xref: /linux/drivers/tty/serial/bcm63xx_uart.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732) 
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 #include <linux/serial_bcm63xx.h>
33 #include <linux/io.h>
34 #include <linux/of.h>
35 
36 #define BCM63XX_NR_UARTS	2
37 
38 static struct uart_port ports[BCM63XX_NR_UARTS];
39 
40 /*
41  * rx interrupt mask / stat
42  *
43  * mask:
44  *  - rx fifo full
45  *  - rx fifo above threshold
46  *  - rx fifo not empty for too long
47  */
48 #define UART_RX_INT_MASK	(UART_IR_MASK(UART_IR_RXOVER) |		\
49 				UART_IR_MASK(UART_IR_RXTHRESH) |	\
50 				UART_IR_MASK(UART_IR_RXTIMEOUT))
51 
52 #define UART_RX_INT_STAT	(UART_IR_STAT(UART_IR_RXOVER) |		\
53 				UART_IR_STAT(UART_IR_RXTHRESH) |	\
54 				UART_IR_STAT(UART_IR_RXTIMEOUT))
55 
56 /*
57  * tx interrupt mask / stat
58  *
59  * mask:
60  * - tx fifo empty
61  * - tx fifo below threshold
62  */
63 #define UART_TX_INT_MASK	(UART_IR_MASK(UART_IR_TXEMPTY) |	\
64 				UART_IR_MASK(UART_IR_TXTRESH))
65 
66 #define UART_TX_INT_STAT	(UART_IR_STAT(UART_IR_TXEMPTY) |	\
67 				UART_IR_STAT(UART_IR_TXTRESH))
68 
69 /*
70  * external input interrupt
71  *
72  * mask: any edge on CTS, DCD
73  */
74 #define UART_EXTINP_INT_MASK	(UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
75 				 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
76 
77 /*
78  * handy uart register accessor
79  */
80 static inline unsigned int bcm_uart_readl(struct uart_port *port,
81 					 unsigned int offset)
82 {
83 	return __raw_readl(port->membase + offset);
84 }
85 
86 static inline void bcm_uart_writel(struct uart_port *port,
87 				  unsigned int value, unsigned int offset)
88 {
89 	__raw_writel(value, port->membase + offset);
90 }
91 
92 /*
93  * serial core request to check if uart tx fifo is empty
94  */
95 static unsigned int bcm_uart_tx_empty(struct uart_port *port)
96 {
97 	unsigned int val;
98 
99 	val = bcm_uart_readl(port, UART_IR_REG);
100 	return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
101 }
102 
103 /*
104  * serial core request to set RTS and DTR pin state and loopback mode
105  */
106 static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
107 {
108 	unsigned int val;
109 
110 	val = bcm_uart_readl(port, UART_MCTL_REG);
111 	val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
112 	/* invert of written value is reflected on the pin */
113 	if (!(mctrl & TIOCM_DTR))
114 		val |= UART_MCTL_DTR_MASK;
115 	if (!(mctrl & TIOCM_RTS))
116 		val |= UART_MCTL_RTS_MASK;
117 	bcm_uart_writel(port, val, UART_MCTL_REG);
118 
119 	val = bcm_uart_readl(port, UART_CTL_REG);
120 	if (mctrl & TIOCM_LOOP)
121 		val |= UART_CTL_LOOPBACK_MASK;
122 	else
123 		val &= ~UART_CTL_LOOPBACK_MASK;
124 	bcm_uart_writel(port, val, UART_CTL_REG);
125 }
126 
127 /*
128  * serial core request to return RI, CTS, DCD and DSR pin state
129  */
130 static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
131 {
132 	unsigned int val, mctrl;
133 
134 	mctrl = 0;
135 	val = bcm_uart_readl(port, UART_EXTINP_REG);
136 	if (val & UART_EXTINP_RI_MASK)
137 		mctrl |= TIOCM_RI;
138 	if (val & UART_EXTINP_CTS_MASK)
139 		mctrl |= TIOCM_CTS;
140 	if (val & UART_EXTINP_DCD_MASK)
141 		mctrl |= TIOCM_CD;
142 	if (val & UART_EXTINP_DSR_MASK)
143 		mctrl |= TIOCM_DSR;
144 	return mctrl;
145 }
146 
147 /*
148  * serial core request to disable tx ASAP (used for flow control)
149  */
150 static void bcm_uart_stop_tx(struct uart_port *port)
151 {
152 	unsigned int val;
153 
154 	val = bcm_uart_readl(port, UART_CTL_REG);
