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