xref: /openbmc/linux/drivers/tty/serial/bcm63xx_uart.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Derived from many drivers using generic_serial interface.
7  *
8  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
9  *
10  *  Serial driver for BCM63xx integrated UART.
11  *
12  * Hardware flow control was _not_ tested since I only have RX/TX on
13  * my board.
14  */
15 
16 #if defined(CONFIG_SERIAL_BCM63XX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
17 #define SUPPORT_SYSRQ
18 #endif
19 
20 #include <linux/kernel.h>
21 #include <linux/platform_device.h>
22 #include <linux/init.h>
23 #include <linux/delay.h>
24 #include <linux/module.h>
25 #include <linux/console.h>
26 #include <linux/clk.h>
27 #include <linux/tty.h>
28 #include <linux/tty_flip.h>
29 #include <linux/sysrq.h>
30 #include <linux/serial.h>
31 #include <linux/serial_core.h>
32 
33 #include <bcm63xx_clk.h>
34 #include <bcm63xx_irq.h>
35 #include <bcm63xx_regs.h>
36 #include <bcm63xx_io.h>
37 
38 #define BCM63XX_NR_UARTS	2
39 
40 static struct uart_port ports[BCM63XX_NR_UARTS];
41 
42 /*
43  * rx interrupt mask / stat
44  *
45  * mask:
46  *  - rx fifo full
47  *  - rx fifo above threshold
48  *  - rx fifo not empty for too long
49  */
50 #define UART_RX_INT_MASK	(UART_IR_MASK(UART_IR_RXOVER) |		\
51 				UART_IR_MASK(UART_IR_RXTHRESH) |	\
52 				UART_IR_MASK(UART_IR_RXTIMEOUT))
53 
54 #define UART_RX_INT_STAT	(UART_IR_STAT(UART_IR_RXOVER) |		\
55 				UART_IR_STAT(UART_IR_RXTHRESH) |	\
56 				UART_IR_STAT(UART_IR_RXTIMEOUT))
57 
58 /*
59  * tx interrupt mask / stat
60  *
61  * mask:
62  * - tx fifo empty
63  * - tx fifo below threshold
64  */
65 #define UART_TX_INT_MASK	(UART_IR_MASK(UART_IR_TXEMPTY) |	\
66 				UART_IR_MASK(UART_IR_TXTRESH))
67 
68 #define UART_TX_INT_STAT	(UART_IR_STAT(UART_IR_TXEMPTY) |	\
69 				UART_IR_STAT(UART_IR_TXTRESH))
70 
71 /*
72  * external input interrupt
73  *
74  * mask: any edge on CTS, DCD
75  */
76 #define UART_EXTINP_INT_MASK	(UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
77 				 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
78 
79 /*
80  * handy uart register accessor
81  */
82 static inline unsigned int bcm_uart_readl(struct uart_port *port,
83 					 unsigned int offset)
84 {
85 	return bcm_readl(port->membase + offset);
86 }
87 
88 static inline void bcm_uart_writel(struct uart_port *port,
89 				  unsigned int value, unsigned int offset)
90 {
91 	bcm_writel(value, port->membase + offset);
92 }
93 
94 /*
95  * serial core request to check if uart tx fifo is empty
96  */
97 static unsigned int bcm_uart_tx_empty(struct uart_port *port)
98 {
99 	unsigned int val;
100 
101 	val = bcm_uart_readl(port, UART_IR_REG);
102 	return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
103 }
104 
105 /*
106  * serial core request to set RTS and DTR pin state and loopback mode
107  */
108 static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
109 {
110 	unsigned int val;
111 
112 	val = bcm_uart_readl(port, UART_MCTL_REG);
113 	val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
114 	/* invert of written value is reflected on the pin */
115 	if (!(mctrl & TIOCM_DTR))
116 		val |= UART_MCTL_DTR_MASK;
117 	if (!(mctrl & TIOCM_RTS))
118 		val |= UART_MCTL_RTS_MASK;
119 	bcm_uart_writel(port, val, UART_MCTL_REG);
120 
121 	val = bcm_uart_readl(port, UART_CTL_REG);
122 	if (mctrl & TIOCM_LOOP)
123 		val |= UART_CTL_LOOPBACK_MASK;
