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
38static 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 */
80static inline unsigned int bcm_uart_readl(struct uart_port *port,
81					 unsigned int offset)
82{
83	return __raw_readl(port->membase + offset);
84}
85
86static 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 */
95static 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 */
106static 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 */
130static 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 */
150static 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 */
166static 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 */
182static 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 */
194static 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 */
206static 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 */
226static 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 */
234static 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 */
313static 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
356txq_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 */
367static 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 */
401static 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 */
413static 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 */
426static 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 */
443static 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 */
488static 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 */
504static 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 */
589static 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 */
598static 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 */
606static 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 */
619static 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 */
634static 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
656static 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 */
688static 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 */
697static 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 */
732static 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
751static struct uart_driver bcm_uart_driver;
752
753static 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
763static int __init bcm63xx_console_init(void)
764{
765	register_console(&bcm63xx_console);
766	return 0;
767}
768
769console_initcall(bcm63xx_console_init);
770
771static 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
779static 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
789OF_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
796static 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 */
809static 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
864static 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
875static const struct of_device_id bcm63xx_of_match[] = {
876	{ .compatible = "brcm,bcm6345-uart" },
877	{ /* sentinel */ }
878};
879MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
880
881/*
882 * platform driver stuff
883 */
884static 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
893static 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
908static void __exit bcm_uart_exit(void)
909{
910	platform_driver_unregister(&bcm_uart_platform_driver);
911	uart_unregister_driver(&bcm_uart_driver);
912}
913
914module_init(bcm_uart_init);
915module_exit(bcm_uart_exit);
916
917MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
918MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
919MODULE_LICENSE("GPL");
920