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
31 static 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 */
bcm_uart_readl(struct uart_port * port,unsigned int offset)73 static inline unsigned int bcm_uart_readl(struct uart_port *port,
74 unsigned int offset)
75 {
76 return __raw_readl(port->membase + offset);
77 }
78
bcm_uart_writel(struct uart_port * port,unsigned int value,unsigned int offset)79 static 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 */
bcm_uart_tx_empty(struct uart_port * port)88 static 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 */
bcm_uart_set_mctrl(struct uart_port * port,unsigned int mctrl)99 static 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 */
bcm_uart_get_mctrl(struct uart_port * port)123 static 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 */
bcm_uart_stop_tx(struct uart_port * port)143 static 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 */
bcm_uart_start_tx(struct uart_port * port)159 static 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 */
bcm_uart_stop_rx(struct uart_port * port)175 static 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 */
bcm_uart_enable_ms(struct uart_port * port)187 static 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 */
bcm_uart_break_ctl(struct uart_port * port,int ctl)199 static 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 */
bcm_uart_type(struct uart_port * port)219 static 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 */
bcm_uart_do_rx(struct uart_port * port)227 static 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 */
bcm_uart_do_tx(struct uart_port * port)304 static 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 */
bcm_uart_interrupt(int irq,void * dev_id)329 static 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 */
bcm_uart_enable(struct uart_port * port)363 static 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 */
bcm_uart_disable(struct uart_port * port)375 static 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 */
bcm_uart_flush(struct uart_port * port)388 static 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 */
bcm_uart_startup(struct uart_port * port)405 static 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 */
bcm_uart_shutdown(struct uart_port * port)450 static 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 */
bcm_uart_set_termios(struct uart_port * port,struct ktermios * new,const struct ktermios * old)466 static 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 */
bcm_uart_request_port(struct uart_port * port)555 static 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 */
bcm_uart_release_port(struct uart_port * port)564 static 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 */
bcm_uart_config_port(struct uart_port * port,int flags)572 static 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 */
bcm_uart_verify_port(struct uart_port * port,struct serial_struct * serinfo)585 static 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 #ifdef CONFIG_CONSOLE_POLL
600 /*
601 * return true when outstanding tx equals fifo size
602 */
bcm_uart_tx_full(struct uart_port * port)603 static bool bcm_uart_tx_full(struct uart_port *port)
604 {
605 unsigned int val;
606
607 val = bcm_uart_readl(port, UART_MCTL_REG);
608 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
609 return !(port->fifosize - val);
610 }
611
bcm_uart_poll_get_char(struct uart_port * port)612 static int bcm_uart_poll_get_char(struct uart_port *port)
613 {
614 unsigned int iestat;
615
616 iestat = bcm_uart_readl(port, UART_IR_REG);
617 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
618 return NO_POLL_CHAR;
619
620 return bcm_uart_readl(port, UART_FIFO_REG);
621 }
622
bcm_uart_poll_put_char(struct uart_port * port,unsigned char c)623 static void bcm_uart_poll_put_char(struct uart_port *port, unsigned char c)
