xref: /openbmc/linux/drivers/tty/serial/amba-pl010.c (revision 9d749629)
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 	/*
316 	 * Try to enable the clock producer.
317 	 */
318 	retval = clk_prepare_enable(uap->clk);
319 	if (retval)
320 		goto out;
321 
322 	uap->port.uartclk = clk_get_rate(uap->clk);
323 
324 	/*
325 	 * Allocate the IRQ
326 	 */
327 	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
328 	if (retval)
329 		goto clk_dis;
330 
331 	/*
332 	 * initialise the old status of the modem signals
333 	 */
334 	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
335 
336 	/*
337 	 * Finally, enable interrupts
338 	 */
339 	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
340 	       uap->port.membase + UART010_CR);
341 
342 	return 0;
343 
344  clk_dis:
345 	clk_disable_unprepare(uap->clk);
346  out:
347 	return retval;
348 }
349 
350 static void pl010_shutdown(struct uart_port *port)
351 {
352 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
353 
354 	/*
355 	 * Free the interrupt
356 	 */
357 	free_irq(uap->port.irq, uap);
358 
359 	/*
360 	 * disable all interrupts, disable the port
361 	 */
362 	writel(0, uap->port.membase + UART010_CR);
363 
364 	/* disable break condition and fifos */
365 	writel(readb(uap->port.membase + UART010_LCRH) &
366 		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
367 	       uap->port.membase + UART010_LCRH);
368 
369 	/*
370 	 * Shut down the clock producer
371 	 */
372 	clk_disable_unprepare(uap->clk);
373 }
374 
375 static void
376 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
377 		     struct ktermios *old)
378 {
379 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
380 	unsigned int lcr_h, old_cr;
381 	unsigned long flags;
382 	unsigned int baud, quot;
383 
384 	/*
385 	 * Ask the core to calculate the divisor for us.
386 	 */
387 	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
388 	quot = uart_get_divisor(port, baud);
389 
390 	switch (termios->c_cflag & CSIZE) {
391 	case CS5:
392 		lcr_h = UART01x_LCRH_WLEN_5;
393 		break;
394 	case CS6:
395 		lcr_h = UART01x_LCRH_WLEN_6;
396 		break;
397 	case CS7:
398 		lcr_h = UART01x_LCRH_WLEN_7;
399 		break;
400 	default: // CS8
401 		lcr_h = UART01x_LCRH_WLEN_8;
402 		break;
403 	}
404 	if (termios->c_cflag & CSTOPB)
405 		lcr_h |= UART01x_LCRH_STP2;
406 	if (termios->c_cflag & PARENB) {
407 		lcr_h |= UART01x_LCRH_PEN;
408 		if (!(termios->c_cflag & PARODD))
409 			lcr_h |= UART01x_LCRH_EPS;
410 	}
411 	if (uap->port.fifosize > 1)
412 		lcr_h |= UART01x_LCRH_FEN;
413 
414 	spin_lock_irqsave(&uap->port.lock, flags);
415 
416 	/*
417 	 * Update the per-port timeout.
418 	 */
419 	uart_update_timeout(port, termios->c_cflag, baud);
420 
421 	uap->port.read_status_mask = UART01x_RSR_OE;
422 	if (termios->c_iflag & INPCK)
423 		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
424 	if (termios->c_iflag & (BRKINT | PARMRK))
425 		uap->port.read_status_mask |= UART01x_RSR_BE;
426 
427 	/*
428 	 * Characters to ignore
429 	 */
430 	uap->port.ignore_status_mask = 0;
431 	if (termios->c_iflag & IGNPAR)
432 		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
433 	if (termios->c_iflag & IGNBRK) {
434 		uap->port.ignore_status_mask |= UART01x_RSR_BE;
435 		/*
436 		 * If we're ignoring parity and break indicators,
437 		 * ignore overruns too (for real raw support).
