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
mcf_tx_empty(struct uart_port * port)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
mcf_get_mctrl(struct uart_port * port)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
mcf_set_mctrl(struct uart_port * port,unsigned int sigs)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
mcf_start_tx(struct uart_port * port)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
mcf_stop_tx(struct uart_port * port)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
mcf_stop_rx(struct uart_port * port)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
mcf_break_ctl(struct uart_port * port,int break_state)134 static void mcf_break_ctl(struct uart_port *port, int break_state)
135 {
136 unsigned long flags;
137
138 uart_port_lock_irqsave(port, &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 uart_port_unlock_irqrestore(port, flags);
144 }
145
146 /****************************************************************************/
147
mcf_startup(struct uart_port * port)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 uart_port_lock_irqsave(port, &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 uart_port_unlock_irqrestore(port, flags);
168
169 return 0;
170 }
171
172 /****************************************************************************/
173
mcf_shutdown(struct uart_port * port)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 uart_port_lock_irqsave(port, &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 uart_port_unlock_irqrestore(port, flags);
190 }
191
192 /****************************************************************************/
193
mcf_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)194 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
195 const 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 uart_port_lock_irqsave(port, &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 uart_port_unlock_irqrestore(port, flags);
277 }
278
279 /****************************************************************************/
280
mcf_rx_chars(struct mcf_uart * pp)281 static void mcf_rx_chars(struct mcf_uart *pp)
282 {
283 struct uart_port *port = &pp->port;
284 u8 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 tty_flip_buffer_push(&port->state->port);
323 }
324
325 /****************************************************************************/
326
mcf_tx_chars(struct mcf_uart * pp)327 static void mcf_tx_chars(struct mcf_uart *pp)
328 {
329 struct uart_port *port = &pp->port;
330 bool pending;
331 u8 ch;
332
333 pending = uart_port_tx(port, ch,
334 readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY,
335 writeb(ch, port->membase + MCFUART_UTB));
336
337 /* Disable TX to negate RTS automatically */
338 if (!pending && (port->rs485.flags & SER_RS485_ENABLED))
339 writeb(MCFUART_UCR_TXDISABLE, port->membase + MCFUART_UCR);
340 }
341
342 /****************************************************************************/
343
mcf_interrupt(int irq,void * data)344 static irqreturn_t mcf_interrupt(int irq, void *data)
345 {
346 struct uart_port *port = data;
347 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
348 unsigned int isr;
349 irqreturn_t ret = IRQ_NONE;
350
351 isr = readb(port->membase + MCFUART_UISR) & pp->imr;
352
353 uart_port_lock(port);
354 if (isr & MCFUART_UIR_RXREADY) {
355 mcf_rx_chars(pp);
356 ret = IRQ_HANDLED;
357 }
358 if (isr & MCFUART_UIR_TXREADY) {
359 mcf_tx_chars(pp);
360 ret = IRQ_HANDLED;
361 }
362 uart_port_unlock(port);
363
364 return ret;
365 }
366
367 /****************************************************************************/
368
mcf_config_port(struct uart_port * port,int flags)369 static void mcf_config_port(struct uart_port *port, int flags)
370 {
371 port->type = PORT_MCF;
372 port->fifosize = MCFUART_TXFIFOSIZE;
373
374 /* Clear mask, so no surprise interrupts. */
375 writeb(0, port->membase + MCFUART_UIMR);
376
377 if (request_irq(port->irq, mcf_interrupt, 0, "UART", port))
378 printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
379 "interrupt vector=%d\n", port->line, port->irq);
380 }
381
382 /****************************************************************************/
383
mcf_type(struct uart_port * port)384 static const char *mcf_type(struct uart_port *port)
385 {
386 return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
387 }
388
389 /****************************************************************************/
390
mcf_request_port(struct uart_port * port)391 static int mcf_request_port(struct uart_port *port)
392 {
393 /* UARTs always present */
394 return 0;
395 }
396
397 /****************************************************************************/
398
mcf_release_port(struct uart_port * port)399 static void mcf_release_port(struct uart_port *port)
400 {
401 /* Nothing to release... */
402 }
403
404 /****************************************************************************/
