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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
33#include <bcm63xx_clk.h>
34#include <bcm63xx_irq.h>
35#include <bcm63xx_regs.h>
36#include <bcm63xx_io.h>
37
38#define BCM63XX_NR_UARTS 2
39
40static struct uart_port ports[BCM63XX_NR_UARTS];
41
42/*
43 * rx interrupt mask / stat
44 *
45 * mask:
46 * - rx fifo full
47 * - rx fifo above threshold
48 * - rx fifo not empty for too long
49 */
50#define UART_RX_INT_MASK (UART_IR_MASK(UART_IR_RXOVER) | \
51 UART_IR_MASK(UART_IR_RXTHRESH) | \
52 UART_IR_MASK(UART_IR_RXTIMEOUT))
53
54#define UART_RX_INT_STAT (UART_IR_STAT(UART_IR_RXOVER) | \
55 UART_IR_STAT(UART_IR_RXTHRESH) | \
56 UART_IR_STAT(UART_IR_RXTIMEOUT))
57
58/*
59 * tx interrupt mask / stat
60 *
61 * mask:
62 * - tx fifo empty
63 * - tx fifo below threshold
64 */
65#define UART_TX_INT_MASK (UART_IR_MASK(UART_IR_TXEMPTY) | \
66 UART_IR_MASK(UART_IR_TXTRESH))
67
68#define UART_TX_INT_STAT (UART_IR_STAT(UART_IR_TXEMPTY) | \
69 UART_IR_STAT(UART_IR_TXTRESH))
70
71/*
72 * external input interrupt
73 *
74 * mask: any edge on CTS, DCD
75 */
76#define UART_EXTINP_INT_MASK (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
77 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
78
79/*
80 * handy uart register accessor
81 */
82static inline unsigned int bcm_uart_readl(struct uart_port *port,
83 unsigned int offset)
84{
85 return bcm_readl(port->membase + offset);
86}
87
88static inline void bcm_uart_writel(struct uart_port *port,
89 unsigned int value, unsigned int offset)
90{
91 bcm_writel(value, port->membase + offset);
92}
93
94/*
95 * serial core request to check if uart tx fifo is empty
96 */
97static unsigned int bcm_uart_tx_empty(struct uart_port *port)
98{
99 unsigned int val;
100
101 val = bcm_uart_readl(port, UART_IR_REG);
102 return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
103}
104
105/*
106 * serial core request to set RTS and DTR pin state and loopback mode
107 */
108static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
109{
110 unsigned int val;
111
112 val = bcm_uart_readl(port, UART_MCTL_REG);
113 val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
114 /* invert of written value is reflected on the pin */
115 if (!(mctrl & TIOCM_DTR))
116 val |= UART_MCTL_DTR_MASK;
117 if (!(mctrl & TIOCM_RTS))
118 val |= UART_MCTL_RTS_MASK;
119 bcm_uart_writel(port, val, UART_MCTL_REG);
120
121 val = bcm_uart_readl(port, UART_CTL_REG);
122 if (mctrl & TIOCM_LOOP)
123 val |= UART_CTL_LOOPBACK_MASK;
124 else
125 val &= ~UART_CTL_LOOPBACK_MASK;
126 bcm_uart_writel(port, val, UART_CTL_REG);
127}
128
129/*
130 * serial core request to return RI, CTS, DCD and DSR pin state
131 */
132static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
133{
134 unsigned int val, mctrl;
135
136 mctrl = 0;
137 val = bcm_uart_readl(port, UART_EXTINP_REG);
138 if (val & UART_EXTINP_RI_MASK)
139 mctrl |= TIOCM_RI;
140 if (val & UART_EXTINP_CTS_MASK)
141 mctrl |= TIOCM_CTS;
142 if (val & UART_EXTINP_DCD_MASK)
143 mctrl |= TIOCM_CD;
144 if (val & UART_EXTINP_DSR_MASK)
145 mctrl |= TIOCM_DSR;
146 return mctrl;
147}
148
149/*
150 * serial core request to disable tx ASAP (used for flow control)
151 */
152static void bcm_uart_stop_tx(struct uart_port *port)
153{
154 unsigned int val;
155
156 val = bcm_uart_readl(port, UART_CTL_REG);
157 val &= ~(UART_CTL_TXEN_MASK);
158 bcm_uart_writel(port, val, UART_CTL_REG);
159
160 val = bcm_uart_readl(port, UART_IR_REG);
161 val &= ~UART_TX_INT_MASK;
162 bcm_uart_writel(port, val, UART_IR_REG);
163}
164
165/*
166 * serial core request to (re)enable tx
167 */
168static void bcm_uart_start_tx(struct uart_port *port)
