xref: /openbmc/linux/drivers/tty/serial/amba-pl010.c (revision 30614cf3)
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  */
68 struct 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 
76 static void pl010_stop_tx(struct uart_port *port)
77 {
78 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
79 	unsigned int cr;
80 
81 	cr = readb(uap->port.membase + UART010_CR);
82 	cr &= ~UART010_CR_TIE;
83 	writel(cr, uap->port.membase + UART010_CR);
84 }
85 
86 static void pl010_start_tx(struct uart_port *port)
87 {
88 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
89 	unsigned int cr;
90 
91 	cr = readb(uap->port.membase + UART010_CR);
92 	cr |= UART010_CR_TIE;
93 	writel(cr, uap->port.membase + UART010_CR);
94 }
95 
96 static void pl010_stop_rx(struct uart_port *port)
97 {
98 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
99 	unsigned int cr;
100 
101 	cr = readb(uap->port.membase + UART010_CR);
102 	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
103 	writel(cr, uap->port.membase + UART010_CR);
104 }
105 
106 static void pl010_enable_ms(struct uart_port *port)
107 {
108 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
109 	unsigned int cr;
110 
111 	cr = readb(uap->port.membase + UART010_CR);
112 	cr |= UART010_CR_MSIE;
113 	writel(cr, uap->port.membase + UART010_CR);
114 }
115 
116 static void pl010_rx_chars(struct uart_amba_port *uap)
117 {
118 	unsigned int status, ch, flag, rsr, max_count = 256;
119 
120 	status = readb(uap->port.membase + UART01x_FR);
121 	while (UART_RX_DATA(status) && max_count--) {
122 		ch = readb(uap->port.membase + UART01x_DR);
123 		flag = TTY_NORMAL;
124 
125 		uap->port.icount.rx++;
126 
127 		/*
128 		 * Note that the error handling code is
129 		 * out of the main execution path
130 		 */
131 		rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
132 		if (unlikely(rsr & UART01x_RSR_ANY)) {
133 			writel(0, uap->port.membase + UART01x_ECR);
134 
135 			if (rsr & UART01x_RSR_BE) {
136 				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
137 				uap->port.icount.brk++;
138 				if (uart_handle_break(&uap->port))
139 					goto ignore_char;
140 			} else if (rsr & UART01x_RSR_PE)
141 				uap->port.icount.parity++;
142 			else if (rsr & UART01x_RSR_FE)
143 				uap->port.icount.frame++;
144 			if (rsr & UART01x_RSR_OE)
145 				uap->port.icount.overrun++;
146 
147 			rsr &= uap->port.read_status_mask;
148 
149 			if (rsr & UART01x_RSR_BE)
150 				flag = TTY_BREAK;
151 			else if (rsr & UART01x_RSR_PE)
152 				flag = TTY_PARITY;
153 			else if (rsr & UART01x_RSR_FE)
154 				flag = TTY_FRAME;
155 		}
156 
157 		if (uart_handle_sysrq_char(&uap->port, ch))
158 			goto ignore_char;
159 
160 		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
161 
162 	ignore_char:
163 		status = readb(uap->port.membase + UART01x_FR);
164 	}
165 	spin_unlock(&uap->port.lock);
166 	tty_flip_buffer_push(&uap->port.state->port);
167 	spin_lock(&uap->port.lock);
168 }
169 
170 static void pl010_tx_chars(struct uart_amba_port *uap)
171 {
172 	struct circ_buf *xmit = &uap->port.state->xmit;
173 	int count;
174 
175 	if (uap->port.x_char) {
176 		writel(uap->port.x_char, uap->port.membase + UART01x_DR);
177 		uap->port.icount.tx++;
178 		uap->port.x_char = 0;
179 		return;
180 	}
181 	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
182 		pl010_stop_tx(&uap->port);
183 		return;
184 	}
185 
186 	count = uap->port.fifosize >> 1;
187 	do {
188 		writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
189 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
190 		uap->port.icount.tx++;
191 		if (uart_circ_empty(xmit))
192 			break;
193 	} while (--count > 0);
194 
195 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
196 		uart_write_wakeup(&uap->port);
197 
198 	if (uart_circ_empty(xmit))
199 		pl010_stop_tx(&uap->port);
200 }
201 
202 static void pl010_modem_status(struct uart_amba_port *uap)
203 {
204 	unsigned int status, delta;
205 
206 	writel(0, uap->port.membase + UART010_ICR);
207 
208 	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
209 
210 	delta = status ^ uap->old_status;
211 	uap->old_status = status;
212 
213 	if (!delta)
214 		return;
215 
216 	if (delta & UART01x_FR_DCD)
217 		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
218 
219 	if (delta & UART01x_FR_DSR)
220 		uap->port.icount.dsr++;