155 	val &= ~(UART_CTL_TXEN_MASK);
156 	bcm_uart_writel(port, val, UART_CTL_REG);
157 
158 	val = bcm_uart_readl(port, UART_IR_REG);
159 	val &= ~UART_TX_INT_MASK;
160 	bcm_uart_writel(port, val, UART_IR_REG);
161 }
162 
163 /*
164  * serial core request to (re)enable tx
165  */
166 static void bcm_uart_start_tx(struct uart_port *port)
167 {
168 	unsigned int val;
169 
170 	val = bcm_uart_readl(port, UART_IR_REG);
171 	val |= UART_TX_INT_MASK;
172 	bcm_uart_writel(port, val, UART_IR_REG);
173 
174 	val = bcm_uart_readl(port, UART_CTL_REG);
175 	val |= UART_CTL_TXEN_MASK;
176 	bcm_uart_writel(port, val, UART_CTL_REG);
177 }
178 
179 /*
180  * serial core request to stop rx, called before port shutdown
181  */
182 static void bcm_uart_stop_rx(struct uart_port *port)
183 {
184 	unsigned int val;
185 
186 	val = bcm_uart_readl(port, UART_IR_REG);
187 	val &= ~UART_RX_INT_MASK;
188 	bcm_uart_writel(port, val, UART_IR_REG);
189 }
190 
191 /*
192  * serial core request to enable modem status interrupt reporting
193  */
194 static void bcm_uart_enable_ms(struct uart_port *port)
195 {
196 	unsigned int val;
197 
198 	val = bcm_uart_readl(port, UART_IR_REG);
199 	val |= UART_IR_MASK(UART_IR_EXTIP);
200 	bcm_uart_writel(port, val, UART_IR_REG);
201 }
202 
203 /*
204  * serial core request to start/stop emitting break char
205  */
206 static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
207 {
208 	unsigned long flags;
209 	unsigned int val;
210 
211 	spin_lock_irqsave(&port->lock, flags);
212 
213 	val = bcm_uart_readl(port, UART_CTL_REG);
214 	if (ctl)
215 		val |= UART_CTL_XMITBRK_MASK;
216 	else
217 		val &= ~UART_CTL_XMITBRK_MASK;
218 	bcm_uart_writel(port, val, UART_CTL_REG);
219 
220 	spin_unlock_irqrestore(&port->lock, flags);
221 }
222 
223 /*
224  * return port type in string format
225  */
226 static const char *bcm_uart_type(struct uart_port *port)
227 {
228 	return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
229 }
230 
231 /*
232  * read all chars in rx fifo and send them to core
233  */
234 static void bcm_uart_do_rx(struct uart_port *port)
235 {
236 	struct tty_port *tty_port = &port->state->port;
237 	unsigned int max_count;
238 
239 	/* limit number of char read in interrupt, should not be
240 	 * higher than fifo size anyway since we're much faster than
241 	 * serial port */
242 	max_count = 32;
243 	do {
244 		unsigned int iestat, c, cstat;
245 		char flag;
246 
247 		/* get overrun/fifo empty information from ier
248 		 * register */
249 		iestat = bcm_uart_readl(port, UART_IR_REG);
250 
251 		if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
252 			unsigned int val;
253 
254 			/* fifo reset is required to clear
255 			 * interrupt */
256 			val = bcm_uart_readl(port, UART_CTL_REG);
257 			val |= UART_CTL_RSTRXFIFO_MASK;
258 			bcm_uart_writel(port, val, UART_CTL_REG);
259 
260 			port->icount.overrun++;
261 			tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
262 		}
263 
264 		if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
265 			break;
266 
267 		cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
268 		port->icount.rx++;
269 		flag = TTY_NORMAL;
270 		c &= 0xff;
271 
272 		if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
273 			/* do stats first */
274 			if (cstat & UART_FIFO_BRKDET_MASK) {
275 				port->icount.brk++;
276 				if (uart_handle_break(port))
277 					continue;
278 			}
279 
280 			if (cstat & UART_FIFO_PARERR_MASK)
281 				port->icount.parity++;
282 			if (cstat & UART_FIFO_FRAMEERR_MASK)