169{
170 unsigned int val;
171
172 val = bcm_uart_readl(port, UART_IR_REG);
173 val |= UART_TX_INT_MASK;
174 bcm_uart_writel(port, val, UART_IR_REG);
175
176 val = bcm_uart_readl(port, UART_CTL_REG);
177 val |= UART_CTL_TXEN_MASK;
178 bcm_uart_writel(port, val, UART_CTL_REG);
179}
180
181/*
182 * serial core request to stop rx, called before port shutdown
183 */
184static void bcm_uart_stop_rx(struct uart_port *port)
185{
186 unsigned int val;
187
188 val = bcm_uart_readl(port, UART_IR_REG);
189 val &= ~UART_RX_INT_MASK;
190 bcm_uart_writel(port, val, UART_IR_REG);
191}
192
193/*
194 * serial core request to enable modem status interrupt reporting
195 */
196static void bcm_uart_enable_ms(struct uart_port *port)
197{
198 unsigned int val;
199
200 val = bcm_uart_readl(port, UART_IR_REG);
201 val |= UART_IR_MASK(UART_IR_EXTIP);
202 bcm_uart_writel(port, val, UART_IR_REG);
203}
204
205/*
206 * serial core request to start/stop emitting break char
207 */
208static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
209{
210 unsigned long flags;
211 unsigned int val;
212
213 spin_lock_irqsave(&port->lock, flags);
214
215 val = bcm_uart_readl(port, UART_CTL_REG);
216 if (ctl)
217 val |= UART_CTL_XMITBRK_MASK;
218 else
219 val &= ~UART_CTL_XMITBRK_MASK;
220 bcm_uart_writel(port, val, UART_CTL_REG);
221
222 spin_unlock_irqrestore(&port->lock, flags);
223}
224
225/*
226 * return port type in string format
227 */
228static const char *bcm_uart_type(struct uart_port *port)
229{
230 return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
231}
232
233/*
234 * read all chars in rx fifo and send them to core
235 */
236static void bcm_uart_do_rx(struct uart_port *port)
237{
238 struct tty_struct *tty;
239 unsigned int max_count;
240
241 /* limit number of char read in interrupt, should not be
242 * higher than fifo size anyway since we're much faster than
243 * serial port */
244 max_count = 32;
245 tty = port->state->port.tty;
246 do {
247 unsigned int iestat, c, cstat;
248 char flag;
249
250 /* get overrun/fifo empty information from ier
251 * register */
252 iestat = bcm_uart_readl(port, UART_IR_REG);
253
254 if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
255 unsigned int val;
256
257 /* fifo reset is required to clear
258 * interrupt */
259 val = bcm_uart_readl(port, UART_CTL_REG);
260 val |= UART_CTL_RSTRXFIFO_MASK;
261 bcm_uart_writel(port, val, UART_CTL_REG);
262
263 port->icount.overrun++;
264 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
265 }
266
267 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
268 break;
269
270 cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
271 port->icount.rx++;
272 flag = TTY_NORMAL;
273 c &= 0xff;
274
275 if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
276 /* do stats first */
277 if (cstat & UART_FIFO_BRKDET_MASK) {
278 port->icount.brk++;
279 if (uart_handle_break(port))
280 continue;
281 }
282
283 if (cstat & UART_FIFO_PARERR_MASK)
284 port->icount.parity++;
285 if (cstat & UART_FIFO_FRAMEERR_MASK)
286 port->icount.frame++;
287
288 /* update flag wrt read_status_mask */
289 cstat &= port->read_status_mask;
290 if (cstat & UART_FIFO_BRKDET_MASK)
291 flag = TTY_BREAK;
292 if (cstat & UART_FIFO_FRAMEERR_MASK)
293 flag = TTY_FRAME;
294 if (cstat & UART_FIFO_PARERR_MASK)
295 flag = TTY_PARITY;
296 }
297
298 if (uart_handle_sysrq_char(port, c))
299 continue;
300
301
302 if ((cstat & port->ignore_status_mask) == 0)
303 tty_insert_flip_char(tty, c, flag);
304
305 } while (--max_count);
306
307 tty_flip_buffer_push(tty);
308}
309
310/*
311 * fill tx fifo with chars to send, stop when fifo is about to be full
312 * or when all chars have been sent.