221 
222 	if (delta & UART01x_FR_CTS)
223 		uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
224 
225 	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
226 }
227 
228 static irqreturn_t pl010_int(int irq, void *dev_id)
229 {
230 	struct uart_amba_port *uap = dev_id;
231 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
232 	int handled = 0;
233 
234 	spin_lock(&uap->port.lock);
235 
236 	status = readb(uap->port.membase + UART010_IIR);
237 	if (status) {
238 		do {
239 			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
240 				pl010_rx_chars(uap);
241 			if (status & UART010_IIR_MIS)
242 				pl010_modem_status(uap);
243 			if (status & UART010_IIR_TIS)
244 				pl010_tx_chars(uap);
245 
246 			if (pass_counter-- == 0)
247 				break;
248 
249 			status = readb(uap->port.membase + UART010_IIR);
250 		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
251 				   UART010_IIR_TIS));
252 		handled = 1;
253 	}
254 
255 	spin_unlock(&uap->port.lock);
256 
257 	return IRQ_RETVAL(handled);
258 }
259 
260 static unsigned int pl010_tx_empty(struct uart_port *port)
261 {
262 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
263 	unsigned int status = readb(uap->port.membase + UART01x_FR);
264 	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
265 }
266 
267 static unsigned int pl010_get_mctrl(struct uart_port *port)
268 {
269 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
270 	unsigned int result = 0;
271 	unsigned int status;
272 
273 	status = readb(uap->port.membase + UART01x_FR);
274 	if (status & UART01x_FR_DCD)
275 		result |= TIOCM_CAR;
276 	if (status & UART01x_FR_DSR)
277 		result |= TIOCM_DSR;
278 	if (status & UART01x_FR_CTS)
279 		result |= TIOCM_CTS;
280 
281 	return result;
282 }
283 
284 static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
285 {
286 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
287 
288 	if (uap->data)
289 		uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
290 }
291 
292 static void pl010_break_ctl(struct uart_port *port, int break_state)
293 {
294 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
295 	unsigned long flags;
296 	unsigned int lcr_h;
297 
298 	spin_lock_irqsave(&uap->port.lock, flags);
299 	lcr_h = readb(uap->port.membase + UART010_LCRH);
300 	if (break_state == -1)
301 		lcr_h |= UART01x_LCRH_BRK;
302 	else
303 		lcr_h &= ~UART01x_LCRH_BRK;
304 	writel(lcr_h, uap->port.membase + UART010_LCRH);
305 	spin_unlock_irqrestore(&uap->port.lock, flags);
306 }
307 
308 static int pl010_startup(struct uart_port *port)
309 {
310 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
311 	int retval;
312 
313 	/*
314 	 * Try to enable the clock producer.
315 	 */
316 	retval = clk_prepare_enable(uap->clk);
317 	if (retval)
318 		goto out;
319 
320 	uap->port.uartclk = clk_get_rate(uap->clk);
321 
322 	/*
323 	 * Allocate the IRQ
324 	 */
325 	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
326 	if (retval)
327 		goto clk_dis;
328 
329 	/*
330 	 * initialise the old status of the modem signals
331 	 */
332 	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
333 
334 	/*
335 	 * Finally, enable interrupts
336 	 */
337 	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
338 	       uap->port.membase + UART010_CR);
339 
340 	return 0;
341 
342  clk_dis:
343 	clk_disable_unprepare(uap->clk);
344  out:
345 	return retval;
346 }
347 
348 static void pl010_shutdown(struct uart_port *port)
349 {
350 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
351 
352 	/*
353 	 * Free the interrupt
354 	 */
355 	free_irq(uap->port.irq, uap);
356 
357 	/*
358 	 * disable all interrupts, disable the port
359 	 */
360 	writel(0, uap->port.membase + UART010_CR);
361 
362 	/* disable break condition and fifos */
363 	writel(readb(uap->port.membase + UART010_LCRH) &
364 		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
365 	       uap->port.membase + UART010_LCRH);
366 
367 	/*
368 	 * Shut down the clock producer
369 	 */
370 	clk_disable_unprepare(uap->clk);
371 }
372 
373 static void
374 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
375 		     struct ktermios *old)
376 {
377 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
378 	unsigned int lcr_h, old_cr;
379 	unsigned long flags;
380 	unsigned int baud, quot;
381 
382 	/*
383 	 * Ask the core to calculate the divisor for us.