124 	else
125 		val &= ~UART_CTL_LOOPBACK_MASK;
126 	bcm_uart_writel(port, val, UART_CTL_REG);
127 }
128 
129 /*
130  * serial core request to return RI, CTS, DCD and DSR pin state
131  */
132 static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
133 {
134 	unsigned int val, mctrl;
135 
136 	mctrl = 0;
137 	val = bcm_uart_readl(port, UART_EXTINP_REG);
138 	if (val & UART_EXTINP_RI_MASK)
139 		mctrl |= TIOCM_RI;
140 	if (val & UART_EXTINP_CTS_MASK)
141 		mctrl |= TIOCM_CTS;
142 	if (val & UART_EXTINP_DCD_MASK)
143 		mctrl |= TIOCM_CD;
144 	if (val & UART_EXTINP_DSR_MASK)
145 		mctrl |= TIOCM_DSR;
146 	return mctrl;
147 }
148 
149 /*
150  * serial core request to disable tx ASAP (used for flow control)
151  */
152 static void bcm_uart_stop_tx(struct uart_port *port)
153 {
154 	unsigned int val;
155 
156 	val = bcm_uart_readl(port, UART_CTL_REG);
157 	val &= ~(UART_CTL_TXEN_MASK);
158 	bcm_uart_writel(port, val, UART_CTL_REG);
159 
160 	val = bcm_uart_readl(port, UART_IR_REG);
161 	val &= ~UART_TX_INT_MASK;
162 	bcm_uart_writel(port, val, UART_IR_REG);
163 }
164 
165 /*
166  * serial core request to (re)enable tx
167  */
168 static void bcm_uart_start_tx(struct uart_port *port)
169 {
170 	unsigned int val;
171 
172 	val = bcm_uart_readl(port, UART_IR_REG);
173 	val |= UART_TX_INT_MASK;
174 	bcm_uart_writel(port, val, UART_IR_REG);
175 
176 	val = bcm_uart_readl(port, UART_CTL_REG);
177 	val |= UART_CTL_TXEN_MASK;
178 	bcm_uart_writel(port, val, UART_CTL_REG);
179 }
180 
181 /*
182  * serial core request to stop rx, called before port shutdown
183  */
184 static void bcm_uart_stop_rx(struct uart_port *port)
185 {
186 	unsigned int val;
187 
188 	val = bcm_uart_readl(port, UART_IR_REG);
189 	val &= ~UART_RX_INT_MASK;
190 	bcm_uart_writel(port, val, UART_IR_REG);
191 }
192 
193 /*
194  * serial core request to enable modem status interrupt reporting
195  */
196 static void bcm_uart_enable_ms(struct uart_port *port)
197 {
198 	unsigned int val;
199 
200 	val = bcm_uart_readl(port, UART_IR_REG);
201 	val |= UART_IR_MASK(UART_IR_EXTIP);
202 	bcm_uart_writel(port, val, UART_IR_REG);
203 }
204 
205 /*
206  * serial core request to start/stop emitting break char
207  */
208 static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
209 {
210 	unsigned long flags;
211 	unsigned int val;
212 
213 	spin_lock_irqsave(&port->lock, flags);
214 
215 	val = bcm_uart_readl(port, UART_CTL_REG);
216 	if (ctl)
217 		val |= UART_CTL_XMITBRK_MASK;
218 	else
219 		val &= ~UART_CTL_XMITBRK_MASK;
220 	bcm_uart_writel(port, val, UART_CTL_REG);
221 
222 	spin_unlock_irqrestore(&port->lock, flags);
223 }
224 
225 /*
226  * return port type in string format
227  */
228 static const char *bcm_uart_type(struct uart_port *port)
229 {
230 	return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
231 }
232 
233 /*
234  * read all chars in rx fifo and send them to core
235  */
236 static void bcm_uart_do_rx(struct uart_port *port)
237 {
238 	struct tty_struct *tty;
239 	unsigned int max_count;
240 
241 	/* limit number of char read in interrupt, should not be
242 	 * higher than fifo size anyway since we're much faster than
243 	 * serial port */
244 	max_count = 32;
245 	tty = port->state->port.tty;
246 	do {
247 		unsigned int iestat, c, cstat;
248 		char flag;
249 
250 		/* get overrun/fifo empty information from ier
251 		 * register */
252 		iestat = bcm_uart_readl(port, UART_IR_REG);