313 */
314static void bcm_uart_do_tx(struct uart_port *port)
315{
316 struct circ_buf *xmit;
317 unsigned int val, max_count;
318
319 if (port->x_char) {
320 bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
321 port->icount.tx++;
322 port->x_char = 0;
323 return;
324 }
325
326 if (uart_tx_stopped(port)) {
327 bcm_uart_stop_tx(port);
328 return;
329 }
330
331 xmit = &port->state->xmit;
332 if (uart_circ_empty(xmit))
333 goto txq_empty;
334
335 val = bcm_uart_readl(port, UART_MCTL_REG);
336 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
337 max_count = port->fifosize - val;
338
339 while (max_count--) {
340 unsigned int c;
341
342 c = xmit->buf[xmit->tail];
343 bcm_uart_writel(port, c, UART_FIFO_REG);
344 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
345 port->icount.tx++;
346 if (uart_circ_empty(xmit))
347 break;
348 }
349
350 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
351 uart_write_wakeup(port);
352
353 if (uart_circ_empty(xmit))
354 goto txq_empty;
355 return;
356
357txq_empty:
358 /* nothing to send, disable transmit interrupt */
359 val = bcm_uart_readl(port, UART_IR_REG);
360 val &= ~UART_TX_INT_MASK;
361 bcm_uart_writel(port, val, UART_IR_REG);
362 return;
363}
364
365/*
366 * process uart interrupt
367 */
368static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
369{
370 struct uart_port *port;
371 unsigned int irqstat;
372
373 port = dev_id;
374 spin_lock(&port->lock);
375
376 irqstat = bcm_uart_readl(port, UART_IR_REG);
377 if (irqstat & UART_RX_INT_STAT)
378 bcm_uart_do_rx(port);
379
380 if (irqstat & UART_TX_INT_STAT)
381 bcm_uart_do_tx(port);
382
383 if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
384 unsigned int estat;
385
386 estat = bcm_uart_readl(port, UART_EXTINP_REG);
387 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
388 uart_handle_cts_change(port,
389 estat & UART_EXTINP_CTS_MASK);
390 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
391 uart_handle_dcd_change(port,
392 estat & UART_EXTINP_DCD_MASK);
393 }
394
395 spin_unlock(&port->lock);
396 return IRQ_HANDLED;
397}
398
399/*
400 * enable rx & tx operation on uart
401 */
402static void bcm_uart_enable(struct uart_port *port)
403{
404 unsigned int val;
405
406 val = bcm_uart_readl(port, UART_CTL_REG);
407 val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
408 bcm_uart_writel(port, val, UART_CTL_REG);
409}
410
411/*
412 * disable rx & tx operation on uart
413 */
414static void bcm_uart_disable(struct uart_port *port)
415{
416 unsigned int val;
417
418 val = bcm_uart_readl(port, UART_CTL_REG);
419 val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
420 UART_CTL_RXEN_MASK);
421 bcm_uart_writel(port, val, UART_CTL_REG);
422}
423
424/*
425 * clear all unread data in rx fifo and unsent data in tx fifo
426 */
427static void bcm_uart_flush(struct uart_port *port)
428{
429 unsigned int val;
430
431 /* empty rx and tx fifo */
432 val = bcm_uart_readl(port, UART_CTL_REG);
433 val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
434 bcm_uart_writel(port, val, UART_CTL_REG);
435
436 /* read any pending char to make sure all irq status are
437 * cleared */
438 (void)bcm_uart_readl(port, UART_FIFO_REG);
439}
440
441/*
442 * serial core request to initialize uart and start rx operation
443 */
444static int bcm_uart_startup(struct uart_port *port)
445{
446 unsigned int val;
447 int ret;
448
449 /* mask all irq and flush port */
450 bcm_uart_disable(port);
451 bcm_uart_writel(port, 0, UART_IR_REG);
452 bcm_uart_flush(port);
453
454 /* clear any pending external input interrupt */
455 (void)bcm_uart_readl(port, UART_EXTINP_REG);
456
457 /* set rx/tx fifo thresh to fifo half size */
458 val = bcm_uart_readl(port, UART_MCTL_REG);
459 val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
460 val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
461 val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
