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Linux 4.19-rc7
[linux-2.6/btrfs-unstable.git] / drivers / tty / serial / mcf.c
blob7dbfb4cde124be4c6c13e1f4d08ac18cbd534beb
1 // SPDX-License-Identifier: GPL-2.0+
2 /****************************************************************************/
3
4 /*
5 * mcf.c -- Freescale ColdFire UART driver
6 *
7 * (C) Copyright 2003-2007, Greg Ungerer <gerg@uclinux.org>
8 */
9
10 /****************************************************************************/
11
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/module.h>
16 #include <linux/console.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/serial.h>
20 #include <linux/serial_core.h>
21 #include <linux/io.h>
22 #include <linux/uaccess.h>
23 #include <linux/platform_device.h>
24 #include <asm/coldfire.h>
25 #include <asm/mcfsim.h>
26 #include <asm/mcfuart.h>
27 #include <asm/nettel.h>
28
29 /****************************************************************************/
30
31 /*
32 * Some boards implement the DTR/DCD lines using GPIO lines, most
33 * don't. Dummy out the access macros for those that don't. Those
34 * that do should define these macros somewhere in there board
35 * specific inlude files.
36 */
37 #if !defined(mcf_getppdcd)
38 #define mcf_getppdcd(p) (1)
39 #endif
40 #if !defined(mcf_getppdtr)
41 #define mcf_getppdtr(p) (1)
42 #endif
43 #if !defined(mcf_setppdtr)
44 #define mcf_setppdtr(p, v) do { } while (0)
45 #endif
46
47 /****************************************************************************/
48
49 /*
50 * Local per-uart structure.
51 */
52 struct mcf_uart {
53 struct uart_port port;
54 unsigned int sigs; /* Local copy of line sigs */
55 unsigned char imr; /* Local IMR mirror */
56 };
57
58 /****************************************************************************/
59
60 static unsigned int mcf_tx_empty(struct uart_port *port)
61 {
62 return (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXEMPTY) ?
63 TIOCSER_TEMT : 0;
64 }
65
66 /****************************************************************************/
67
68 static unsigned int mcf_get_mctrl(struct uart_port *port)
69 {
70 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
71 unsigned int sigs;
72
73 sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
74 0 : TIOCM_CTS;
75 sigs |= (pp->sigs & TIOCM_RTS);
76 sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
77 sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
78
79 return sigs;
80 }
81
82 /****************************************************************************/
83
84 static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
85 {
86 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
87
88 pp->sigs = sigs;
89 mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
90 if (sigs & TIOCM_RTS)
91 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
92 else
93 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
94 }
95
96 /****************************************************************************/
97
98 static void mcf_start_tx(struct uart_port *port)
99 {
100 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
101
102 if (port->rs485.flags & SER_RS485_ENABLED) {
103 /* Enable Transmitter */
104 writeb(MCFUART_UCR_TXENABLE, port->membase + MCFUART_UCR);
105 /* Manually assert RTS */
106 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
107 }
108 pp->imr |= MCFUART_UIR_TXREADY;
109 writeb(pp->imr, port->membase + MCFUART_UIMR);
110 }
111
112 /****************************************************************************/
113
114 static void mcf_stop_tx(struct uart_port *port)
115 {
116 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
117
118 pp->imr &= ~MCFUART_UIR_TXREADY;
119 writeb(pp->imr, port->membase + MCFUART_UIMR);
120 }
121
122 /****************************************************************************/
123
124 static void mcf_stop_rx(struct uart_port *port)
125 {
126 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
127
128 pp->imr &= ~MCFUART_UIR_RXREADY;
129 writeb(pp->imr, port->membase + MCFUART_UIMR);
130 }
131
132 /****************************************************************************/
133
