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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#if defined(CONFIG_SERIAL_BCM63XX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
14#define SUPPORT_SYSRQ
15#endif
16
17#include <linux/kernel.h>
18#include <linux/platform_device.h>
19#include <linux/init.h>
20#include <linux/delay.h>
21#include <linux/module.h>
22#include <linux/console.h>
23#include <linux/clk.h>
24#include <linux/tty.h>
25#include <linux/tty_flip.h>
26#include <linux/sysrq.h>
27#include <linux/serial.h>
28#include <linux/serial_core.h>
29#include <linux/serial_bcm63xx.h>
30#include <linux/io.h>
31#include <linux/of.h>
32
33#define BCM63XX_NR_UARTS 2
34
35static struct uart_port ports[BCM63XX_NR_UARTS];
36
37/*
38 * rx interrupt mask / stat
39 *
40 * mask:
41 * - rx fifo full
42 * - rx fifo above threshold
43 * - rx fifo not empty for too long
44 */
45#define UART_RX_INT_MASK (UART_IR_MASK(UART_IR_RXOVER) | \
46 UART_IR_MASK(UART_IR_RXTHRESH) | \
47 UART_IR_MASK(UART_IR_RXTIMEOUT))
48
49#define UART_RX_INT_STAT (UART_IR_STAT(UART_IR_RXOVER) | \
50 UART_IR_STAT(UART_IR_RXTHRESH) | \
51 UART_IR_STAT(UART_IR_RXTIMEOUT))
52
53/*
54 * tx interrupt mask / stat
55 *
56 * mask:
57 * - tx fifo empty
58 * - tx fifo below threshold
59 */
60#define UART_TX_INT_MASK (UART_IR_MASK(UART_IR_TXEMPTY) | \
61 UART_IR_MASK(UART_IR_TXTRESH))
62
63#define UART_TX_INT_STAT (UART_IR_STAT(UART_IR_TXEMPTY) | \
64 UART_IR_STAT(UART_IR_TXTRESH))
65
66/*
67 * external input interrupt
68 *
69 * mask: any edge on CTS, DCD
70 */
71#define UART_EXTINP_INT_MASK (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
72 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
73
74/*
75 * handy uart register accessor
76 */
77static inline unsigned int bcm_uart_readl(struct uart_port *port,
78 unsigned int offset)
79{
80 return __raw_readl(port->membase + offset);
81}
82
83static inline void bcm_uart_writel(struct uart_port *port,
84 unsigned int value, unsigned int offset)
85{
86 __raw_writel(value, port->membase + offset);
87}
88
89/*
90 * serial core request to check if uart tx fifo is empty
91 */
92static unsigned int bcm_uart_tx_empty(struct uart_port *port)
93{
94 unsigned int val;
95
96 val = bcm_uart_readl(port, UART_IR_REG);
97 return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
98}
99
100/*
101 * serial core request to set RTS and DTR pin state and loopback mode
102 */
103static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
104{
105 unsigned int val;
106
107 val = bcm_uart_readl(port, UART_MCTL_REG);
108 val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
109 /* invert of written value is reflected on the pin */
110 if (!(mctrl & TIOCM_DTR))
111 val |= UART_MCTL_DTR_MASK;
112 if (!(mctrl & TIOCM_RTS))
113 val |= UART_MCTL_RTS_MASK;
114 bcm_uart_writel(port, val, UART_MCTL_REG);
115
116 val = bcm_uart_readl(port, UART_CTL_REG);
117 if (mctrl & TIOCM_LOOP)
118 val |= UART_CTL_LOOPBACK_MASK;
119 else
120 val &= ~UART_CTL_LOOPBACK_MASK;
121 bcm_uart_writel(port, val, UART_CTL_REG);
122}
123
124/*
125 * serial core request to return RI, CTS, DCD and DSR pin state
126 */
127static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
128{
129 unsigned int val, mctrl;
130
131 mctrl = 0;
132 val = bcm_uart_readl(port, UART_EXTINP_REG);
133 if (val & UART_EXTINP_RI_MASK)
134 mctrl |= TIOCM_RI;
135 if (val & UART_EXTINP_CTS_MASK)
136 mctrl |= TIOCM_CTS;
137 if (val & UART_EXTINP_DCD_MASK)
138 mctrl |= TIOCM_CD;
139 if (val & UART_EXTINP_DSR_MASK)
140 mctrl |= TIOCM_DSR;
141 return mctrl;
142}
143
144/*
145 * serial core request to disable tx ASAP (used for flow control)
146 */
147static void bcm_uart_stop_tx(struct uart_port *port)
148{
149 unsigned int val;
150
151 val = bcm_uart_readl(port, UART_CTL_REG);
152 val &= ~(UART_CTL_TXEN_MASK);
153 bcm_uart_writel(port, val, UART_CTL_REG);
154
155 val = bcm_uart_readl(port, UART_IR_REG);
156 val &= ~UART_TX_INT_MASK;
157 bcm_uart_writel(port, val, UART_IR_REG);
158}
159
160/*
161 * serial core request to (re)enable tx
162 */
163static void bcm_uart_start_tx(struct uart_port *port)
164{
165 unsigned int val;
166
167 val = bcm_uart_readl(port, UART_IR_REG);
168 val |= UART_TX_INT_MASK;
169 bcm_uart_writel(port, val, UART_IR_REG);
170
171 val = bcm_uart_readl(port, UART_CTL_REG);
172 val |= UART_CTL_TXEN_MASK;
173 bcm_uart_writel(port, val, UART_CTL_REG);
174}
175
176/*
177 * serial core request to stop rx, called before port shutdown
178 */
179static void bcm_uart_stop_rx(struct uart_port *port)
180{
181 unsigned int val;
182
183 val = bcm_uart_readl(port, UART_IR_REG);
184 val &= ~UART_RX_INT_MASK;
185 bcm_uart_writel(port, val, UART_IR_REG);
186}
187
188/*
189 * serial core request to enable modem status interrupt reporting
190 */
191static void bcm_uart_enable_ms(struct uart_port *port)
