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[net-next-2.6.git] / drivers / serial / serial_ks8695.c
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2c7ee6ab
AV		 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
a09e64fb
RK		 29#include <mach/regs-uart.h>
30#include <mach/regs-irq.h>
2c7ee6ab
AV		 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
457cd4f5
DH		 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}
2c7ee6ab
AV		 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)) {
c47a830c
DH		 113 /* use disable_irq_nosync() and not disable_irq() to avoid self
114 * imposed deadlock by not waiting for irq handler to end,
115 * since this ks8695uart_stop_tx() is called from interrupt context.
116 */
117 disable_irq_nosync(KS8695_IRQ_UART_TX);
457cd4f5 118 tx_enable(port, 0);
2c7ee6ab
AV		 119 }
120}
121
122static void ks8695uart_start_tx(struct uart_port *port)
123{
124 if (!tx_enabled(port)) {
125 enable_irq(KS8695_IRQ_UART_TX);
457cd4f5 126 tx_enable(port, 1);
2c7ee6ab
AV		 127 }
128}
129
130static void ks8695uart_stop_rx(struct uart_port *port)
131{
132 if (rx_enabled(port)) {
133 disable_irq(KS8695_IRQ_UART_RX);
457cd4f5 134 rx_enable(port, 0);
2c7ee6ab
AV		 135 }
136}
137
138static void ks8695uart_enable_ms(struct uart_port *port)
139{
457cd4f5
DH		 140 if (!ms_enabled(port)) {
141 enable_irq(KS8695_IRQ_UART_MODEM_STATUS);
142 ms_enable(port,1);
143 }
2c7ee6ab
AV		 144}
145
146static void ks8695uart_disable_ms(struct uart_port *port)
147{
457cd4f5
DH		 148 if (ms_enabled(port)) {
149 disable_irq(KS8695_IRQ_UART_MODEM_STATUS);
150 ms_enable(port,0);
151 }
2c7ee6ab
AV		 152}
153
154static irqreturn_t ks8695uart_rx_chars(int irq, void *dev_id)
155{
156 struct uart_port *port = dev_id;
ebd2c8f6 157 struct tty_struct *tty = port->state->port.tty;
2c7ee6ab
AV		 158 unsigned int status, ch, lsr, flg, max_count = 256;
159
160 status = UART_GET_LSR(port); /* clears pending LSR interrupts */
161 while ((status & URLS_URDR) && max_count--) {
162 ch = UART_GET_CHAR(port);
163 flg = TTY_NORMAL;
164
165 port->icount.rx++;
166
167 /*
168 * Note that the error handling code is
169 * out of the main execution path
170 */
171 lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX;
172 if (unlikely(lsr & (URLS_URBI | URLS_URPE | URLS_URFE | URLS_URROE))) {
173 if (lsr & URLS_URBI) {
174 lsr &= ~(URLS_URFE | URLS_URPE);
175 port->icount.brk++;
176 if (uart_handle_break(port))
177 goto ignore_char;
178 }
179 if (lsr & URLS_URPE)
180 port->icount.parity++;
181 if (lsr & URLS_URFE)
182 port->icount.frame++;
183 if (lsr & URLS_URROE)
184 port->icount.overrun++;
185
186 lsr &= port->read_status_mask;
187
188 if (lsr & URLS_URBI)
189 flg = TTY_BREAK;
190 else if (lsr & URLS_URPE)
191 flg = TTY_PARITY;
192 else if (lsr & URLS_URFE)
193 flg = TTY_FRAME;
194 }
195
196 if (uart_handle_sysrq_char(port, ch))
197 goto ignore_char;
198
199 uart_insert_char(port, lsr, URLS_URROE, ch, flg);
200
201ignore_char:
202 status = UART_GET_LSR(port);
203 }
204 tty_flip_buffer_push(tty);
205
206 return IRQ_HANDLED;
207}
208
209
210static irqreturn_t ks8695uart_tx_chars(int irq, void *dev_id)
