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 */
52struct 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
60static 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
68static 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
84static 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(val: MCFUART_UOP_RTS, addr: port->membase + MCFUART_UOP1);
92 else
93 writeb(val: MCFUART_UOP_RTS, addr: port->membase + MCFUART_UOP0);
94}
95
96/****************************************************************************/
97
98static 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(val: MCFUART_UCR_TXENABLE, addr: port->membase + MCFUART_UCR);
105 /* Manually assert RTS */
106 writeb(val: MCFUART_UOP_RTS, addr: port->membase + MCFUART_UOP1);
107 }
108 pp->imr |= MCFUART_UIR_TXREADY;
109 writeb(val: pp->imr, addr: port->membase + MCFUART_UIMR);
110}
111
112/****************************************************************************/
113
114static 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(val: pp->imr, addr: port->membase + MCFUART_UIMR);
120}
121
122/****************************************************************************/
123
124static 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(val: pp->imr, addr: port->membase + MCFUART_UIMR);
130}
131
132/****************************************************************************/
133
134static void mcf_break_ctl(struct uart_port *port, int break_state)
135{
136 unsigned long flags;
137
138 uart_port_lock_irqsave(up: port, flags: &flags);
139 if (break_state == -1)
140 writeb(val: MCFUART_UCR_CMDBREAKSTART, addr: port->membase + MCFUART_UCR);
141 else
142 writeb(val: MCFUART_UCR_CMDBREAKSTOP, addr: port->membase + MCFUART_UCR);
143 uart_port_unlock_irqrestore(up: port, flags);
144}
145
146/****************************************************************************/
147
148static 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(up: port, flags: &flags);
154
155 /* Reset UART, get it into known state... */
156 writeb(val: MCFUART_UCR_CMDRESETRX, addr: port->membase + MCFUART_UCR);
157 writeb(val: MCFUART_UCR_CMDRESETTX, addr: port->membase + MCFUART_UCR);
158
159 /* Enable the UART transmitter and receiver */
160 writeb(val: MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
161 addr: port->membase + MCFUART_UCR);
162
163 /* Enable RX interrupts now */
164 pp->imr = MCFUART_UIR_RXREADY;
165 writeb(val: pp->imr, addr: port->membase + MCFUART_UIMR);
166
167 uart_port_unlock_irqrestore(up: port, flags);
168
169 return 0;
170}
171
172/****************************************************************************/
173
174static 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(up: port, flags: &flags);
180
181 /* Disable all interrupts now */
182 pp->imr = 0;
183 writeb(val: pp->imr, addr: port->membase + MCFUART_UIMR);
184
185 /* Disable UART transmitter and receiver */
186 writeb(val: MCFUART_UCR_CMDRESETRX, addr: port->membase + MCFUART_UCR);
187 writeb(val: MCFUART_UCR_CMDRESETTX, addr: port->membase + MCFUART_UCR);
188
189 uart_port_unlock_irqrestore(up: port, flags);
190}
191
192/****************************************************************************/
193
194static 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, min: 0, max: 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(up: port, flags: &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, cflag: 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(up: port, flags);
277}
278
279/****************************************************************************/
280
281static 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: &port->state->port);
323}
324
325/****************************************************************************/
326
327static 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
344static 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(up: 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(up: port);
363
364 return ret;
365}
366
367/****************************************************************************/
368
369static 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(irq: port->irq, handler: mcf_interrupt, flags: 0, name: "UART", dev: 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
384static const char *mcf_type(struct uart_port *port)
385{
386 return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
387}
388
389/****************************************************************************/
390
391static int mcf_request_port(struct uart_port *port)
392{
393 /* UARTs always present */
394 return 0;
395}
396
397/****************************************************************************/
398
399static void mcf_release_port(struct uart_port *port)
400{
401 /* Nothing to release... */
402}
403
404/****************************************************************************/
405
406static 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 */
416static 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
438static 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 */
447static 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
465static 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
473int __init early_mcf_setup(struct mcf_platform_uart *platp)
474{
475 struct uart_port *port;
476 int i;
477
478 for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
479 port = &mcf_ports[i].port;
480
481 port->line = i;
482 port->type = PORT_MCF;
483 port->mapbase = platp[i].mapbase;
484 port->membase = (platp[i].membase) ? platp[i].membase :
485 (unsigned char __iomem *) port->mapbase;
486 port->iotype = SERIAL_IO_MEM;
487 port->irq = platp[i].irq;