192{
193 unsigned int val;
194
195 val = bcm_uart_readl(port, UART_IR_REG);
196 val |= UART_IR_MASK(UART_IR_EXTIP);
197 bcm_uart_writel(port, val, UART_IR_REG);
198}
199
200/*
201 * serial core request to start/stop emitting break char
202 */
203static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
204{
205 unsigned long flags;
206 unsigned int val;
207
208 spin_lock_irqsave(&port->lock, flags);
209
210 val = bcm_uart_readl(port, UART_CTL_REG);
211 if (ctl)
212 val |= UART_CTL_XMITBRK_MASK;
213 else
214 val &= ~UART_CTL_XMITBRK_MASK;
215 bcm_uart_writel(port, val, UART_CTL_REG);
216
217 spin_unlock_irqrestore(&port->lock, flags);
218}
219
220/*
221 * return port type in string format
222 */
223static const char *bcm_uart_type(struct uart_port *port)
224{
225 return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
226}
227
228/*
229 * read all chars in rx fifo and send them to core
230 */
231static void bcm_uart_do_rx(struct uart_port *port)
232{
233 struct tty_port *tty_port = &port->state->port;
234 unsigned int max_count;
235
236 /* limit number of char read in interrupt, should not be
237 * higher than fifo size anyway since we're much faster than
238 * serial port */
239 max_count = 32;
240 do {
241 unsigned int iestat, c, cstat;
242 char flag;
243
244 /* get overrun/fifo empty information from ier
245 * register */
246 iestat = bcm_uart_readl(port, UART_IR_REG);
247
248 if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
249 unsigned int val;
250
251 /* fifo reset is required to clear
252 * interrupt */
253 val = bcm_uart_readl(port, UART_CTL_REG);
254 val |= UART_CTL_RSTRXFIFO_MASK;
255 bcm_uart_writel(port, val, UART_CTL_REG);
256
257 port->icount.overrun++;
258 tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
259 }
260
261 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
262 break;
263
264 cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
265 port->icount.rx++;
266 flag = TTY_NORMAL;
267 c &= 0xff;
268
269 if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
270 /* do stats first */
271 if (cstat & UART_FIFO_BRKDET_MASK) {
272 port->icount.brk++;
273 if (uart_handle_break(port))
274 continue;
275 }
276
277 if (cstat & UART_FIFO_PARERR_MASK)
278 port->icount.parity++;
279 if (cstat & UART_FIFO_FRAMEERR_MASK)
280 port->icount.frame++;
281
282 /* update flag wrt read_status_mask */
283 cstat &= port->read_status_mask;
284 if (cstat & UART_FIFO_BRKDET_MASK)
285 flag = TTY_BREAK;
286 if (cstat & UART_FIFO_FRAMEERR_MASK)
287 flag = TTY_FRAME;
288 if (cstat & UART_FIFO_PARERR_MASK)
289 flag = TTY_PARITY;
290 }
291
292 if (uart_handle_sysrq_char(port, c))
293 continue;
294
295
296 if ((cstat & port->ignore_status_mask) == 0)
297 tty_insert_flip_char(tty_port, c, flag);
298
299 } while (--max_count);
300
301 spin_unlock(&port->lock);
302 tty_flip_buffer_push(tty_port);
303 spin_lock(&port->lock);
304}
305
306/*
307 * fill tx fifo with chars to send, stop when fifo is about to be full
308 * or when all chars have been sent.
309 */
310static void bcm_uart_do_tx(struct uart_port *port)
311{
312 struct circ_buf *xmit;
313 unsigned int val, max_count;
314
315 if (port->x_char) {
316 bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
317 port->icount.tx++;
318 port->x_char = 0;
319 return;
320 }
321
322 if (uart_tx_stopped(port)) {
323 bcm_uart_stop_tx(port);
324 return;
325 }
326
327 xmit = &port->state->xmit;
328 if (uart_circ_empty(xmit))
329 goto txq_empty;
330
331 val = bcm_uart_readl(port, UART_MCTL_REG);
332 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
333 max_count = port->fifosize - val;
334
335 while (max_count--) {
336 unsigned int c;
337
338 c = xmit->buf[xmit->tail];
339 bcm_uart_writel(port, c, UART_FIFO_REG);
340 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
341 port->icount.tx++;
342 if (uart_circ_empty(xmit))
343 break;
344 }
345
346 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
347 uart_write_wakeup(port);
348
349 if (uart_circ_empty(xmit))
350 goto txq_empty;
351 return;
352
353txq_empty:
354 /* nothing to send, disable transmit interrupt */
355 val = bcm_uart_readl(port, UART_IR_REG);
356 val &= ~UART_TX_INT_MASK;
357 bcm_uart_writel(port, val, UART_IR_REG);
358 return;
359}
360
361/*
362 * process uart interrupt
363 */
364static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
365{
366 struct uart_port *port;
367 unsigned int irqstat;
368
369 port = dev_id;
370 spin_lock(&port->lock);
371
372 irqstat = bcm_uart_readl(port, UART_IR_REG);
373 if (irqstat & UART_RX_INT_STAT)
374 bcm_uart_do_rx(port);
375
376 if (irqstat & UART_TX_INT_STAT)
377 bcm_uart_do_tx(port);
378
379 if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
380 unsigned int estat;
381
382 estat = bcm_uart_readl(port, UART_EXTINP_REG);
383 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
