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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 dev_name(port->dev), 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 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");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Derived from many drivers using generic_serial interface.
4 *
5 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
6 *
7 * Serial driver for BCM63xx integrated UART.
8 *
9 * Hardware flow control was _not_ tested since I only have RX/TX on
10 * my board.
11 */
12
13#include <linux/kernel.h>
14#include <linux/platform_device.h>
15#include <linux/init.h>
16#include <linux/delay.h>
17#include <linux/module.h>
18#include <linux/console.h>
19#include <linux/clk.h>
20#include <linux/tty.h>
21#include <linux/tty_flip.h>
22#include <linux/sysrq.h>
23#include <linux/serial.h>
24#include <linux/serial_core.h>
25#include <linux/serial_bcm63xx.h>
26#include <linux/io.h>
27#include <linux/of.h>
28
29#define BCM63XX_NR_UARTS 2
30
31static struct uart_port ports[BCM63XX_NR_UARTS];
32
33/*
34 * rx interrupt mask / stat
35 *
36 * mask:
37 * - rx fifo full
38 * - rx fifo above threshold
39 * - rx fifo not empty for too long
40 */
41#define UART_RX_INT_MASK (UART_IR_MASK(UART_IR_RXOVER) | \
42 UART_IR_MASK(UART_IR_RXTHRESH) | \
43 UART_IR_MASK(UART_IR_RXTIMEOUT))
44
45#define UART_RX_INT_STAT (UART_IR_STAT(UART_IR_RXOVER) | \
46 UART_IR_STAT(UART_IR_RXTHRESH) | \
47 UART_IR_STAT(UART_IR_RXTIMEOUT))
48
49/*
50 * tx interrupt mask / stat
51 *
52 * mask:
53 * - tx fifo empty
54 * - tx fifo below threshold
55 */
56#define UART_TX_INT_MASK (UART_IR_MASK(UART_IR_TXEMPTY) | \
57 UART_IR_MASK(UART_IR_TXTRESH))
58
59#define UART_TX_INT_STAT (UART_IR_STAT(UART_IR_TXEMPTY) | \
60 UART_IR_STAT(UART_IR_TXTRESH))
61
62/*
63 * external input interrupt
64 *
65 * mask: any edge on CTS, DCD
66 */
67#define UART_EXTINP_INT_MASK (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
68 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
69
70/*
71 * handy uart register accessor
72 */
73static inline unsigned int bcm_uart_readl(struct uart_port *port,
74 unsigned int offset)
75{
76 return __raw_readl(port->membase + offset);
77}
78
79static inline void bcm_uart_writel(struct uart_port *port,
80 unsigned int value, unsigned int offset)
81{
82 __raw_writel(value, port->membase + offset);
83}
84
85/*
86 * serial core request to check if uart tx fifo is empty
87 */
88static unsigned int bcm_uart_tx_empty(struct uart_port *port)
89{
90 unsigned int val;
91
92 val = bcm_uart_readl(port, UART_IR_REG);
93 return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
94}
95
96/*
97 * serial core request to set RTS and DTR pin state and loopback mode
98 */
99static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
100{
101 unsigned int val;
102
103 val = bcm_uart_readl(port, UART_MCTL_REG);
104 val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
105 /* invert of written value is reflected on the pin */
106 if (!(mctrl & TIOCM_DTR))
107 val |= UART_MCTL_DTR_MASK;
108 if (!(mctrl & TIOCM_RTS))
109 val |= UART_MCTL_RTS_MASK;
110 bcm_uart_writel(port, val, UART_MCTL_REG);
111
112 val = bcm_uart_readl(port, UART_CTL_REG);
113 if (mctrl & TIOCM_LOOP)
114 val |= UART_CTL_LOOPBACK_MASK;
115 else
116 val &= ~UART_CTL_LOOPBACK_MASK;
117 bcm_uart_writel(port, val, UART_CTL_REG);
118}
119
120/*
121 * serial core request to return RI, CTS, DCD and DSR pin state
122 */
123static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
124{
125 unsigned int val, mctrl;
126
127 mctrl = 0;
128 val = bcm_uart_readl(port, UART_EXTINP_REG);
129 if (val & UART_EXTINP_RI_MASK)
130 mctrl |= TIOCM_RI;
131 if (val & UART_EXTINP_CTS_MASK)
132 mctrl |= TIOCM_CTS;