462 bcm_uart_writel(port, val, UART_MCTL_REG);
463
464 /* set rx fifo timeout to 1 char time */
465 val = bcm_uart_readl(port, UART_CTL_REG);
466 val &= ~UART_CTL_RXTMOUTCNT_MASK;
467 val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
468 bcm_uart_writel(port, val, UART_CTL_REG);
469
470 /* report any edge on dcd and cts */
471 val = UART_EXTINP_INT_MASK;
472 val |= UART_EXTINP_DCD_NOSENSE_MASK;
473 val |= UART_EXTINP_CTS_NOSENSE_MASK;
474 bcm_uart_writel(port, val, UART_EXTINP_REG);
475
476 /* register irq and enable rx interrupts */
477 ret = request_irq(port->irq, bcm_uart_interrupt, 0,
478 bcm_uart_type(port), port);
479 if (ret)
480 return ret;
481 bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
482 bcm_uart_enable(port);
483 return 0;
484}
485
486/*
487 * serial core request to flush & disable uart
488 */
489static void bcm_uart_shutdown(struct uart_port *port)
490{
491 unsigned long flags;
492
493 spin_lock_irqsave(&port->lock, flags);
494 bcm_uart_writel(port, 0, UART_IR_REG);
495 spin_unlock_irqrestore(&port->lock, flags);
496
497 bcm_uart_disable(port);
498 bcm_uart_flush(port);
499 free_irq(port->irq, port);
500}
501
502/*
503 * serial core request to change current uart setting
504 */
505static void bcm_uart_set_termios(struct uart_port *port,
506 struct ktermios *new,
507 struct ktermios *old)
508{
509 unsigned int ctl, baud, quot, ier;
510 unsigned long flags;
511
512 spin_lock_irqsave(&port->lock, flags);
513
514 /* disable uart while changing speed */
515 bcm_uart_disable(port);
516 bcm_uart_flush(port);
517
518 /* update Control register */
519 ctl = bcm_uart_readl(port, UART_CTL_REG);
520 ctl &= ~UART_CTL_BITSPERSYM_MASK;
521
522 switch (new->c_cflag & CSIZE) {
523 case CS5:
524 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
525 break;
526 case CS6:
527 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
528 break;
529 case CS7:
530 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
531 break;
532 default:
533 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
534 break;
535 }
536
537 ctl &= ~UART_CTL_STOPBITS_MASK;
538 if (new->c_cflag & CSTOPB)
539 ctl |= UART_CTL_STOPBITS_2;
540 else
541 ctl |= UART_CTL_STOPBITS_1;
542
543 ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
544 if (new->c_cflag & PARENB)
545 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
546 ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
547 if (new->c_cflag & PARODD)
548 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
549 bcm_uart_writel(port, ctl, UART_CTL_REG);
550
551 /* update Baudword register */
552 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
553 quot = uart_get_divisor(port, baud) - 1;
554 bcm_uart_writel(port, quot, UART_BAUD_REG);
555
556 /* update Interrupt register */
557 ier = bcm_uart_readl(port, UART_IR_REG);
558
559 ier &= ~UART_IR_MASK(UART_IR_EXTIP);
560 if (UART_ENABLE_MS(port, new->c_cflag))
561 ier |= UART_IR_MASK(UART_IR_EXTIP);
562
563 bcm_uart_writel(port, ier, UART_IR_REG);
564
565 /* update read/ignore mask */
566 port->read_status_mask = UART_FIFO_VALID_MASK;
567 if (new->c_iflag & INPCK) {
568 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
569 port->read_status_mask |= UART_FIFO_PARERR_MASK;
570 }
571 if (new->c_iflag & (BRKINT))
572 port->read_status_mask |= UART_FIFO_BRKDET_MASK;
573
574 port->ignore_status_mask = 0;
575 if (new->c_iflag & IGNPAR)
576 port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
577 if (new->c_iflag & IGNBRK)
578 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
579 if (!(new->c_cflag & CREAD))
580 port->ignore_status_mask |= UART_FIFO_VALID_MASK;
581
582 uart_update_timeout(port, new->c_cflag, baud);
583 bcm_uart_enable(port);
584 spin_unlock_irqrestore(&port->lock, flags);
585}
586
587/*
588 * serial core request to claim uart iomem
589 */
590static int bcm_uart_request_port(struct uart_port *port)
