xref: /openbmc/linux/drivers/tty/serial/amba-pl010.c (revision db181ce0)
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 	unsigned int status, ch, flag, rsr, max_count = 256;
120 
121 	status = readb(uap->port.membase + UART01x_FR);
122 	while (UART_RX_DATA(status) && max_count--) {
123 		ch = readb(uap->port.membase + UART01x_DR);
124 		flag = TTY_NORMAL;
125 
126 		uap->port.icount.rx++;
127 
128 		/*
129 		 * Note that the error handling code is
130 		 * out of the main execution path
131 		 */
132 		rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
133 		if (unlikely(rsr & UART01x_RSR_ANY)) {
134 			writel(0, uap->port.membase + UART01x_ECR);
135 
136 			if (rsr & UART01x_RSR_BE) {
137 				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
138 				uap->port.icount.brk++;
139 				if (uart_handle_break(&uap->port))
140 					goto ignore_char;
141 			} else if (rsr & UART01x_RSR_PE)
142 				uap->port.icount.parity++;
143 			else if (rsr & UART01x_RSR_FE)
144 				uap->port.icount.frame++;
145 			if (rsr & UART01x_RSR_OE)
146 				uap->port.icount.overrun++;
147 
148 			rsr &= uap->port.read_status_mask;
149 
150 			if (rsr & UART01x_RSR_BE)
151 				flag = TTY_BREAK;
152 			else if (rsr & UART01x_RSR_PE)
153 				flag = TTY_PARITY;
154 			else if (rsr & UART01x_RSR_FE)
155 				flag = TTY_FRAME;
156 		}
157 
158 		if (uart_handle_sysrq_char(&uap->port, ch))
159 			goto ignore_char;
160 
161 		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
162 
163 	ignore_char:
164 		status = readb(uap->port.membase + UART01x_FR);
165 	}
166 	spin_unlock(&uap->port.lock);
167 	tty_flip_buffer_push(&uap->port.state->port);
168 	spin_lock(&uap->port.lock);
169 }
170 
171 static void pl010_tx_chars(struct uart_amba_port *uap)
172 {
173 	struct circ_buf *xmit = &uap->port.state->xmit;
174 	int count;
175 
176 	if (uap->port.x_char) {
177 		writel(uap->port.x_char, uap->port.membase + UART01x_DR);
178 		uap->port.icount.tx++;
179 		uap->port.x_char = 0;
180 		return;
181 	}
182 	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
183 		pl010_stop_tx(&uap->port);
184 		return;
185 	}
186 
187 	count = uap->port.fifosize >> 1;
188 	do {
189 		writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
190 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
191 		uap->port.icount.tx++;
192 		if (uart_circ_empty(xmit))
193 			break;
194 	} while (--count > 0);
195 
196 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
197 		uart_write_wakeup(&uap->port);
198 
199 	if (uart_circ_empty(xmit))
200 		pl010_stop_tx(&uap->port);
201 }
202 
203 static void pl010_modem_status(struct uart_amba_port *uap)
204 {
205 	unsigned int status, delta;
206 
207 	writel(0, uap->port.membase + UART010_ICR);
208 
209 	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
210 
211 	delta = status ^ uap->old_status;
212 	uap->old_status = status;
213 
214 	if (!delta)
215 		return;
216 
217 	if (delta & UART01x_FR_DCD)
218 		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
219 
220 	if (delta & UART01x_FR_DSR)
221 		uap->port.icount.dsr++;
222 
223 	if (delta & UART01x_FR_CTS)
224 		uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
225 
226 	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
227 }
228 
229 static irqreturn_t pl010_int(int irq, void *dev_id)
230 {
231 	struct uart_amba_port *uap = dev_id;
232 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
233 	int handled = 0;
234 
235 	spin_lock(&uap->port.lock);
236 
237 	status = readb(uap->port.membase + UART010_IIR);
238 	if (status) {
239 		do {
240 			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
241 				pl010_rx_chars(uap);
242 			if (status & UART010_IIR_MIS)
243 				pl010_modem_status(uap);
244 			if (status & UART010_IIR_TIS)
245 				pl010_tx_chars(uap);
246 
247 			if (pass_counter-- == 0)
248 				break;
249 
250 			status = readb(uap->port.membase + UART010_IIR);
251 		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
252 				   UART010_IIR_TIS));
253 		handled = 1;
254 	}
255 
256 	spin_unlock(&uap->port.lock);
257 
258 	return IRQ_RETVAL(handled);
259 }
260 