134 static void mcf_break_ctl(struct uart_port *port, int break_state)
135 {
136 unsigned long flags;
137
138 spin_lock_irqsave(&port->lock, flags);
139 if (break_state == -1)
140 writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
141 else
142 writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
143 spin_unlock_irqrestore(&port->lock, flags);
144 }
145
146 /****************************************************************************/
147
148 static int mcf_startup(struct uart_port *port)
149 {
150 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
151 unsigned long flags;
152
153 spin_lock_irqsave(&port->lock, flags);
154
155 /* Reset UART, get it into known state... */
156 writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
157 writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
158
159 /* Enable the UART transmitter and receiver */
160 writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
161 port->membase + MCFUART_UCR);
162
163 /* Enable RX interrupts now */
164 pp->imr = MCFUART_UIR_RXREADY;
165 writeb(pp->imr, port->membase + MCFUART_UIMR);
166
167 spin_unlock_irqrestore(&port->lock, flags);
168
169 return 0;
170 }
171
172 /****************************************************************************/
173
174 static void mcf_shutdown(struct uart_port *port)
175 {
176 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
177 unsigned long flags;
178
179 spin_lock_irqsave(&port->lock, flags);
180
181 /* Disable all interrupts now */
182 pp->imr = 0;
183 writeb(pp->imr, port->membase + MCFUART_UIMR);
184
185 /* Disable UART transmitter and receiver */
186 writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
187 writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
188
189 spin_unlock_irqrestore(&port->lock, flags);
190 }
191
192 /****************************************************************************/
193
194 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
195 struct ktermios *old)
196 {
197 unsigned long flags;
198 unsigned int baud, baudclk;
199 #if defined(CONFIG_M5272)
200 unsigned int baudfr;
201 #endif
202 unsigned char mr1, mr2;
203
204 baud = uart_get_baud_rate(port, termios, old, 0, 230400);
205 #if defined(CONFIG_M5272)
206 baudclk = (MCF_BUSCLK / baud) / 32;
207 baudfr = (((MCF_BUSCLK / baud) + 1) / 2) % 16;
208 #else
209 baudclk = ((MCF_BUSCLK / baud) + 16) / 32;
210 #endif
211
212 mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
213 mr2 = 0;
214
215 switch (termios->c_cflag & CSIZE) {
216 case CS5: mr1 |= MCFUART_MR1_CS5; break;
217 case CS6: mr1 |= MCFUART_MR1_CS6; break;
218 case CS7: mr1 |= MCFUART_MR1_CS7; break;
219 case CS8:
220 default: mr1 |= MCFUART_MR1_CS8; break;
221 }
222
223 if (termios->c_cflag & PARENB) {
224 if (termios->c_cflag & CMSPAR) {
225 if (termios->c_cflag & PARODD)
226 mr1 |= MCFUART_MR1_PARITYMARK;
227 else
228 mr1 |= MCFUART_MR1_PARITYSPACE;
229 } else {
230 if (termios->c_cflag & PARODD)
231 mr1 |= MCFUART_MR1_PARITYODD;
232 else
233 mr1 |= MCFUART_MR1_PARITYEVEN;
234 }
235 } else {
236 mr1 |= MCFUART_MR1_PARITYNONE;
237 }
238
239 /*
240 * FIXME: port->read_status_mask and port->ignore_status_mask
241 * need to be initialized based on termios settings for
242 * INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
243 */
244
245 if (termios->c_cflag & CSTOPB)
246 mr2 |= MCFUART_MR2_STOP2;
247 else
248 mr2 |= MCFUART_MR2_STOP1;
249
250 if (termios->c_cflag & CRTSCTS) {
251 mr1 |= MCFUART_MR1_RXRTS;
252 mr2 |= MCFUART_MR2_TXCTS;
253 }
254
255 spin_lock_irqsave(&port->lock, flags);
256 if (port->rs485.flags & SER_RS485_ENABLED) {
257 dev_dbg(port->dev, "Setting UART to RS485\n");
258 mr2 |= MCFUART_MR2_TXRTS;
259 }
260
261 uart_update_timeout(port, termios->c_cflag, baud);
262 writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
263 writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
264 writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
265 writeb(mr1, port->membase + MCFUART_UMR);
266 writeb(mr2, port->membase + MCFUART_UMR);
267 writeb((baudclk & 0xff00) >> 8, port->membase + MCFUART_UBG1);
268 writeb((baudclk & 0xff), port->membase + MCFUART_UBG2);
269 #if defined(CONFIG_M5272)