591{
592 unsigned int size;
593
594 size = RSET_UART_SIZE;
595 if (!request_mem_region(port->mapbase, size, "bcm63xx")) {
596 dev_err(port->dev, "Memory region busy\n");
597 return -EBUSY;
598 }
599
600 port->membase = ioremap(port->mapbase, size);
601 if (!port->membase) {
602 dev_err(port->dev, "Unable to map registers\n");
603 release_mem_region(port->mapbase, size);
604 return -EBUSY;
605 }
606 return 0;
607}
608
609/*
610 * serial core request to release uart iomem
611 */
612static void bcm_uart_release_port(struct uart_port *port)
613{
614 release_mem_region(port->mapbase, RSET_UART_SIZE);
615 iounmap(port->membase);
616}
617
618/*
619 * serial core request to do any port required autoconfiguration
620 */
621static void bcm_uart_config_port(struct uart_port *port, int flags)
622{
623 if (flags & UART_CONFIG_TYPE) {
624 if (bcm_uart_request_port(port))
625 return;
626 port->type = PORT_BCM63XX;
627 }
628}
629
630/*
631 * serial core request to check that port information in serinfo are
632 * suitable
633 */
634static int bcm_uart_verify_port(struct uart_port *port,
635 struct serial_struct *serinfo)
636{
637 if (port->type != PORT_BCM63XX)
638 return -EINVAL;
639 if (port->irq != serinfo->irq)
640 return -EINVAL;
641 if (port->iotype != serinfo->io_type)
642 return -EINVAL;
643 if (port->mapbase != (unsigned long)serinfo->iomem_base)
644 return -EINVAL;
645 return 0;
646}
647
648/* serial core callbacks */
649static struct uart_ops bcm_uart_ops = {
650 .tx_empty = bcm_uart_tx_empty,
651 .get_mctrl = bcm_uart_get_mctrl,
652 .set_mctrl = bcm_uart_set_mctrl,
653 .start_tx = bcm_uart_start_tx,
654 .stop_tx = bcm_uart_stop_tx,
655 .stop_rx = bcm_uart_stop_rx,
656 .enable_ms = bcm_uart_enable_ms,
657 .break_ctl = bcm_uart_break_ctl,
658 .startup = bcm_uart_startup,
659 .shutdown = bcm_uart_shutdown,
660 .set_termios = bcm_uart_set_termios,
661 .type = bcm_uart_type,
662 .release_port = bcm_uart_release_port,
663 .request_port = bcm_uart_request_port,
664 .config_port = bcm_uart_config_port,
665 .verify_port = bcm_uart_verify_port,
666};
667
668
669
670#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
671static inline void wait_for_xmitr(struct uart_port *port)
672{
673 unsigned int tmout;
674
675 /* Wait up to 10ms for the character(s) to be sent. */
676 tmout = 10000;
677 while (--tmout) {
678 unsigned int val;
679
680 val = bcm_uart_readl(port, UART_IR_REG);
681 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
682 break;
683 udelay(1);
684 }
685
686 /* Wait up to 1s for flow control if necessary */
687 if (port->flags & UPF_CONS_FLOW) {
688 tmout = 1000000;
689 while (--tmout) {
690 unsigned int val;
691
692 val = bcm_uart_readl(port, UART_EXTINP_REG);
693 if (val & UART_EXTINP_CTS_MASK)
694 break;
695 udelay(1);
696 }
697 }
698}
699
700/*
701 * output given char
702 */
703static void bcm_console_putchar(struct uart_port *port, int ch)
704{
705 wait_for_xmitr(port);
706 bcm_uart_writel(port, ch, UART_FIFO_REG);
707}
708
709/*
710 * console core request to output given string
711 */
712static void bcm_console_write(struct console *co, const char *s,
713 unsigned int count)
714{
715 struct uart_port *port;
716 unsigned long flags;
717 int locked;
718
719 port = &ports[co->index];
720
721 local_irq_save(flags);
722 if (port->sysrq) {
723 /* bcm_uart_interrupt() already took the lock */
724 locked = 0;
725 } else if (oops_in_progress) {
726 locked = spin_trylock(&port->lock);
727 } else {
728 spin_lock(&port->lock);
729 locked = 1;
730 }
731
732 /* call helper to deal with \r\n */
733 uart_console_write(port, s, count, bcm_console_putchar);
734
735 /* and wait for char to be transmitted */
736 wait_for_xmitr(port);
737
738 if (locked)
739 spin_unlock(&port->lock);
740 local_irq_restore(flags);
741}
742
743/*
744 * console core request to setup given console, find matching uart
745 * port and setup it.
