LCRH_PEN;
415 		if (!(termios->c_cflag & PARODD))
416 			lcr_h |= UART01x_LCRH_EPS;
417 	}
418 	if (uap->port.fifosize > 1)
419 		lcr_h |= UART01x_LCRH_FEN;
420 
421 	spin_lock_irqsave(&uap->port.lock, flags);
422 
423 	/*
424 	 * Update the per-port timeout.
425 	 */
426 	uart_update_timeout(port, termios->c_cflag, baud);
427 
428 	uap->port.read_status_mask = UART01x_RSR_OE;
429 	if (termios->c_iflag & INPCK)
430 		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
431 	if (termios->c_iflag & (BRKINT | PARMRK))
432 		uap->port.read_status_mask |= UART01x_RSR_BE;
433 
434 	/*
435 	 * Characters to ignore
436 	 */
437 	uap->port.ignore_status_mask = 0;
438 	if (termios->c_iflag & IGNPAR)
439 		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
440 	if (termios->c_iflag & IGNBRK) {
441 		uap->port.ignore_status_mask |= UART01x_RSR_BE;
442 		/*
443 		 * If we're ignoring parity and break indicators,
444 		 * ignore overruns too (for real raw support).
445 		 */
446 		if (termios->c_iflag & IGNPAR)
447 			uap->port.ignore_status_mask |= UART01x_RSR_OE;
448 	}
449 
450 	/*
451 	 * Ignore all characters if CREAD is not set.
452 	 */
453 	if ((termios->c_cflag & CREAD) == 0)
454 		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
455 
456 	/* first, disable everything */
457 	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
458 
459 	if (UART_ENABLE_MS(port, termios->c_cflag))
460 		old_cr |= UART010_CR_MSIE;
461 
462 	writel(0, uap->port.membase + UART010_CR);
463 
464 	/* Set baud rate */
465 	quot -= 1;
466 	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
467 	writel(quot & 0xff, uap->port.membase + UART010_LCRL);
468 
469 	/*
470 	 * ----------v----------v----------v----------v-----
471 	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
472 	 * ----------^----------^----------^----------^-----
473 	 */
474 	writel(lcr_h, uap->port.membase + UART010_LCRH);
475 	writel(old_cr, uap->port.membase + UART010_CR);
476 
477 	spin_unlock_irqrestore(&uap->port.lock, flags);
478 }
479 
480 static void pl010_set_ldisc(struct uart_port *port, int new)
481 {
482 	if (new == N_PPS) {
483 		port->flags |= UPF_HARDPPS_CD;
484 		pl010_enable_ms(port);
485 	} else
486 		port->flags &= ~UPF_HARDPPS_CD;
487 }
488 
489 static const char *pl010_type(struct uart_port *port)
490 {
491 	return port->type == PORT_AMBA ? "AMBA" : NULL;
492 }
493 
494 /*
495  * Release the memory region(s) being used by 'port'
496  */
497 static void pl010_release_port(struct uart_port *port)
498 {
499 	release_mem_region(port->mapbase, UART_PORT_SIZE);
500 }
501 
502 /*
503  * Request the memory region(s) being used by 'port'
504  */
505 static int pl010_request_port(struct uart_port *port)
506 {
507 	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
508 			!= NULL ? 0 : -EBUSY;
509 }
510 
511 /*
512  * Configure/autoconfigure the port.
513  */
514 static void pl010_config_port(struct uart_port *port, int flags)
515 {
516 	if (flags & UART_CONFIG_TYPE) {
517 		port->type = PORT_AMBA;
518 		pl010_request_port(port);
519 	}
520 }
521 
522 /*
523  * verify the new serial_struct (for TIOCSSERIAL).