133 if (val & UART_EXTINP_DCD_MASK)
134 mctrl |= TIOCM_CD;
135 if (val & UART_EXTINP_DSR_MASK)
136 mctrl |= TIOCM_DSR;
137 return mctrl;
138}
139
140/*
141 * serial core request to disable tx ASAP (used for flow control)
142 */
143static void bcm_uart_stop_tx(struct uart_port *port)
144{
145 unsigned int val;
146
147 val = bcm_uart_readl(port, UART_CTL_REG);
148 val &= ~(UART_CTL_TXEN_MASK);
149 bcm_uart_writel(port, val, UART_CTL_REG);
150
151 val = bcm_uart_readl(port, UART_IR_REG);
152 val &= ~UART_TX_INT_MASK;
153 bcm_uart_writel(port, val, UART_IR_REG);
154}
155
156/*
157 * serial core request to (re)enable tx
158 */
159static void bcm_uart_start_tx(struct uart_port *port)
160{
161 unsigned int val;
162
163 val = bcm_uart_readl(port, UART_IR_REG);
164 val |= UART_TX_INT_MASK;
165 bcm_uart_writel(port, val, UART_IR_REG);
166
167 val = bcm_uart_readl(port, UART_CTL_REG);
168 val |= UART_CTL_TXEN_MASK;
169 bcm_uart_writel(port, val, UART_CTL_REG);
170}
171
172/*
173 * serial core request to stop rx, called before port shutdown
174 */
175static void bcm_uart_stop_rx(struct uart_port *port)
176{
177 unsigned int val;
178
179 val = bcm_uart_readl(port, UART_IR_REG);
180 val &= ~UART_RX_INT_MASK;
181 bcm_uart_writel(port, val, UART_IR_REG);
182}
183
184/*
185 * serial core request to enable modem status interrupt reporting
186 */
187static void bcm_uart_enable_ms(struct uart_port *port)
188{
189 unsigned int val;
190
191 val = bcm_uart_readl(port, UART_IR_REG);
192 val |= UART_IR_MASK(UART_IR_EXTIP);
193 bcm_uart_writel(port, val, UART_IR_REG);
194}
195
196/*
197 * serial core request to start/stop emitting break char
198 */
199static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
200{
201 unsigned long flags;
202 unsigned int val;
203
204 spin_lock_irqsave(&port->lock, flags);
205
206 val = bcm_uart_readl(port, UART_CTL_REG);
207 if (ctl)
208 val |= UART_CTL_XMITBRK_MASK;
209 else
210 val &= ~UART_CTL_XMITBRK_MASK;
211 bcm_uart_writel(port, val, UART_CTL_REG);
212
213 spin_unlock_irqrestore(&port->lock, flags);
214}
215
216/*
217 * return port type in string format
218 */
219static const char *bcm_uart_type(struct uart_port *port)
220{
221 return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
222}
223
224/*
225 * read all chars in rx fifo and send them to core
226 */
227static void bcm_uart_do_rx(struct uart_port *port)
228{
229 struct tty_port *tty_port = &port->state->port;
230 unsigned int max_count;
231
232 /* limit number of char read in interrupt, should not be
233 * higher than fifo size anyway since we're much faster than
234 * serial port */
235 max_count = 32;
236 do {
237 unsigned int iestat, c, cstat;
238 char flag;
239
240 /* get overrun/fifo empty information from ier
241 * register */
242 iestat = bcm_uart_readl(port, UART_IR_REG);
243
244 if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
245 unsigned int val;
246
247 /* fifo reset is required to clear
248 * interrupt */
249 val = bcm_uart_readl(port, UART_CTL_REG);
250 val |= UART_CTL_RSTRXFIFO_MASK;
251 bcm_uart_writel(port, val, UART_CTL_REG);
252
253 port->icount.overrun++;
254 tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
255 }
256
257 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
258 break;
259
260 cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
261 port->icount.rx++;
262 flag = TTY_NORMAL;
263 c &= 0xff;
264
265 if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
266 /* do stats first */
267 if (cstat & UART_FIFO_BRKDET_MASK) {
268 port->icount.brk++;
269 if (uart_handle_break(port))
270 continue;
271 }
272
273 if (cstat & UART_FIFO_PARERR_MASK)
274 port->icount.parity++;
275 if (cstat & UART_FIFO_FRAMEERR_MASK)
276 port->icount.frame++;
277
278 /* update flag wrt read_status_mask */