405
mcf_verify_port(struct uart_port * port,struct serial_struct * ser)406 static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
407 {
408 if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
409 return -EINVAL;
410 return 0;
411 }
412
413 /****************************************************************************/
414
415 /* Enable or disable the RS485 support */
mcf_config_rs485(struct uart_port * port,struct ktermios * termios,struct serial_rs485 * rs485)416 static int mcf_config_rs485(struct uart_port *port, struct ktermios *termios,
417 struct serial_rs485 *rs485)
418 {
419 unsigned char mr1, mr2;
420
421 /* Get mode registers */
422 mr1 = readb(port->membase + MCFUART_UMR);
423 mr2 = readb(port->membase + MCFUART_UMR);
424 if (rs485->flags & SER_RS485_ENABLED) {
425 dev_dbg(port->dev, "Setting UART to RS485\n");
426 /* Automatically negate RTS after TX completes */
427 mr2 |= MCFUART_MR2_TXRTS;
428 } else {
429 dev_dbg(port->dev, "Setting UART to RS232\n");
430 mr2 &= ~MCFUART_MR2_TXRTS;
431 }
432 writeb(mr1, port->membase + MCFUART_UMR);
433 writeb(mr2, port->membase + MCFUART_UMR);
434
435 return 0;
436 }
437
438 static const struct serial_rs485 mcf_rs485_supported = {
439 .flags = SER_RS485_ENABLED | SER_RS485_RTS_AFTER_SEND,
440 };
441
442 /****************************************************************************/
443
444 /*
445 * Define the basic serial functions we support.
446 */
447 static const struct uart_ops mcf_uart_ops = {
448 .tx_empty = mcf_tx_empty,
449 .get_mctrl = mcf_get_mctrl,
450 .set_mctrl = mcf_set_mctrl,
451 .start_tx = mcf_start_tx,
452 .stop_tx = mcf_stop_tx,
453 .stop_rx = mcf_stop_rx,
454 .break_ctl = mcf_break_ctl,
455 .startup = mcf_startup,
456 .shutdown = mcf_shutdown,
457 .set_termios = mcf_set_termios,
458 .type = mcf_type,
459 .request_port = mcf_request_port,
460 .release_port = mcf_release_port,
461 .config_port = mcf_config_port,
462 .verify_port = mcf_verify_port,
463 };
464
465 static struct mcf_uart mcf_ports[4];
466
467 #define MCF_MAXPORTS ARRAY_SIZE(mcf_ports)
468
469 /****************************************************************************/
470 #if defined(CONFIG_SERIAL_MCF_CONSOLE)
471 /****************************************************************************/
472
mcf_console_putc(struct console * co,const char c)473 static void mcf_console_putc(struct console *co, const char c)
474 {
475 struct uart_port *port = &(mcf_ports + co->index)->port;
476 int i;
477
478 for (i = 0; (i < 0x10000); i++) {
479 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
480 break;
481 }
482 writeb(c, port->membase + MCFUART_UTB);
483 for (i = 0; (i < 0x10000); i++) {
484 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
485 break;
486 }
487 }
488
489 /****************************************************************************/
490
mcf_console_write(struct console * co,const char * s,unsigned int count)491 static void mcf_console_write(struct console *co, const char *s, unsigned int count)
492 {
493 for (; (count); count--, s++) {
494 mcf_console_putc(co, *s);
495 if (*s == '\n')
496 mcf_console_putc(co, '\r');
497 }
498 }
499
500 /****************************************************************************/
501
mcf_console_setup(struct console * co,char * options)502 static int __init mcf_console_setup(struct console *co, char *options)
503 {
504 struct uart_port *port;
505 int baud = CONFIG_SERIAL_MCF_BAUDRATE;
506 int bits = 8;
507 int parity = 'n';
508 int flow = 'n';
509
510 if ((co->index < 0) || (co->index >= MCF_MAXPORTS))
511 co->index = 0;
512 port = &mcf_ports[co->index].port;
513 if (port->membase == 0)
514 return -ENODEV;
515
516 if (options)
517 uart_parse_options(options, &baud, &parity, &bits, &flow);
518
519 return uart_set_options(port, co, baud, parity, bits, flow);
520 }
521
522 /****************************************************************************/
523
524 static struct uart_driver mcf_driver;
525
526 static struct console mcf_console = {
527 .name = "ttyS",
528 .write = mcf_console_write,
529 .device = uart_console_device,
530 .setup = mcf_console_setup,
531 .flags = CON_PRINTBUFFER,
532 .index = -1,
533 .data = &mcf_driver,
534 };
535
mcf_console_init(void)536 static int __init mcf_console_init(void)
537 {
538 register_console(&mcf_console);
539 return 0;
540 }
541
542 console_initcall(mcf_console_init);
543
544 #define MCF_CONSOLE &mcf_console
545
546 /****************************************************************************/
547 #else
548 /****************************************************************************/
549
550 #define MCF_CONSOLE NULL
551
552 /****************************************************************************/
553 #endif /* CONFIG_SERIAL_MCF_CONSOLE */
554 /****************************************************************************/
555
556 /*
557 * Define the mcf UART driver structure.
