1 /*
2 * linux/drivers/char/clps711x.c
3 *
4 * Driver for CLPS711x serial ports
5 *
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 *
8 * Copyright 1999 ARM Limited
9 * Copyright (C) 2000 Deep Blue Solutions Ltd.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 *
25 * $Id: clps711x.c,v 1.42 2002/07/28 10:03:28 rmk Exp $
26 *
27 */
28
29 #if defined(CONFIG_SERIAL_CLPS711X_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
30 #define SUPPORT_SYSRQ
31 #endif
32
33 #include <linux/module.h>
34 #include <linux/ioport.h>
35 #include <linux/init.h>
36 #include <linux/console.h>
37 #include <linux/sysrq.h>
38 #include <linux/spinlock.h>
39 #include <linux/device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/serial.h>
44
45 #include <asm/hardware.h>
46 #include <asm/io.h>
47 #include <asm/irq.h>
48 #include <asm/hardware/clps7111.h>
49
50 #define UART_NR 2
51
52 #define SERIAL_CLPS711X_MAJOR 204
53 #define SERIAL_CLPS711X_MINOR 40
54 #define SERIAL_CLPS711X_NR UART_NR
55
56 /*
57 * We use the relevant SYSCON register as a base address for these ports.
58 */
59 #define UBRLCR(port) ((port)->iobase + UBRLCR1 - SYSCON1)
60 #define UARTDR(port) ((port)->iobase + UARTDR1 - SYSCON1)
61 #define SYSFLG(port) ((port)->iobase + SYSFLG1 - SYSCON1)
62 #define SYSCON(port) ((port)->iobase + SYSCON1 - SYSCON1)
63
64 #define TX_IRQ(port) ((port)->irq)
65 #define RX_IRQ(port) ((port)->irq + 1)
66
67 #define UART_ANY_ERR (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR)
68
69 #define tx_enabled(port) ((port)->unused[0])
70
71 static void clps711xuart_stop_tx(struct uart_port *port)
72 {
73 if (tx_enabled(port)) {
74 disable_irq(TX_IRQ(port));
75 tx_enabled(port) = 0;
76 }
77 }
78
79 static void clps711xuart_start_tx(struct uart_port *port)
80 {
81 if (!tx_enabled(port)) {
82 enable_irq(TX_IRQ(port));
83 tx_enabled(port) = 1;
84 }
85 }
86
87 static void clps711xuart_stop_rx(struct uart_port *port)
88 {
89 disable_irq(RX_IRQ(port));
90 }
91
92 static void clps711xuart_enable_ms(struct uart_port *port)
93 {
94 }
95
96 static irqreturn_t clps711xuart_int_rx(int irq, void *dev_id)
97 {
98 struct uart_port *port = dev_id;
99 struct tty_struct *tty = port->info->tty;
100 unsigned int status, ch, flg;
101
102 status = clps_readl(SYSFLG(port));
103 while (!(status & SYSFLG_URXFE)) {
104 ch = clps_readl(UARTDR(port));
105
106 port->icount.rx++;
107
108 flg = TTY_NORMAL;
109
110 /*
111 * Note that the error handling code is
112 * out of the main execution path
113 */
114 if (unlikely(ch & UART_ANY_ERR)) {
115 if (ch & UARTDR_PARERR)
116 port->icount.parity++;
117 else if (ch & UARTDR_FRMERR)
118 port->icount.frame++;
119 if (ch & UARTDR_OVERR)
120 port->icount.overrun++;
121
122 ch &= port->read_status_mask;
123
124 if (ch & UARTDR_PARERR)
125 flg = TTY_PARITY;
126 else if (ch & UARTDR_FRMERR)
127 flg = TTY_FRAME;
128
129 #ifdef SUPPORT_SYSRQ
130 port->sysrq = 0;
131 #endif
132 }
133
134 if (uart_handle_sysrq_char(port, ch))
135 goto ignore_char;
136
137 /*
138 * CHECK: does overrun affect the current character?
139 * ASSUMPTION: it does not.