253 		if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
254 			break;
255 
256 		cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
257 		port->icount.rx++;
258 		flag = TTY_NORMAL;
259 		c &= 0xff;
260 
261 		if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
262 			/* do stats first */
263 			if (cstat & UART_FIFO_BRKDET_MASK) {
264 				port->icount.brk++;
265 				if (uart_handle_break(port))
266 					continue;
267 			}
268 
269 			if (cstat & UART_FIFO_PARERR_MASK)
270 				port->icount.parity++;
271 			if (cstat & UART_FIFO_FRAMEERR_MASK)
272 				port->icount.frame++;
273 
274 			/* update flag wrt read_status_mask */
275 			cstat &= port->read_status_mask;
276 			if (cstat & UART_FIFO_BRKDET_MASK)
277 				flag = TTY_BREAK;
278 			if (cstat & UART_FIFO_FRAMEERR_MASK)
279 				flag = TTY_FRAME;
280 			if (cstat & UART_FIFO_PARERR_MASK)
281 				flag = TTY_PARITY;
282 		}
283 
284 		if (uart_handle_sysrq_char(port, c))
285 			continue;
286 
287 		if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
288 			port->icount.overrun++;
289 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
290 		}
291 
292 		if ((cstat & port->ignore_status_mask) == 0)
293 			tty_insert_flip_char(tty, c, flag);
294 
295 	} while (--max_count);
296 
297 	tty_flip_buffer_push(tty);
298 }
299 
300 /*
301  * fill tx fifo with chars to send, stop when fifo is about to be full
302  * or when all chars have been sent.
303  */
304 static void bcm_uart_do_tx(struct uart_port *port)
305 {
306 	struct circ_buf *xmit;
307 	unsigned int val, max_count;
308 
309 	if (port->x_char) {
310 		bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
311 		port->icount.tx++;
312 		port->x_char = 0;
313 		return;
314 	}
315 
316 	if (uart_tx_stopped(port)) {
317 		bcm_uart_stop_tx(port);
318 		return;
319 	}
320 
321 	xmit = &port->state->xmit;
322 	if (uart_circ_empty(xmit))
323 		goto txq_empty;
324 
325 	val = bcm_uart_readl(port, UART_MCTL_REG);
326 	val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
327 	max_count = port->fifosize - val;
328 
329 	while (max_count--) {
330 		unsigned int c;
331 
332 		c = xmit->buf[xmit->tail];
333 		bcm_uart_writel(port, c, UART_FIFO_REG);
334 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
335 		port->icount.tx++;
336 		if (uart_circ_empty(xmit))
337 			break;
338 	}
339 
340 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
341 		uart_write_wakeup(port);
342 
343 	if (uart_circ_empty(xmit))
344 		goto txq_empty;
345 	return;
346 
347 txq_empty:
348 	/* nothing to send, disable transmit interrupt */
349 	val = bcm_uart_readl(port, UART_IR_REG);
350 	val &= ~UART_TX_INT_MASK;
351 	bcm_uart_writel(port, val, UART_IR_REG);
352 	return;
353 }
354 
355 /*
356  * process uart interrupt
357  */
358 static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
359 {
360 	struct uart_port *port;
361 	unsigned int irqstat;
362 
363 	port = dev_id;
364 	spin_lock(&port->lock);
365 
366 	irqstat = bcm_uart_readl(port, UART_IR_REG);
367 	if (irqstat & UART_RX_INT_STAT)
368 		bcm_uart_do_rx(port);
369 
370 	if (irqstat & UART_TX_INT_STAT)
371 		bcm_uart_do_tx(port);
372 
373 	if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
374 		unsigned int estat;
375 
376 		estat = bcm_uart_readl(port, UART_EXTINP_REG);
377 		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
378 			uart_handle_cts_change(port,
379 					       estat & UART_EXTINP_CTS_MASK);