384 uart_handle_cts_change(port,
385 estat & UART_EXTINP_CTS_MASK);
386 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
387 uart_handle_dcd_change(port,
388 estat & UART_EXTINP_DCD_MASK);
389 }
390
391 spin_unlock(&port->lock);
392 return IRQ_HANDLED;
393}
394
395/*
396 * enable rx & tx operation on uart
397 */
398static void bcm_uart_enable(struct uart_port *port)
399{
400 unsigned int val;
401
402 val = bcm_uart_readl(port, UART_CTL_REG);
403 val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
404 bcm_uart_writel(port, val, UART_CTL_REG);
405}
406
407/*
408 * disable rx & tx operation on uart
409 */
410static void bcm_uart_disable(struct uart_port *port)
411{
412 unsigned int val;
413
414 val = bcm_uart_readl(port, UART_CTL_REG);
415 val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
416 UART_CTL_RXEN_MASK);
417 bcm_uart_writel(port, val, UART_CTL_REG);
418}
419
420/*
421 * clear all unread data in rx fifo and unsent data in tx fifo
422 */
423static void bcm_uart_flush(struct uart_port *port)
424{
425 unsigned int val;
426
427 /* empty rx and tx fifo */
428 val = bcm_uart_readl(port, UART_CTL_REG);
429 val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
430 bcm_uart_writel(port, val, UART_CTL_REG);
431
432 /* read any pending char to make sure all irq status are
433 * cleared */
434 (void)bcm_uart_readl(port, UART_FIFO_REG);
435}
436
437/*
438 * serial core request to initialize uart and start rx operation
439 */
440static int bcm_uart_startup(struct uart_port *port)
441{
442 unsigned int val;
443 int ret;
444
445 /* mask all irq and flush port */
446 bcm_uart_disable(port);
447 bcm_uart_writel(port, 0, UART_IR_REG);
448 bcm_uart_flush(port);
449
450 /* clear any pending external input interrupt */
451 (void)bcm_uart_readl(port, UART_EXTINP_REG);
452
453 /* set rx/tx fifo thresh to fifo half size */
454 val = bcm_uart_readl(port, UART_MCTL_REG);
455 val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
456 val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
457 val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
458 bcm_uart_writel(port, val, UART_MCTL_REG);
459
460 /* set rx fifo timeout to 1 char time */
461 val = bcm_uart_readl(port, UART_CTL_REG);
462 val &= ~UART_CTL_RXTMOUTCNT_MASK;
463 val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
464 bcm_uart_writel(port, val, UART_CTL_REG);
465
466 /* report any edge on dcd and cts */
467 val = UART_EXTINP_INT_MASK;
468 val |= UART_EXTINP_DCD_NOSENSE_MASK;
469 val |= UART_EXTINP_CTS_NOSENSE_MASK;
470 bcm_uart_writel(port, val, UART_EXTINP_REG);
471
472 /* register irq and enable rx interrupts */
473 ret = request_irq(port->irq, bcm_uart_interrupt, 0,
474 dev_name(port->dev), port);
475 if (ret)
476 return ret;
477 bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
478 bcm_uart_enable(port);
479 return 0;
480}
481
482/*
483 * serial core request to flush & disable uart
484 */
485static void bcm_uart_shutdown(struct uart_port *port)
486{
487 unsigned long flags;
488
489 spin_lock_irqsave(&port->lock, flags);
490 bcm_uart_writel(port, 0, UART_IR_REG);
491 spin_unlock_irqrestore(&port->lock, flags);
492
493 bcm_uart_disable(port);
494 bcm_uart_flush(port);
495 free_irq(port->irq, port);
496}
497
498/*
499 * serial core request to change current uart setting
500 */
501static void bcm_uart_set_termios(struct uart_port *port,
502 struct ktermios *new,
503 struct ktermios *old)
504{
505 unsigned int ctl, baud, quot, ier;
506 unsigned long flags;
507 int tries;
508
509 spin_lock_irqsave(&port->lock, flags);
510
511 /* Drain the hot tub fully before we power it off for the winter. */
512 for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
513 mdelay(10);
514
515 /* disable uart while changing speed */
516 bcm_uart_disable(port);
517 bcm_uart_flush(port);
518
519 /* update Control register */
520 ctl = bcm_uart_readl(port, UART_CTL_REG);
521 ctl &= ~UART_CTL_BITSPERSYM_MASK;
522
523 switch (new->c_cflag & CSIZE) {
524 case CS5:
525 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
526 break;
527 case CS6:
528 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
529 break;
530 case CS7:
531 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
532 break;
533 default:
534 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
535 break;
536 }
537
538 ctl &= ~UART_CTL_STOPBITS_MASK;
539 if (new->c_cflag & CSTOPB)
540 ctl |= UART_CTL_STOPBITS_2;
541 else
542 ctl |= UART_CTL_STOPBITS_1;
543
544 ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
545 if (new->c_cflag & PARENB)
546 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
547 ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
548 if (new->c_cflag & PARODD)
549 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
550 bcm_uart_writel(port, ctl, UART_CTL_REG);