624 {
625 while (bcm_uart_tx_full(port)) {
626 cpu_relax();
627 }
628
629 bcm_uart_writel(port, c, UART_FIFO_REG);
630 }
631 #endif
632
633 /* serial core callbacks */
634 static const 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 #ifdef CONFIG_CONSOLE_POLL
652 .poll_get_char = bcm_uart_poll_get_char,
653 .poll_put_char = bcm_uart_poll_put_char,
654 #endif
655 };
656
657
658
659 #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
wait_for_xmitr(struct uart_port * port)660 static void wait_for_xmitr(struct uart_port *port)
661 {
662 unsigned int tmout;
663
664 /* Wait up to 10ms for the character(s) to be sent. */
665 tmout = 10000;
666 while (--tmout) {
667 unsigned int val;
668
669 val = bcm_uart_readl(port, UART_IR_REG);
670 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
671 break;
672 udelay(1);
673 }
674
675 /* Wait up to 1s for flow control if necessary */
676 if (port->flags & UPF_CONS_FLOW) {
677 tmout = 1000000;
678 while (--tmout) {
679 unsigned int val;
680
681 val = bcm_uart_readl(port, UART_EXTINP_REG);
682 if (val & UART_EXTINP_CTS_MASK)
683 break;
684 udelay(1);
685 }
686 }
687 }
688
689 /*
690 * output given char
691 */
bcm_console_putchar(struct uart_port * port,unsigned char ch)692 static void bcm_console_putchar(struct uart_port *port, unsigned char ch)
693 {
694 wait_for_xmitr(port);
695 bcm_uart_writel(port, ch, UART_FIFO_REG);
696 }
697
698 /*
699 * console core request to output given string
700 */
bcm_console_write(struct console * co,const char * s,unsigned int count)701 static void bcm_console_write(struct console *co, const char *s,
702 unsigned int count)
703 {
704 struct uart_port *port;
705 unsigned long flags;
706 int locked;
707
708 port = &ports[co->index];
709
710 local_irq_save(flags);
711 if (port->sysrq) {
712 /* bcm_uart_interrupt() already took the lock */
713 locked = 0;
714 } else if (oops_in_progress) {
715 locked = spin_trylock(&port->lock);
716 } else {
717 spin_lock(&port->lock);
718 locked = 1;
719 }
720
721 /* call helper to deal with \r\n */
722 uart_console_write(port, s, count, bcm_console_putchar);
723
724 /* and wait for char to be transmitted */
725 wait_for_xmitr(port);
726
727 if (locked)
728 spin_unlock(&port->lock);
729 local_irq_restore(flags);
730 }
731
732 /*
733 * console core request to setup given console, find matching uart
734 * port and setup it.
735 */
bcm_console_setup(struct console * co,char * options)736 static int bcm_console_setup(struct console *co, char *options)
737 {
738 struct uart_port *port;
739 int baud = 9600;
740 int bits = 8;
741 int parity = 'n';
742 int flow = 'n';
743
744 if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
745 return -EINVAL;
746 port = &ports[co->index];
747 if (!port->membase)
748 return -ENODEV;
749 if (options)
750 uart_parse_options(options, &baud, &parity, &bits, &flow);
751
752 return uart_set_options(port, co, baud, parity, bits, flow);
753 }
754
755 static struct uart_driver bcm_uart_driver;
756
757 static struct console bcm63xx_console = {
758 .name = "ttyS",
759 .write = bcm_console_write,
760 .device = uart_console_device,
761 .setup = bcm_console_setup,
762 .flags = CON_PRINTBUFFER,
763 .index = -1,
764 .data = &bcm_uart_driver,
765 };
766
bcm63xx_console_init(void)767 static int __init bcm63xx_console_init(void)
768 {
769 register_console(&bcm63xx_console);
770 return 0;
771 }
772
773 console_initcall(bcm63xx_console_init);
774
bcm_early_write(struct console * con,const char * s,unsigned n)775 static void bcm_early_write(struct console *con, const char *s, unsigned n)
776 {
777 struct earlycon_device *dev = con->data;
778
779 uart_console_write(&dev->port, s, n, bcm_console_putchar);
780 wait_for_xmitr(&dev->port);
781 }
782