270 writeb((baudfr & 0x0f), port->membase + MCFUART_UFPD);
271 #endif
272 writeb(MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER,
273 port->membase + MCFUART_UCSR);
274 writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
275 port->membase + MCFUART_UCR);
276 spin_unlock_irqrestore(&port->lock, flags);
277 }
278
279 /****************************************************************************/
280
281 static void mcf_rx_chars(struct mcf_uart *pp)
282 {
283 struct uart_port *port = &pp->port;
284 unsigned char status, ch, flag;
285
286 while ((status = readb(port->membase + MCFUART_USR)) & MCFUART_USR_RXREADY) {
287 ch = readb(port->membase + MCFUART_URB);
288 flag = TTY_NORMAL;
289 port->icount.rx++;
290
291 if (status & MCFUART_USR_RXERR) {
292 writeb(MCFUART_UCR_CMDRESETERR,
293 port->membase + MCFUART_UCR);
294
295 if (status & MCFUART_USR_RXBREAK) {
296 port->icount.brk++;
297 if (uart_handle_break(port))
298 continue;
299 } else if (status & MCFUART_USR_RXPARITY) {
300 port->icount.parity++;
301 } else if (status & MCFUART_USR_RXOVERRUN) {
302 port->icount.overrun++;
303 } else if (status & MCFUART_USR_RXFRAMING) {
304 port->icount.frame++;
305 }
306
307 status &= port->read_status_mask;
308
309 if (status & MCFUART_USR_RXBREAK)
310 flag = TTY_BREAK;
311 else if (status & MCFUART_USR_RXPARITY)
312 flag = TTY_PARITY;
313 else if (status & MCFUART_USR_RXFRAMING)
314 flag = TTY_FRAME;
315 }
316
317 if (uart_handle_sysrq_char(port, ch))
318 continue;
319 uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
320 }
321
322 spin_unlock(&port->lock);
323 tty_flip_buffer_push(&port->state->port);
324 spin_lock(&port->lock);
325 }
326
327 /****************************************************************************/
328
329 static void mcf_tx_chars(struct mcf_uart *pp)
330 {
331 struct uart_port *port = &pp->port;
332 struct circ_buf *xmit = &port->state->xmit;
333
334 if (port->x_char) {
335 /* Send special char - probably flow control */
336 writeb(port->x_char, port->membase + MCFUART_UTB);
337 port->x_char = 0;
338 port->icount.tx++;
339 return;
340 }
341
342 while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
343 if (xmit->head == xmit->tail)
344 break;
345 writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
346 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
347 port->icount.tx++;
348 }
349
350 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
351 uart_write_wakeup(port);
352
353 if (xmit->head == xmit->tail) {
354 pp->imr &= ~MCFUART_UIR_TXREADY;
355 writeb(pp->imr, port->membase + MCFUART_UIMR);
356 /* Disable TX to negate RTS automatically */
357 if (port->rs485.flags & SER_RS485_ENABLED)
358 writeb(MCFUART_UCR_TXDISABLE,
359 port->membase + MCFUART_UCR);
360 }
361 }
362
363 /****************************************************************************/
364
365 static irqreturn_t mcf_interrupt(int irq, void *data)
366 {
367 struct uart_port *port = data;
368 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
369 unsigned int isr;
370 irqreturn_t ret = IRQ_NONE;
371
372 isr = readb(port->membase + MCFUART_UISR) & pp->imr;
373
374 spin_lock(&port->lock);
375 if (isr & MCFUART_UIR_RXREADY) {
376 mcf_rx_chars(pp);
377 ret = IRQ_HANDLED;
378 }
379 if (isr & MCFUART_UIR_TXREADY) {
380 mcf_tx_chars(pp);
381 ret = IRQ_HANDLED;
382 }
383 spin_unlock(&port->lock);
384
385 return ret;
386 }
387
388 /****************************************************************************/
389
390 static void mcf_config_port(struct uart_port *port, int flags)
391 {
392 port->type = PORT_MCF;
393 port->fifosize = MCFUART_TXFIFOSIZE;
394
395 /* Clear mask, so no surprise interrupts. */
396 writeb(0, port->membase + MCFUART_UIMR);
397
398 if (request_irq(port->irq, mcf_interrupt, 0, "UART", port))
399 printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
400 "interrupt vector=%d\n", port->line, port->irq);
401 }
402
403 /****************************************************************************/
404
405 static const char *mcf_type(struct uart_port *port)
406 {
407 return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
408 }
409
410 /****************************************************************************/