380 		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
381 			uart_handle_dcd_change(port,
382 					       estat & UART_EXTINP_DCD_MASK);
383 	}
384 
385 	spin_unlock(&port->lock);
386 	return IRQ_HANDLED;
387 }
388 
389 /*
390  * enable rx & tx operation on uart
391  */
392 static void bcm_uart_enable(struct uart_port *port)
393 {
394 	unsigned int val;
395 
396 	val = bcm_uart_readl(port, UART_CTL_REG);
397 	val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
398 	bcm_uart_writel(port, val, UART_CTL_REG);
399 }
400 
401 /*
402  * disable rx & tx operation on uart
403  */
404 static void bcm_uart_disable(struct uart_port *port)
405 {
406 	unsigned int val;
407 
408 	val = bcm_uart_readl(port, UART_CTL_REG);
409 	val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
410 		 UART_CTL_RXEN_MASK);
411 	bcm_uart_writel(port, val, UART_CTL_REG);
412 }
413 
414 /*
415  * clear all unread data in rx fifo and unsent data in tx fifo
416  */
417 static void bcm_uart_flush(struct uart_port *port)
418 {
419 	unsigned int val;
420 
421 	/* empty rx and tx fifo */
422 	val = bcm_uart_readl(port, UART_CTL_REG);
423 	val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
424 	bcm_uart_writel(port, val, UART_CTL_REG);
425 
426 	/* read any pending char to make sure all irq status are
427 	 * cleared */
428 	(void)bcm_uart_readl(port, UART_FIFO_REG);
429 }
430 
431 /*
432  * serial core request to initialize uart and start rx operation
433  */
434 static int bcm_uart_startup(struct uart_port *port)
435 {
436 	unsigned int val;
437 	int ret;
438 
439 	/* mask all irq and flush port */
440 	bcm_uart_disable(port);
441 	bcm_uart_writel(port, 0, UART_IR_REG);
442 	bcm_uart_flush(port);
443 
444 	/* clear any pending external input interrupt */
445 	(void)bcm_uart_readl(port, UART_EXTINP_REG);
446 
447 	/* set rx/tx fifo thresh to fifo half size */
448 	val = bcm_uart_readl(port, UART_MCTL_REG);
449 	val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
450 	val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
451 	val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
452 	bcm_uart_writel(port, val, UART_MCTL_REG);
453 
454 	/* set rx fifo timeout to 1 char time */
455 	val = bcm_uart_readl(port, UART_CTL_REG);
456 	val &= ~UART_CTL_RXTMOUTCNT_MASK;
457 	val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
458 	bcm_uart_writel(port, val, UART_CTL_REG);
459 
460 	/* report any edge on dcd and cts */
461 	val = UART_EXTINP_INT_MASK;
462 	val |= UART_EXTINP_DCD_NOSENSE_MASK;
463 	val |= UART_EXTINP_CTS_NOSENSE_MASK;
464 	bcm_uart_writel(port, val, UART_EXTINP_REG);
465 
466 	/* register irq and enable rx interrupts */
467 	ret = request_irq(port->irq, bcm_uart_interrupt, 0,
468 			  bcm_uart_type(port), port);
469 	if (ret)
470 		return ret;
471 	bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
472 	bcm_uart_enable(port);
473 	return 0;
474 }
475 
476 /*
477  * serial core request to flush & disable uart
478  */
479 static void bcm_uart_shutdown(struct uart_port *port)
480 {
481 	unsigned long flags;
482 
483 	spin_lock_irqsave(&port->lock, flags);
484 	bcm_uart_writel(port, 0, UART_IR_REG);
485 	spin_unlock_irqrestore(&port->lock, flags);
486 
487 	bcm_uart_disable(port);
488 	bcm_uart_flush(port);
489 	free_irq(port->irq, port);
490 }
491 
492 /*
493  * serial core request to change current uart setting
494  */