488 port->uartclk = MCF_BUSCLK;
489 port->flags = UPF_BOOT_AUTOCONF;
490 port->rs485_config = mcf_config_rs485;
491 port->rs485_supported = mcf_rs485_supported;
492 port->ops = &mcf_uart_ops;
493 }
494
495 return 0;
496}
497
498/****************************************************************************/
499
500static void mcf_console_putc(struct console *co, const char c)
501{
502 struct uart_port *port = &(mcf_ports + co->index)->port;
503 int i;
504
505 for (i = 0; (i < 0x10000); i++) {
506 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
507 break;
508 }
509 writeb(c, port->membase + MCFUART_UTB);
510 for (i = 0; (i < 0x10000); i++) {
511 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
512 break;
513 }
514}
515
516/****************************************************************************/
517
518static void mcf_console_write(struct console *co, const char *s, unsigned int count)
519{
520 for (; (count); count--, s++) {
521 mcf_console_putc(co, *s);
522 if (*s == '\n')
523 mcf_console_putc(co, '\r');
524 }
525}
526
527/****************************************************************************/
528
529static int __init mcf_console_setup(struct console *co, char *options)
530{
531 struct uart_port *port;
532 int baud = CONFIG_SERIAL_MCF_BAUDRATE;
533 int bits = 8;
534 int parity = 'n';
535 int flow = 'n';
536
537 if ((co->index < 0) || (co->index >= MCF_MAXPORTS))
538 co->index = 0;
539 port = &mcf_ports[co->index].port;
540 if (port->membase == 0)
541 return -ENODEV;
542
543 if (options)
544 uart_parse_options(options, &baud, &parity, &bits, &flow);
545
546 return uart_set_options(port, co, baud, parity, bits, flow);
547}
548
549/****************************************************************************/
550
551static struct uart_driver mcf_driver;
552
553static struct console mcf_console = {
554 .name = "ttyS",
555 .write = mcf_console_write,
556 .device = uart_console_device,
557 .setup = mcf_console_setup,
558 .flags = CON_PRINTBUFFER,
559 .index = -1,
560 .data = &mcf_driver,
561};
562
563static int __init mcf_console_init(void)
564{
565 register_console(&mcf_console);
566 return 0;
567}
568
569console_initcall(mcf_console_init);
570
571#define MCF_CONSOLE &mcf_console
572
573/****************************************************************************/
574#else
575/****************************************************************************/
576
577#define MCF_CONSOLE NULL
578
579/****************************************************************************/
580#endif /* CONFIG_SERIAL_MCF_CONSOLE */
581/****************************************************************************/
582
583/*
584 * Define the mcf UART driver structure.
585 */
586static struct uart_driver mcf_driver = {
587 .owner = THIS_MODULE,
588 .driver_name = "mcf",
589 .dev_name = "ttyS",
590 .major = TTY_MAJOR,
591 .minor = 64,
592 .nr = MCF_MAXPORTS,
593 .cons = MCF_CONSOLE,
594};
595
596/****************************************************************************/
597
598static int mcf_probe(struct platform_device *pdev)
599{
600 struct mcf_platform_uart *platp = dev_get_platdata(dev: &pdev->dev);
601 struct uart_port *port;
602 int i;
603
604 for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
605 port = &mcf_ports[i].port;
606
607 port->line = i;
608 port->type = PORT_MCF;
609 port->mapbase = platp[i].mapbase;
610 port->membase = (platp[i].membase) ? platp[i].membase :
611 (unsigned char __iomem *) platp[i].mapbase;
612 port->dev = &pdev->dev;
613 port->iotype = SERIAL_IO_MEM;
614 port->irq = platp[i].irq;
615 port->uartclk = MCF_BUSCLK;
616 port->ops = &mcf_uart_ops;
617 port->flags = UPF_BOOT_AUTOCONF;
618 port->rs485_config = mcf_config_rs485;
619 port->rs485_supported = mcf_rs485_supported;
620 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MCF_CONSOLE);
621
622 uart_add_one_port(&mcf_driver, port);
623 }
624
625 return 0;
626}
627
628/****************************************************************************/
629
630static int mcf_remove(struct platform_device *pdev)
631{
632 struct uart_port *port;
633 int i;
634
635 for (i = 0; (i < MCF_MAXPORTS); i++) {
636 port = &mcf_ports[i].port;
637 if (port)
638 uart_remove_one_port(reg: &mcf_driver, port);
639 }
640
641 return 0;
642}
643
644/****************************************************************************/
645
646static struct platform_driver mcf_platform_driver = {
647 .probe = mcf_probe,
648 .remove = mcf_remove,
649 .driver = {
650 .name = "mcfuart",
651 },
652};
653
654/****************************************************************************/
655
656static int __init mcf_init(void)
657{
658 int rc;
659
660 printk("ColdFire internal UART serial driver\n");
661
662 rc = uart_register_driver(uart: &mcf_driver);
663 if (rc)
664 return rc;
665 rc = platform_driver_register(&mcf_platform_driver);
666 if (rc) {
667 uart_unregister_driver(uart: &mcf_driver);
668 return rc;
669 }
670 return 0;
671}
672
673/****************************************************************************/
674
675static void __exit mcf_exit(void)
676{
677 platform_driver_unregister(&mcf_platform_driver);
678 uart_unregister_driver(uart: &mcf_driver);
679}
680
681/****************************************************************************/
682
683module_init(mcf_init);
684module_exit(mcf_exit);
685
686MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
687MODULE_DESCRIPTION("Freescale ColdFire UART driver");
688MODULE_LICENSE("GPL");
689MODULE_ALIAS("platform:mcfuart");
690
691/****************************************************************************/
692

source code of linux/drivers/tty/serial/mcf.c