283 				port->icount.frame++;
284 
285 			/* update flag wrt read_status_mask */
286 			cstat &= port->read_status_mask;
287 			if (cstat & UART_FIFO_BRKDET_MASK)
288 				flag = TTY_BREAK;
289 			if (cstat & UART_FIFO_FRAMEERR_MASK)
290 				flag = TTY_FRAME;
291 			if (cstat & UART_FIFO_PARERR_MASK)
292 				flag = TTY_PARITY;
293 		}
294 
295 		if (uart_handle_sysrq_char(port, c))
296 			continue;
297 
298 
299 		if ((cstat & port->ignore_status_mask) == 0)
300 			tty_insert_flip_char(tty_port, c, flag);
301 
302 	} while (--max_count);
303 
304 	spin_unlock(&port->lock);
305 	tty_flip_buffer_push(tty_port);
306 	spin_lock(&port->lock);
307 }
308 
309 /*
310  * fill tx fifo with chars to send, stop when fifo is about to be full
311  * or when all chars have been sent.
312  */
313 static void bcm_uart_do_tx(struct uart_port *port)
314 {
315 	struct circ_buf *xmit;
316 	unsigned int val, max_count;
317 
318 	if (port->x_char) {
319 		bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
320 		port->icount.tx++;
321 		port->x_char = 0;
322 		return;
323 	}
324 
325 	if (uart_tx_stopped(port)) {
326 		bcm_uart_stop_tx(port);
327 		return;
328 	}
329 
330 	xmit = &port->state->xmit;
331 	if (uart_circ_empty(xmit))
332 		goto txq_empty;
333 
334 	val = bcm_uart_readl(port, UART_MCTL_REG);
335 	val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
336 	max_count = port->fifosize - val;
337 
338 	while (max_count--) {
339 		unsigned int c;
340 
341 		c = xmit->buf[xmit->tail];
342 		bcm_uart_writel(port, c, UART_FIFO_REG);
343 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
344 		port->icount.tx++;
345 		if (uart_circ_empty(xmit))
346 			break;
347 	}
348 
349 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
350 		uart_write_wakeup(port);
351 
352 	if (uart_circ_empty(xmit))
353 		goto txq_empty;
354 	return;
355 
356 txq_empty:
357 	/* nothing to send, disable transmit interrupt */
358 	val = bcm_uart_readl(port, UART_IR_REG);
359 	val &= ~UART_TX_INT_MASK;
360 	bcm_uart_writel(port, val, UART_IR_REG);
361 	return;
362 }
363 
364 /*
365  * process uart interrupt
366  */
367 static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
368 {
369 	struct uart_port *port;
370 	unsigned int irqstat;
371 
372 	port = dev_id;
373 	spin_lock(&port->lock);
374 
375 	irqstat = bcm_uart_readl(port, UART_IR_REG);
376 	if (irqstat & UART_RX_INT_STAT)
377 		bcm_uart_do_rx(port);
378 
379 	if (irqstat & UART_TX_INT_STAT)
380 		bcm_uart_do_tx(port);
381 
382 	if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
383 		unsigned int estat;
384 
385 		estat = bcm_uart_readl(port, UART_EXTINP_REG);
386 		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
387 			uart_handle_cts_change(port,
388 					       estat & UART_EXTINP_CTS_MASK);
389 		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
390 			uart_handle_dcd_change(port,
391 					       estat & UART_EXTINP_DCD_MASK);
392 	}
393 
394 	spin_unlock(&port->lock);
395 	return IRQ_HANDLED;
396 }
397 
398 /*
399  * enable rx & tx operation on uart
400  */
401 static void bcm_uart_enable(struct uart_port *port)
402 {
403 	unsigned int val;
404 
405 	val = bcm_uart_readl(port, UART_CTL_REG);
406 	val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
407 	bcm_uart_writel(port, val, UART_CTL_REG);
408 }
409 
410 /*
411  * disable rx & tx operation on uart
412  */
413 static void bcm_uart_disable(struct uart_port *port)
414 {
415 	unsigned int val;
416 
417 	val = bcm_uart_readl(port, UART_CTL_REG);