524  */
525 static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
526 {
527 	int ret = 0;
528 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
529 		ret = -EINVAL;
530 	if (ser->irq < 0 || ser->irq >= nr_irqs)
531 		ret = -EINVAL;
532 	if (ser->baud_base < 9600)
533 		ret = -EINVAL;
534 	return ret;
535 }
536 
537 static struct uart_ops amba_pl010_pops = {
538 	.tx_empty	= pl010_tx_empty,
539 	.set_mctrl	= pl010_set_mctrl,
540 	.get_mctrl	= pl010_get_mctrl,
541 	.stop_tx	= pl010_stop_tx,
542 	.start_tx	= pl010_start_tx,
543 	.stop_rx	= pl010_stop_rx,
544 	.enable_ms	= pl010_enable_ms,
545 	.break_ctl	= pl010_break_ctl,
546 	.startup	= pl010_startup,
547 	.shutdown	= pl010_shutdown,
548 	.set_termios	= pl010_set_termios,
549 	.set_ldisc	= pl010_set_ldisc,
550 	.type		= pl010_type,
551 	.release_port	= pl010_release_port,
552 	.request_port	= pl010_request_port,
553 	.config_port	= pl010_config_port,
554 	.verify_port	= pl010_verify_port,
555 };
556 
557 static struct uart_amba_port *amba_ports[UART_NR];
558 
559 #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
560 
561 static void pl010_console_putchar(struct uart_port *port, int ch)
562 {
563 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
564 	unsigned int status;
565 
566 	do {
567 		status = readb(uap->port.membase + UART01x_FR);
568 		barrier();
569 	} while (!UART_TX_READY(status));
570 	writel(ch, uap->port.membase + UART01x_DR);
571 }
572 
573 static void
574 pl010_console_write(struct console *co, const char *s, unsigned int count)
575 {
576 	struct uart_amba_port *uap = amba_ports[co->index];
577 	unsigned int status, old_cr;
578 
579 	clk_enable(uap->clk);
580 
581 	/*
582 	 *	First save the CR then disable the interrupts
583 	 */
584 	old_cr = readb(uap->port.membase + UART010_CR);
585 	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
586 
587 	uart_console_write(&uap->port, s, count, pl010_console_putchar);
588 
589 	/*
590 	 *	Finally, wait for transmitter to become empty
591 	 *	and restore the TCR
592 	 */
593 	do {
594 		status = readb(uap->port.membase + UART01x_FR);
595 		barrier();
596 	} while (status & UART01x_FR_BUSY);
597 	writel(old_cr, uap->port.membase + UART010_CR);
598 
599 	clk_disable(uap->clk);
600 }
601 
602 static void __init
603 pl010_console_get_options(struct uart_amba_port *uap, int *baud,
604 			     int *parity, int *bits)
605 {
606 	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
607 		unsigned int lcr_h, quot;
608 		lcr_h = readb(uap->port.membase + UART010_LCRH);
609 
610 		*parity = 'n';
611 		if (lcr_h & UART01x_LCRH_PEN) {
612 			if (lcr_h & UART01x_LCRH_EPS)
613 				*parity = 'e';
614 			else
615 				*parity = 'o';
616 		}
617 
618 		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
619 			*bits = 7;
620 		else
621 			*bits = 8;
622 
623 		quot = readb(uap->port.membase + UART010_LCRL) |
624 		       readb(uap->port.membase + UART010_LCRM) << 8;
625 		*baud = uap->port.uartclk / (16 * (quot + 1));
626 	}
627 }
628 
629 static int __init pl010_console_setup(struct console *co, char *options)
630 {
631 	struct uart_amba_port *uap;
632 	int baud = 38400;
633 	int bits = 8;
634 	int parity = 'n';
635 	int flow = 'n';
636 	int ret;
637 
638 	/*
639 	 * Check whether an invalid uart number has been specified, and
640 	 * if so, search for the first available port that does have
641 	 * console support.
642 	 */
643 	if (co->index >= UART_NR)
644 		co->index = 0;
645 	uap = amba_ports[co->index];
646 	if (!uap)
647 		return -ENODEV;
648 
649 	ret = clk_prepare(uap->clk);
650 	if (ret)
651 		return ret;
652 
653 	uap->port.uartclk = clk_get_rate(uap->clk);
654 
655 	if (options)
656 		uart_parse_options(options, &baud, &parity, &bits, &flow);
657 	else
658 		pl010_console_get_options(uap, &baud, &parity, &bits);
659 
660 	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
661 }
662 
663 static struct uart_driver amba_reg;
664 static struct console amba_console = {
665 	.name		= "ttyAM",