261 static unsigned int pl010_tx_empty(struct uart_port *port)
262 {
263 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
264 	unsigned int status = readb(uap->port.membase + UART01x_FR);
265 	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
266 }
267 
268 static unsigned int pl010_get_mctrl(struct uart_port *port)
269 {
270 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
271 	unsigned int result = 0;
272 	unsigned int status;
273 
274 	status = readb(uap->port.membase + UART01x_FR);
275 	if (status & UART01x_FR_DCD)
276 		result |= TIOCM_CAR;
277 	if (status & UART01x_FR_DSR)
278 		result |= TIOCM_DSR;
279 	if (status & UART01x_FR_CTS)
280 		result |= TIOCM_CTS;
281 
282 	return result;
283 }
284 
285 static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
286 {
287 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
288 
289 	if (uap->data)
290 		uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
291 }
292 
293 static void pl010_break_ctl(struct uart_port *port, int break_state)
294 {
295 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
296 	unsigned long flags;
297 	unsigned int lcr_h;
298 
299 	spin_lock_irqsave(&uap->port.lock, flags);
300 	lcr_h = readb(uap->port.membase + UART010_LCRH);
301 	if (break_state == -1)
302 		lcr_h |= UART01x_LCRH_BRK;
303 	else
304 		lcr_h &= ~UART01x_LCRH_BRK;
305 	writel(lcr_h, uap->port.membase + UART010_LCRH);
306 	spin_unlock_irqrestore(&uap->port.lock, flags);
307 }
308 
309 static int pl010_startup(struct uart_port *port)
310 {
311 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
312 	int retval;
313 
314 	/*
315 	 * Try to enable the clock producer.
316 	 */
317 	retval = clk_prepare_enable(uap->clk);
318 	if (retval)
319 		goto out;
320 
321 	uap->port.uartclk = clk_get_rate(uap->clk);
322 
323 	/*
324 	 * Allocate the IRQ
325 	 */
326 	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
327 	if (retval)
328 		goto clk_dis;
329 
330 	/*
331 	 * initialise the old status of the modem signals
332 	 */
333 	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
334 
335 	/*
336 	 * Finally, enable interrupts
337 	 */
338 	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
339 	       uap->port.membase + UART010_CR);
340 
341 	return 0;
342 
343  clk_dis:
344 	clk_disable_unprepare(uap->clk);
345  out:
346 	return retval;
347 }
348 
349 static void pl010_shutdown(struct uart_port *port)
350 {
351 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
352 
353 	/*
354 	 * Free the interrupt
355 	 */
356 	free_irq(uap->port.irq, uap);
357 
358 	/*
359 	 * disable all interrupts, disable the port
360 	 */
361 	writel(0, uap->port.membase + UART010_CR);
362 
363 	/* disable break condition and fifos */
364 	writel(readb(uap->port.membase + UART010_LCRH) &
365 		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
366 	       uap->port.membase + UART010_LCRH);
367 
368 	/*
369 	 * Shut down the clock producer
370 	 */
371 	clk_disable_unprepare(uap->clk);
372 }
373 
374 static void
375 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
376 		     struct ktermios *old)
377 {
378 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
379 	unsigned int lcr_h, old_cr;
380 	unsigned long flags;
381 	unsigned int baud, quot;
382 
383 	/*
384 	 * Ask the core to calculate the divisor for us.
385 	 */
386 	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
387 	quot = uart_get_divisor(port, baud);
388 
389 	switch (termios->c_cflag & CSIZE) {
390 	case CS5:
391 		lcr_h = UART01x_LCRH_WLEN_5;
392 		break;
393 	case CS6:
394 		lcr_h = UART01x_LCRH_WLEN_6;
395 		break;
396 	case CS7:
397 		lcr_h = UART01x_LCRH_WLEN_7;
398 		break;
399 	default: // CS8
400 		lcr_h = UART01x_LCRH_WLEN_8;
401 		break;
402 	}
403 	if (termios->c_cflag & CSTOPB)
404 		lcr_h |= UART01x_LCRH_STP2;
405 	if (termios->c_cflag & PARENB) {
406 		lcr_h |= UART01x_LCRH_PEN;
407 		if (!(termios->c_cflag & PARODD))
408 			lcr_h |= UART01x_LCRH_EPS;
409 	}
410 	if (uap->port.fifosize > 1)
411 		lcr_h |= UART01x_LCRH_FEN;
412 
413 	spin_lock_irqsave(&uap->port.lock, flags);
414 
415 	/*
416 	 * Update the per-port timeout.