418 	val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
419 		 UART_CTL_RXEN_MASK);
420 	bcm_uart_writel(port, val, UART_CTL_REG);
421 }
422 
423 /*
424  * clear all unread data in rx fifo and unsent data in tx fifo
425  */
426 static void bcm_uart_flush(struct uart_port *port)
427 {
428 	unsigned int val;
429 
430 	/* empty rx and tx fifo */
431 	val = bcm_uart_readl(port, UART_CTL_REG);
432 	val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
433 	bcm_uart_writel(port, val, UART_CTL_REG);
434 
435 	/* read any pending char to make sure all irq status are
436 	 * cleared */
437 	(void)bcm_uart_readl(port, UART_FIFO_REG);
438 }
439 
440 /*
441  * serial core request to initialize uart and start rx operation
442  */
443 static int bcm_uart_startup(struct uart_port *port)
444 {
445 	unsigned int val;
446 	int ret;
447 
448 	/* mask all irq and flush port */
449 	bcm_uart_disable(port);
450 	bcm_uart_writel(port, 0, UART_IR_REG);
451 	bcm_uart_flush(port);
452 
453 	/* clear any pending external input interrupt */
454 	(void)bcm_uart_readl(port, UART_EXTINP_REG);
455 
456 	/* set rx/tx fifo thresh to fifo half size */
457 	val = bcm_uart_readl(port, UART_MCTL_REG);
458 	val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
459 	val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
460 	val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
461 	bcm_uart_writel(port, val, UART_MCTL_REG);
462 
463 	/* set rx fifo timeout to 1 char time */
464 	val = bcm_uart_readl(port, UART_CTL_REG);
465 	val &= ~UART_CTL_RXTMOUTCNT_MASK;
466 	val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
467 	bcm_uart_writel(port, val, UART_CTL_REG);
468 
469 	/* report any edge on dcd and cts */
470 	val = UART_EXTINP_INT_MASK;
471 	val |= UART_EXTINP_DCD_NOSENSE_MASK;
472 	val |= UART_EXTINP_CTS_NOSENSE_MASK;
473 	bcm_uart_writel(port, val, UART_EXTINP_REG);
474 
475 	/* register irq and enable rx interrupts */
476 	ret = request_irq(port->irq, bcm_uart_interrupt, 0,
477 			  bcm_uart_type(port), port);
478 	if (ret)
479 		return ret;
480 	bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
481 	bcm_uart_enable(port);
482 	return 0;
483 }
484 
485 /*
486  * serial core request to flush & disable uart
487  */
488 static void bcm_uart_shutdown(struct uart_port *port)
489 {
490 	unsigned long flags;
491 
492 	spin_lock_irqsave(&port->lock, flags);
493 	bcm_uart_writel(port, 0, UART_IR_REG);
494 	spin_unlock_irqrestore(&port->lock, flags);
495 
496 	bcm_uart_disable(port);
497 	bcm_uart_flush(port);
498 	free_irq(port->irq, port);
499 }
500 
501 /*
502  * serial core request to change current uart setting
503  */
504 static void bcm_uart_set_termios(struct uart_port *port,
505 				 struct ktermios *new,
506 				 struct ktermios *old)
507 {
508 	unsigned int ctl, baud, quot, ier;
509 	unsigned long flags;
510 
511 	spin_lock_irqsave(&port->lock, flags);
512 
513 	/* disable uart while changing speed */
514 	bcm_uart_disable(port);
515 	bcm_uart_flush(port);
516 
517 	/* update Control register */
518 	ctl = bcm_uart_readl(port, UART_CTL_REG);
519 	ctl &= ~UART_CTL_BITSPERSYM_MASK;
520 
521 	switch (new->c_cflag & CSIZE) {
522 	case CS5:
523 		ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
524 		break;
525 	case CS6:
526 		ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
527 		break;
528 	case CS7:
529 		ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
530 		break;
531 	default:
532 		ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