551
552 /* update Baudword register */
553 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
554 quot = uart_get_divisor(port, baud) - 1;
555 bcm_uart_writel(port, quot, UART_BAUD_REG);
556
557 /* update Interrupt register */
558 ier = bcm_uart_readl(port, UART_IR_REG);
559
560 ier &= ~UART_IR_MASK(UART_IR_EXTIP);
561 if (UART_ENABLE_MS(port, new->c_cflag))
562 ier |= UART_IR_MASK(UART_IR_EXTIP);
563
564 bcm_uart_writel(port, ier, UART_IR_REG);
565
566 /* update read/ignore mask */
567 port->read_status_mask = UART_FIFO_VALID_MASK;
568 if (new->c_iflag & INPCK) {
569 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
570 port->read_status_mask |= UART_FIFO_PARERR_MASK;
571 }
572 if (new->c_iflag & (IGNBRK | BRKINT))
573 port->read_status_mask |= UART_FIFO_BRKDET_MASK;
574
575 port->ignore_status_mask = 0;
576 if (new->c_iflag & IGNPAR)
577 port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
578 if (new->c_iflag & IGNBRK)
579 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
580 if (!(new->c_cflag & CREAD))
581 port->ignore_status_mask |= UART_FIFO_VALID_MASK;
582
583 uart_update_timeout(port, new->c_cflag, baud);
584 bcm_uart_enable(port);
585 spin_unlock_irqrestore(&port->lock, flags);
586}
587
588/*
589 * serial core request to claim uart iomem
590 */
591static int bcm_uart_request_port(struct uart_port *port)
592{
593 /* UARTs always present */
594 return 0;
595}
596
597/*
598 * serial core request to release uart iomem
599 */
600static void bcm_uart_release_port(struct uart_port *port)
601{
602 /* Nothing to release ... */
603}
604
605/*
606 * serial core request to do any port required autoconfiguration
607 */
608static void bcm_uart_config_port(struct uart_port *port, int flags)
609{
610 if (flags & UART_CONFIG_TYPE) {
611 if (bcm_uart_request_port(port))
612 return;
613 port->type = PORT_BCM63XX;
614 }
615}
616
617/*
618 * serial core request to check that port information in serinfo are
619 * suitable
620 */
621static int bcm_uart_verify_port(struct uart_port *port,
622 struct serial_struct *serinfo)
623{
624 if (port->type != PORT_BCM63XX)
625 return -EINVAL;
626 if (port->irq != serinfo->irq)
627 return -EINVAL;
628 if (port->iotype != serinfo->io_type)
629 return -EINVAL;
630 if (port->mapbase != (unsigned long)serinfo->iomem_base)
631 return -EINVAL;
632 return 0;
633}
634
635/* serial core callbacks */
636static const struct uart_ops bcm_uart_ops = {
637 .tx_empty = bcm_uart_tx_empty,
638 .get_mctrl = bcm_uart_get_mctrl,
639 .set_mctrl = bcm_uart_set_mctrl,
640 .start_tx = bcm_uart_start_tx,
641 .stop_tx = bcm_uart_stop_tx,
642 .stop_rx = bcm_uart_stop_rx,
643 .enable_ms = bcm_uart_enable_ms,
644 .break_ctl = bcm_uart_break_ctl,
645 .startup = bcm_uart_startup,
646 .shutdown = bcm_uart_shutdown,
647 .set_termios = bcm_uart_set_termios,
648 .type = bcm_uart_type,
649 .release_port = bcm_uart_release_port,
650 .request_port = bcm_uart_request_port,
651 .config_port = bcm_uart_config_port,
652 .verify_port = bcm_uart_verify_port,
653};
654
655
656
657#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
658static void wait_for_xmitr(struct uart_port *port)
659{
660 unsigned int tmout;
661
662 /* Wait up to 10ms for the character(s) to be sent. */
663 tmout = 10000;
664 while (--tmout) {
665 unsigned int val;
666
667 val = bcm_uart_readl(port, UART_IR_REG);
668 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
669 break;
670 udelay(1);
671 }
672
673 /* Wait up to 1s for flow control if necessary */
674 if (port->flags & UPF_CONS_FLOW) {
675 tmout = 1000000;
676 while (--tmout) {
677 unsigned int val;
678
679 val = bcm_uart_readl(port, UART_EXTINP_REG);
680 if (val & UART_EXTINP_CTS_MASK)
681 break;
682 udelay(1);
683 }
684 }
685}
686
687/*
688 * output given char
689 */
690static void bcm_console_putchar(struct uart_port *port, int ch)
691{
692 wait_for_xmitr(port);
693 bcm_uart_writel(port, ch, UART_FIFO_REG);
694}
695
696/*
697 * console core request to output given string
698 */
699static void bcm_console_write(struct console *co, const char *s,
700 unsigned int count)
701{
702 struct uart_port *port;
703 unsigned long flags;
704 int locked;
705
706 port = &ports[co->index];
707
708 local_irq_save(flags);
709 if (port->sysrq) {
710 /* bcm_uart_interrupt() already took the lock */
711 locked = 0;
712 } else if (oops_in_progress) {
713 locked = spin_trylock(&port->lock);
714 } else {
715 spin_lock(&port->lock);
716 locked = 1;
717 }
718
719 /* call helper to deal with \r\n */
720 uart_console_write(port, s, count, bcm_console_putchar);
721
722 /* and wait for char to be transmitted */
723 wait_for_xmitr(port);
724
725 if (locked)
726 spin_unlock(&port->lock);
727 local_irq_restore(flags);
728}
729
730/*
731 * console core request to setup given console, find matching uart
732 * port and setup it.
