tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * drivers/serial/serial_ks8695.c
3 *
4 * Driver for KS8695 serial ports
5 *
6 * Based on drivers/serial/serial_amba.c, by Kam Lee.
7 *
8 * Copyright 2002-2005 Micrel Inc.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 */
16#include <linux/module.h>
17#include <linux/tty.h>
18#include <linux/ioport.h>
19#include <linux/init.h>
20#include <linux/serial.h>
21#include <linux/console.h>
22#include <linux/sysrq.h>
23#include <linux/device.h>
24
25#include <asm/io.h>
26#include <asm/irq.h>
27#include <asm/mach/irq.h>
28
29#include <mach/regs-uart.h>
30#include <mach/regs-irq.h>
31
32#if defined(CONFIG_SERIAL_KS8695_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
33#define SUPPORT_SYSRQ
34#endif
35
36#include <linux/serial_core.h>
37
38
39#define SERIAL_KS8695_MAJOR 204
40#define SERIAL_KS8695_MINOR 16
41#define SERIAL_KS8695_DEVNAME "ttyAM"
42
43#define SERIAL_KS8695_NR 1
44
45/*
46 * Access macros for the KS8695 UART
47 */
48#define UART_GET_CHAR(p) (__raw_readl((p)->membase + KS8695_URRB) & 0xFF)
49#define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + KS8695_URTH)
50#define UART_GET_FCR(p) __raw_readl((p)->membase + KS8695_URFC)
51#define UART_PUT_FCR(p, c) __raw_writel((c), (p)->membase + KS8695_URFC)
52#define UART_GET_MSR(p) __raw_readl((p)->membase + KS8695_URMS)
53#define UART_GET_LSR(p) __raw_readl((p)->membase + KS8695_URLS)
54#define UART_GET_LCR(p) __raw_readl((p)->membase + KS8695_URLC)
55#define UART_PUT_LCR(p, c) __raw_writel((c), (p)->membase + KS8695_URLC)
56#define UART_GET_MCR(p) __raw_readl((p)->membase + KS8695_URMC)
57#define UART_PUT_MCR(p, c) __raw_writel((c), (p)->membase + KS8695_URMC)
58#define UART_GET_BRDR(p) __raw_readl((p)->membase + KS8695_URBD)
59#define UART_PUT_BRDR(p, c) __raw_writel((c), (p)->membase + KS8695_URBD)
60
61#define KS8695_CLR_TX_INT() __raw_writel(1 << KS8695_IRQ_UART_TX, KS8695_IRQ_VA + KS8695_INTST)
62
63#define UART_DUMMY_LSR_RX 0x100
64#define UART_PORT_SIZE (KS8695_USR - KS8695_URRB + 4)
65
66static inline int tx_enabled(struct uart_port *port)
67{
68 return port->unused[0] & 1;
69}
70
71static inline int rx_enabled(struct uart_port *port)
72{
73 return port->unused[0] & 2;
74}
75
76static inline int ms_enabled(struct uart_port *port)
77{
78 return port->unused[0] & 4;
79}
80
81static inline void ms_enable(struct uart_port *port, int enabled)
82{
83 if(enabled)
84 port->unused[0] |= 4;
85 else
86 port->unused[0] &= ~4;
87}
88
89static inline void rx_enable(struct uart_port *port, int enabled)
90{
91 if(enabled)
92 port->unused[0] |= 2;
93 else
94 port->unused[0] &= ~2;
95}
96
97static inline void tx_enable(struct uart_port *port, int enabled)
98{
99 if(enabled)
100 port->unused[0] |= 1;
101 else
102 port->unused[0] &= ~1;
103}
104
105
106#ifdef SUPPORT_SYSRQ
107static struct console ks8695_console;
108#endif
109
110static void ks8695uart_stop_tx(struct uart_port *port)
111{
112 if (tx_enabled(port)) {
113 disable_irq(KS8695_IRQ_UART_TX);
114 tx_enable(port, 0);
115 }
116}
117
118static void ks8695uart_start_tx(struct uart_port *port)
119{
120 if (!tx_enabled(port)) {
121 enable_irq(KS8695_IRQ_UART_TX);
122 tx_enable(port, 1);
123 }
124}
125
126static void ks8695uart_stop_rx(struct uart_port *port)
127{
128 if (rx_enabled(port)) {
129 disable_irq(KS8695_IRQ_UART_RX);
130 rx_enable(port, 0);
131 }
132}
133
134static void ks8695uart_enable_ms(struct uart_port *port)
135{
136 if (!ms_enabled(port)) {
137 enable_irq(KS8695_IRQ_UART_MODEM_STATUS);