211{
212 struct uart_port *port = dev_id;
ebd2c8f6 213 struct circ_buf *xmit = &port->state->xmit;
2c7ee6ab
AV		 214 unsigned int count;
215
216 if (port->x_char) {
217 KS8695_CLR_TX_INT();
218 UART_PUT_CHAR(port, port->x_char);
219 port->icount.tx++;
220 port->x_char = 0;
221 return IRQ_HANDLED;
222 }
223
224 if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
225 ks8695uart_stop_tx(port);
226 return IRQ_HANDLED;
227 }
228
229 count = 16; /* fifo size */
230 while (!uart_circ_empty(xmit) && (count-- > 0)) {
231 KS8695_CLR_TX_INT();
232 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
233
234 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
235 port->icount.tx++;
236 }
237
238 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
239 uart_write_wakeup(port);
240
241 if (uart_circ_empty(xmit))
242 ks8695uart_stop_tx(port);
243
244 return IRQ_HANDLED;
245}
246
247static irqreturn_t ks8695uart_modem_status(int irq, void *dev_id)
248{
249 struct uart_port *port = dev_id;
250 unsigned int status;
251
252 /*
253 * clear modem interrupt by reading MSR
254 */
255 status = UART_GET_MSR(port);
256
257 if (status & URMS_URDDCD)
258 uart_handle_dcd_change(port, status & URMS_URDDCD);
259
260 if (status & URMS_URDDST)
261 port->icount.dsr++;
262
263 if (status & URMS_URDCTS)
264 uart_handle_cts_change(port, status & URMS_URDCTS);
265
266 if (status & URMS_URTERI)
267 port->icount.rng++;
268
bdc04e31 269 wake_up_interruptible(&port->state->port.delta_msr_wait);
2c7ee6ab
AV		 270
271 return IRQ_HANDLED;
272}
273
274static unsigned int ks8695uart_tx_empty(struct uart_port *port)
275{
276 return (UART_GET_LSR(port) & URLS_URTE) ? TIOCSER_TEMT : 0;
277}
278
279static unsigned int ks8695uart_get_mctrl(struct uart_port *port)
280{
281 unsigned int result = 0;
282 unsigned int status;
283
284 status = UART_GET_MSR(port);
285 if (status & URMS_URDCD)
286 result |= TIOCM_CAR;
287 if (status & URMS_URDSR)
288 result |= TIOCM_DSR;
289 if (status & URMS_URCTS)
290 result |= TIOCM_CTS;
291 if (status & URMS_URRI)
292 result |= TIOCM_RI;
293
294 return result;
295}
296
297static void ks8695uart_set_mctrl(struct uart_port *port, u_int mctrl)
298{
299 unsigned int mcr;
300
301 mcr = UART_GET_MCR(port);
302 if (mctrl & TIOCM_RTS)
303 mcr |= URMC_URRTS;
304 else
305 mcr &= ~URMC_URRTS;
306
307 if (mctrl & TIOCM_DTR)
308 mcr |= URMC_URDTR;
309 else
310 mcr &= ~URMC_URDTR;
311
312 UART_PUT_MCR(port, mcr);
313}
314
315static void ks8695uart_break_ctl(struct uart_port *port, int break_state)
316{
317 unsigned int lcr;
318
319 lcr = UART_GET_LCR(port);
320
321 if (break_state == -1)
322 lcr |= URLC_URSBC;
323 else
324 lcr &= ~URLC_URSBC;
325
326 UART_PUT_LCR(port, lcr);
327}
328
329static int ks8695uart_startup(struct uart_port *port)
330{
331 int retval;
332
333 set_irq_flags(KS8695_IRQ_UART_TX, IRQF_VALID | IRQF_NOAUTOEN);
457cd4f5
DH		 334 tx_enable(port, 0);
335 rx_enable(port, 1);
336 ms_enable(port, 1);
2c7ee6ab
AV		 337
338 /*
339 * Allocate the IRQ
340 */
341 retval = request_irq(KS8695_IRQ_UART_TX, ks8695uart_tx_chars, IRQF_DISABLED, "UART TX", port);
342 if (retval)
343 goto err_tx;