666 	.write		= pl010_console_write,
667 	.device		= uart_console_device,
668 	.setup		= pl010_console_setup,
669 	.flags		= CON_PRINTBUFFER,
670 	.index		= -1,
671 	.data		= &amba_reg,
672 };
673 
674 #define AMBA_CONSOLE	&amba_console
675 #else
676 #define AMBA_CONSOLE	NULL
677 #endif
678 
679 static struct uart_driver amba_reg = {
680 	.owner			= THIS_MODULE,
681 	.driver_name		= "ttyAM",
682 	.dev_name		= "ttyAM",
683 	.major			= SERIAL_AMBA_MAJOR,
684 	.minor			= SERIAL_AMBA_MINOR,
685 	.nr			= UART_NR,
686 	.cons			= AMBA_CONSOLE,
687 };
688 
689 static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
690 {
691 	struct uart_amba_port *uap;
692 	void __iomem *base;
693 	int i, ret;
694 
695 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
696 		if (amba_ports[i] == NULL)
697 			break;
698 
699 	if (i == ARRAY_SIZE(amba_ports)) {
700 		ret = -EBUSY;
701 		goto out;
702 	}
703 
704 	uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
705 	if (!uap) {
706 		ret = -ENOMEM;
707 		goto out;
708 	}
709 
710 	base = ioremap(dev->res.start, resource_size(&dev->res));
711 	if (!base) {
712 		ret = -ENOMEM;
713 		goto free;
714 	}
715 
716 	uap->clk = clk_get(&dev->dev, NULL);
717 	if (IS_ERR(uap->clk)) {
718 		ret = PTR_ERR(uap->clk);
719 		goto unmap;
720 	}
721 
722 	uap->port.dev = &dev->dev;
723 	uap->port.mapbase = dev->res.start;
724 	uap->port.membase = base;
725 	uap->port.iotype = UPIO_MEM;
726 	uap->port.irq = dev->irq[0];
727 	uap->port.fifosize = 16;
728 	uap->port.ops = &amba_pl010_pops;
729 	uap->port.flags = UPF_BOOT_AUTOCONF;
730 	uap->port.line = i;
731 	uap->dev = dev;
732 	uap->data = dev->dev.platform_data;
733 
734 	amba_ports[i] = uap;
735 
736 	amba_set_drvdata(dev, uap);
737 	ret = uart_add_one_port(&amba_reg, &uap->port);
738 	if (ret) {
739 		amba_set_drvdata(dev, NULL);
740 		amba_ports[i] = NULL;
741 		clk_put(uap->clk);
742  unmap:
743 		iounmap(base);
744  free:
745 		kfree(uap);
746 	}
747  out:
748 	return ret;
749 }
750 
751 static int pl010_remove(struct amba_device *dev)
752 {
753 	struct uart_amba_port *uap = amba_get_drvdata(dev);
754 	int i;
755 
756 	amba_set_drvdata(dev, NULL);
757 
758 	uart_remove_one_port(&amba_reg, &uap->port);
759 
760 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
761 		if (amba_ports[i] == uap)
762 			amba_ports[i] = NULL;
763 
764 	iounmap(uap->port.membase);
765 	clk_put(uap->clk);
766 	kfree(uap);
767 	return 0;
768 }
769 
770 static int pl010_suspend(struct amba_device *dev, pm_message_t state)
771 {
772 	struct uart_amba_port *uap = amba_get_drvdata(dev);
773 
774 	if (uap)
775 		uart_suspend_port(&amba_reg, &uap->port);
776 
777 	return 0;
778 }
779 
780 static int pl010_resume(struct amba_device *dev)
781 {
782 	struct uart_amba_port *uap = amba_get_drvdata(dev);
783 
784 	if (uap)
785 		uart_resume_port(&amba_reg, &uap->port);
786 
787 	return 0;
788 }
789 
790 static struct amba_id pl010_ids[] = {
791 	{
792 		.id	= 0x00041010,
793 		.mask	= 0x000fffff,
794 	},
795 	{ 0, 0 },
796 };
797 
798 MODULE_DEVICE_TABLE(amba, pl010_ids);
799 
800 static struct amba_driver pl010_driver = {
801 	.drv = {
802 		.name	= "uart-pl010",
803 	},
804 	.id_table	= pl010_ids,
805 	.probe		= pl010_probe,
806 	.remove		= pl010_remove,
807 	.suspend	= pl010_suspend,
808 	.resume		= pl010_resume,
809 };
810 
811 static int __init pl010_init(void)
812 {
813 	int ret;
814 
815 	printk(KERN_INFO "Serial: AMBA driver\n");
816 
817 	ret = uart_register_driver(&amba_reg);
818 	if (ret == 0) {
819 		ret = amba_driver_register(&pl010_driver);
820 		if (ret)
821 			uart_unregister_driver(&amba_reg);
822 	}
823 	return ret;
824 }
825 
826 static void __exit pl010_exit(void)
827 {
828 	amba_driver_unregister(&pl010_driver);
829 	uart_unregister_driver(&amba_reg);
830 }
831 
832 module_init(pl010_init);
833 module_exit(pl010_exit);
834 
835 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
836 MODULE_DESCRIPTION("ARM AMBA serial port driver");
837 MODULE_LICENSE("GPL");
838