495 static void bcm_uart_set_termios(struct uart_port *port,
496 				 struct ktermios *new,
497 				 struct ktermios *old)
498 {
499 	unsigned int ctl, baud, quot, ier;
500 	unsigned long flags;
501 
502 	spin_lock_irqsave(&port->lock, flags);
503 
504 	/* disable uart while changing speed */
505 	bcm_uart_disable(port);
506 	bcm_uart_flush(port);
507 
508 	/* update Control register */
509 	ctl = bcm_uart_readl(port, UART_CTL_REG);
510 	ctl &= ~UART_CTL_BITSPERSYM_MASK;
511 
512 	switch (new->c_cflag & CSIZE) {
513 	case CS5:
514 		ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
515 		break;
516 	case CS6:
517 		ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
518 		break;
519 	case CS7:
520 		ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
521 		break;
522 	default:
523 		ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
524 		break;
525 	}
526 
527 	ctl &= ~UART_CTL_STOPBITS_MASK;
528 	if (new->c_cflag & CSTOPB)
529 		ctl |= UART_CTL_STOPBITS_2;
530 	else
531 		ctl |= UART_CTL_STOPBITS_1;
532 
533 	ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
534 	if (new->c_cflag & PARENB)
535 		ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
536 	ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
537 	if (new->c_cflag & PARODD)
538 		ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
539 	bcm_uart_writel(port, ctl, UART_CTL_REG);
540 
541 	/* update Baudword register */
542 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
543 	quot = uart_get_divisor(port, baud) - 1;
544 	bcm_uart_writel(port, quot, UART_BAUD_REG);
545 
546 	/* update Interrupt register */
547 	ier = bcm_uart_readl(port, UART_IR_REG);
548 
549 	ier &= ~UART_IR_MASK(UART_IR_EXTIP);
550 	if (UART_ENABLE_MS(port, new->c_cflag))
551 		ier |= UART_IR_MASK(UART_IR_EXTIP);
552 
553 	bcm_uart_writel(port, ier, UART_IR_REG);
554 
555 	/* update read/ignore mask */
556 	port->read_status_mask = UART_FIFO_VALID_MASK;
557 	if (new->c_iflag & INPCK) {
558 		port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
559 		port->read_status_mask |= UART_FIFO_PARERR_MASK;
560 	}
561 	if (new->c_iflag & (BRKINT))
562 		port->read_status_mask |= UART_FIFO_BRKDET_MASK;
563 
564 	port->ignore_status_mask = 0;
565 	if (new->c_iflag & IGNPAR)
566 		port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
567 	if (new->c_iflag & IGNBRK)
568 		port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
569 	if (!(new->c_cflag & CREAD))
570 		port->ignore_status_mask |= UART_FIFO_VALID_MASK;
571 
572 	uart_update_timeout(port, new->c_cflag, baud);
573 	bcm_uart_enable(port);
574 	spin_unlock_irqrestore(&port->lock, flags);
575 }
576 
577 /*
578  * serial core request to claim uart iomem
579  */
580 static int bcm_uart_request_port(struct uart_port *port)
581 {
582 	unsigned int size;
583 
584 	size = RSET_UART_SIZE;
585 	if (!request_mem_region(port->mapbase, size, "bcm63xx")) {
586 		dev_err(port->dev, "Memory region busy\n");
587 		return -EBUSY;
588 	}
589 
590 	port->membase = ioremap(port->mapbase, size);
591 	if (!port->membase) {
592 		dev_err(port->dev, "Unable to map registers\n");
593 		release_mem_region(port->mapbase, size);
594 		return -EBUSY;
595 	}
596 	return 0;
597 }
598 
599 /*
600  * serial core request to release uart iomem
601  */
602 static void bcm_uart_release_port(struct uart_port *port)
603 {
604 	release_mem_region(port->mapbase, RSET_UART_SIZE);
605 	iounmap(port->membase);