279 cstat &= port->read_status_mask;
280 if (cstat & UART_FIFO_BRKDET_MASK)
281 flag = TTY_BREAK;
282 if (cstat & UART_FIFO_FRAMEERR_MASK)
283 flag = TTY_FRAME;
284 if (cstat & UART_FIFO_PARERR_MASK)
285 flag = TTY_PARITY;
286 }
287
288 if (uart_handle_sysrq_char(port, c))
289 continue;
290
291
292 if ((cstat & port->ignore_status_mask) == 0)
293 tty_insert_flip_char(tty_port, c, flag);
294
295 } while (--max_count);
296
297 tty_flip_buffer_push(tty_port);
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 */
304static void bcm_uart_do_tx(struct uart_port *port)
305{
306 unsigned int val;
307 bool pending;
308 u8 ch;
309
310 val = bcm_uart_readl(port, UART_MCTL_REG);
311 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
312
313 pending = uart_port_tx_limited(port, ch, port->fifosize - val,
314 true,
315 bcm_uart_writel(port, ch, UART_FIFO_REG),
316 ({}));
317 if (pending)
318 return;
319
320 /* nothing to send, disable transmit interrupt */
321 val = bcm_uart_readl(port, UART_IR_REG);
322 val &= ~UART_TX_INT_MASK;
323 bcm_uart_writel(port, val, UART_IR_REG);
324}
325
326/*
327 * process uart interrupt
328 */
329static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
330{
331 struct uart_port *port;
332 unsigned int irqstat;
333
334 port = dev_id;
335 spin_lock(&port->lock);
336
337 irqstat = bcm_uart_readl(port, UART_IR_REG);
338 if (irqstat & UART_RX_INT_STAT)
339 bcm_uart_do_rx(port);
340
341 if (irqstat & UART_TX_INT_STAT)
342 bcm_uart_do_tx(port);
343
344 if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
345 unsigned int estat;
346
347 estat = bcm_uart_readl(port, UART_EXTINP_REG);
348 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
349 uart_handle_cts_change(port,
350 estat & UART_EXTINP_CTS_MASK);
351 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
352 uart_handle_dcd_change(port,
353 estat & UART_EXTINP_DCD_MASK);
354 }
355
356 spin_unlock(&port->lock);
357 return IRQ_HANDLED;
358}
359
360/*
361 * enable rx & tx operation on uart
362 */
363static void bcm_uart_enable(struct uart_port *port)
364{
365 unsigned int val;
366
367 val = bcm_uart_readl(port, UART_CTL_REG);
368 val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
369 bcm_uart_writel(port, val, UART_CTL_REG);
370}
371
372/*
373 * disable rx & tx operation on uart
374 */
375static void bcm_uart_disable(struct uart_port *port)
376{
377 unsigned int val;
378
379 val = bcm_uart_readl(port, UART_CTL_REG);
380 val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
381 UART_CTL_RXEN_MASK);
382 bcm_uart_writel(port, val, UART_CTL_REG);
383}
384
385/*
386 * clear all unread data in rx fifo and unsent data in tx fifo
387 */
388static void bcm_uart_flush(struct uart_port *port)
389{
390 unsigned int val;
391
392 /* empty rx and tx fifo */
393 val = bcm_uart_readl(port, UART_CTL_REG);
394 val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
395 bcm_uart_writel(port, val, UART_CTL_REG);
396
397 /* read any pending char to make sure all irq status are
398 * cleared */
399 (void)bcm_uart_readl(port, UART_FIFO_REG);
400}
401
402/*
403 * serial core request to initialize uart and start rx operation
404 */
405static int bcm_uart_startup(struct uart_port *port)
406{
407 unsigned int val;
408 int ret;
409
410 /* mask all irq and flush port */
411 bcm_uart_disable(port);
412 bcm_uart_writel(port, 0, UART_IR_REG);
413 bcm_uart_flush(port);
414
415 /* clear any pending external input interrupt */
416 (void)bcm_uart_readl(port, UART_EXTINP_REG);
417
418 /* set rx/tx fifo thresh to fifo half size */
419 val = bcm_uart_readl(port, UART_MCTL_REG);
420 val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
421 val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
422 val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
