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