138 ms_enable(port,1);
139 }
140}
141
142static void ks8695uart_disable_ms(struct uart_port *port)
143{
144 if (ms_enabled(port)) {
145 disable_irq(KS8695_IRQ_UART_MODEM_STATUS);
146 ms_enable(port,0);
147 }
148}
149
150static irqreturn_t ks8695uart_rx_chars(int irq, void *dev_id)
151{
152 struct uart_port *port = dev_id;
153 struct tty_struct *tty = port->info->port.tty;
154 unsigned int status, ch, lsr, flg, max_count = 256;
155
156 status = UART_GET_LSR(port); /* clears pending LSR interrupts */
157 while ((status & URLS_URDR) && max_count--) {
158 ch = UART_GET_CHAR(port);
159 flg = TTY_NORMAL;
160
161 port->icount.rx++;
162
163 /*
164 * Note that the error handling code is
165 * out of the main execution path
166 */
167 lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX;
168 if (unlikely(lsr & (URLS_URBI | URLS_URPE | URLS_URFE | URLS_URROE))) {
169 if (lsr & URLS_URBI) {
170 lsr &= ~(URLS_URFE | URLS_URPE);
171 port->icount.brk++;
172 if (uart_handle_break(port))
173 goto ignore_char;
174 }
175 if (lsr & URLS_URPE)
176 port->icount.parity++;
177 if (lsr & URLS_URFE)
178 port->icount.frame++;
179 if (lsr & URLS_URROE)
180 port->icount.overrun++;
181
182 lsr &= port->read_status_mask;
183
184 if (lsr & URLS_URBI)
185 flg = TTY_BREAK;
186 else if (lsr & URLS_URPE)
187 flg = TTY_PARITY;
188 else if (lsr & URLS_URFE)
189 flg = TTY_FRAME;
190 }
191
192 if (uart_handle_sysrq_char(port, ch))
193 goto ignore_char;
194
195 uart_insert_char(port, lsr, URLS_URROE, ch, flg);
196
197ignore_char:
198 status = UART_GET_LSR(port);
199 }
200 tty_flip_buffer_push(tty);
201
202 return IRQ_HANDLED;
203}
204
205
206static irqreturn_t ks8695uart_tx_chars(int irq, void *dev_id)
207{
208 struct uart_port *port = dev_id;
209 struct circ_buf *xmit = &port->info->xmit;
210 unsigned int count;
211
212 if (port->x_char) {
213 KS8695_CLR_TX_INT();
214 UART_PUT_CHAR(port, port->x_char);
215 port->icount.tx++;
216 port->x_char = 0;
217 return IRQ_HANDLED;
218 }
219
220 if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
221 ks8695uart_stop_tx(port);
222 return IRQ_HANDLED;
223 }
224
225 count = 16; /* fifo size */
226 while (!uart_circ_empty(xmit) && (count-- > 0)) {
227 KS8695_CLR_TX_INT();
228 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
229
230 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
231 port->icount.tx++;
232 }
233
234 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
235 uart_write_wakeup(port);
236
237 if (uart_circ_empty(xmit))
238 ks8695uart_stop_tx(port);
239
240 return IRQ_HANDLED;
241}
242
243static irqreturn_t ks8695uart_modem_status(int irq, void *dev_id)
244{
245 struct uart_port *port = dev_id;
246 unsigned int status;
247
248 /*
249 * clear modem interrupt by reading MSR
250 */
251 status = UART_GET_MSR(port);
252
253 if (status & URMS_URDDCD)
254 uart_handle_dcd_change(port, status & URMS_URDDCD);
255
256 if (status & URMS_URDDST)
257 port->icount.dsr++;
258
259 if (status & URMS_URDCTS)
260 uart_handle_cts_change(port, status & URMS_URDCTS);
261
262 if (status & URMS_URTERI)
263 port->icount.rng++;
264
265 wake_up_interruptible(&port->info->delta_msr_wait);
266
267 return IRQ_HANDLED;
268}
269
270static unsigned int ks8695uart_tx_empty(struct uart_port *port)
271{
272 return (UART_GET_LSR(port) & URLS_URTE) ? TIOCSER_TEMT : 0;
273}
274
275static unsigned int ks8695uart_get_mctrl(struct uart_port *port)
276{
277 unsigned int result = 0;
278 unsigned int status;
279
280 status = UART_GET_MSR(port);
281 if (status & URMS_URDCD)