533 		break;
534 	}
535 
536 	ctl &= ~UART_CTL_STOPBITS_MASK;
537 	if (new->c_cflag & CSTOPB)
538 		ctl |= UART_CTL_STOPBITS_2;
539 	else
540 		ctl |= UART_CTL_STOPBITS_1;
541 
542 	ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
543 	if (new->c_cflag & PARENB)
544 		ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
545 	ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
546 	if (new->c_cflag & PARODD)
547 		ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
548 	bcm_uart_writel(port, ctl, UART_CTL_REG);
549 
550 	/* update Baudword register */
551 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
552 	quot = uart_get_divisor(port, baud) - 1;
553 	bcm_uart_writel(port, quot, UART_BAUD_REG);
554 
555 	/* update Interrupt register */
556 	ier = bcm_uart_readl(port, UART_IR_REG);
557 
558 	ier &= ~UART_IR_MASK(UART_IR_EXTIP);
559 	if (UART_ENABLE_MS(port, new->c_cflag))
560 		ier |= UART_IR_MASK(UART_IR_EXTIP);
561 
562 	bcm_uart_writel(port, ier, UART_IR_REG);
563 
564 	/* update read/ignore mask */
565 	port->read_status_mask = UART_FIFO_VALID_MASK;
566 	if (new->c_iflag & INPCK) {
567 		port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
568 		port->read_status_mask |= UART_FIFO_PARERR_MASK;
569 	}
570 	if (new->c_iflag & (IGNBRK | BRKINT))
571 		port->read_status_mask |= UART_FIFO_BRKDET_MASK;
572 
573 	port->ignore_status_mask = 0;
574 	if (new->c_iflag & IGNPAR)
575 		port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
576 	if (new->c_iflag & IGNBRK)
577 		port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
578 	if (!(new->c_cflag & CREAD))
579 		port->ignore_status_mask |= UART_FIFO_VALID_MASK;
580 
581 	uart_update_timeout(port, new->c_cflag, baud);
582 	bcm_uart_enable(port);
583 	spin_unlock_irqrestore(&port->lock, flags);
584 }
585 
586 /*
587  * serial core request to claim uart iomem
588  */
589 static int bcm_uart_request_port(struct uart_port *port)
590 {
591 	/* UARTs always present */
592 	return 0;
593 }
594 
595 /*
596  * serial core request to release uart iomem
597  */
598 static void bcm_uart_release_port(struct uart_port *port)
599 {
600 	/* Nothing to release ... */
601 }
602 
603 /*
604  * serial core request to do any port required autoconfiguration
605  */
606 static void bcm_uart_config_port(struct uart_port *port, int flags)
607 {
608 	if (flags & UART_CONFIG_TYPE) {
609 		if (bcm_uart_request_port(port))
610 			return;
611 		port->type = PORT_BCM63XX;
612 	}
613 }
614 
615 /*
616  * serial core request to check that port information in serinfo are
617  * suitable
618  */
619 static int bcm_uart_verify_port(struct uart_port *port,
620 				struct serial_struct *serinfo)
621 {
622 	if (port->type != PORT_BCM63XX)
623 		return -EINVAL;
624 	if (port->irq != serinfo->irq)
625 		return -EINVAL;
626 	if (port->iotype != serinfo->io_type)
627 		return -EINVAL;
628 	if (port->mapbase != (unsigned long)serinfo->iomem_base)
629 		return -EINVAL;
630 	return 0;
631 }
632 
633 /* serial core callbacks */
634 static struct uart_ops bcm_uart_ops = {
635 	.tx_empty	= bcm_uart_tx_empty,
636 	.get_mctrl	= bcm_uart_get_mctrl,
637 	.set_mctrl	= bcm_uart_set_mctrl,
638 	.start_tx	= bcm_uart_start_tx,
639 	.stop_tx	= bcm_uart_stop_tx,
640 	.stop_rx	= bcm_uart_stop_rx,
641 	.enable_ms	= bcm_uart_enable_ms,
642 	.break_ctl	= bcm_uart_break_ctl,
643 	.startup	= bcm_uart_startup,
644 	.shutdown	= bcm_uart_shutdown,
645 	.set_termios	= bcm_uart_set_termios,
646 	.type		= bcm_uart_type,
647 	.release_port	= bcm_uart_release_port,