423 bcm_uart_writel(port, val, UART_MCTL_REG);
424
425 /* set rx fifo timeout to 1 char time */
426 val = bcm_uart_readl(port, UART_CTL_REG);
427 val &= ~UART_CTL_RXTMOUTCNT_MASK;
428 val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
429 bcm_uart_writel(port, val, UART_CTL_REG);
430
431 /* report any edge on dcd and cts */
432 val = UART_EXTINP_INT_MASK;
433 val |= UART_EXTINP_DCD_NOSENSE_MASK;
434 val |= UART_EXTINP_CTS_NOSENSE_MASK;
435 bcm_uart_writel(port, val, UART_EXTINP_REG);
436
437 /* register irq and enable rx interrupts */
438 ret = request_irq(port->irq, bcm_uart_interrupt, 0,
439 dev_name(port->dev), port);
440 if (ret)
441 return ret;
442 bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
443 bcm_uart_enable(port);
444 return 0;
445}
446
447/*
448 * serial core request to flush & disable uart
449 */
450static void bcm_uart_shutdown(struct uart_port *port)
451{
452 unsigned long flags;
453
454 spin_lock_irqsave(&port->lock, flags);
455 bcm_uart_writel(port, 0, UART_IR_REG);
456 spin_unlock_irqrestore(&port->lock, flags);
457
458 bcm_uart_disable(port);
459 bcm_uart_flush(port);
460 free_irq(port->irq, port);
461}
462
463/*
464 * serial core request to change current uart setting
465 */
466static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
467 const struct ktermios *old)
468{
469 unsigned int ctl, baud, quot, ier;
470 unsigned long flags;
471 int tries;
472
473 spin_lock_irqsave(&port->lock, flags);
474
475 /* Drain the hot tub fully before we power it off for the winter. */
476 for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
477 mdelay(10);
478
479 /* disable uart while changing speed */
480 bcm_uart_disable(port);
481 bcm_uart_flush(port);
482
483 /* update Control register */
484 ctl = bcm_uart_readl(port, UART_CTL_REG);
485 ctl &= ~UART_CTL_BITSPERSYM_MASK;
486
487 switch (new->c_cflag & CSIZE) {
488 case CS5:
489 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
490 break;
491 case CS6:
492 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
493 break;
494 case CS7:
495 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
496 break;
497 default:
498 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
499 break;
500 }
501
502 ctl &= ~UART_CTL_STOPBITS_MASK;
503 if (new->c_cflag & CSTOPB)
504 ctl |= UART_CTL_STOPBITS_2;
505 else
506 ctl |= UART_CTL_STOPBITS_1;
507
508 ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
509 if (new->c_cflag & PARENB)
510 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
511 ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
512 if (new->c_cflag & PARODD)
513 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
514 bcm_uart_writel(port, ctl, UART_CTL_REG);
515
516 /* update Baudword register */
517 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
518 quot = uart_get_divisor(port, baud) - 1;
519 bcm_uart_writel(port, quot, UART_BAUD_REG);
520
521 /* update Interrupt register */
522 ier = bcm_uart_readl(port, UART_IR_REG);
523
524 ier &= ~UART_IR_MASK(UART_IR_EXTIP);
525 if (UART_ENABLE_MS(port, new->c_cflag))
526 ier |= UART_IR_MASK(UART_IR_EXTIP);
527
528 bcm_uart_writel(port, ier, UART_IR_REG);
529
530 /* update read/ignore mask */
531 port->read_status_mask = UART_FIFO_VALID_MASK;
532 if (new->c_iflag & INPCK) {
533 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
534 port->read_status_mask |= UART_FIFO_PARERR_MASK;
535 }
536 if (new->c_iflag & (IGNBRK | BRKINT))
537 port->read_status_mask |= UART_FIFO_BRKDET_MASK;
538
539 port->ignore_status_mask = 0;
540 if (new->c_iflag & IGNPAR)
541 port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
542 if (new->c_iflag & IGNBRK)
543 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
544 if (!(new->c_cflag & CREAD))