384 	 */
385 	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
386 	quot = uart_get_divisor(port, baud);
387 
388 	switch (termios->c_cflag & CSIZE) {
389 	case CS5:
390 		lcr_h = UART01x_LCRH_WLEN_5;
391 		break;
392 	case CS6:
393 		lcr_h = UART01x_LCRH_WLEN_6;
394 		break;
395 	case CS7:
396 		lcr_h = UART01x_LCRH_WLEN_7;
397 		break;
398 	default: // CS8
399 		lcr_h = UART01x_LCRH_WLEN_8;
400 		break;
401 	}
402 	if (termios->c_cflag & CSTOPB)
403 		lcr_h |= UART01x_LCRH_STP2;
404 	if (termios->c_cflag & PARENB) {
405 		lcr_h |= UART01x_LCRH_PEN;
406 		if (!(termios->c_cflag & PARODD))
407 			lcr_h |= UART01x_LCRH_EPS;
408 	}
409 	if (uap->port.fifosize > 1)
410 		lcr_h |= UART01x_LCRH_FEN;
411 
412 	spin_lock_irqsave(&uap->port.lock, flags);
413 
414 	/*
415 	 * Update the per-port timeout.
416 	 */
417 	uart_update_timeout(port, termios->c_cflag, baud);
418 
419 	uap->port.read_status_mask = UART01x_RSR_OE;
420 	if (termios->c_iflag & INPCK)
421 		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
422 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
423 		uap->port.read_status_mask |= UART01x_RSR_BE;
424 
425 	/*
426 	 * Characters to ignore
427 	 */
428 	uap->port.ignore_status_mask = 0;
429 	if (termios->c_iflag & IGNPAR)
430 		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
431 	if (termios->c_iflag & IGNBRK) {
432 		uap->port.ignore_status_mask |= UART01x_RSR_BE;
433 		/*
434 		 * If we're ignoring parity and break indicators,
435 		 * ignore overruns too (for real raw support).
436 		 */
437 		if (termios->c_iflag & IGNPAR)
438 			uap->port.ignore_status_mask |= UART01x_RSR_OE;
439 	}
440 
441 	/*
442 	 * Ignore all characters if CREAD is not set.
443 	 */
444 	if ((termios->c_cflag & CREAD) == 0)
445 		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
446 
447 	/* first, disable everything */
448 	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
449 
450 	if (UART_ENABLE_MS(port, termios->c_cflag))
451 		old_cr |= UART010_CR_MSIE;
452 
453 	writel(0, uap->port.membase + UART010_CR);
454 
455 	/* Set baud rate */
456 	quot -= 1;
457 	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
458 	writel(quot & 0xff, uap->port.membase + UART010_LCRL);
459 
460 	/*
461 	 * ----------v----------v----------v----------v-----
462 	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
463 	 * ----------^----------^----------^----------^-----
464 	 */
465 	writel(lcr_h, uap->port.membase + UART010_LCRH);
466 	writel(old_cr, uap->port.membase + UART010_CR);
467 
468 	spin_unlock_irqrestore(&uap->port.lock, flags);
469 }
470 
471 static void pl010_set_ldisc(struct uart_port *port, int new)
472 {
473 	if (new == N_PPS) {
474 		port->flags |= UPF_HARDPPS_CD;
475 		pl010_enable_ms(port);
476 	} else
477 		port->flags &= ~UPF_HARDPPS_CD;
478 }
479 
480 static const char *pl010_type(struct uart_port *port)
481 {
482 	return port->type == PORT_AMBA ? "AMBA" : NULL;
483 }
484 
485 /*
486  * Release the memory region(s) being used by 'port'
487  */
488 static void pl010_release_port(struct uart_port *port)
489 {
490 	release_mem_region(port->mapbase, UART_PORT_SIZE);
491 }
492 
493 /*
494  * Request the memory region(s) being used by 'port'
495  */
496 static int pl010_request_port(struct uart_port *port)
497 {
498 	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
499 			!= NULL ? 0 : -EBUSY;
500 }
501 
502 /*
503  * Configure/autoconfigure the port.
504  */
505 static void pl010_config_port(struct uart_port *port, int flags)
506 {
507 	if (flags & UART_CONFIG_TYPE) {
508 		port->type = PORT_AMBA;
509 		pl010_request_port(port);
510 	}
511 }
512 
513 /*
514  * verify the new serial_struct (for TIOCSSERIAL).