bcm_early_console_setup(struct earlycon_device * device,const char * opt)783 static int __init bcm_early_console_setup(struct earlycon_device *device,
784 const char *opt)
785 {
786 if (!device->port.membase)
787 return -ENODEV;
788
789 device->con->write = bcm_early_write;
790 return 0;
791 }
792
793 OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
794
795 #define BCM63XX_CONSOLE (&bcm63xx_console)
796 #else
797 #define BCM63XX_CONSOLE NULL
798 #endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
799
800 static struct uart_driver bcm_uart_driver = {
801 .owner = THIS_MODULE,
802 .driver_name = "bcm63xx_uart",
803 .dev_name = "ttyS",
804 .major = TTY_MAJOR,
805 .minor = 64,
806 .nr = BCM63XX_NR_UARTS,
807 .cons = BCM63XX_CONSOLE,
808 };
809
810 /*
811 * platform driver probe/remove callback
812 */
bcm_uart_probe(struct platform_device * pdev)813 static int bcm_uart_probe(struct platform_device *pdev)
814 {
815 struct resource *res_mem;
816 struct uart_port *port;
817 struct clk *clk;
818 int ret;
819
820 if (pdev->dev.of_node) {
821 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
822
823 if (pdev->id < 0)
824 pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
825 }
826
827 if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
828 return -EINVAL;
829
830 port = &ports[pdev->id];
831 if (port->membase)
832 return -EBUSY;
833 memset(port, 0, sizeof(*port));
834
835 port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
836 if (IS_ERR(port->membase))
837 return PTR_ERR(port->membase);
838 port->mapbase = res_mem->start;
839
840 ret = platform_get_irq(pdev, 0);
841 if (ret < 0)
842 return ret;
843 port->irq = ret;
844
845 clk = clk_get(&pdev->dev, "refclk");
846 if (IS_ERR(clk) && pdev->dev.of_node)
847 clk = of_clk_get(pdev->dev.of_node, 0);
848
849 if (IS_ERR(clk))
850 return -ENODEV;
851
852 port->iotype = UPIO_MEM;
853 port->ops = &bcm_uart_ops;
854 port->flags = UPF_BOOT_AUTOCONF;
855 port->dev = &pdev->dev;
856 port->fifosize = 16;
857 port->uartclk = clk_get_rate(clk) / 2;
858 port->line = pdev->id;
859 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE);
860 clk_put(clk);
861
862 ret = uart_add_one_port(&bcm_uart_driver, port);
863 if (ret) {
864 ports[pdev->id].membase = NULL;
865 return ret;
866 }
867 platform_set_drvdata(pdev, port);
868 return 0;
869 }
870
bcm_uart_remove(struct platform_device * pdev)871 static int bcm_uart_remove(struct platform_device *pdev)
872 {
873 struct uart_port *port;
874
875 port = platform_get_drvdata(pdev);
876 uart_remove_one_port(&bcm_uart_driver, port);
877 /* mark port as free */
878 ports[pdev->id].membase = NULL;
879 return 0;
880 }
881
882 static const struct of_device_id bcm63xx_of_match[] = {
883 { .compatible = "brcm,bcm6345-uart" },
884 { /* sentinel */ }
885 };
886 MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
887
888 /*
889 * platform driver stuff
890 */
891 static struct platform_driver bcm_uart_platform_driver = {
892 .probe = bcm_uart_probe,
893 .remove = bcm_uart_remove,
894 .driver = {
895 .name = "bcm63xx_uart",
896 .of_match_table = bcm63xx_of_match,
897 },
898 };
899
bcm_uart_init(void)900 static int __init bcm_uart_init(void)
901 {
902 int ret;
903
904 ret = uart_register_driver(&bcm_uart_driver);
905 if (ret)
906 return ret;
907
908 ret = platform_driver_register(&bcm_uart_platform_driver);
909 if (ret)
910 uart_unregister_driver(&bcm_uart_driver);
911
912 return ret;
913 }
914
bcm_uart_exit(void)915 static void __exit bcm_uart_exit(void)
916 {
917 platform_driver_unregister(&bcm_uart_platform_driver);
918 uart_unregister_driver(&bcm_uart_driver);
919 }
920
921 module_init(bcm_uart_init);
922 module_exit(bcm_uart_exit);
923
924 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
925 MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
926 MODULE_LICENSE("GPL");
927