282 result |= TIOCM_CAR;
283 if (status & URMS_URDSR)
284 result |= TIOCM_DSR;
285 if (status & URMS_URCTS)
286 result |= TIOCM_CTS;
287 if (status & URMS_URRI)
288 result |= TIOCM_RI;
289
290 return result;
291}
292
293static void ks8695uart_set_mctrl(struct uart_port *port, u_int mctrl)
294{
295 unsigned int mcr;
296
297 mcr = UART_GET_MCR(port);
298 if (mctrl & TIOCM_RTS)
299 mcr |= URMC_URRTS;
300 else
301 mcr &= ~URMC_URRTS;
302
303 if (mctrl & TIOCM_DTR)
304 mcr |= URMC_URDTR;
305 else
306 mcr &= ~URMC_URDTR;
307
308 UART_PUT_MCR(port, mcr);
309}
310
311static void ks8695uart_break_ctl(struct uart_port *port, int break_state)
312{
313 unsigned int lcr;
314
315 lcr = UART_GET_LCR(port);
316
317 if (break_state == -1)
318 lcr |= URLC_URSBC;
319 else
320 lcr &= ~URLC_URSBC;
321
322 UART_PUT_LCR(port, lcr);
323}
324
325static int ks8695uart_startup(struct uart_port *port)
326{
327 int retval;
328
329 set_irq_flags(KS8695_IRQ_UART_TX, IRQF_VALID | IRQF_NOAUTOEN);
330 tx_enable(port, 0);
331 rx_enable(port, 1);
332 ms_enable(port, 1);
333
334 /*
335 * Allocate the IRQ
336 */
337 retval = request_irq(KS8695_IRQ_UART_TX, ks8695uart_tx_chars, IRQF_DISABLED, "UART TX", port);
338 if (retval)
339 goto err_tx;
340
341 retval = request_irq(KS8695_IRQ_UART_RX, ks8695uart_rx_chars, IRQF_DISABLED, "UART RX", port);
342 if (retval)
343 goto err_rx;
344
345 retval = request_irq(KS8695_IRQ_UART_LINE_STATUS, ks8695uart_rx_chars, IRQF_DISABLED, "UART LineStatus", port);
346 if (retval)
347 goto err_ls;
348
349 retval = request_irq(KS8695_IRQ_UART_MODEM_STATUS, ks8695uart_modem_status, IRQF_DISABLED, "UART ModemStatus", port);
350 if (retval)
351 goto err_ms;
352
353 return 0;
354
355err_ms:
356 free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
357err_ls:
358 free_irq(KS8695_IRQ_UART_RX, port);
359err_rx:
360 free_irq(KS8695_IRQ_UART_TX, port);
361err_tx:
362 return retval;
363}
364
365static void ks8695uart_shutdown(struct uart_port *port)
366{
367 /*
368 * Free the interrupt
369 */
370 free_irq(KS8695_IRQ_UART_RX, port);
371 free_irq(KS8695_IRQ_UART_TX, port);
372 free_irq(KS8695_IRQ_UART_MODEM_STATUS, port);
373 free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
374
375 /* disable break condition and fifos */
376 UART_PUT_LCR(port, UART_GET_LCR(port) & ~URLC_URSBC);
377 UART_PUT_FCR(port, UART_GET_FCR(port) & ~URFC_URFE);
378}
379
380static void ks8695uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old)
381{
382 unsigned int lcr, fcr = 0;
383 unsigned long flags;
384 unsigned int baud, quot;
385
386 /*
387 * Ask the core to calculate the divisor for us.
388 */
389 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
390 quot = uart_get_divisor(port, baud);
391
392 switch (termios->c_cflag & CSIZE) {
393 case CS5:
394 lcr = URCL_5;
395 break;
396 case CS6:
397 lcr = URCL_6;
398 break;
399 case CS7:
400 lcr = URCL_7;
401 break;
402 default:
403 lcr = URCL_8;
404 break;
405 }
406
407 /* stop bits */
408 if (termios->c_cflag & CSTOPB)
409 lcr |= URLC_URSB;
410
411 /* parity */
412 if (termios->c_cflag & PARENB) {
413 if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */
414 if (termios->c_cflag & PARODD)
415 lcr |= URPE_MARK;
416 else
417 lcr |= URPE_SPACE;
418 }
419 else if (termios->c_cflag & PARODD)
420 lcr |= URPE_ODD;
421 else
422 lcr |= URPE_EVEN;
423 }
424
425 if (port->fifosize > 1)
426 fcr = URFC_URFRT_8 | URFC_URTFR | URFC_URRFR | URFC_URFE;
427
428 spin_lock_irqsave(&port->lock, flags);
429
430 /*
431 * Update the per-port timeout.