733 */
734static int bcm_console_setup(struct console *co, char *options)
735{
736 struct uart_port *port;
737 int baud = 9600;
738 int bits = 8;
739 int parity = 'n';
740 int flow = 'n';
741
742 if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
743 return -EINVAL;
744 port = &ports[co->index];
745 if (!port->membase)
746 return -ENODEV;
747 if (options)
748 uart_parse_options(options, &baud, &parity, &bits, &flow);
749
750 return uart_set_options(port, co, baud, parity, bits, flow);
751}
752
753static struct uart_driver bcm_uart_driver;
754
755static struct console bcm63xx_console = {
756 .name = "ttyS",
757 .write = bcm_console_write,
758 .device = uart_console_device,
759 .setup = bcm_console_setup,
760 .flags = CON_PRINTBUFFER,
761 .index = -1,
762 .data = &bcm_uart_driver,
763};
764
765static int __init bcm63xx_console_init(void)
766{
767 register_console(&bcm63xx_console);
768 return 0;
769}
770
771console_initcall(bcm63xx_console_init);
772
773static void bcm_early_write(struct console *con, const char *s, unsigned n)
774{
775 struct earlycon_device *dev = con->data;
776
777 uart_console_write(&dev->port, s, n, bcm_console_putchar);
778 wait_for_xmitr(&dev->port);
779}
780
781static int __init bcm_early_console_setup(struct earlycon_device *device,
782 const char *opt)
783{
784 if (!device->port.membase)
785 return -ENODEV;
786
787 device->con->write = bcm_early_write;
788 return 0;
789}
790
791OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
792
793#define BCM63XX_CONSOLE (&bcm63xx_console)
794#else
795#define BCM63XX_CONSOLE NULL
796#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
797
798static struct uart_driver bcm_uart_driver = {
799 .owner = THIS_MODULE,
800 .driver_name = "bcm63xx_uart",
801 .dev_name = "ttyS",
802 .major = TTY_MAJOR,
803 .minor = 64,
804 .nr = BCM63XX_NR_UARTS,
805 .cons = BCM63XX_CONSOLE,
806};
807
808/*
809 * platform driver probe/remove callback
810 */
811static int bcm_uart_probe(struct platform_device *pdev)
812{
813 struct resource *res_mem, *res_irq;
814 struct uart_port *port;
815 struct clk *clk;
816 int ret;
817
818 if (pdev->dev.of_node) {
819 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
820
821 if (pdev->id < 0)
822 pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
823 }
824
825 if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
826 return -EINVAL;
827
828 port = &ports[pdev->id];
829 if (port->membase)
830 return -EBUSY;
831 memset(port, 0, sizeof(*port));
832
833 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
834 if (!res_mem)
835 return -ENODEV;
836
837 port->mapbase = res_mem->start;
838 port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
839 if (IS_ERR(port->membase))
840 return PTR_ERR(port->membase);
841
842 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
843 if (!res_irq)
844 return -ENODEV;
845
846 clk = clk_get(&pdev->dev, "refclk");
847 if (IS_ERR(clk) && pdev->dev.of_node)
848 clk = of_clk_get(pdev->dev.of_node, 0);
849
850 if (IS_ERR(clk))
851 return -ENODEV;
852
853 port->iotype = UPIO_MEM;
854 port->irq = res_irq->start;
855 port->ops = &bcm_uart_ops;
856 port->flags = UPF_BOOT_AUTOCONF;
857 port->dev = &pdev->dev;
858 port->fifosize = 16;
859 port->uartclk = clk_get_rate(clk) / 2;
860 port->line = pdev->id;
861 clk_put(clk);
862
863 ret = uart_add_one_port(&bcm_uart_driver, port);
864 if (ret) {
865 ports[pdev->id].membase = NULL;
866 return ret;
867 }
868 platform_set_drvdata(pdev, port);
869 return 0;
870}
871
872static int bcm_uart_remove(struct platform_device *pdev)
873{
874 struct uart_port *port;
875
876 port = platform_get_drvdata(pdev);
877 uart_remove_one_port(&bcm_uart_driver, port);
878 /* mark port as free */
879 ports[pdev->id].membase = NULL;
880 return 0;
881}
882
883static const struct of_device_id bcm63xx_of_match[] = {
884 { .compatible = "brcm,bcm6345-uart" },
885 { /* sentinel */ }
886};
887MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
888
889/*
890 * platform driver stuff
891 */
892static struct platform_driver bcm_uart_platform_driver = {
893 .probe = bcm_uart_probe,
894 .remove = bcm_uart_remove,
895 .driver = {
896 .name = "bcm63xx_uart",
897 .of_match_table = bcm63xx_of_match,
898 },
899};
900
901static int __init bcm_uart_init(void)
902{
903 int ret;
904
905 ret = uart_register_driver(&bcm_uart_driver);
906 if (ret)
907 return ret;
908
909 ret = platform_driver_register(&bcm_uart_platform_driver);
910 if (ret)
911 uart_unregister_driver(&bcm_uart_driver);
912
913 return ret;
914}
915
916static void __exit bcm_uart_exit(void)
917{
918 platform_driver_unregister(&bcm_uart_platform_driver);
919 uart_unregister_driver(&bcm_uart_driver);
920}
921
922module_init(bcm_uart_init);
923module_exit(bcm_uart_exit);
924
925MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
926MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
927MODULE_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 uart_port_lock_irqsave(port, &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 uart_port_unlock_irqrestore(port, 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_prepare_sysrq_char(port, c))
289 continue;
290
291 if ((cstat & port->ignore_status_mask) == 0)
292 tty_insert_flip_char(tty_port, c, flag);
293
294 } while (--max_count);
295
296 tty_flip_buffer_push(tty_port);
297}
298
299/*
300 * fill tx fifo with chars to send, stop when fifo is about to be full
301 * or when all chars have been sent.