515  */
516 static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
517 {
518 	int ret = 0;
519 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
520 		ret = -EINVAL;
521 	if (ser->irq < 0 || ser->irq >= nr_irqs)
522 		ret = -EINVAL;
523 	if (ser->baud_base < 9600)
524 		ret = -EINVAL;
525 	return ret;
526 }
527 
528 static struct uart_ops amba_pl010_pops = {
529 	.tx_empty	= pl010_tx_empty,
530 	.set_mctrl	= pl010_set_mctrl,
531 	.get_mctrl	= pl010_get_mctrl,
532 	.stop_tx	= pl010_stop_tx,
533 	.start_tx	= pl010_start_tx,
534 	.stop_rx	= pl010_stop_rx,
535 	.enable_ms	= pl010_enable_ms,
536 	.break_ctl	= pl010_break_ctl,
537 	.startup	= pl010_startup,
538 	.shutdown	= pl010_shutdown,
539 	.set_termios	= pl010_set_termios,
540 	.set_ldisc	= pl010_set_ldisc,
541 	.type		= pl010_type,
542 	.release_port	= pl010_release_port,
543 	.request_port	= pl010_request_port,
544 	.config_port	= pl010_config_port,
545 	.verify_port	= pl010_verify_port,
546 };
547 
548 static struct uart_amba_port *amba_ports[UART_NR];
549 
550 #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
551 
552 static void pl010_console_putchar(struct uart_port *port, int ch)
553 {
554 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
555 	unsigned int status;
556 
557 	do {
558 		status = readb(uap->port.membase + UART01x_FR);
559 		barrier();
560 	} while (!UART_TX_READY(status));
561 	writel(ch, uap->port.membase + UART01x_DR);
562 }
563 
564 static void
565 pl010_console_write(struct console *co, const char *s, unsigned int count)
566 {
567 	struct uart_amba_port *uap = amba_ports[co->index];
568 	unsigned int status, old_cr;
569 
570 	clk_enable(uap->clk);
571 
572 	/*
573 	 *	First save the CR then disable the interrupts
574 	 */
575 	old_cr = readb(uap->port.membase + UART010_CR);
576 	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
577 
578 	uart_console_write(&uap->port, s, count, pl010_console_putchar);
579 
580 	/*
581 	 *	Finally, wait for transmitter to become empty
582 	 *	and restore the TCR
583 	 */
584 	do {
585 		status = readb(uap->port.membase + UART01x_FR);
586 		barrier();
587 	} while (status & UART01x_FR_BUSY);
588 	writel(old_cr, uap->port.membase + UART010_CR);
589 
590 	clk_disable(uap->clk);
591 }
592 
593 static void __init
594 pl010_console_get_options(struct uart_amba_port *uap, int *baud,
595 			     int *parity, int *bits)
596 {
597 	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
598 		unsigned int lcr_h, quot;
599 		lcr_h = readb(uap->port.membase + UART010_LCRH);
600 
601 		*parity = 'n';
602 		if (lcr_h & UART01x_LCRH_PEN) {
603 			if (lcr_h & UART01x_LCRH_EPS)
604 				*parity = 'e';
605 			else
606 				*parity = 'o';
607 		}
608 
609 		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
610 			*bits = 7;
611 		else
612 			*bits = 8;
613 
614 		quot = readb(uap->port.membase + UART010_LCRL) |
615 		       readb(uap->port.membase + UART010_LCRM) << 8;
616 		*baud = uap->port.uartclk / (16 * (quot + 1));
617 	}
618 }
619 
620 static int __init pl010_console_setup(struct console *co, char *options)
621 {
622 	struct uart_amba_port *uap;
623 	int baud = 38400;
624 	int bits = 8;
625 	int parity = 'n';
626 	int flow = 'n';
627 	int ret;
628 
629 	/*
630 	 * Check whether an invalid uart number has been specified, and
631 	 * if so, search for the first available port that does have
632 	 * console support.