140 */
141 uart_insert_char(port, ch, UARTDR_OVERR, ch, flg);
142
143 ignore_char:
144 status = clps_readl(SYSFLG(port));
145 }
146 tty_flip_buffer_push(tty);
147 return IRQ_HANDLED;
148 }
149
150 static irqreturn_t clps711xuart_int_tx(int irq, void *dev_id)
151 {
152 struct uart_port *port = dev_id;
153 struct circ_buf *xmit = &port->info->xmit;
154 int count;
155
156 if (port->x_char) {
157 clps_writel(port->x_char, UARTDR(port));
158 port->icount.tx++;
159 port->x_char = 0;
160 return IRQ_HANDLED;
161 }
162 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
163 clps711xuart_stop_tx(port);
164 return IRQ_HANDLED;
165 }
166
167 count = port->fifosize >> 1;
168 do {
169 clps_writel(xmit->buf[xmit->tail], UARTDR(port));
170 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
171 port->icount.tx++;
172 if (uart_circ_empty(xmit))
173 break;
174 } while (--count > 0);
175
176 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
177 uart_write_wakeup(port);
178
179 if (uart_circ_empty(xmit))
180 clps711xuart_stop_tx(port);
181
182 return IRQ_HANDLED;
183 }
184
185 static unsigned int clps711xuart_tx_empty(struct uart_port *port)
186 {
187 unsigned int status = clps_readl(SYSFLG(port));
188 return status & SYSFLG_UBUSY ? 0 : TIOCSER_TEMT;
189 }
190
191 static unsigned int clps711xuart_get_mctrl(struct uart_port *port)
192 {
193 unsigned int port_addr;
194 unsigned int result = 0;
195 unsigned int status;
196
197 port_addr = SYSFLG(port);
198 if (port_addr == SYSFLG1) {
199 status = clps_readl(SYSFLG1);
200 if (status & SYSFLG1_DCD)
201 result |= TIOCM_CAR;
202 if (status & SYSFLG1_DSR)
203 result |= TIOCM_DSR;
204 if (status & SYSFLG1_CTS)
205 result |= TIOCM_CTS;
206 }
207
208 return result;
209 }
210
211 static void
212 clps711xuart_set_mctrl_null(struct uart_port *port, unsigned int mctrl)
213 {
214 }
215
216 static void clps711xuart_break_ctl(struct uart_port *port, int break_state)
217 {
218 unsigned long flags;
219 unsigned int ubrlcr;
220
221 spin_lock_irqsave(&port->lock, flags);
222 ubrlcr = clps_readl(UBRLCR(port));
223 if (break_state == -1)
224 ubrlcr |= UBRLCR_BREAK;
225 else
226 ubrlcr &= ~UBRLCR_BREAK;
227 clps_writel(ubrlcr, UBRLCR(port));
228 spin_unlock_irqrestore(&port->lock, flags);
229 }
230
231 static int clps711xuart_startup(struct uart_port *port)
232 {
233 unsigned int syscon;
234 int retval;
235
236 tx_enabled(port) = 1;
237
238 /*
239 * Allocate the IRQs
240 */
241 retval = request_irq(TX_IRQ(port), clps711xuart_int_tx, 0,
242 "clps711xuart_tx", port);
243 if (retval)
244 return retval;
245
246 retval = request_irq(RX_IRQ(port), clps711xuart_int_rx, 0,
247 "clps711xuart_rx", port);
248 if (retval) {
249 free_irq(TX_IRQ(port), port);
250 return retval;
251 }
252
253 /*
254 * enable the port
255 */
256 syscon = clps_readl(SYSCON(port));
257 syscon |= SYSCON_UARTEN;
258 clps_writel(syscon, SYSCON(port));
259
260 return 0;
261 }
262
263 static void clps711xuart_shutdown(struct uart_port *port)
264 {
265 unsigned int ubrlcr, syscon;
266
267 /*
268 * Free the interrupt
269 */
270 free_irq(TX_IRQ(port), port); /* TX interrupt */
271 free_irq(RX_IRQ(port), port); /* RX interrupt */
272
273 /*
274 * disable the port
275 */
276 syscon = clps_readl(SYSCON(port));
277 syscon &= ~SYSCON_UARTEN;
278 clps_writel(syscon, SYSCON(port));
279
280 /*
281 * disable break condition and fifos
282 */
283 ubrlcr = clps_readl(UBRLCR(port));
284 ubrlcr &= ~(UBRLCR_FIFOEN | UBRLCR_BREAK);
285 clps_writel(ubrlcr, UBRLCR(port));
286 }
287
288 static void
289 clps711xuart_set_termios(struct uart_port *port, struct ktermios *termios,
290 struct ktermios *old)
291 {
292 unsigned int ubrlcr, baud, quot;
293 unsigned long flags;
294
295 /*
296 * We don't implement CREAD.
297 */
298 termios->c_cflag |= CREAD;
299
300 /*
301 * Ask the core to calculate the divisor for us.