648 	.request_port	= bcm_uart_request_port,
649 	.config_port	= bcm_uart_config_port,
650 	.verify_port	= bcm_uart_verify_port,
651 };
652 
653 
654 
655 #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
656 static inline void wait_for_xmitr(struct uart_port *port)
657 {
658 	unsigned int tmout;
659 
660 	/* Wait up to 10ms for the character(s) to be sent. */
661 	tmout = 10000;
662 	while (--tmout) {
663 		unsigned int val;
664 
665 		val = bcm_uart_readl(port, UART_IR_REG);
666 		if (val & UART_IR_STAT(UART_IR_TXEMPTY))
667 			break;
668 		udelay(1);
669 	}
670 
671 	/* Wait up to 1s for flow control if necessary */
672 	if (port->flags & UPF_CONS_FLOW) {
673 		tmout = 1000000;
674 		while (--tmout) {
675 			unsigned int val;
676 
677 			val = bcm_uart_readl(port, UART_EXTINP_REG);
678 			if (val & UART_EXTINP_CTS_MASK)
679 				break;
680 			udelay(1);
681 		}
682 	}
683 }
684 
685 /*
686  * output given char
687  */
688 static void bcm_console_putchar(struct uart_port *port, int ch)
689 {
690 	wait_for_xmitr(port);
691 	bcm_uart_writel(port, ch, UART_FIFO_REG);
692 }
693 
694 /*
695  * console core request to output given string
696  */
697 static void bcm_console_write(struct console *co, const char *s,
698 			      unsigned int count)
699 {
700 	struct uart_port *port;
701 	unsigned long flags;
702 	int locked;
703 
704 	port = &ports[co->index];
705 
706 	local_irq_save(flags);
707 	if (port->sysrq) {
708 		/* bcm_uart_interrupt() already took the lock */
709 		locked = 0;
710 	} else if (oops_in_progress) {
711 		locked = spin_trylock(&port->lock);
712 	} else {
713 		spin_lock(&port->lock);
714 		locked = 1;
715 	}
716 
717 	/* call helper to deal with \r\n */
718 	uart_console_write(port, s, count, bcm_console_putchar);
719 
720 	/* and wait for char to be transmitted */
721 	wait_for_xmitr(port);
722 
723 	if (locked)
724 		spin_unlock(&port->lock);
725 	local_irq_restore(flags);
726 }
727 
728 /*
729  * console core request to setup given console, find matching uart
730  * port and setup it.
731  */
732 static int bcm_console_setup(struct console *co, char *options)
733 {
734 	struct uart_port *port;
735 	int baud = 9600;
736 	int bits = 8;
737 	int parity = 'n';
738 	int flow = 'n';
739 
740 	if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
741 		return -EINVAL;
742 	port = &ports[co->index];
743 	if (!port->membase)
744 		return -ENODEV;
745 	if (options)
746 		uart_parse_options(options, &baud, &parity, &bits, &flow);
747 
748 	return uart_set_options(port, co, baud, parity, bits, flow);
749 }
750 
751 static struct uart_driver bcm_uart_driver;
752 
753 static struct console bcm63xx_console = {
754 	.name		= "ttyS",
755 	.write		= bcm_console_write,
756 	.device		= uart_console_device,
757 	.setup		= bcm_console_setup,
758 	.flags		= CON_PRINTBUFFER,
759 	.index		= -1,
760 	.data		= &bcm_uart_driver,
761 };
762 
763 static int __init bcm63xx_console_init(void)
764 {
765 	register_console(&bcm63xx_console);
766 	return 0;
767 }
768 
769 console_initcall(bcm63xx_console_init);
770 
771 static void bcm_early_write(struct console *con, const char *s, unsigned n)
772 {
773 	struct earlycon_device *dev = con->data;
774 
775 	uart_console_write(&dev->port, s, n, bcm_console_putchar);
776 	wait_for_xmitr(&dev->port);
777 }
778 
779 static int __init bcm_early_console_setup(struct earlycon_device *device,
780 					  const char *opt)
781 {
782 	if (!device->port.membase)
783 		return -ENODEV;
784 
785 	device->con->write = bcm_early_write;