606 }
607 
608 /*
609  * serial core request to do any port required autoconfiguration
610  */
611 static void bcm_uart_config_port(struct uart_port *port, int flags)
612 {
613 	if (flags & UART_CONFIG_TYPE) {
614 		if (bcm_uart_request_port(port))
615 			return;
616 		port->type = PORT_BCM63XX;
617 	}
618 }
619 
620 /*
621  * serial core request to check that port information in serinfo are
622  * suitable
623  */
624 static int bcm_uart_verify_port(struct uart_port *port,
625 				struct serial_struct *serinfo)
626 {
627 	if (port->type != PORT_BCM63XX)
628 		return -EINVAL;
629 	if (port->irq != serinfo->irq)
630 		return -EINVAL;
631 	if (port->iotype != serinfo->io_type)
632 		return -EINVAL;
633 	if (port->mapbase != (unsigned long)serinfo->iomem_base)
634 		return -EINVAL;
635 	return 0;
636 }
637 
638 /* serial core callbacks */
639 static struct uart_ops bcm_uart_ops = {
640 	.tx_empty	= bcm_uart_tx_empty,
641 	.get_mctrl	= bcm_uart_get_mctrl,
642 	.set_mctrl	= bcm_uart_set_mctrl,
643 	.start_tx	= bcm_uart_start_tx,
644 	.stop_tx	= bcm_uart_stop_tx,
645 	.stop_rx	= bcm_uart_stop_rx,
646 	.enable_ms	= bcm_uart_enable_ms,
647 	.break_ctl	= bcm_uart_break_ctl,
648 	.startup	= bcm_uart_startup,
649 	.shutdown	= bcm_uart_shutdown,
650 	.set_termios	= bcm_uart_set_termios,
651 	.type		= bcm_uart_type,
652 	.release_port	= bcm_uart_release_port,
653 	.request_port	= bcm_uart_request_port,
654 	.config_port	= bcm_uart_config_port,
655 	.verify_port	= bcm_uart_verify_port,
656 };
657 
658 
659 
660 #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
661 static inline void wait_for_xmitr(struct uart_port *port)
662 {
663 	unsigned int tmout;
664 
665 	/* Wait up to 10ms for the character(s) to be sent. */
666 	tmout = 10000;
667 	while (--tmout) {
668 		unsigned int val;
669 
670 		val = bcm_uart_readl(port, UART_IR_REG);
671 		if (val & UART_IR_STAT(UART_IR_TXEMPTY))
672 			break;
673 		udelay(1);
674 	}
675 
676 	/* Wait up to 1s for flow control if necessary */
677 	if (port->flags & UPF_CONS_FLOW) {
678 		tmout = 1000000;
679 		while (--tmout) {
680 			unsigned int val;
681 
682 			val = bcm_uart_readl(port, UART_EXTINP_REG);
683 			if (val & UART_EXTINP_CTS_MASK)
684 				break;
685 			udelay(1);
686 		}
687 	}
688 }
689 
690 /*
691  * output given char
692  */
693 static void bcm_console_putchar(struct uart_port *port, int ch)
694 {
695 	wait_for_xmitr(port);
696 	bcm_uart_writel(port, ch, UART_FIFO_REG);
697 }
698 
699 /*
700  * console core request to output given string
701  */
702 static void bcm_console_write(struct console *co, const char *s,
703 			      unsigned int count)
704 {
705 	struct uart_port *port;
706 	unsigned long flags;
707 	int locked;
708 
709 	port = &ports[co->index];
710 
711 	local_irq_save(flags);
712 	if (port->sysrq) {
713 		/* bcm_uart_interrupt() already took the lock */
714 		locked = 0;
715 	} else if (oops_in_progress) {
716 		locked = spin_trylock(&port->lock);
717 	} else {
718 		spin_lock(&port->lock);
719 		locked = 1;
720 	}
721 
722 	/* call helper to deal with \r\n */
723 	uart_console_write(port, s, count, bcm_console_putchar);
724 
725 	/* and wait for char to be transmitted */
726 	wait_for_xmitr(port);
727 
728 	if (locked)
729 		spin_unlock(&port->lock);
730 	local_irq_restore(flags);
731 }
732 
733 /*
734  * console core request to setup given console, find matching uart
735  * port and setup it.