302 */
303static void bcm_uart_do_tx(struct uart_port *port)
304{
305 unsigned int val;
306 bool pending;
307 u8 ch;
308
309 val = bcm_uart_readl(port, UART_MCTL_REG);
310 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
311 pending = uart_port_tx_limited_flags(port, ch, UART_TX_NOSTOP,
312 port->fifosize - val,
313 true,
314 bcm_uart_writel(port, ch, UART_FIFO_REG),
315 ({}));
316 if (pending)
317 return;
318
319 /* nothing to send, disable transmit interrupt */
320 val = bcm_uart_readl(port, UART_IR_REG);
321 val &= ~UART_TX_INT_MASK;
322 bcm_uart_writel(port, val, UART_IR_REG);
323
324 if (uart_tx_stopped(port))
325 bcm_uart_stop_tx(port);
326}
327
328/*
329 * process uart interrupt
330 */
331static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
332{
333 struct uart_port *port;
334 unsigned int irqstat;
335
336 port = dev_id;
337 uart_port_lock(port);
338
339 irqstat = bcm_uart_readl(port, UART_IR_REG);
340 if (irqstat & UART_RX_INT_STAT)
341 bcm_uart_do_rx(port);
342
343 if (irqstat & UART_TX_INT_STAT)
344 bcm_uart_do_tx(port);
345
346 if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
347 unsigned int estat;
348
349 estat = bcm_uart_readl(port, UART_EXTINP_REG);
350 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
351 uart_handle_cts_change(port,
352 estat & UART_EXTINP_CTS_MASK);
353 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
354 uart_handle_dcd_change(port,
355 estat & UART_EXTINP_DCD_MASK);
356 }
357
358 uart_unlock_and_check_sysrq(port);
359 return IRQ_HANDLED;
360}
361
362/*
363 * enable rx & tx operation on uart
364 */
365static void bcm_uart_enable(struct uart_port *port)
366{
367 unsigned int val;
368
369 val = bcm_uart_readl(port, UART_CTL_REG);
370 val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
371 bcm_uart_writel(port, val, UART_CTL_REG);
372}
373
374/*
375 * disable rx & tx operation on uart
376 */
377static void bcm_uart_disable(struct uart_port *port)
378{
379 unsigned int val;
380
381 val = bcm_uart_readl(port, UART_CTL_REG);
382 val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
383 UART_CTL_RXEN_MASK);
384 bcm_uart_writel(port, val, UART_CTL_REG);
385}
386
387/*
388 * clear all unread data in rx fifo and unsent data in tx fifo
389 */
390static void bcm_uart_flush(struct uart_port *port)
391{
392 unsigned int val;
393
394 /* empty rx and tx fifo */
395 val = bcm_uart_readl(port, UART_CTL_REG);
396 val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
397 bcm_uart_writel(port, val, UART_CTL_REG);
398
399 /* read any pending char to make sure all irq status are
400 * cleared */
401 (void)bcm_uart_readl(port, UART_FIFO_REG);
402}
403
404/*
405 * serial core request to initialize uart and start rx operation
406 */
407static int bcm_uart_startup(struct uart_port *port)
408{
409 unsigned int val;
410 int ret;
411
412 /* mask all irq and flush port */
413 bcm_uart_disable(port);
414 bcm_uart_writel(port, 0, UART_IR_REG);
415 bcm_uart_flush(port);
416
417 /* clear any pending external input interrupt */
418 (void)bcm_uart_readl(port, UART_EXTINP_REG);
419
420 /* set rx/tx fifo thresh to fifo half size */
421 val = bcm_uart_readl(port, UART_MCTL_REG);
422 val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
423 val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
424 val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
425 bcm_uart_writel(port, val, UART_MCTL_REG);
426
427 /* set rx fifo timeout to 1 char time */
428 val = bcm_uart_readl(port, UART_CTL_REG);
429 val &= ~UART_CTL_RXTMOUTCNT_MASK;
430 val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
431 bcm_uart_writel(port, val, UART_CTL_REG);
432
433 /* report any edge on dcd and cts */
434 val = UART_EXTINP_INT_MASK;
435 val |= UART_EXTINP_DCD_NOSENSE_MASK;
436 val |= UART_EXTINP_CTS_NOSENSE_MASK;
437 bcm_uart_writel(port, val, UART_EXTINP_REG);
438
439 /* register irq and enable rx interrupts */
440 ret = request_irq(port->irq, bcm_uart_interrupt, 0,
441 dev_name(port->dev), port);
442 if (ret)
443 return ret;
444 bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
445 bcm_uart_enable(port);
446 return 0;
447}
448
449/*
450 * serial core request to flush & disable uart
451 */
452static void bcm_uart_shutdown(struct uart_port *port)
453{
454 unsigned long flags;
455
456 uart_port_lock_irqsave(port, &flags);
457 bcm_uart_writel(port, 0, UART_IR_REG);
458 uart_port_unlock_irqrestore(port, flags);
459
460 bcm_uart_disable(port);
461 bcm_uart_flush(port);
462 free_irq(port->irq, port);
463}
464
465/*
466 * serial core request to change current uart setting
467 */
468static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
469 const struct ktermios *old)
470{
471 unsigned int ctl, baud, quot, ier;
472 unsigned long flags;
473 int tries;
474
475 uart_port_lock_irqsave(port, &flags);
476
477 /* Drain the hot tub fully before we power it off for the winter. */
478 for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
479 mdelay(10);
480
481 /* disable uart while changing speed */
482 bcm_uart_disable(port);
483 bcm_uart_flush(port);
484
485 /* update Control register */
486 ctl = bcm_uart_readl(port, UART_CTL_REG);
487 ctl &= ~UART_CTL_BITSPERSYM_MASK;
488
489 switch (new->c_cflag & CSIZE) {
490 case CS5:
491 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
492 break;
493 case CS6:
494 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
495 break;
496 case CS7:
497 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
498 break;
499 default:
500 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
501 break;
502 }
503
504 ctl &= ~UART_CTL_STOPBITS_MASK;
505 if (new->c_cflag & CSTOPB)
506 ctl |= UART_CTL_STOPBITS_2;
507 else
508 ctl |= UART_CTL_STOPBITS_1;
509
510 ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