438 		 */
439 		if (termios->c_iflag & IGNPAR)
440 			uap->port.ignore_status_mask |= UART01x_RSR_OE;
441 	}
442 
443 	/*
444 	 * Ignore all characters if CREAD is not set.
445 	 */
446 	if ((termios->c_cflag & CREAD) == 0)
447 		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;
448 
449 	/* first, disable everything */
450 	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;
451 
452 	if (UART_ENABLE_MS(port, termios->c_cflag))
453 		old_cr |= UART010_CR_MSIE;
454 
455 	writel(0, uap->port.membase + UART010_CR);
456 
457 	/* Set baud rate */
458 	quot -= 1;
459 	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
460 	writel(quot & 0xff, uap->port.membase + UART010_LCRL);
461 
462 	/*
463 	 * ----------v----------v----------v----------v-----
464 	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
465 	 * ----------^----------^----------^----------^-----
466 	 */
467 	writel(lcr_h, uap->port.membase + UART010_LCRH);
468 	writel(old_cr, uap->port.membase + UART010_CR);
469 
470 	spin_unlock_irqrestore(&uap->port.lock, flags);
471 }
472 
473 static void pl010_set_ldisc(struct uart_port *port, int new)
474 {
475 	if (new == N_PPS) {
476 		port->flags |= UPF_HARDPPS_CD;
477 		pl010_enable_ms(port);
478 	} else
479 		port->flags &= ~UPF_HARDPPS_CD;
480 }
481 
482 static const char *pl010_type(struct uart_port *port)
483 {
484 	return port->type == PORT_AMBA ? "AMBA" : NULL;
485 }
486 
487 /*
488  * Release the memory region(s) being used by 'port'
489  */
490 static void pl010_release_port(struct uart_port *port)
491 {
492 	release_mem_region(port->mapbase, UART_PORT_SIZE);
493 }
494 
495 /*
496  * Request the memory region(s) being used by 'port'
497  */
498 static int pl010_request_port(struct uart_port *port)
499 {
500 	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
501 			!= NULL ? 0 : -EBUSY;
502 }
503 
504 /*
505  * Configure/autoconfigure the port.
506  */
507 static void pl010_config_port(struct uart_port *port, int flags)
508 {
509 	if (flags & UART_CONFIG_TYPE) {
510 		port->type = PORT_AMBA;
511 		pl010_request_port(port);
512 	}
513 }
514 
515 /*
516  * verify the new serial_struct (for TIOCSSERIAL).
517  */
518 static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
519 {
520 	int ret = 0;
521 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
522 		ret = -EINVAL;
523 	if (ser->irq < 0 || ser->irq >= nr_irqs)
524 		ret = -EINVAL;
525 	if (ser->baud_base < 9600)
526 		ret = -EINVAL;
527 	return ret;
528 }
529 
530 static struct uart_ops amba_pl010_pops = {
531 	.tx_empty	= pl010_tx_empty,
532 	.set_mctrl	= pl010_set_mctrl,
533 	.get_mctrl	= pl010_get_mctrl,
534 	.stop_tx	= pl010_stop_tx,
535 	.start_tx	= pl010_start_tx,
536 	.stop_rx	= pl010_stop_rx,
537 	.enable_ms	= pl010_enable_ms,
538 	.break_ctl	= pl010_break_ctl,
539 	.startup	= pl010_startup,
540 	.shutdown	= pl010_shutdown,
541 	.set_termios	= pl010_set_termios,
542 	.set_ldisc	= pl010_set_ldisc,
543 	.type		= pl010_type,
544 	.release_port	= pl010_release_port,
545 	.request_port	= pl010_request_port,
546 	.config_port	= pl010_config_port,
547 	.verify_port	= pl010_verify_port,
548 };
549 
550 static struct uart_amba_port *amba_ports[UART_NR];
551 
552 #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
553 
554 static void pl010_console_putchar(struct uart_port *port, int ch)