736  */
737 static int bcm_console_setup(struct console *co, char *options)
738 {
739 	struct uart_port *port;
740 	int baud = 9600;
741 	int bits = 8;
742 	int parity = 'n';
743 	int flow = 'n';
744 
745 	if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
746 		return -EINVAL;
747 	port = &ports[co->index];
748 	if (!port->membase)
749 		return -ENODEV;
750 	if (options)
751 		uart_parse_options(options, &baud, &parity, &bits, &flow);
752 
753 	return uart_set_options(port, co, baud, parity, bits, flow);
754 }
755 
756 static struct uart_driver bcm_uart_driver;
757 
758 static struct console bcm63xx_console = {
759 	.name		= "ttyS",
760 	.write		= bcm_console_write,
761 	.device		= uart_console_device,
762 	.setup		= bcm_console_setup,
763 	.flags		= CON_PRINTBUFFER,
764 	.index		= -1,
765 	.data		= &bcm_uart_driver,
766 };
767 
768 static int __init bcm63xx_console_init(void)
769 {
770 	register_console(&bcm63xx_console);
771 	return 0;
772 }
773 
774 console_initcall(bcm63xx_console_init);
775 
776 #define BCM63XX_CONSOLE	(&bcm63xx_console)
777 #else
778 #define BCM63XX_CONSOLE	NULL
779 #endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
780 
781 static struct uart_driver bcm_uart_driver = {
782 	.owner		= THIS_MODULE,
783 	.driver_name	= "bcm63xx_uart",
784 	.dev_name	= "ttyS",
785 	.major		= TTY_MAJOR,
786 	.minor		= 64,
787 	.nr		= BCM63XX_NR_UARTS,
788 	.cons		= BCM63XX_CONSOLE,
789 };
790 
791 /*
792  * platform driver probe/remove callback
793  */
794 static int __devinit bcm_uart_probe(struct platform_device *pdev)
795 {
796 	struct resource *res_mem, *res_irq;
797 	struct uart_port *port;
798 	struct clk *clk;
799 	int ret;
800 
801 	if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
802 		return -EINVAL;
803 
804 	if (ports[pdev->id].membase)
805 		return -EBUSY;
806 
807 	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
808 	if (!res_mem)
809 		return -ENODEV;
810 
811 	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
812 	if (!res_irq)
813 		return -ENODEV;
814 
815 	clk = clk_get(&pdev->dev, "periph");
816 	if (IS_ERR(clk))
817 		return -ENODEV;
818 
819 	port = &ports[pdev->id];
820 	memset(port, 0, sizeof(*port));
821 	port->iotype = UPIO_MEM;
822 	port->mapbase = res_mem->start;
823 	port->irq = res_irq->start;
824 	port->ops = &bcm_uart_ops;
825 	port->flags = UPF_BOOT_AUTOCONF;
826 	port->dev = &pdev->dev;
827 	port->fifosize = 16;
828 	port->uartclk = clk_get_rate(clk) / 2;
829 	port->line = pdev->id;
830 	clk_put(clk);
831 
832 	ret = uart_add_one_port(&bcm_uart_driver, port);
833 	if (ret) {
834 		ports[pdev->id].membase = 0;
835 		return ret;
836 	}
837 	platform_set_drvdata(pdev, port);
838 	return 0;
839 }
840 
841 static int __devexit bcm_uart_remove(struct platform_device *pdev)
842 {
843 	struct uart_port *port;
844 
845 	port = platform_get_drvdata(pdev);
846 	uart_remove_one_port(&bcm_uart_driver, port);
847 	platform_set_drvdata(pdev, NULL);
848 	/* mark port as free */
849 	ports[pdev->id].membase = 0;
850 	return 0;
851 }
852 
853 /*
854  * platform driver stuff
855  */
856 static struct platform_driver bcm_uart_platform_driver = {
857 	.probe	= bcm_uart_probe,
858 	.remove	= __devexit_p(bcm_uart_remove),
859 	.driver	= {
860 		.owner = THIS_MODULE,
861 		.name  = "bcm63xx_uart",
862 	},
863 };
864 
865 static int __init bcm_uart_init(void)
866 {
867 	int ret;
868 
869 	ret = uart_register_driver(&bcm_uart_driver);
870 	if (ret)
871 		return ret;
872 
873 	ret = platform_driver_register(&bcm_uart_platform_driver);
874 	if (ret)
875 		uart_unregister_driver(&bcm_uart_driver);
876 
877 	return ret;
878 }
879 
880 static void __exit bcm_uart_exit(void)
881 {
882 	platform_driver_unregister(&bcm_uart_platform_driver);
883 	uart_unregister_driver(&bcm_uart_driver);
884 }
885 
886 module_init(bcm_uart_init);
887 module_exit(bcm_uart_exit);
888 
889 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
890 MODULE_DESCRIPTION("Broadcom 63<xx integrated uart driver");
891 MODULE_LICENSE("GPL");
892