545 port->ignore_status_mask |= UART_FIFO_VALID_MASK;
546
547 uart_update_timeout(port, new->c_cflag, baud);
548 bcm_uart_enable(port);
549 spin_unlock_irqrestore(&port->lock, flags);
550}
551
552/*
553 * serial core request to claim uart iomem
554 */
555static int bcm_uart_request_port(struct uart_port *port)
556{
557 /* UARTs always present */
558 return 0;
559}
560
561/*
562 * serial core request to release uart iomem
563 */
564static void bcm_uart_release_port(struct uart_port *port)
565{
566 /* Nothing to release ... */
567}
568
569/*
570 * serial core request to do any port required autoconfiguration
571 */
572static void bcm_uart_config_port(struct uart_port *port, int flags)
573{
574 if (flags & UART_CONFIG_TYPE) {
575 if (bcm_uart_request_port(port))
576 return;
577 port->type = PORT_BCM63XX;
578 }
579}
580
581/*
582 * serial core request to check that port information in serinfo are
583 * suitable
584 */
585static int bcm_uart_verify_port(struct uart_port *port,
586 struct serial_struct *serinfo)
587{
588 if (port->type != PORT_BCM63XX)
589 return -EINVAL;
590 if (port->irq != serinfo->irq)
591 return -EINVAL;
592 if (port->iotype != serinfo->io_type)
593 return -EINVAL;
594 if (port->mapbase != (unsigned long)serinfo->iomem_base)
595 return -EINVAL;
596 return 0;
597}
598
599/* serial core callbacks */
600static const struct uart_ops bcm_uart_ops = {
601 .tx_empty = bcm_uart_tx_empty,
602 .get_mctrl = bcm_uart_get_mctrl,
603 .set_mctrl = bcm_uart_set_mctrl,
604 .start_tx = bcm_uart_start_tx,
605 .stop_tx = bcm_uart_stop_tx,
606 .stop_rx = bcm_uart_stop_rx,
607 .enable_ms = bcm_uart_enable_ms,
608 .break_ctl = bcm_uart_break_ctl,
609 .startup = bcm_uart_startup,
610 .shutdown = bcm_uart_shutdown,
611 .set_termios = bcm_uart_set_termios,
612 .type = bcm_uart_type,
613 .release_port = bcm_uart_release_port,
614 .request_port = bcm_uart_request_port,
615 .config_port = bcm_uart_config_port,
616 .verify_port = bcm_uart_verify_port,
617};
618
619
620
621#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
622static void wait_for_xmitr(struct uart_port *port)
623{
624 unsigned int tmout;
625
626 /* Wait up to 10ms for the character(s) to be sent. */
627 tmout = 10000;
628 while (--tmout) {
629 unsigned int val;
630
631 val = bcm_uart_readl(port, UART_IR_REG);
632 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
633 break;
634 udelay(1);
635 }
636
637 /* Wait up to 1s for flow control if necessary */
638 if (port->flags & UPF_CONS_FLOW) {
639 tmout = 1000000;
640 while (--tmout) {
641 unsigned int val;
642
643 val = bcm_uart_readl(port, UART_EXTINP_REG);
644 if (val & UART_EXTINP_CTS_MASK)
645 break;
646 udelay(1);
647 }
648 }
649}
650
651/*
652 * output given char
653 */
654static void bcm_console_putchar(struct uart_port *port, unsigned char ch)
655{
656 wait_for_xmitr(port);
657 bcm_uart_writel(port, ch, UART_FIFO_REG);
658}
659
660/*
661 * console core request to output given string
662 */
663static void bcm_console_write(struct console *co, const char *s,
664 unsigned int count)
665{
666 struct uart_port *port;
667 unsigned long flags;
668 int locked;
669
670 port = &ports[co->index];
671
672 local_irq_save(flags);
673 if (port->sysrq) {
674 /* bcm_uart_interrupt() already took the lock */
675 locked = 0;
676 } else if (oops_in_progress) {
677 locked = spin_trylock(&port->lock);
678 } else {
679 spin_lock(&port->lock);
680 locked = 1;
681 }
682
683 /* call helper to deal with \r\n */
684 uart_console_write(port, s, count, bcm_console_putchar);
685
686 /* and wait for char to be transmitted */
687 wait_for_xmitr(port);
688
689 if (locked)
690 spin_unlock(&port->lock);
691 local_irq_restore(flags);
692}
693
694/*
695 * console core request to setup given console, find matching uart
696 * port and setup it.