633 	 */
634 	if (co->index >= UART_NR)
635 		co->index = 0;
636 	uap = amba_ports[co->index];
637 	if (!uap)
638 		return -ENODEV;
639 
640 	ret = clk_prepare(uap->clk);
641 	if (ret)
642 		return ret;
643 
644 	uap->port.uartclk = clk_get_rate(uap->clk);
645 
646 	if (options)
647 		uart_parse_options(options, &baud, &parity, &bits, &flow);
648 	else
649 		pl010_console_get_options(uap, &baud, &parity, &bits);
650 
651 	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
652 }
653 
654 static struct uart_driver amba_reg;
655 static struct console amba_console = {
656 	.name		= "ttyAM",
657 	.write		= pl010_console_write,
658 	.device		= uart_console_device,
659 	.setup		= pl010_console_setup,
660 	.flags		= CON_PRINTBUFFER,
661 	.index		= -1,
662 	.data		= &amba_reg,
663 };
664 
665 #define AMBA_CONSOLE	&amba_console
666 #else
667 #define AMBA_CONSOLE	NULL
668 #endif
669 
670 static struct uart_driver amba_reg = {
671 	.owner			= THIS_MODULE,
672 	.driver_name		= "ttyAM",
673 	.dev_name		= "ttyAM",
674 	.major			= SERIAL_AMBA_MAJOR,
675 	.minor			= SERIAL_AMBA_MINOR,
676 	.nr			= UART_NR,
677 	.cons			= AMBA_CONSOLE,
678 };
679 
680 static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
681 {
682 	struct uart_amba_port *uap;
683 	void __iomem *base;
684 	int i, ret;
685 
686 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
687 		if (amba_ports[i] == NULL)
688 			break;
689 
690 	if (i == ARRAY_SIZE(amba_ports))
691 		return -EBUSY;
692 
693 	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
694 			   GFP_KERNEL);
695 	if (!uap)
696 		return -ENOMEM;
697 
698 	base = devm_ioremap(&dev->dev, dev->res.start,
699 			    resource_size(&dev->res));
700 	if (!base)
701 		return -ENOMEM;
702 
703 	uap->clk = devm_clk_get(&dev->dev, NULL);
704 	if (IS_ERR(uap->clk))
705 		return PTR_ERR(uap->clk);
706 
707 	uap->port.dev = &dev->dev;
708 	uap->port.mapbase = dev->res.start;
709 	uap->port.membase = base;
710 	uap->port.iotype = UPIO_MEM;
711 	uap->port.irq = dev->irq[0];
712 	uap->port.fifosize = 16;
713 	uap->port.ops = &amba_pl010_pops;
714 	uap->port.flags = UPF_BOOT_AUTOCONF;
715 	uap->port.line = i;
716 	uap->dev = dev;
717 	uap->data = dev_get_platdata(&dev->dev);
718 
719 	amba_ports[i] = uap;
720 
721 	amba_set_drvdata(dev, uap);
722 	ret = uart_add_one_port(&amba_reg, &uap->port);
723 	if (ret)
724 		amba_ports[i] = NULL;
725 
726 	return ret;
727 }
728 
729 static int pl010_remove(struct amba_device *dev)
730 {
731 	struct uart_amba_port *uap = amba_get_drvdata(dev);
732 	int i;
733 
734 	uart_remove_one_port(&amba_reg, &uap->port);
735 
736 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
737 		if (amba_ports[i] == uap)
738 			amba_ports[i] = NULL;
739 
740 	return 0;
741 }
742 
743 #ifdef CONFIG_PM_SLEEP
744 static int pl010_suspend(struct device *dev)
745 {
746 	struct uart_amba_port *uap = dev_get_drvdata(dev);
747 
748 	if (uap)
749 		uart_suspend_port(&amba_reg, &uap->port);
750 
751 	return 0;
752 }
753 
754 static int pl010_resume(struct device *dev)
755 {
756 	struct uart_amba_port *uap = dev_get_drvdata(dev);
757 
758 	if (uap)
759 		uart_resume_port(&amba_reg, &uap->port);
760 
761 	return 0;
762 }
763 #endif
764 
765 static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
766 
767 static struct amba_id pl010_ids[] = {
768 	{
769 		.id	= 0x00041010,
770 		.mask	= 0x000fffff,
771 	},
772 	{ 0, 0 },
773 };
774 
775 MODULE_DEVICE_TABLE(amba, pl010_ids);
776 
777 static struct amba_driver pl010_driver = {
778 	.drv = {
779 		.name	= "uart-pl010",
780 		.pm	= &pl010_dev_pm_ops,
781 	},
782 	.id_table	= pl010_ids,
783 	.probe		= pl010_probe,
784 	.remove		= pl010_remove,
785 };
786 
787 static int __init pl010_init(void)
788 {
789 	int ret;
790 
791 	printk(KERN_INFO "Serial: AMBA driver\n");
792 
793 	ret = uart_register_driver(&amba_reg);
794 	if (ret == 0) {
795 		ret = amba_driver_register(&pl010_driver);
796 		if (ret)
797 			uart_unregister_driver(&amba_reg);
798 	}
799 	return ret;
800 }
801 
802 static void __exit pl010_exit(void)
803 {
804 	amba_driver_unregister(&pl010_driver);
805 	uart_unregister_driver(&amba_reg);
806 }
807 
808 module_init(pl010_init);
809 module_exit(pl010_exit);
810 
811 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
812 MODULE_DESCRIPTION("ARM AMBA serial port driver");
813 MODULE_LICENSE("GPL");
814