344
345 retval = request_irq(KS8695_IRQ_UART_RX, ks8695uart_rx_chars, IRQF_DISABLED, "UART RX", port);
346 if (retval)
347 goto err_rx;
348
349 retval = request_irq(KS8695_IRQ_UART_LINE_STATUS, ks8695uart_rx_chars, IRQF_DISABLED, "UART LineStatus", port);
350 if (retval)
e45c7a43 351 goto err_ls;
2c7ee6ab
AV		 352
353 retval = request_irq(KS8695_IRQ_UART_MODEM_STATUS, ks8695uart_modem_status, IRQF_DISABLED, "UART ModemStatus", port);
354 if (retval)
e45c7a43 355 goto err_ms;
2c7ee6ab
AV		 356
357 return 0;
358
359err_ms:
360 free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
361err_ls:
362 free_irq(KS8695_IRQ_UART_RX, port);
363err_rx:
364 free_irq(KS8695_IRQ_UART_TX, port);
365err_tx:
366 return retval;
367}
368
369static void ks8695uart_shutdown(struct uart_port *port)
370{
371 /*
372 * Free the interrupt
373 */
374 free_irq(KS8695_IRQ_UART_RX, port);
375 free_irq(KS8695_IRQ_UART_TX, port);
376 free_irq(KS8695_IRQ_UART_MODEM_STATUS, port);
377 free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
378
379 /* disable break condition and fifos */
380 UART_PUT_LCR(port, UART_GET_LCR(port) & ~URLC_URSBC);
381 UART_PUT_FCR(port, UART_GET_FCR(port) & ~URFC_URFE);
382}
383
384static void ks8695uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old)
385{
386 unsigned int lcr, fcr = 0;
387 unsigned long flags;
388 unsigned int baud, quot;
389
390 /*
391 * Ask the core to calculate the divisor for us.
392 */
393 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
394 quot = uart_get_divisor(port, baud);
395
396 switch (termios->c_cflag & CSIZE) {
397 case CS5:
398 lcr = URCL_5;
399 break;
400 case CS6:
401 lcr = URCL_6;
402 break;
403 case CS7:
404 lcr = URCL_7;
405 break;
406 default:
407 lcr = URCL_8;
408 break;
409 }
410
411 /* stop bits */
412 if (termios->c_cflag & CSTOPB)
413 lcr |= URLC_URSB;
414
415 /* parity */
416 if (termios->c_cflag & PARENB) {
417 if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */
418 if (termios->c_cflag & PARODD)
419 lcr |= URPE_MARK;
420 else
421 lcr |= URPE_SPACE;
422 }
423 else if (termios->c_cflag & PARODD)
424 lcr |= URPE_ODD;
425 else
426 lcr |= URPE_EVEN;
427 }
428
429 if (port->fifosize > 1)
430 fcr = URFC_URFRT_8 | URFC_URTFR | URFC_URRFR | URFC_URFE;
431
432 spin_lock_irqsave(&port->lock, flags);
433
434 /*
435 * Update the per-port timeout.
436 */
437 uart_update_timeout(port, termios->c_cflag, baud);
438
439 port->read_status_mask = URLS_URROE;
440 if (termios->c_iflag & INPCK)
441 port->read_status_mask |= (URLS_URFE | URLS_URPE);
442 if (termios->c_iflag & (BRKINT | PARMRK))
443 port->read_status_mask |= URLS_URBI;
444
445 /*
446 * Characters to ignore
447 */
448 port->ignore_status_mask = 0;
449 if (termios->c_iflag & IGNPAR)
450 port->ignore_status_mask |= (URLS_URFE | URLS_URPE);
451 if (termios->c_iflag & IGNBRK) {
452 port->ignore_status_mask |= URLS_URBI;
453 /*
454 * If we're ignoring parity and break indicators,
455 * ignore overruns too (for real raw support).
456 */
457 if (termios->c_iflag & IGNPAR)
458 port->ignore_status_mask |= URLS_URROE;
459 }
460
461 /*
462 * Ignore all characters if CREAD is not set.