558 */
559 static struct uart_driver mcf_driver = {
560 .owner = THIS_MODULE,
561 .driver_name = "mcf",
562 .dev_name = "ttyS",
563 .major = TTY_MAJOR,
564 .minor = 64,
565 .nr = MCF_MAXPORTS,
566 .cons = MCF_CONSOLE,
567 };
568
569 /****************************************************************************/
570
mcf_probe(struct platform_device * pdev)571 static int mcf_probe(struct platform_device *pdev)
572 {
573 struct mcf_platform_uart *platp = dev_get_platdata(&pdev->dev);
574 struct uart_port *port;
575 int i;
576
577 for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
578 port = &mcf_ports[i].port;
579
580 port->line = i;
581 port->type = PORT_MCF;
582 port->mapbase = platp[i].mapbase;
583 port->membase = (platp[i].membase) ? platp[i].membase :
584 (unsigned char __iomem *) platp[i].mapbase;
585 port->dev = &pdev->dev;
586 port->iotype = SERIAL_IO_MEM;
587 port->irq = platp[i].irq;
588 port->uartclk = MCF_BUSCLK;
589 port->ops = &mcf_uart_ops;
590 port->flags = UPF_BOOT_AUTOCONF;
591 port->rs485_config = mcf_config_rs485;
592 port->rs485_supported = mcf_rs485_supported;
593 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MCF_CONSOLE);
594
595 uart_add_one_port(&mcf_driver, port);
596 }
597
598 return 0;
599 }
600
601 /****************************************************************************/
602
mcf_remove(struct platform_device * pdev)603 static void mcf_remove(struct platform_device *pdev)
604 {
605 struct uart_port *port;
606 int i;
607
608 for (i = 0; (i < MCF_MAXPORTS); i++) {
609 port = &mcf_ports[i].port;
610 if (port)
611 uart_remove_one_port(&mcf_driver, port);
612 }
613 }
614
615 /****************************************************************************/
616
617 static struct platform_driver mcf_platform_driver = {
618 .probe = mcf_probe,
619 .remove_new = mcf_remove,
620 .driver = {
621 .name = "mcfuart",
622 },
623 };
624
625 /****************************************************************************/
626
mcf_init(void)627 static int __init mcf_init(void)
628 {
629 int rc;
630
631 printk("ColdFire internal UART serial driver\n");
632
633 rc = uart_register_driver(&mcf_driver);
634 if (rc)
635 return rc;
636 rc = platform_driver_register(&mcf_platform_driver);
637 if (rc) {
638 uart_unregister_driver(&mcf_driver);
639 return rc;
640 }
641 return 0;
642 }
643
644 /****************************************************************************/
645
mcf_exit(void)646 static void __exit mcf_exit(void)
647 {
648 platform_driver_unregister(&mcf_platform_driver);
649 uart_unregister_driver(&mcf_driver);
650 }
651
652 /****************************************************************************/
653
654 module_init(mcf_init);
655 module_exit(mcf_exit);
656
657 MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
658 MODULE_DESCRIPTION("Freescale ColdFire UART driver");
659 MODULE_LICENSE("GPL");
660 MODULE_ALIAS("platform:mcfuart");
661
662 /****************************************************************************/
663