511 if (new->c_cflag & PARENB)
512 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
513 ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
514 if (new->c_cflag & PARODD)
515 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
516 bcm_uart_writel(port, ctl, UART_CTL_REG);
517
518 /* update Baudword register */
519 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
520 quot = uart_get_divisor(port, baud) - 1;
521 bcm_uart_writel(port, quot, UART_BAUD_REG);
522
523 /* update Interrupt register */
524 ier = bcm_uart_readl(port, UART_IR_REG);
525
526 ier &= ~UART_IR_MASK(UART_IR_EXTIP);
527 if (UART_ENABLE_MS(port, new->c_cflag))
528 ier |= UART_IR_MASK(UART_IR_EXTIP);
529
530 bcm_uart_writel(port, ier, UART_IR_REG);
531
532 /* update read/ignore mask */
533 port->read_status_mask = UART_FIFO_VALID_MASK;
534 if (new->c_iflag & INPCK) {
535 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
536 port->read_status_mask |= UART_FIFO_PARERR_MASK;
537 }
538 if (new->c_iflag & (IGNBRK | BRKINT))
539 port->read_status_mask |= UART_FIFO_BRKDET_MASK;
540
541 port->ignore_status_mask = 0;
542 if (new->c_iflag & IGNPAR)
543 port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
544 if (new->c_iflag & IGNBRK)
545 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
546 if (!(new->c_cflag & CREAD))
547 port->ignore_status_mask |= UART_FIFO_VALID_MASK;
548
549 uart_update_timeout(port, new->c_cflag, baud);
550 bcm_uart_enable(port);
551 uart_port_unlock_irqrestore(port, flags);
552}
553
554/*
555 * serial core request to claim uart iomem
556 */
557static int bcm_uart_request_port(struct uart_port *port)
558{
559 /* UARTs always present */
560 return 0;
561}
562
563/*
564 * serial core request to release uart iomem
565 */
566static void bcm_uart_release_port(struct uart_port *port)
567{
568 /* Nothing to release ... */
569}
570
571/*
572 * serial core request to do any port required autoconfiguration
573 */
574static void bcm_uart_config_port(struct uart_port *port, int flags)
575{
576 if (flags & UART_CONFIG_TYPE) {
577 if (bcm_uart_request_port(port))
578 return;
579 port->type = PORT_BCM63XX;
580 }
581}
582
583/*
584 * serial core request to check that port information in serinfo are
585 * suitable
586 */
587static int bcm_uart_verify_port(struct uart_port *port,
588 struct serial_struct *serinfo)
589{
590 if (port->type != PORT_BCM63XX)
591 return -EINVAL;
592 if (port->irq != serinfo->irq)
593 return -EINVAL;
594 if (port->iotype != serinfo->io_type)
595 return -EINVAL;
596 if (port->mapbase != (unsigned long)serinfo->iomem_base)
597 return -EINVAL;
598 return 0;
599}
600
601#ifdef CONFIG_CONSOLE_POLL
602/*
603 * return true when outstanding tx equals fifo size
604 */
605static bool bcm_uart_tx_full(struct uart_port *port)
606{
607 unsigned int val;
608
609 val = bcm_uart_readl(port, UART_MCTL_REG);
610 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
611 return !(port->fifosize - val);
612}
613
614static int bcm_uart_poll_get_char(struct uart_port *port)
615{
616 unsigned int iestat;
617
618 iestat = bcm_uart_readl(port, UART_IR_REG);
619 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
620 return NO_POLL_CHAR;
621
622 return bcm_uart_readl(port, UART_FIFO_REG);
623}
624
625static void bcm_uart_poll_put_char(struct uart_port *port, unsigned char c)
626{
627 while (bcm_uart_tx_full(port)) {
628 cpu_relax();
629 }
630
631 bcm_uart_writel(port, c, UART_FIFO_REG);
632}
633#endif
634
635/* serial core callbacks */
636static const struct uart_ops bcm_uart_ops = {
637 .tx_empty = bcm_uart_tx_empty,
638 .get_mctrl = bcm_uart_get_mctrl,
639 .set_mctrl = bcm_uart_set_mctrl,
640 .start_tx = bcm_uart_start_tx,
641 .stop_tx = bcm_uart_stop_tx,
642 .stop_rx = bcm_uart_stop_rx,
643 .enable_ms = bcm_uart_enable_ms,
644 .break_ctl = bcm_uart_break_ctl,
645 .startup = bcm_uart_startup,
646 .shutdown = bcm_uart_shutdown,
647 .set_termios = bcm_uart_set_termios,
648 .type = bcm_uart_type,
649 .release_port = bcm_uart_release_port,
650 .request_port = bcm_uart_request_port,
651 .config_port = bcm_uart_config_port,
652 .verify_port = bcm_uart_verify_port,
653#ifdef CONFIG_CONSOLE_POLL
654 .poll_get_char = bcm_uart_poll_get_char,
655 .poll_put_char = bcm_uart_poll_put_char,
656#endif
657};
658
659
660
661#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
662static void wait_for_xmitr(struct uart_port *port)
663{
664 unsigned int tmout;
665
666 /* Wait up to 10ms for the character(s) to be sent. */
667 tmout = 10000;
668 while (--tmout) {
669 unsigned int val;
670
671 val = bcm_uart_readl(port, UART_IR_REG);
672 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
673 break;
674 udelay(1);
675 }
676
677 /* Wait up to 1s for flow control if necessary */
678 if (port->flags & UPF_CONS_FLOW) {
679 tmout = 1000000;
680 while (--tmout) {
681 unsigned int val;
682
683 val = bcm_uart_readl(port, UART_EXTINP_REG);
684 if (val & UART_EXTINP_CTS_MASK)
685 break;
686 udelay(1);
687 }
688 }
689}
690
691/*
692 * output given char
693 */
694static void bcm_console_putchar(struct uart_port *port, unsigned char ch)
695{
696 wait_for_xmitr(port);
697 bcm_uart_writel(port, ch, UART_FIFO_REG);
698}
699
700/*
701 * console core request to output given string
702 */
703static void bcm_console_write(struct console *co, const char *s,
704 unsigned int count)
705{
706 struct uart_port *port;
707 unsigned long flags;
708 int locked = 1;
709
710 port = &ports[co->index];
711
712 if (oops_in_progress)
713 locked = uart_port_trylock_irqsave(port, &flags);
714 else
715 uart_port_lock_irqsave(port, &flags);
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 uart_port_unlock_irqrestore(port, flags);
725}
726
727/*
728 * console core request to setup given console, find matching uart
729 * port and setup it.