417 	 */
418 	uart_update_timeout(port, termios->c_cflag, baud);
419 
420 	uap->port.read_status_mask = UART01x_RSR_OE;
421 	if (termios->c_iflag & INPCK)
422 		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
423 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
424 		uap->port.read_status_mask |= UART01x_RSR_BE;
425 
426 	/*
427 	 * Characters to ignore
428 	 */
429 	uap->port.ignore_status_mask = 0;
430 	if (termios->c_iflag & IGNPAR)
431 		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
432 	if (termios->c_iflag & IGNBRK) {
433 		uap->port.ignore_status_mask |= UART01x_RSR_BE;
434 		/*
435 		 * If we're ignoring parity and break indicators,
436 		 * ignore overruns too (for real raw support).
437 		 */
438 		if (termios->c_iflag & IGNPAR)
439 			uap->port.ignore_status_mask |= UART01x_RSR_OE;
440 	}
441 
442 	/*
443 	 * Ignore all characters if CREAD is not set.
444 	 */
445 	if ((termios->c_cflag & CREAD) == 0)
446 		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
447 
448 	/* first, disable everything */
449 	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
450 
451 	if (UART_ENABLE_MS(port, termios->c_cflag))
452 		old_cr |= UART010_CR_MSIE;
453 
454 	writel(0, uap->port.membase + UART010_CR);
455 
456 	/* Set baud rate */
457 	quot -= 1;
458 	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
459 	writel(quot & 0xff, uap->port.membase + UART010_LCRL);
460 
461 	/*
462 	 * ----------v----------v----------v----------v-----
463 	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
464 	 * ----------^----------^----------^----------^-----
465 	 */
466 	writel(lcr_h, uap->port.membase + UART010_LCRH);
467 	writel(old_cr, uap->port.membase + UART010_CR);
468 
469 	spin_unlock_irqrestore(&uap->port.lock, flags);
470 }
471 
472 static void pl010_set_ldisc(struct uart_port *port, int new)
473 {
474 	if (new == N_PPS) {
475 		port->flags |= UPF_HARDPPS_CD;
476 		pl010_enable_ms(port);
477 	} else
478 		port->flags &= ~UPF_HARDPPS_CD;
479 }
480 
481 static const char *pl010_type(struct uart_port *port)
482 {
483 	return port->type == PORT_AMBA ? "AMBA" : NULL;
484 }
485 
486 /*
487  * Release the memory region(s) being used by 'port'
488  */
489 static void pl010_release_port(struct uart_port *port)
490 {
491 	release_mem_region(port->mapbase, UART_PORT_SIZE);
492 }
493 
494 /*
495  * Request the memory region(s) being used by 'port'
496  */
497 static int pl010_request_port(struct uart_port *port)
498 {
499 	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
500 			!= NULL ? 0 : -EBUSY;
501 }
502 
503 /*
504  * Configure/autoconfigure the port.
505  */
506 static void pl010_config_port(struct uart_port *port, int flags)
507 {
508 	if (flags & UART_CONFIG_TYPE) {
509 		port->type = PORT_AMBA;
510 		pl010_request_port(port);
511 	}
512 }
513 
514 /*
515  * verify the new serial_struct (for TIOCSSERIAL).