411
412 static int mcf_request_port(struct uart_port *port)
413 {
414 /* UARTs always present */
415 return 0;
416 }
417
418 /****************************************************************************/
419
420 static void mcf_release_port(struct uart_port *port)
421 {
422 /* Nothing to release... */
423 }
424
425 /****************************************************************************/
426
427 static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
428 {
429 if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
430 return -EINVAL;
431 return 0;
432 }
433
434 /****************************************************************************/
435
436 /* Enable or disable the RS485 support */
437 static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
438 {
439 unsigned char mr1, mr2;
440
441 /* Get mode registers */
442 mr1 = readb(port->membase + MCFUART_UMR);
443 mr2 = readb(port->membase + MCFUART_UMR);
444 if (rs485->flags & SER_RS485_ENABLED) {
445 dev_dbg(port->dev, "Setting UART to RS485\n");
446 /* Automatically negate RTS after TX completes */
447 mr2 |= MCFUART_MR2_TXRTS;
448 } else {
449 dev_dbg(port->dev, "Setting UART to RS232\n");
450 mr2 &= ~MCFUART_MR2_TXRTS;
451 }
452 writeb(mr1, port->membase + MCFUART_UMR);
453 writeb(mr2, port->membase + MCFUART_UMR);
454 port->rs485 = *rs485;
455
456 return 0;
457 }
458
459 /****************************************************************************/
460
461 /*
462 * Define the basic serial functions we support.
463 */
464 static const struct uart_ops mcf_uart_ops = {
465 .tx_empty = mcf_tx_empty,
466 .get_mctrl = mcf_get_mctrl,
467 .set_mctrl = mcf_set_mctrl,
468 .start_tx = mcf_start_tx,
469 .stop_tx = mcf_stop_tx,
470 .stop_rx = mcf_stop_rx,
471 .break_ctl = mcf_break_ctl,
472 .startup = mcf_startup,
473 .shutdown = mcf_shutdown,
474 .set_termios = mcf_set_termios,
475 .type = mcf_type,
476 .request_port = mcf_request_port,
477 .release_port = mcf_release_port,
478 .config_port = mcf_config_port,
479 .verify_port = mcf_verify_port,
480 };
481
482 static struct mcf_uart mcf_ports[4];
483
484 #define MCF_MAXPORTS ARRAY_SIZE(mcf_ports)
485
486 /****************************************************************************/
487 #if defined(CONFIG_SERIAL_MCF_CONSOLE)
488 /****************************************************************************/
489
490 int __init early_mcf_setup(struct mcf_platform_uart *platp)
491 {
492 struct uart_port *port;
493 int i;
494
495 for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
496 port = &mcf_ports[i].port;
497
498 port->line = i;
499 port->type = PORT_MCF;
500 port->mapbase = platp[i].mapbase;
501 port->membase = (platp[i].membase) ? platp[i].membase :
502 (unsigned char __iomem *) port->mapbase;
503 port->iotype = SERIAL_IO_MEM;
504 port->irq = platp[i].irq;
505 port->uartclk = MCF_BUSCLK;
506 port->flags = UPF_BOOT_AUTOCONF;
507 port->rs485_config = mcf_config_rs485;
508 port->ops = &mcf_uart_ops;
509 }
510
511 return 0;
512 }
513
514 /****************************************************************************/
515
516 static void mcf_console_putc(struct console *co, const char c)
517 {
518 struct uart_port *port = &(mcf_ports + co->index)->port;
519 int i;
520
521 for (i = 0; (i < 0x10000); i++) {
522 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
523 break;
524 }
525 writeb(c, port->membase + MCFUART_UTB);
526 for (i = 0; (i < 0x10000); i++) {
527 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
528 break;
529 }
530 }
531
532 /****************************************************************************/
533
534 static void mcf_console_write(struct console *co, const char *s, unsigned int count)
535 {
536 for (; (count); count--, s++) {
537 mcf_console_putc(co, *s);
538 if (*s == '\n')
539 mcf_console_putc(co, '\r');
540 }
541 }
542
543 /****************************************************************************/
544
545 static int __init mcf_console_setup(struct console *co, char *options)
546 {
547 struct uart_port *port;
548 int baud = CONFIG_SERIAL_MCF_BAUDRATE;
549 int bits = 8;
550 int parity = 'n';
551 int flow = 'n';
552
553 if ((co->index < 0) || (co->index >= MCF_MAXPORTS))
