1 /*
2  *  Driver for SA11x0 serial ports
3  *
4  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5  *
6  *  Copyright (C) 2000 Deep Blue Solutions Ltd.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 
23 #if defined(CONFIG_SERIAL_SA1100_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
24 #define SUPPORT_SYSRQ
25 #endif
26 
27 #include <linux/module.h>
28 #include <linux/ioport.h>
29 #include <linux/init.h>
30 #include <linux/console.h>
31 #include <linux/sysrq.h>
32 #include <linux/platform_device.h>
33 #include <linux/tty.h>
34 #include <linux/tty_flip.h>
35 #include <linux/serial_core.h>
36 #include <linux/serial.h>
37 #include <linux/io.h>
38 
39 #include <asm/irq.h>
40 #include <mach/hardware.h>
41 #include <mach/irqs.h>
42 #include <asm/mach/serial_sa1100.h>
43 
44 /* We've been assigned a range on the "Low-density serial ports" major */
45 #define SERIAL_SA1100_MAJOR	204
46 #define MINOR_START		5
47 
48 #define NR_PORTS		3
49 
50 #define SA1100_ISR_PASS_LIMIT	256
51 
52 /*
53  * Convert from ignore_status_mask or read_status_mask to UTSR[01]
54  */
55 #define SM_TO_UTSR0(x)	((x) & 0xff)
56 #define SM_TO_UTSR1(x)	((x) >> 8)
57 #define UTSR0_TO_SM(x)	((x))
58 #define UTSR1_TO_SM(x)	((x) << 8)
59 
60 #define UART_GET_UTCR0(sport)	__raw_readl((sport)->port.membase + UTCR0)
61 #define UART_GET_UTCR1(sport)	__raw_readl((sport)->port.membase + UTCR1)
62 #define UART_GET_UTCR2(sport)	__raw_readl((sport)->port.membase + UTCR2)
63 #define UART_GET_UTCR3(sport)	__raw_readl((sport)->port.membase + UTCR3)
64 #define UART_GET_UTSR0(sport)	__raw_readl((sport)->port.membase + UTSR0)
65 #define UART_GET_UTSR1(sport)	__raw_readl((sport)->port.membase + UTSR1)
66 #define UART_GET_CHAR(sport)	__raw_readl((sport)->port.membase + UTDR)
67 
68 #define UART_PUT_UTCR0(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR0)
69 #define UART_PUT_UTCR1(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR1)
70 #define UART_PUT_UTCR2(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR2)
71 #define UART_PUT_UTCR3(sport,v)	__raw_writel((v),(sport)->port.membase + UTCR3)
72 #define UART_PUT_UTSR0(sport,v)	__raw_writel((v),(sport)->port.membase + UTSR0)
73 #define UART_PUT_UTSR1(sport,v)	__raw_writel((v),(sport)->port.membase + UTSR1)
74 #define UART_PUT_CHAR(sport,v)	__raw_writel((v),(sport)->port.membase + UTDR)
75 
76 /*
77  * This is the size of our serial port register set.
78  */
79 #define UART_PORT_SIZE	0x24
80 
81 /*
82  * This determines how often we check the modem status signals
83  * for any change.  They generally aren't connected to an IRQ
84  * so we have to poll them.  We also check immediately before
85  * filling the TX fifo incase CTS has been dropped.
86  */
87 #define MCTRL_TIMEOUT	(250*HZ/1000)
88 
89 struct sa1100_port {
90 	struct uart_port	port;
91 	struct timer_list	timer;
92 	unsigned int		old_status;
93 };
94 
95 /*
96  * Handle any change of modem status signal since we were last called.
97  */
sa1100_mctrl_check(struct sa1100_port * sport)98 static void sa1100_mctrl_check(struct sa1100_port *sport)
99 {
100 	unsigned int status, changed;
101 
102 	status = sport->port.ops->get_mctrl(&sport->port);
103 	changed = status ^ sport->old_status;
104 
105 	if (changed == 0)
106 		return;
107 
108 	sport->old_status = status;
109 
110 	if (changed & TIOCM_RI)
111 		sport->port.icount.rng++;
112 	if (changed & TIOCM_DSR)
113 		sport->port.icount.dsr++;
114 	if (changed & TIOCM_CAR)
115 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
116 	if (changed & TIOCM_CTS)
117 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
118 
119 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
120 }
121 
122 /*
123  * This is our per-port timeout handler, for checking the
124  * modem status signals.