555 {
556 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
557 	unsigned int status;
558 
559 	do {
560 		status = readb(uap->port.membase + UART01x_FR);
561 		barrier();
562 	} while (!UART_TX_READY(status));
563 	writel(ch, uap->port.membase + UART01x_DR);
564 }
565 
566 static void
567 pl010_console_write(struct console *co, const char *s, unsigned int count)
568 {
569 	struct uart_amba_port *uap = amba_ports[co->index];
570 	unsigned int status, old_cr;
571 
572 	clk_enable(uap->clk);
573 
574 	/*
575 	 *	First save the CR then disable the interrupts
576 	 */
577 	old_cr = readb(uap->port.membase + UART010_CR);
578 	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);
579 
580 	uart_console_write(&uap->port, s, count, pl010_console_putchar);
581 
582 	/*
583 	 *	Finally, wait for transmitter to become empty
584 	 *	and restore the TCR
585 	 */
586 	do {
587 		status = readb(uap->port.membase + UART01x_FR);
588 		barrier();
589 	} while (status & UART01x_FR_BUSY);
590 	writel(old_cr, uap->port.membase + UART010_CR);
591 
592 	clk_disable(uap->clk);
593 }
594 
595 static void __init
596 pl010_console_get_options(struct uart_amba_port *uap, int *baud,
597 			     int *parity, int *bits)
598 {
599 	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
600 		unsigned int lcr_h, quot;
601 		lcr_h = readb(uap->port.membase + UART010_LCRH);
602 
603 		*parity = 'n';
604 		if (lcr_h & UART01x_LCRH_PEN) {
605 			if (lcr_h & UART01x_LCRH_EPS)
606 				*parity = 'e';
607 			else
608 				*parity = 'o';
609 		}
610 
611 		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
612 			*bits = 7;
613 		else
614 			*bits = 8;
615 
616 		quot = readb(uap->port.membase + UART010_LCRL) |
617 		       readb(uap->port.membase + UART010_LCRM) << 8;
618 		*baud = uap->port.uartclk / (16 * (quot + 1));
619 	}
620 }
621 
622 static int __init pl010_console_setup(struct console *co, char *options)
623 {
624 	struct uart_amba_port *uap;
625 	int baud = 38400;
626 	int bits = 8;
627 	int parity = 'n';
628 	int flow = 'n';
629 	int ret;
630 
631 	/*
632 	 * Check whether an invalid uart number has been specified, and
633 	 * if so, search for the first available port that does have
634 	 * console support.
635 	 */
636 	if (co->index >= UART_NR)
637 		co->index = 0;
638 	uap = amba_ports[co->index];
639 	if (!uap)
640 		return -ENODEV;
641 
642 	ret = clk_prepare(uap->clk);
643 	if (ret)
644 		return ret;
645 
646 	uap->port.uartclk = clk_get_rate(uap->clk);
647 
648 	if (options)
649 		uart_parse_options(options, &baud, &parity, &bits, &flow);
650 	else
651 		pl010_console_get_options(uap, &baud, &parity, &bits);
652 
653 	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
654 }
655 
656 static struct uart_driver amba_reg;
657 static struct console amba_console = {
658 	.name		= "ttyAM",
659 	.write		= pl010_console_write,
660 	.device		= uart_console_device,
661 	.setup		= pl010_console_setup,
662 	.flags		= CON_PRINTBUFFER,
663 	.index		= -1,
664 	.data		= &amba_reg,
665 };
666 
667 #define AMBA_CONSOLE	&amba_console
668 #else
669 #define AMBA_CONSOLE	NULL
670 #endif
671 
672 static struct uart_driver amba_reg = {
673 	.owner			= THIS_MODULE,
674 	.driver_name		= "ttyAM",
675 	.dev_name		= "ttyAM",
676 	.major			= SERIAL_AMBA_MAJOR,