463 */
464 if ((termios->c_cflag & CREAD) == 0)
465 port->ignore_status_mask |= UART_DUMMY_LSR_RX;
466
467 /* first, disable everything */
468 if (UART_ENABLE_MS(port, termios->c_cflag))
469 ks8695uart_enable_ms(port);
470 else
471 ks8695uart_disable_ms(port);
472
473 /* Set baud rate */
474 UART_PUT_BRDR(port, quot);
475
476 UART_PUT_LCR(port, lcr);
477 UART_PUT_FCR(port, fcr);
478
479 spin_unlock_irqrestore(&port->lock, flags);
480}
481
482static const char *ks8695uart_type(struct uart_port *port)
483{
484 return port->type == PORT_KS8695 ? "KS8695" : NULL;
485}
486
487/*
488 * Release the memory region(s) being used by 'port'
489 */
490static void ks8695uart_release_port(struct uart_port *port)
491{
492 release_mem_region(port->mapbase, UART_PORT_SIZE);
493}
494
495/*
496 * Request the memory region(s) being used by 'port'
497 */
498static int ks8695uart_request_port(struct uart_port *port)
499{
500 return request_mem_region(port->mapbase, UART_PORT_SIZE,
501 "serial_ks8695") != NULL ? 0 : -EBUSY;
502}
503
504/*
505 * Configure/autoconfigure the port.
506 */
507static void ks8695uart_config_port(struct uart_port *port, int flags)
508{
509 if (flags & UART_CONFIG_TYPE) {
510 port->type = PORT_KS8695;
511 ks8695uart_request_port(port);
512 }
513}
514
515/*
516 * verify the new serial_struct (for TIOCSSERIAL).
517 */
518static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser)
519{
520 int ret = 0;
521
522 if (ser->type != PORT_UNKNOWN && ser->type != PORT_KS8695)
523 ret = -EINVAL;
524 if (ser->irq != port->irq)
525 ret = -EINVAL;
526 if (ser->baud_base < 9600)
527 ret = -EINVAL;
528 return ret;
529}
530
531static struct uart_ops ks8695uart_pops = {
532 .tx_empty = ks8695uart_tx_empty,
533 .set_mctrl = ks8695uart_set_mctrl,
534 .get_mctrl = ks8695uart_get_mctrl,
535 .stop_tx = ks8695uart_stop_tx,
536 .start_tx = ks8695uart_start_tx,
537 .stop_rx = ks8695uart_stop_rx,
538 .enable_ms = ks8695uart_enable_ms,
539 .break_ctl = ks8695uart_break_ctl,
540 .startup = ks8695uart_startup,
541 .shutdown = ks8695uart_shutdown,
542 .set_termios = ks8695uart_set_termios,
543 .type = ks8695uart_type,
544 .release_port = ks8695uart_release_port,
545 .request_port = ks8695uart_request_port,
546 .config_port = ks8695uart_config_port,
547 .verify_port = ks8695uart_verify_port,
548};
549
550static struct uart_port ks8695uart_ports[SERIAL_KS8695_NR] = {
551 {
552 .membase = (void *) KS8695_UART_VA,
553 .mapbase = KS8695_UART_VA,
554 .iotype = SERIAL_IO_MEM,
555 .irq = KS8695_IRQ_UART_TX,
0a51810a 556 .uartclk = KS8695_CLOCK_RATE * 16,
2c7ee6ab
AV		 557 .fifosize = 16,
558 .ops = &ks8695uart_pops,
559 .flags = ASYNC_BOOT_AUTOCONF,
560 .line = 0,
561 }
562};
563
564#ifdef CONFIG_SERIAL_KS8695_CONSOLE
565static void ks8695_console_putchar(struct uart_port *port, int ch)
566{
567 while (!(UART_GET_LSR(port) & URLS_URTHRE))
568 barrier();
569
570 UART_PUT_CHAR(port, ch);
571}
572
573static void ks8695_console_write(struct console *co, const char *s, u_int count)
574{
575 struct uart_port *port = ks8695uart_ports + co->index;
576