125  */
sa1100_timeout(unsigned long data)126 static void sa1100_timeout(unsigned long data)
127 {
128 	struct sa1100_port *sport = (struct sa1100_port *)data;
129 	unsigned long flags;
130 
131 	if (sport->port.state) {
132 		spin_lock_irqsave(&sport->port.lock, flags);
133 		sa1100_mctrl_check(sport);
134 		spin_unlock_irqrestore(&sport->port.lock, flags);
135 
136 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
137 	}
138 }
139 
140 /*
141  * interrupts disabled on entry
142  */
sa1100_stop_tx(struct uart_port * port)143 static void sa1100_stop_tx(struct uart_port *port)
144 {
145 	struct sa1100_port *sport = (struct sa1100_port *)port;
146 	u32 utcr3;
147 
148 	utcr3 = UART_GET_UTCR3(sport);
149 	UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_TIE);
150 	sport->port.read_status_mask &= ~UTSR0_TO_SM(UTSR0_TFS);
151 }
152 
153 /*
154  * port locked and interrupts disabled
155  */
sa1100_start_tx(struct uart_port * port)156 static void sa1100_start_tx(struct uart_port *port)
157 {
158 	struct sa1100_port *sport = (struct sa1100_port *)port;
159 	u32 utcr3;
160 
161 	utcr3 = UART_GET_UTCR3(sport);
162 	sport->port.read_status_mask |= UTSR0_TO_SM(UTSR0_TFS);
163 	UART_PUT_UTCR3(sport, utcr3 | UTCR3_TIE);
164 }
165 
166 /*
167  * Interrupts enabled
168  */
sa1100_stop_rx(struct uart_port * port)169 static void sa1100_stop_rx(struct uart_port *port)
170 {
171 	struct sa1100_port *sport = (struct sa1100_port *)port;
172 	u32 utcr3;
173 
174 	utcr3 = UART_GET_UTCR3(sport);
175 	UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_RIE);
176 }
177 
178 /*
179  * Set the modem control timer to fire immediately.
180  */
sa1100_enable_ms(struct uart_port * port)181 static void sa1100_enable_ms(struct uart_port *port)
182 {
183 	struct sa1100_port *sport = (struct sa1100_port *)port;
184 
185 	mod_timer(&sport->timer, jiffies);
186 }
187 
188 static void
sa1100_rx_chars(struct sa1100_port * sport)189 sa1100_rx_chars(struct sa1100_port *sport)
190 {
191 	struct tty_struct *tty = sport->port.state->port.tty;
192 	unsigned int status, ch, flg;
193 
194 	status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
195 		 UTSR0_TO_SM(UART_GET_UTSR0(sport));
196 	while (status & UTSR1_TO_SM(UTSR1_RNE)) {
197 		ch = UART_GET_CHAR(sport);
198 
199 		sport->port.icount.rx++;
200 
201 		flg = TTY_NORMAL;
202 
203 		/*
204 		 * note that the error handling code is
205 		 * out of the main execution path
206 		 */
207 		if (status & UTSR1_TO_SM(UTSR1_PRE | UTSR1_FRE | UTSR1_ROR)) {
208 			if (status & UTSR1_TO_SM(UTSR1_PRE))
209 				sport->port.icount.parity++;
210 			else if (status & UTSR1_TO_SM(UTSR1_FRE))
211 				sport->port.icount.frame++;
212 			if (status & UTSR1_TO_SM(UTSR1_ROR))
213 				sport->port.icount.overrun++;
214 
215 			status &= sport->port.read_status_mask;
216 
217 			if (status & UTSR1_TO_SM(UTSR1_PRE))
218 				flg = TTY_PARITY;
219 			else if (status & UTSR1_TO_SM(UTSR1_FRE))
220 				flg = TTY_FRAME;
221 
222 #ifdef SUPPORT_SYSRQ
223 			sport->port.sysrq = 0;
224 #endif
225 		}
226 
227 		if (uart_handle_sysrq_char(&sport->port, ch))
228 			goto ignore_char;
229 
230 		uart_insert_char(&sport->port, status, UTSR1_TO_SM(UTSR1_ROR), ch, flg);
231 
232 	ignore_char:
233 		status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
234 			 UTSR0_TO_SM(UART_GET_UTSR0(sport));
235 	}
236 	tty_flip_buffer_push(tty);
237 }
238 
sa1100_tx_chars(struct sa1100_port * sport)239 static void sa1100_tx_chars(struct sa1100_port *sport)
240 {
241 	struct circ_buf *xmit = &sport->port.state->xmit;
242 
243 	if (sport->port.x_char) {
244 		UART_PUT_CHAR(sport, sport->port.x_char);
245 		sport->port.icount.tx++;
246 		sport->port.x_char = 0;
247 		return;
248 	}
249 
250 	/*
251 	 * Check the modem control lines before
252 	 * transmitting anything.