516  */
517 static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
518 {
519 	int ret = 0;
520 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
521 		ret = -EINVAL;
522 	if (ser->irq < 0 || ser->irq >= nr_irqs)
523 		ret = -EINVAL;
524 	if (ser->baud_base < 9600)
525 		ret = -EINVAL;
526 	return ret;
527 }
528 
529 static struct uart_ops amba_pl010_pops = {
530 	.tx_empty	= pl010_tx_empty,
531 	.set_mctrl	= pl010_set_mctrl,
532 	.get_mctrl	= pl010_get_mctrl,
533 	.stop_tx	= pl010_stop_tx,
534 	.start_tx	= pl010_start_tx,
535 	.stop_rx	= pl010_stop_rx,
536 	.enable_ms	= pl010_enable_ms,
537 	.break_ctl	= pl010_break_ctl,
538 	.startup	= pl010_startup,
539 	.shutdown	= pl010_shutdown,
540 	.set_termios	= pl010_set_termios,
541 	.set_ldisc	= pl010_set_ldisc,
542 	.type		= pl010_type,
543 	.release_port	= pl010_release_port,
544 	.request_port	= pl010_request_port,
545 	.config_port	= pl010_config_port,
546 	.verify_port	= pl010_verify_port,
547 };
548 
549 static struct uart_amba_port *amba_ports[UART_NR];
550 
551 #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
552 
553 static void pl010_console_putchar(struct uart_port *port, int ch)
554 {
555 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
556 	unsigned int status;
557 
558 	do {
559 		status = readb(uap->port.membase + UART01x_FR);
560 		barrier();
561 	} while (!UART_TX_READY(status));
562 	writel(ch, uap->port.membase + UART01x_DR);
563 }
564 
565 static void
566 pl010_console_write(struct console *co, const char *s, unsigned int count)
567 {
568 	struct uart_amba_port *uap = amba_ports[co->index];
569 	unsigned int status, old_cr;
570 
571 	clk_enable(uap->clk);
572 
573 	/*
574 	 *	First save the CR then disable the interrupts
575 	 */
576 	old_cr = readb(uap->port.membase + UART010_CR);
577 	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
578 
579 	uart_console_write(&uap->port, s, count, pl010_console_putchar);
580 
581 	/*
582 	 *	Finally, wait for transmitter to become empty
583 	 *	and restore the TCR
584 	 */
585 	do {
586 		status = readb(uap->port.membase + UART01x_FR);
587 		barrier();
588 	} while (status & UART01x_FR_BUSY);
589 	writel(old_cr, uap->port.membase + UART010_CR);
590 
591 	clk_disable(uap->clk);
592 }
593 
594 static void __init
595 pl010_console_get_options(struct uart_amba_port *uap, int *baud,
596 			     int *parity, int *bits)
597 {
598 	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
599 		unsigned int lcr_h, quot;
600 		lcr_h = readb(uap->port.membase + UART010_LCRH);
601 
602 		*parity = 'n';
603 		if (lcr_h & UART01x_LCRH_PEN) {
604 			if (lcr_h & UART01x_LCRH_EPS)
605 				*parity = 'e';
606 			else
607 				*parity = 'o';
608 		}
609 
610 		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
611 			*bits = 7;
612 		else
613 			*bits = 8;
614 
615 		quot = readb(uap->port.membase + UART010_LCRL) |
616 		       readb(uap->port.membase + UART010_LCRM) << 8;
617 		*baud = uap->port.uartclk / (16 * (quot + 1));
618 	}
619 }
620 
621 static int __init pl010_console_setup(struct console *co, char *options)
622 {
623 	struct uart_amba_port *uap;
624 	int baud = 38400;
625 	int bits = 8;
626 	int parity = 'n';
627 	int flow = 'n';
628 	int ret;
629 
630 	/*
631 	 * Check whether an invalid uart number has been specified, and
632 	 * if so, search for the first available port that does have
633 	 * console support.
634 	 */
635 	if (co->index >= UART_NR)
636 		co->index = 0;
637 	uap = amba_ports[co->index];
638 	if (!uap)
639 		return -ENODEV;
640 
641 	ret = clk_prepare(uap->clk);
642 	if (ret)
643 		return ret;
644 
645 	uap->port.uartclk = clk_get_rate(uap->clk);
646 
647 	if (options)
648 		uart_parse_options(options, &baud, &parity, &bits, &flow);
649 	else
650 		pl010_console_get_options(uap, &baud, &parity, &bits);
651 
652 	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
653 }
654 
655 static struct uart_driver amba_reg;
656 static struct console amba_console = {
657 	.name		= "ttyAM",