302 */
303 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
304 quot = uart_get_divisor(port, baud);
305
306 switch (termios->c_cflag & CSIZE) {
307 case CS5:
308 ubrlcr = UBRLCR_WRDLEN5;
309 break;
310 case CS6:
311 ubrlcr = UBRLCR_WRDLEN6;
312 break;
313 case CS7:
314 ubrlcr = UBRLCR_WRDLEN7;
315 break;
316 default: // CS8
317 ubrlcr = UBRLCR_WRDLEN8;
318 break;
319 }
320 if (termios->c_cflag & CSTOPB)
321 ubrlcr |= UBRLCR_XSTOP;
322 if (termios->c_cflag & PARENB) {
323 ubrlcr |= UBRLCR_PRTEN;
324 if (!(termios->c_cflag & PARODD))
325 ubrlcr |= UBRLCR_EVENPRT;
326 }
327 if (port->fifosize > 1)
328 ubrlcr |= UBRLCR_FIFOEN;
329
330 spin_lock_irqsave(&port->lock, flags);
331
332 /*
333 * Update the per-port timeout.
334 */
335 uart_update_timeout(port, termios->c_cflag, baud);
336
337 port->read_status_mask = UARTDR_OVERR;
338 if (termios->c_iflag & INPCK)
339 port->read_status_mask |= UARTDR_PARERR | UARTDR_FRMERR;
340
341 /*
342 * Characters to ignore
343 */
344 port->ignore_status_mask = 0;
345 if (termios->c_iflag & IGNPAR)
346 port->ignore_status_mask |= UARTDR_FRMERR | UARTDR_PARERR;
347 if (termios->c_iflag & IGNBRK) {
348 /*
349 * If we're ignoring parity and break indicators,
350 * ignore overruns to (for real raw support).
351 */
352 if (termios->c_iflag & IGNPAR)
353 port->ignore_status_mask |= UARTDR_OVERR;
354 }
355
356 quot -= 1;
357
358 clps_writel(ubrlcr | quot, UBRLCR(port));
359
360 spin_unlock_irqrestore(&port->lock, flags);
361 }
362
363 static const char *clps711xuart_type(struct uart_port *port)
364 {
365 return port->type == PORT_CLPS711X ? "CLPS711x" : NULL;
366 }
367
368 /*
369 * Configure/autoconfigure the port.
370 */
371 static void clps711xuart_config_port(struct uart_port *port, int flags)
372 {
373 if (flags & UART_CONFIG_TYPE)
374 port->type = PORT_CLPS711X;
375 }
376
377 static void clps711xuart_release_port(struct uart_port *port)
378 {
379 }
380
381 static int clps711xuart_request_port(struct uart_port *port)
382 {
383 return 0;
384 }
385
386 static struct uart_ops clps711x_pops = {
387 .tx_empty = clps711xuart_tx_empty,
388 .set_mctrl = clps711xuart_set_mctrl_null,
389 .get_mctrl = clps711xuart_get_mctrl,
390 .stop_tx = clps711xuart_stop_tx,
391 .start_tx = clps711xuart_start_tx,
392 .stop_rx = clps711xuart_stop_rx,
393 .enable_ms = clps711xuart_enable_ms,
394 .break_ctl = clps711xuart_break_ctl,
395 .startup = clps711xuart_startup,
396 .shutdown = clps711xuart_shutdown,
397 .set_termios = clps711xuart_set_termios,
398 .type = clps711xuart_type,
399 .config_port = clps711xuart_config_port,
400 .release_port = clps711xuart_release_port,
401 .request_port = clps711xuart_request_port,
402 };
403
404 static struct uart_port clps711x_ports[UART_NR] = {
405 {
406 .iobase = SYSCON1,
407 .irq = IRQ_UTXINT1, /* IRQ_URXINT1, IRQ_UMSINT */
408 .uartclk = 3686400,
409 .fifosize = 16,
410 .ops = &clps711x_pops,
411 .line = 0,
412 .flags = UPF_BOOT_AUTOCONF,
413 },
414 {
415 .iobase = SYSCON2,
416 .irq = IRQ_UTXINT2, /* IRQ_URXINT2 */
417 .uartclk = 3686400,
418 .fifosize = 16,
419 .ops = &clps711x_pops,
420 .line = 1,
421 .flags = UPF_BOOT_AUTOCONF,
422 }
423 };
424
425 #ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
426 static void clps711xuart_console_putchar(struct uart_port *port, int ch)
427 {
428 while (clps_readl(SYSFLG(port)) & SYSFLG_UTXFF)
429 barrier();
430 clps_writel(ch, UARTDR(port));
431 }
432
433 /*
434 * Print a string to the serial port trying not to disturb
435 * any possible real use of the port...
436 *
437 * The console_lock must be held when we get here.