730 */
731static int bcm_console_setup(struct console *co, char *options)
732{
733 struct uart_port *port;
734 int baud = 9600;
735 int bits = 8;
736 int parity = 'n';
737 int flow = 'n';
738
739 if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
740 return -EINVAL;
741 port = &ports[co->index];
742 if (!port->membase)
743 return -ENODEV;
744 if (options)
745 uart_parse_options(options, &baud, &parity, &bits, &flow);
746
747 return uart_set_options(port, co, baud, parity, bits, flow);
748}
749
750static struct uart_driver bcm_uart_driver;
751
752static struct console bcm63xx_console = {
753 .name = "ttyS",
754 .write = bcm_console_write,
755 .device = uart_console_device,
756 .setup = bcm_console_setup,
757 .flags = CON_PRINTBUFFER,
758 .index = -1,
759 .data = &bcm_uart_driver,
760};
761
762static int __init bcm63xx_console_init(void)
763{
764 register_console(&bcm63xx_console);
765 return 0;
766}
767
768console_initcall(bcm63xx_console_init);
769
770static void bcm_early_write(struct console *con, const char *s, unsigned n)
771{
772 struct earlycon_device *dev = con->data;
773
774 uart_console_write(&dev->port, s, n, bcm_console_putchar);
775 wait_for_xmitr(&dev->port);
776}
777
778static int __init bcm_early_console_setup(struct earlycon_device *device,
779 const char *opt)
780{
781 if (!device->port.membase)
782 return -ENODEV;
783
784 device->con->write = bcm_early_write;
785 return 0;
786}
787
788OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
789
790#define BCM63XX_CONSOLE (&bcm63xx_console)
791#else
792#define BCM63XX_CONSOLE NULL
793#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
794
795static struct uart_driver bcm_uart_driver = {
796 .owner = THIS_MODULE,
797 .driver_name = "bcm63xx_uart",
798 .dev_name = "ttyS",
799 .major = TTY_MAJOR,
800 .minor = 64,
801 .nr = BCM63XX_NR_UARTS,
802 .cons = BCM63XX_CONSOLE,
803};
804
805/*
806 * platform driver probe/remove callback
807 */
808static int bcm_uart_probe(struct platform_device *pdev)
809{
810 struct resource *res_mem;
811 struct uart_port *port;
812 struct clk *clk;
813 int ret;
814
815 if (pdev->dev.of_node) {
816 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
817
818 if (pdev->id < 0)
819 pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
820 }
821
822 if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
823 return -EINVAL;
824
825 port = &ports[pdev->id];
826 if (port->membase)
827 return -EBUSY;
828 memset(port, 0, sizeof(*port));
829
830 port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
831 if (IS_ERR(port->membase))
832 return PTR_ERR(port->membase);
833 port->mapbase = res_mem->start;
834
835 ret = platform_get_irq(pdev, 0);
836 if (ret < 0)
837 return ret;
838 port->irq = ret;
839
840 clk = clk_get(&pdev->dev, "refclk");
841 if (IS_ERR(clk) && pdev->dev.of_node)
842 clk = of_clk_get(pdev->dev.of_node, 0);
843
844 if (IS_ERR(clk))
845 return -ENODEV;
846
847 port->iotype = UPIO_MEM;
848 port->ops = &bcm_uart_ops;
849 port->flags = UPF_BOOT_AUTOCONF;
850 port->dev = &pdev->dev;
851 port->fifosize = 16;
852 port->uartclk = clk_get_rate(clk) / 2;
853 port->line = pdev->id;
854 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE);
855 clk_put(clk);
856
857 ret = uart_add_one_port(&bcm_uart_driver, port);
858 if (ret) {
859 ports[pdev->id].membase = NULL;
860 return ret;
861 }
862 platform_set_drvdata(pdev, port);
863 return 0;
864}
865
866static void bcm_uart_remove(struct platform_device *pdev)
867{
868 struct uart_port *port;
869
870 port = platform_get_drvdata(pdev);
871 uart_remove_one_port(&bcm_uart_driver, port);
872 /* mark port as free */
873 ports[pdev->id].membase = NULL;
874}
875
876static const struct of_device_id bcm63xx_of_match[] = {
877 { .compatible = "brcm,bcm6345-uart" },
878 { /* sentinel */ }
879};
880MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
881
882/*
883 * platform driver stuff
884 */
885static struct platform_driver bcm_uart_platform_driver = {
886 .probe = bcm_uart_probe,
887 .remove = bcm_uart_remove,
888 .driver = {
889 .name = "bcm63xx_uart",
890 .of_match_table = bcm63xx_of_match,
891 },
892};
893
894static int __init bcm_uart_init(void)
895{
896 int ret;
897
898 ret = uart_register_driver(&bcm_uart_driver);
899 if (ret)
900 return ret;
901
902 ret = platform_driver_register(&bcm_uart_platform_driver);
903 if (ret)
904 uart_unregister_driver(&bcm_uart_driver);
905
906 return ret;
907}
908
909static void __exit bcm_uart_exit(void)
910{
911 platform_driver_unregister(&bcm_uart_platform_driver);
912 uart_unregister_driver(&bcm_uart_driver);
913}
914
915module_init(bcm_uart_init);
916module_exit(bcm_uart_exit);
917
918MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
919MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
920MODULE_LICENSE("GPL");