432 */
433 uart_update_timeout(port, termios->c_cflag, baud);
434
435 port->read_status_mask = URLS_URROE;
436 if (termios->c_iflag & INPCK)
437 port->read_status_mask |= (URLS_URFE | URLS_URPE);
438 if (termios->c_iflag & (BRKINT | PARMRK))
439 port->read_status_mask |= URLS_URBI;
440
441 /*
442 * Characters to ignore
443 */
444 port->ignore_status_mask = 0;
445 if (termios->c_iflag & IGNPAR)
446 port->ignore_status_mask |= (URLS_URFE | URLS_URPE);
447 if (termios->c_iflag & IGNBRK) {
448 port->ignore_status_mask |= URLS_URBI;
449 /*
450 * If we're ignoring parity and break indicators,
451 * ignore overruns too (for real raw support).
452 */
453 if (termios->c_iflag & IGNPAR)
454 port->ignore_status_mask |= URLS_URROE;
455 }
456
457 /*
458 * Ignore all characters if CREAD is not set.
459 */
460 if ((termios->c_cflag & CREAD) == 0)
461 port->ignore_status_mask |= UART_DUMMY_LSR_RX;
462
463 /* first, disable everything */
464 if (UART_ENABLE_MS(port, termios->c_cflag))
465 ks8695uart_enable_ms(port);
466 else
467 ks8695uart_disable_ms(port);
468
469 /* Set baud rate */
470 UART_PUT_BRDR(port, quot);
471
472 UART_PUT_LCR(port, lcr);
473 UART_PUT_FCR(port, fcr);
474
475 spin_unlock_irqrestore(&port->lock, flags);
476}
477
478static const char *ks8695uart_type(struct uart_port *port)
479{
480 return port->type == PORT_KS8695 ? "KS8695" : NULL;
481}
482
483/*
484 * Release the memory region(s) being used by 'port'
485 */
486static void ks8695uart_release_port(struct uart_port *port)
487{
488 release_mem_region(port->mapbase, UART_PORT_SIZE);
489}
490
491/*
492 * Request the memory region(s) being used by 'port'
493 */
494static int ks8695uart_request_port(struct uart_port *port)
495{
496 return request_mem_region(port->mapbase, UART_PORT_SIZE,
497 "serial_ks8695") != NULL ? 0 : -EBUSY;
498}
499
500/*
501 * Configure/autoconfigure the port.
502 */
503static void ks8695uart_config_port(struct uart_port *port, int flags)
504{
505 if (flags & UART_CONFIG_TYPE) {
506 port->type = PORT_KS8695;
507 ks8695uart_request_port(port);
508 }
509}
510
511/*
512 * verify the new serial_struct (for TIOCSSERIAL).
513 */
514static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser)
515{
516 int ret = 0;
517
518 if (ser->type != PORT_UNKNOWN && ser->type != PORT_KS8695)
519 ret = -EINVAL;
520 if (ser->irq != port->irq)
521 ret = -EINVAL;
522 if (ser->baud_base < 9600)
523 ret = -EINVAL;
524 return ret;
525}
526
527static struct uart_ops ks8695uart_pops = {
528 .tx_empty = ks8695uart_tx_empty,
529 .set_mctrl = ks8695uart_set_mctrl,
530 .get_mctrl = ks8695uart_get_mctrl,
531 .stop_tx = ks8695uart_stop_tx,
532 .start_tx = ks8695uart_start_tx,
533 .stop_rx = ks8695uart_stop_rx,
534 .enable_ms = ks8695uart_enable_ms,
535 .break_ctl = ks8695uart_break_ctl,
536 .startup = ks8695uart_startup,
537 .shutdown = ks8695uart_shutdown,
538 .set_termios = ks8695uart_set_termios,
539 .type = ks8695uart_type,
540 .release_port = ks8695uart_release_port,
541 .request_port = ks8695uart_request_port,
542 .config_port = ks8695uart_config_port,
543 .verify_port = ks8695uart_verify_port,
544};
545
546static struct uart_port ks8695uart_ports[SERIAL_KS8695_NR] = {
547 {
548 .membase = (void *) KS8695_UART_VA,
549 .mapbase = KS8695_UART_VA,
550 .iotype = SERIAL_IO_MEM,
551 .irq = KS8695_IRQ_UART_TX,
552 .uartclk = KS8695_CLOCK_RATE * 16,
553 .fifosize = 16,
554 .ops = &ks8695uart_pops,