677 	.minor			= SERIAL_AMBA_MINOR,
678 	.nr			= UART_NR,
679 	.cons			= AMBA_CONSOLE,
680 };
681 
682 static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
683 {
684 	struct uart_amba_port *uap;
685 	void __iomem *base;
686 	int i, ret;
687 
688 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
689 		if (amba_ports[i] == NULL)
690 			break;
691 
692 	if (i == ARRAY_SIZE(amba_ports)) {
693 		ret = -EBUSY;
694 		goto out;
695 	}
696 
697 	uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
698 	if (!uap) {
699 		ret = -ENOMEM;
700 		goto out;
701 	}
702 
703 	base = ioremap(dev->res.start, resource_size(&dev->res));
704 	if (!base) {
705 		ret = -ENOMEM;
706 		goto free;
707 	}
708 
709 	uap->clk = clk_get(&dev->dev, NULL);
710 	if (IS_ERR(uap->clk)) {
711 		ret = PTR_ERR(uap->clk);
712 		goto unmap;
713 	}
714 
715 	uap->port.dev = &dev->dev;
716 	uap->port.mapbase = dev->res.start;
717 	uap->port.membase = base;
718 	uap->port.iotype = UPIO_MEM;
719 	uap->port.irq = dev->irq[0];
720 	uap->port.fifosize = 16;
721 	uap->port.ops = &amba_pl010_pops;
722 	uap->port.flags = UPF_BOOT_AUTOCONF;
723 	uap->port.line = i;
724 	uap->dev = dev;
725 	uap->data = dev->dev.platform_data;
726 
727 	amba_ports[i] = uap;
728 
729 	amba_set_drvdata(dev, uap);
730 	ret = uart_add_one_port(&amba_reg, &uap->port);
731 	if (ret) {
732 		amba_set_drvdata(dev, NULL);
733 		amba_ports[i] = NULL;
734 		clk_put(uap->clk);
735  unmap:
736 		iounmap(base);
737  free:
738 		kfree(uap);
739 	}
740  out:
741 	return ret;
742 }
743 
744 static int pl010_remove(struct amba_device *dev)
745 {
746 	struct uart_amba_port *uap = amba_get_drvdata(dev);
747 	int i;
748 
749 	amba_set_drvdata(dev, NULL);
750 
751 	uart_remove_one_port(&amba_reg, &uap->port);
752 
753 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
754 		if (amba_ports[i] == uap)
755 			amba_ports[i] = NULL;
756 
757 	iounmap(uap->port.membase);
758 	clk_put(uap->clk);
759 	kfree(uap);
760 	return 0;
761 }
762 
763 static int pl010_suspend(struct amba_device *dev, pm_message_t state)
764 {
765 	struct uart_amba_port *uap = amba_get_drvdata(dev);
766 
767 	if (uap)
768 		uart_suspend_port(&amba_reg, &uap->port);
769 
770 	return 0;
771 }
772 
773 static int pl010_resume(struct amba_device *dev)
774 {
775 	struct uart_amba_port *uap = amba_get_drvdata(dev);
776 
777 	if (uap)
778 		uart_resume_port(&amba_reg, &uap->port);
779 
780 	return 0;
781 }
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 	},
797 	.id_table	= pl010_ids,
798 	.probe		= pl010_probe,
799 	.remove		= pl010_remove,
800 	.suspend	= pl010_suspend,
801 	.resume		= pl010_resume,
802 };
803 
804 static int __init pl010_init(void)
805 {
806 	int ret;
807 
808 	printk(KERN_INFO "Serial: AMBA driver\n");
809 
810 	ret = uart_register_driver(&amba_reg);
811 	if (ret == 0) {
812 		ret = amba_driver_register(&pl010_driver);
813 		if (ret)
814 			uart_unregister_driver(&amba_reg);
815 	}
816 	return ret;
817 }
818 
819 static void __exit pl010_exit(void)
820 {
821 	amba_driver_unregister(&pl010_driver);
822 	uart_unregister_driver(&amba_reg);
823 }
824 
825 module_init(pl010_init);
826 module_exit(pl010_exit);
827 
828 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
829 MODULE_DESCRIPTION("ARM AMBA serial port driver");
830 MODULE_LICENSE("GPL");
831