438 *
439 * Note that this is called with interrupts already disabled
440 */
441 static void
442 clps711xuart_console_write(struct console *co, const char *s,
443 unsigned int count)
444 {
445 struct uart_port *port = clps711x_ports + co->index;
446 unsigned int status, syscon;
447
448 /*
449 * Ensure that the port is enabled.
450 */
451 syscon = clps_readl(SYSCON(port));
452 clps_writel(syscon | SYSCON_UARTEN, SYSCON(port));
453
454 uart_console_write(port, s, count, clps711xuart_console_putchar);
455
456 /*
457 * Finally, wait for transmitter to become empty
458 * and restore the uart state.
459 */
460 do {
461 status = clps_readl(SYSFLG(port));
462 } while (status & SYSFLG_UBUSY);
463
464 clps_writel(syscon, SYSCON(port));
465 }
466
467 static void __init
468 clps711xuart_console_get_options(struct uart_port *port, int *baud,
469 int *parity, int *bits)
470 {
471 if (clps_readl(SYSCON(port)) & SYSCON_UARTEN) {
472 unsigned int ubrlcr, quot;
473
474 ubrlcr = clps_readl(UBRLCR(port));
475
476 *parity = 'n';
477 if (ubrlcr & UBRLCR_PRTEN) {
478 if (ubrlcr & UBRLCR_EVENPRT)
479 *parity = 'e';
480 else
481 *parity = 'o';
482 }
483
484 if ((ubrlcr & UBRLCR_WRDLEN_MASK) == UBRLCR_WRDLEN7)
485 *bits = 7;
486 else
487 *bits = 8;
488
489 quot = ubrlcr & UBRLCR_BAUD_MASK;
490 *baud = port->uartclk / (16 * (quot + 1));
491 }
492 }
493
494 static int __init clps711xuart_console_setup(struct console *co, char *options)
495 {
496 struct uart_port *port;
497 int baud = 38400;
498 int bits = 8;
499 int parity = 'n';
500 int flow = 'n';
501
502 /*
503 * Check whether an invalid uart number has been specified, and
504 * if so, search for the first available port that does have
505 * console support.
506 */
507 port = uart_get_console(clps711x_ports, UART_NR, co);
508
509 if (options)
510 uart_parse_options(options, &baud, &parity, &bits, &flow);
511 else
512 clps711xuart_console_get_options(port, &baud, &parity, &bits);
513
514 return uart_set_options(port, co, baud, parity, bits, flow);
515 }
516
517 static struct uart_driver clps711x_reg;
518 static struct console clps711x_console = {
519 .name = "ttyCL",
520 .write = clps711xuart_console_write,
521 .device = uart_console_device,
522 .setup = clps711xuart_console_setup,
523 .flags = CON_PRINTBUFFER,
524 .index = -1,
525 .data = &clps711x_reg,
526 };
527
528 static int __init clps711xuart_console_init(void)
529 {
530 register_console(&clps711x_console);
531 return 0;
532 }
533 console_initcall(clps711xuart_console_init);
534
535 #define CLPS711X_CONSOLE &clps711x_console
536 #else
537 #define CLPS711X_CONSOLE NULL
538 #endif
539
540 static struct uart_driver clps711x_reg = {
541 .driver_name = "ttyCL",
542 .dev_name = "ttyCL",
543 .major = SERIAL_CLPS711X_MAJOR,
544 .minor = SERIAL_CLPS711X_MINOR,
545 .nr = UART_NR,
546
547 .cons = CLPS711X_CONSOLE,
548 };
549
550 static int __init clps711xuart_init(void)
551 {
552 int ret, i;
553
554 printk(KERN_INFO "Serial: CLPS711x driver $Revision: 1.42 $\n");
555
556 ret = uart_register_driver(&clps711x_reg);
557 if (ret)
558 return ret;
559
560 for (i = 0; i < UART_NR; i++)
561 uart_add_one_port(&clps711x_reg, &clps711x_ports[i]);
562
563 return 0;
564 }
565
566 static void __exit clps711xuart_exit(void)
567 {
568 int i;
569
570 for (i = 0; i < UART_NR; i++)
571 uart_remove_one_port(&clps711x_reg, &clps711x_ports[i]);
572
573 uart_unregister_driver(&clps711x_reg);
574 }
575
576 module_init(clps711xuart_init);
577 module_exit(clps711xuart_exit);
578
579 MODULE_AUTHOR("Deep Blue Solutions Ltd");
580 MODULE_DESCRIPTION("CLPS-711x generic serial driver $Revision: 1.42 $");
581 MODULE_LICENSE("GPL");
582 MODULE_ALIAS_CHARDEV(SERIAL_CLPS711X_MAJOR, SERIAL_CLPS711X_MINOR);
583
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