555 .flags = ASYNC_BOOT_AUTOCONF,
556 .line = 0,
557 }
558};
559
560#ifdef CONFIG_SERIAL_KS8695_CONSOLE
561static void ks8695_console_putchar(struct uart_port *port, int ch)
562{
563 while (!(UART_GET_LSR(port) & URLS_URTHRE))
564 barrier();
565
566 UART_PUT_CHAR(port, ch);
567}
568
569static void ks8695_console_write(struct console *co, const char *s, u_int count)
570{
571 struct uart_port *port = ks8695uart_ports + co->index;
572
573 uart_console_write(port, s, count, ks8695_console_putchar);
574}
575
576static void __init ks8695_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
577{
578 unsigned int lcr;
579
580 lcr = UART_GET_LCR(port);
581
582 switch (lcr & URLC_PARITY) {
583 case URPE_ODD:
584 *parity = 'o';
585 break;
586 case URPE_EVEN:
587 *parity = 'e';
588 break;
589 default:
590 *parity = 'n';
591 }
592
593 switch (lcr & URLC_URCL) {
594 case URCL_5:
595 *bits = 5;
596 break;
597 case URCL_6:
598 *bits = 6;
599 break;
600 case URCL_7:
601 *bits = 7;
602 break;
603 default:
604 *bits = 8;
605 }
606
607 *baud = port->uartclk / (UART_GET_BRDR(port) & 0x0FFF);
608 *baud /= 16;
609 *baud &= 0xFFFFFFF0;
610}
611
612static int __init ks8695_console_setup(struct console *co, char *options)
613{
614 struct uart_port *port;
615 int baud = 115200;
616 int bits = 8;
617 int parity = 'n';
618 int flow = 'n';
619
620 /*
621 * Check whether an invalid uart number has been specified, and
622 * if so, search for the first available port that does have
623 * console support.
624 */
625 port = uart_get_console(ks8695uart_ports, SERIAL_KS8695_NR, co);
626
627 if (options)
628 uart_parse_options(options, &baud, &parity, &bits, &flow);
629 else
630 ks8695_console_get_options(port, &baud, &parity, &bits);
631
632 return uart_set_options(port, co, baud, parity, bits, flow);
633}
634
635static struct uart_driver ks8695_reg;
636
637static struct console ks8695_console = {
638 .name = SERIAL_KS8695_DEVNAME,
639 .write = ks8695_console_write,
640 .device = uart_console_device,
641 .setup = ks8695_console_setup,
642 .flags = CON_PRINTBUFFER,
643 .index = -1,
644 .data = &ks8695_reg,
645};
646
647static int __init ks8695_console_init(void)
648{
649 register_console(&ks8695_console);
650 return 0;
651}
652
653console_initcall(ks8695_console_init);
654
655#define KS8695_CONSOLE &ks8695_console
656#else
657#define KS8695_CONSOLE NULL
658#endif
659
660static struct uart_driver ks8695_reg = {
661 .owner = THIS_MODULE,
662 .driver_name = "serial_ks8695",
663 .dev_name = SERIAL_KS8695_DEVNAME,
664 .major = SERIAL_KS8695_MAJOR,
665 .minor = SERIAL_KS8695_MINOR,
666 .nr = SERIAL_KS8695_NR,
667 .cons = KS8695_CONSOLE,
668};
669
670static int __init ks8695uart_init(void)
671{
672 int i, ret;
673
674 printk(KERN_INFO "Serial: Micrel KS8695 UART driver\n");
675
676 ret = uart_register_driver(&ks8695_reg);
677 if (ret)
678 return ret;
679
680 for (i = 0; i < SERIAL_KS8695_NR; i++)
681 uart_add_one_port(&ks8695_reg, &ks8695uart_ports[0]);
682
683 return 0;
684}
685
686static void __exit ks8695uart_exit(void)
687{
688 int i;
689
690 for (i = 0; i < SERIAL_KS8695_NR; i++)
691 uart_remove_one_port(&ks8695_reg, &ks8695uart_ports[0]);
692 uart_unregister_driver(&ks8695_reg);
693}
694
695module_init(ks8695uart_init);
696module_exit(ks8695uart_exit);
697
698MODULE_DESCRIPTION("KS8695 serial port driver");
699MODULE_AUTHOR("Micrel Inc.");
700MODULE_LICENSE("GPL");