658 	.write		= pl010_console_write,
659 	.device		= uart_console_device,
660 	.setup		= pl010_console_setup,
661 	.flags		= CON_PRINTBUFFER,
662 	.index		= -1,
663 	.data		= &amba_reg,
664 };
665 
666 #define AMBA_CONSOLE	&amba_console
667 #else
668 #define AMBA_CONSOLE	NULL
669 #endif
670 
671 static struct uart_driver amba_reg = {
672 	.owner			= THIS_MODULE,
673 	.driver_name		= "ttyAM",
674 	.dev_name		= "ttyAM",
675 	.major			= SERIAL_AMBA_MAJOR,
676 	.minor			= SERIAL_AMBA_MINOR,
677 	.nr			= UART_NR,
678 	.cons			= AMBA_CONSOLE,
679 };
680 
681 static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
682 {
683 	struct uart_amba_port *uap;
684 	void __iomem *base;
685 	int i, ret;
686 
687 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
688 		if (amba_ports[i] == NULL)
689 			break;
690 
691 	if (i == ARRAY_SIZE(amba_ports)) {
692 		ret = -EBUSY;
693 		goto out;
694 	}
695 
696 	uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
697 	if (!uap) {
698 		ret = -ENOMEM;
699 		goto out;
700 	}
701 
702 	base = ioremap(dev->res.start, resource_size(&dev->res));
703 	if (!base) {
704 		ret = -ENOMEM;
705 		goto free;
706 	}
707 
708 	uap->clk = clk_get(&dev->dev, NULL);
709 	if (IS_ERR(uap->clk)) {
710 		ret = PTR_ERR(uap->clk);
711 		goto unmap;
712 	}
713 
714 	uap->port.dev = &dev->dev;
715 	uap->port.mapbase = dev->res.start;
716 	uap->port.membase = base;
717 	uap->port.iotype = UPIO_MEM;
718 	uap->port.irq = dev->irq[0];
719 	uap->port.fifosize = 16;
720 	uap->port.ops = &amba_pl010_pops;
721 	uap->port.flags = UPF_BOOT_AUTOCONF;
722 	uap->port.line = i;
723 	uap->dev = dev;
724 	uap->data = dev_get_platdata(&dev->dev);
725 
726 	amba_ports[i] = uap;
727 
728 	amba_set_drvdata(dev, uap);
729 	ret = uart_add_one_port(&amba_reg, &uap->port);
730 	if (ret) {
731 		amba_ports[i] = NULL;
732 		clk_put(uap->clk);
733  unmap:
734 		iounmap(base);
735  free:
736 		kfree(uap);
737 	}
738  out:
739 	return ret;
740 }
741 
742 static int pl010_remove(struct amba_device *dev)
743 {
744 	struct uart_amba_port *uap = amba_get_drvdata(dev);
745 	int i;
746 
747 	uart_remove_one_port(&amba_reg, &uap->port);
748 
749 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
750 		if (amba_ports[i] == uap)
751 			amba_ports[i] = NULL;
752 
753 	iounmap(uap->port.membase);
754 	clk_put(uap->clk);
755 	kfree(uap);
756 	return 0;
757 }
758 
759 #ifdef CONFIG_PM_SLEEP
760 static int pl010_suspend(struct device *dev)
761 {
762 	struct uart_amba_port *uap = dev_get_drvdata(dev);
763 
764 	if (uap)
765 		uart_suspend_port(&amba_reg, &uap->port);
766 
767 	return 0;
768 }
769 
770 static int pl010_resume(struct device *dev)
771 {
772 	struct uart_amba_port *uap = dev_get_drvdata(dev);
773 
774 	if (uap)
775 		uart_resume_port(&amba_reg, &uap->port);
776 
777 	return 0;
778 }
779 #endif
780 
781 static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);
782 
783 static struct amba_id pl010_ids[] = {
784 	{
785 		.id	= 0x00041010,
786 		.mask	= 0x000fffff,
787 	},
788 	{ 0, 0 },
789 };
790 
791 MODULE_DEVICE_TABLE(amba, pl010_ids);
792 
793 static struct amba_driver pl010_driver = {
794 	.drv = {
795 		.name	= "uart-pl010",
796 		.pm	= &pl010_dev_pm_ops,
797 	},
798 	.id_table	= pl010_ids,
799 	.probe		= pl010_probe,
800 	.remove		= pl010_remove,
801 };
802 
803 static int __init pl010_init(void)
804 {
805 	int ret;
806 
807 	printk(KERN_INFO "Serial: AMBA driver\n");
808 
809 	ret = uart_register_driver(&amba_reg);
810 	if (ret == 0) {
811 		ret = amba_driver_register(&pl010_driver);
812 		if (ret)
813 			uart_unregister_driver(&amba_reg);
814 	}
815 	return ret;
816 }
817 
818 static void __exit pl010_exit(void)
819 {
820 	amba_driver_unregister(&pl010_driver);
821 	uart_unregister_driver(&amba_reg);
822 }
823 
824 module_init(pl010_init);
825 module_exit(pl010_exit);
826 
827 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
828 MODULE_DESCRIPTION("ARM AMBA serial port driver");
829 MODULE_LICENSE("GPL");
830