786 	return 0;
787 }
788 
789 OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
790 
791 #define BCM63XX_CONSOLE	(&bcm63xx_console)
792 #else
793 #define BCM63XX_CONSOLE	NULL
794 #endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
795 
796 static struct uart_driver bcm_uart_driver = {
797 	.owner		= THIS_MODULE,
798 	.driver_name	= "bcm63xx_uart",
799 	.dev_name	= "ttyS",
800 	.major		= TTY_MAJOR,
801 	.minor		= 64,
802 	.nr		= BCM63XX_NR_UARTS,
803 	.cons		= BCM63XX_CONSOLE,
804 };
805 
806 /*
807  * platform driver probe/remove callback
808  */
809 static int bcm_uart_probe(struct platform_device *pdev)
810 {
811 	struct resource *res_mem, *res_irq;
812 	struct uart_port *port;
813 	struct clk *clk;
814 	int ret;
815 
816 	if (pdev->dev.of_node)
817 		pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
818 
819 	if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
820 		return -EINVAL;
821 
822 	port = &ports[pdev->id];
823 	if (port->membase)
824 		return -EBUSY;
825 	memset(port, 0, sizeof(*port));
826 
827 	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
828 	if (!res_mem)
829 		return -ENODEV;
830 
831 	port->mapbase = res_mem->start;
832 	port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
833 	if (IS_ERR(port->membase))
834 		return PTR_ERR(port->membase);
835 
836 	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
837 	if (!res_irq)
838 		return -ENODEV;
839 
840 	clk = pdev->dev.of_node ? of_clk_get(pdev->dev.of_node, 0) :
841 				  clk_get(&pdev->dev, "periph");
842 	if (IS_ERR(clk))
843 		return -ENODEV;
844 
845 	port->iotype = UPIO_MEM;
846 	port->irq = res_irq->start;
847 	port->ops = &bcm_uart_ops;
848 	port->flags = UPF_BOOT_AUTOCONF;
849 	port->dev = &pdev->dev;
850 	port->fifosize = 16;
851 	port->uartclk = clk_get_rate(clk) / 2;
852 	port->line = pdev->id;
853 	clk_put(clk);
854 
855 	ret = uart_add_one_port(&bcm_uart_driver, port);
856 	if (ret) {
857 		ports[pdev->id].membase = NULL;
858 		return ret;
859 	}
860 	platform_set_drvdata(pdev, port);
861 	return 0;
862 }
863 
864 static int bcm_uart_remove(struct platform_device *pdev)
865 {
866 	struct uart_port *port;
867 
868 	port = platform_get_drvdata(pdev);
869 	uart_remove_one_port(&bcm_uart_driver, port);
870 	/* mark port as free */
871 	ports[pdev->id].membase = NULL;
872 	return 0;
873 }
874 
875 static const struct of_device_id bcm63xx_of_match[] = {
876 	{ .compatible = "brcm,bcm6345-uart" },
877 	{ /* sentinel */ }
878 };
879 MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
880 
881 /*
882  * platform driver stuff
883  */
884 static struct platform_driver bcm_uart_platform_driver = {
885 	.probe	= bcm_uart_probe,
886 	.remove	= bcm_uart_remove,
887 	.driver	= {
888 		.name  = "bcm63xx_uart",
889 		.of_match_table = bcm63xx_of_match,
890 	},
891 };
892 
893 static int __init bcm_uart_init(void)
894 {
895 	int ret;
896 
897 	ret = uart_register_driver(&bcm_uart_driver);
898 	if (ret)
899 		return ret;
900 
901 	ret = platform_driver_register(&bcm_uart_platform_driver);
902 	if (ret)
903 		uart_unregister_driver(&bcm_uart_driver);
904 
905 	return ret;
906 }
907 
908 static void __exit bcm_uart_exit(void)
909 {
910 	platform_driver_unregister(&bcm_uart_platform_driver);
911 	uart_unregister_driver(&bcm_uart_driver);
912 }
913 
914 module_init(bcm_uart_init);
915 module_exit(bcm_uart_exit);
916 
917 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
918 MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
919 MODULE_LICENSE("GPL");
920