554 co->index = 0;
555 port = &mcf_ports[co->index].port;
556 if (port->membase == 0)
557 return -ENODEV;
558
559 if (options)
560 uart_parse_options(options, &baud, &parity, &bits, &flow);
561
562 return uart_set_options(port, co, baud, parity, bits, flow);
563 }
564
565 /****************************************************************************/
566
567 static struct uart_driver mcf_driver;
568
569 static struct console mcf_console = {
570 .name = "ttyS",
571 .write = mcf_console_write,
572 .device = uart_console_device,
573 .setup = mcf_console_setup,
574 .flags = CON_PRINTBUFFER,
575 .index = -1,
576 .data = &mcf_driver,
577 };
578
579 static int __init mcf_console_init(void)
580 {
581 register_console(&mcf_console);
582 return 0;
583 }
584
585 console_initcall(mcf_console_init);
586
587 #define MCF_CONSOLE &mcf_console
588
589 /****************************************************************************/
590 #else
591 /****************************************************************************/
592
593 #define MCF_CONSOLE NULL
594
595 /****************************************************************************/
596 #endif /* CONFIG_SERIAL_MCF_CONSOLE */
597 /****************************************************************************/
598
599 /*
600 * Define the mcf UART driver structure.
601 */
602 static struct uart_driver mcf_driver = {
603 .owner = THIS_MODULE,
604 .driver_name = "mcf",
605 .dev_name = "ttyS",
606 .major = TTY_MAJOR,
607 .minor = 64,
608 .nr = MCF_MAXPORTS,
609 .cons = MCF_CONSOLE,
610 };
611
612 /****************************************************************************/
613
614 static int mcf_probe(struct platform_device *pdev)
615 {
616 struct mcf_platform_uart *platp = dev_get_platdata(&pdev->dev);
617 struct uart_port *port;
618 int i;
619
620 for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
621 port = &mcf_ports[i].port;
622
623 port->line = i;
624 port->type = PORT_MCF;
625 port->mapbase = platp[i].mapbase;
626 port->membase = (platp[i].membase) ? platp[i].membase :
627 (unsigned char __iomem *) platp[i].mapbase;
628 port->dev = &pdev->dev;
629 port->iotype = SERIAL_IO_MEM;
630 port->irq = platp[i].irq;
631 port->uartclk = MCF_BUSCLK;
632 port->ops = &mcf_uart_ops;
633 port->flags = UPF_BOOT_AUTOCONF;
634 port->rs485_config = mcf_config_rs485;
635
636 uart_add_one_port(&mcf_driver, port);
637 }
638
639 return 0;
640 }
641
642 /****************************************************************************/
643
644 static int mcf_remove(struct platform_device *pdev)
645 {
646 struct uart_port *port;
647 int i;
648
649 for (i = 0; (i < MCF_MAXPORTS); i++) {
650 port = &mcf_ports[i].port;
651 if (port)
652 uart_remove_one_port(&mcf_driver, port);
653 }
654
655 return 0;
656 }
657
658 /****************************************************************************/
659
660 static struct platform_driver mcf_platform_driver = {
661 .probe = mcf_probe,
662 .remove = mcf_remove,
663 .driver = {
664 .name = "mcfuart",
665 },
666 };
667
668 /****************************************************************************/
669
670 static int __init mcf_init(void)
671 {
672 int rc;
673
674 printk("ColdFire internal UART serial driver\n");
675
676 rc = uart_register_driver(&mcf_driver);
677 if (rc)
678 return rc;
679 rc = platform_driver_register(&mcf_platform_driver);
680 if (rc) {
681 uart_unregister_driver(&mcf_driver);
682 return rc;
683 }
684 return 0;
685 }
686
687 /****************************************************************************/
688
689 static void __exit mcf_exit(void)
690 {
691 platform_driver_unregister(&mcf_platform_driver);
692 uart_unregister_driver(&mcf_driver);
693 }
694
695 /****************************************************************************/
696
697 module_init(mcf_init);
698 module_exit(mcf_exit);
699
700 MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
701 MODULE_DESCRIPTION("Freescale ColdFire UART driver");
702 MODULE_LICENSE("GPL");
703 MODULE_ALIAS("platform:mcfuart");
704
705 /****************************************************************************/
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