746 */
747static int bcm_console_setup(struct console *co, char *options)
748{
749 struct uart_port *port;
750 int baud = 9600;
751 int bits = 8;
752 int parity = 'n';
753 int flow = 'n';
754
755 if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
756 return -EINVAL;
757 port = &ports[co->index];
758 if (!port->membase)
759 return -ENODEV;
760 if (options)
761 uart_parse_options(options, &baud, &parity, &bits, &flow);
762
763 return uart_set_options(port, co, baud, parity, bits, flow);
764}
765
766static struct uart_driver bcm_uart_driver;
767
768static struct console bcm63xx_console = {
769 .name = "ttyS",
770 .write = bcm_console_write,
771 .device = uart_console_device,
772 .setup = bcm_console_setup,
773 .flags = CON_PRINTBUFFER,
774 .index = -1,
775 .data = &bcm_uart_driver,
776};
777
778static int __init bcm63xx_console_init(void)
779{
780 register_console(&bcm63xx_console);
781 return 0;
782}
783
784console_initcall(bcm63xx_console_init);
785
786#define BCM63XX_CONSOLE (&bcm63xx_console)
787#else
788#define BCM63XX_CONSOLE NULL
789#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
790
791static struct uart_driver bcm_uart_driver = {
792 .owner = THIS_MODULE,
793 .driver_name = "bcm63xx_uart",
794 .dev_name = "ttyS",
795 .major = TTY_MAJOR,
796 .minor = 64,
797 .nr = BCM63XX_NR_UARTS,
798 .cons = BCM63XX_CONSOLE,
799};
800
801/*
802 * platform driver probe/remove callback
803 */
804static int __devinit bcm_uart_probe(struct platform_device *pdev)
805{
806 struct resource *res_mem, *res_irq;
807 struct uart_port *port;
808 struct clk *clk;
809 int ret;
810
811 if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
812 return -EINVAL;
813
814 if (ports[pdev->id].membase)
815 return -EBUSY;
816
817 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
818 if (!res_mem)
819 return -ENODEV;
820
821 res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
822 if (!res_irq)
823 return -ENODEV;
824
825 clk = clk_get(&pdev->dev, "periph");
826 if (IS_ERR(clk))
827 return -ENODEV;
828
829 port = &ports[pdev->id];
830 memset(port, 0, sizeof(*port));
831 port->iotype = UPIO_MEM;
832 port->mapbase = res_mem->start;
833 port->irq = res_irq->start;
834 port->ops = &bcm_uart_ops;
835 port->flags = UPF_BOOT_AUTOCONF;
836 port->dev = &pdev->dev;
837 port->fifosize = 16;
838 port->uartclk = clk_get_rate(clk) / 2;
839 port->line = pdev->id;
840 clk_put(clk);
841
842 ret = uart_add_one_port(&bcm_uart_driver, port);
843 if (ret) {
844 ports[pdev->id].membase = 0;
845 return ret;
846 }
847 platform_set_drvdata(pdev, port);
848 return 0;
849}
850
851static int __devexit bcm_uart_remove(struct platform_device *pdev)
852{
853 struct uart_port *port;
854
855 port = platform_get_drvdata(pdev);
856 uart_remove_one_port(&bcm_uart_driver, port);
857 platform_set_drvdata(pdev, NULL);
858 /* mark port as free */
859 ports[pdev->id].membase = 0;
860 return 0;
861}
862
863/*
864 * platform driver stuff
865 */
866static struct platform_driver bcm_uart_platform_driver = {
867 .probe = bcm_uart_probe,
868 .remove = __devexit_p(bcm_uart_remove),
869 .driver = {
870 .owner = THIS_MODULE,
871 .name = "bcm63xx_uart",
872 },
873};
874
875static int __init bcm_uart_init(void)
876{
877 int ret;
878
879 ret = uart_register_driver(&bcm_uart_driver);
880 if (ret)
881 return ret;
882
883 ret = platform_driver_register(&bcm_uart_platform_driver);
884 if (ret)
885 uart_unregister_driver(&bcm_uart_driver);
886
887 return ret;
888}
889
890static void __exit bcm_uart_exit(void)
891{
892 platform_driver_unregister(&bcm_uart_platform_driver);
893 uart_unregister_driver(&bcm_uart_driver);
894}
895
896module_init(bcm_uart_init);
897module_exit(bcm_uart_exit);
898
899MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
900MODULE_DESCRIPTION("Broadcom 63<xx integrated uart driver");
901MODULE_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");