697 */
698static int bcm_console_setup(struct console *co, char *options)
699{
700 struct uart_port *port;
701 int baud = 9600;
702 int bits = 8;
703 int parity = 'n';
704 int flow = 'n';
705
706 if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
707 return -EINVAL;
708 port = &ports[co->index];
709 if (!port->membase)
710 return -ENODEV;
711 if (options)
712 uart_parse_options(options, &baud, &parity, &bits, &flow);
713
714 return uart_set_options(port, co, baud, parity, bits, flow);
715}
716
717static struct uart_driver bcm_uart_driver;
718
719static struct console bcm63xx_console = {
720 .name = "ttyS",
721 .write = bcm_console_write,
722 .device = uart_console_device,
723 .setup = bcm_console_setup,
724 .flags = CON_PRINTBUFFER,
725 .index = -1,
726 .data = &bcm_uart_driver,
727};
728
729static int __init bcm63xx_console_init(void)
730{
731 register_console(&bcm63xx_console);
732 return 0;
733}
734
735console_initcall(bcm63xx_console_init);
736
737static void bcm_early_write(struct console *con, const char *s, unsigned n)
738{
739 struct earlycon_device *dev = con->data;
740
741 uart_console_write(&dev->port, s, n, bcm_console_putchar);
742 wait_for_xmitr(&dev->port);
743}
744
745static int __init bcm_early_console_setup(struct earlycon_device *device,
746 const char *opt)
747{
748 if (!device->port.membase)
749 return -ENODEV;
750
751 device->con->write = bcm_early_write;
752 return 0;
753}
754
755OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
756
757#define BCM63XX_CONSOLE (&bcm63xx_console)
758#else
759#define BCM63XX_CONSOLE NULL
760#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
761
762static struct uart_driver bcm_uart_driver = {
763 .owner = THIS_MODULE,
764 .driver_name = "bcm63xx_uart",
765 .dev_name = "ttyS",
766 .major = TTY_MAJOR,
767 .minor = 64,
768 .nr = BCM63XX_NR_UARTS,
769 .cons = BCM63XX_CONSOLE,
770};
771
772/*
773 * platform driver probe/remove callback
774 */
775static int bcm_uart_probe(struct platform_device *pdev)
776{
777 struct resource *res_mem;
778 struct uart_port *port;
779 struct clk *clk;
780 int ret;
781
782 if (pdev->dev.of_node) {
783 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
784
785 if (pdev->id < 0)
786 pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
787 }
788
789 if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
790 return -EINVAL;
791
792 port = &ports[pdev->id];
793 if (port->membase)
794 return -EBUSY;
795 memset(port, 0, sizeof(*port));
796
797 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
798 if (!res_mem)
799 return -ENODEV;
800
801 port->mapbase = res_mem->start;
802 port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
803 if (IS_ERR(port->membase))
804 return PTR_ERR(port->membase);
805
806 ret = platform_get_irq(pdev, 0);
807 if (ret < 0)
808 return ret;
809 port->irq = ret;
810
811 clk = clk_get(&pdev->dev, "refclk");
812 if (IS_ERR(clk) && pdev->dev.of_node)
813 clk = of_clk_get(pdev->dev.of_node, 0);
814
815 if (IS_ERR(clk))
816 return -ENODEV;
817
818 port->iotype = UPIO_MEM;
819 port->ops = &bcm_uart_ops;
820 port->flags = UPF_BOOT_AUTOCONF;
821 port->dev = &pdev->dev;
822 port->fifosize = 16;
823 port->uartclk = clk_get_rate(clk) / 2;
824 port->line = pdev->id;
825 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE);
826 clk_put(clk);
827
828 ret = uart_add_one_port(&bcm_uart_driver, port);
829 if (ret) {
830 ports[pdev->id].membase = NULL;
831 return ret;
832 }
833 platform_set_drvdata(pdev, port);
834 return 0;
835}
836
837static int bcm_uart_remove(struct platform_device *pdev)
838{
839 struct uart_port *port;
840
841 port = platform_get_drvdata(pdev);
842 uart_remove_one_port(&bcm_uart_driver, port);
843 /* mark port as free */
844 ports[pdev->id].membase = NULL;
845 return 0;
846}
847
848static const struct of_device_id bcm63xx_of_match[] = {
849 { .compatible = "brcm,bcm6345-uart" },
850 { /* sentinel */ }
851};
852MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
853
854/*
855 * platform driver stuff
856 */
857static struct platform_driver bcm_uart_platform_driver = {
858 .probe = bcm_uart_probe,
859 .remove = bcm_uart_remove,
860 .driver = {
861 .name = "bcm63xx_uart",
862 .of_match_table = bcm63xx_of_match,
863 },
864};
865
866static int __init bcm_uart_init(void)
867{
868 int ret;
869
870 ret = uart_register_driver(&bcm_uart_driver);
871 if (ret)
872 return ret;
873
874 ret = platform_driver_register(&bcm_uart_platform_driver);
875 if (ret)
876 uart_unregister_driver(&bcm_uart_driver);
877
878 return ret;
879}
880
881static void __exit bcm_uart_exit(void)
882{
883 platform_driver_unregister(&bcm_uart_platform_driver);
884 uart_unregister_driver(&bcm_uart_driver);
885}
886
887module_init(bcm_uart_init);
888module_exit(bcm_uart_exit);
889
890MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
891MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
892MODULE_LICENSE("GPL");