577 uart_console_write(port, s, count, ks8695_console_putchar);
578}
579
580static void __init ks8695_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
581{
582 unsigned int lcr;
583
584 lcr = UART_GET_LCR(port);
585
586 switch (lcr & URLC_PARITY) {
587 case URPE_ODD:
588 *parity = 'o';
589 break;
590 case URPE_EVEN:
591 *parity = 'e';
592 break;
593 default:
594 *parity = 'n';
595 }
596
597 switch (lcr & URLC_URCL) {
598 case URCL_5:
599 *bits = 5;
600 break;
601 case URCL_6:
602 *bits = 6;
603 break;
604 case URCL_7:
605 *bits = 7;
606 break;
607 default:
608 *bits = 8;
609 }
610
611 *baud = port->uartclk / (UART_GET_BRDR(port) & 0x0FFF);
612 *baud /= 16;
613 *baud &= 0xFFFFFFF0;
614}
615
616static int __init ks8695_console_setup(struct console *co, char *options)
617{
618 struct uart_port *port;
619 int baud = 115200;
620 int bits = 8;
621 int parity = 'n';
622 int flow = 'n';
623
624 /*
625 * Check whether an invalid uart number has been specified, and
626 * if so, search for the first available port that does have
627 * console support.
628 */
629 port = uart_get_console(ks8695uart_ports, SERIAL_KS8695_NR, co);
630
631 if (options)
632 uart_parse_options(options, &baud, &parity, &bits, &flow);
633 else
634 ks8695_console_get_options(port, &baud, &parity, &bits);
635
636 return uart_set_options(port, co, baud, parity, bits, flow);
637}
638
486cab2b 639static struct uart_driver ks8695_reg;
2c7ee6ab
AV		 640
641static struct console ks8695_console = {
642 .name = SERIAL_KS8695_DEVNAME,
643 .write = ks8695_console_write,
644 .device = uart_console_device,
645 .setup = ks8695_console_setup,
646 .flags = CON_PRINTBUFFER,
647 .index = -1,
648 .data = &ks8695_reg,
649};
650
651static int __init ks8695_console_init(void)
652{
0ad70740 653 add_preferred_console(SERIAL_KS8695_DEVNAME, 0, NULL);
2c7ee6ab
AV		 654 register_console(&ks8695_console);
655 return 0;
656}
657
658console_initcall(ks8695_console_init);
659
660#define KS8695_CONSOLE &ks8695_console
661#else
662#define KS8695_CONSOLE NULL
663#endif
664
665static struct uart_driver ks8695_reg = {
666 .owner = THIS_MODULE,
667 .driver_name = "serial_ks8695",
668 .dev_name = SERIAL_KS8695_DEVNAME,
669 .major = SERIAL_KS8695_MAJOR,
670 .minor = SERIAL_KS8695_MINOR,
671 .nr = SERIAL_KS8695_NR,
672 .cons = KS8695_CONSOLE,
673};
674
675static int __init ks8695uart_init(void)
676{
677 int i, ret;
678
679 printk(KERN_INFO "Serial: Micrel KS8695 UART driver\n");
680
681 ret = uart_register_driver(&ks8695_reg);
682 if (ret)
683 return ret;
684
685 for (i = 0; i < SERIAL_KS8695_NR; i++)
686 uart_add_one_port(&ks8695_reg, &ks8695uart_ports[0]);
687
688 return 0;
689}
690
691static void __exit ks8695uart_exit(void)
692{
693 int i;
694
695 for (i = 0; i < SERIAL_KS8695_NR; i++)
696 uart_remove_one_port(&ks8695_reg, &ks8695uart_ports[0]);
697 uart_unregister_driver(&ks8695_reg);
698}
699
700module_init(ks8695uart_init);
701module_exit(ks8695uart_exit);
702
703MODULE_DESCRIPTION("KS8695 serial port driver");
704MODULE_AUTHOR("Micrel Inc.");
705MODULE_LICENSE("GPL");
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