253 	 */
254 	sa1100_mctrl_check(sport);
255 
256 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
257 		sa1100_stop_tx(&sport->port);
258 		return;
259 	}
260 
261 	/*
262 	 * Tried using FIFO (not checking TNF) for fifo fill:
263 	 * still had the '4 bytes repeated' problem.
264 	 */
265 	while (UART_GET_UTSR1(sport) & UTSR1_TNF) {
266 		UART_PUT_CHAR(sport, xmit->buf[xmit->tail]);
267 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
268 		sport->port.icount.tx++;
269 		if (uart_circ_empty(xmit))
270 			break;
271 	}
272 
273 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
274 		uart_write_wakeup(&sport->port);
275 
276 	if (uart_circ_empty(xmit))
277 		sa1100_stop_tx(&sport->port);
278 }
279 
sa1100_int(int irq,void * dev_id)280 static irqreturn_t sa1100_int(int irq, void *dev_id)
281 {
282 	struct sa1100_port *sport = dev_id;
283 	unsigned int status, pass_counter = 0;
284 
285 	spin_lock(&sport->port.lock);
286 	status = UART_GET_UTSR0(sport);
287 	status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS;
288 	do {
289 		if (status & (UTSR0_RFS | UTSR0_RID)) {
290 			/* Clear the receiver idle bit, if set */
291 			if (status & UTSR0_RID)
292 				UART_PUT_UTSR0(sport, UTSR0_RID);
293 			sa1100_rx_chars(sport);
294 		}
295 
296 		/* Clear the relevant break bits */
297 		if (status & (UTSR0_RBB | UTSR0_REB))
298 			UART_PUT_UTSR0(sport, status & (UTSR0_RBB | UTSR0_REB));
299 
300 		if (status & UTSR0_RBB)
301 			sport->port.icount.brk++;
302 
303 		if (status & UTSR0_REB)
304 			uart_handle_break(&sport->port);
305 
306 		if (status & UTSR0_TFS)
307 			sa1100_tx_chars(sport);
308 		if (pass_counter++ > SA1100_ISR_PASS_LIMIT)
309 			break;
310 		status = UART_GET_UTSR0(sport);
311 		status &= SM_TO_UTSR0(sport->port.read_status_mask) |
312 			  ~UTSR0_TFS;
313 	} while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID));
314 	spin_unlock(&sport->port.lock);
315 
316 	return IRQ_HANDLED;
317 }
318 
319 /*
320  * Return TIOCSER_TEMT when transmitter is not busy.
321  */
sa1100_tx_empty(struct uart_port * port)322 static unsigned int sa1100_tx_empty(struct uart_port *port)
323 {
324 	struct sa1100_port *sport = (struct sa1100_port *)port;
325 
326 	return UART_GET_UTSR1(sport) & UTSR1_TBY ? 0 : TIOCSER_TEMT;
327 }
328 
sa1100_get_mctrl(struct uart_port * port)329 static unsigned int sa1100_get_mctrl(struct uart_port *port)
330 {
331 	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
332 }
333 
sa1100_set_mctrl(struct uart_port * port,unsigned int mctrl)334 static void sa1100_set_mctrl(struct uart_port *port, unsigned int mctrl)
335 {
336 }
337 
338 /*
339  * Interrupts always disabled.
340  */
sa1100_break_ctl(struct uart_port * port,int break_state)341 static void sa1100_break_ctl(struct uart_port *port, int break_state)
342 {
343 	struct sa1100_port *sport = (struct sa1100_port *)port;
344 	unsigned long flags;
345 	unsigned int utcr3;
346 
347 	spin_lock_irqsave(&sport->port.lock, flags);
348 	utcr3 = UART_GET_UTCR3(sport);
349 	if (break_state == -1)
350 		utcr3 |= UTCR3_BRK;
351 	else
352 		utcr3 &= ~UTCR3_BRK;
353 	UART_PUT_UTCR3(sport, utcr3);
354 	spin_unlock_irqrestore(&sport->port.lock, flags);
355 }
356 
sa1100_startup(struct uart_port * port)357 static int sa1100_startup(struct uart_port *port)
358 {
359 	struct sa1100_port *sport = (struct sa1100_port *)port;
360 	int retval;
361 
362 	/*
363 	 * Allocate the IRQ
364 	 */
365 	retval = request_irq(sport->port.irq, sa1100_int, 0,
366 			     "sa11x0-uart", sport);
367 	if (retval)
368 		return retval;
369 
370 	/*
371 	 * Finally, clear and enable interrupts
372 	 */
373 	UART_PUT_UTSR0(sport, -1);
374 	UART_PUT_UTCR3(sport, UTCR3_RXE | UTCR3_TXE | UTCR3_RIE);
375 
376 	/*
377 	 * Enable modem status interrupts
378 	 */
379 	spin_lock_irq(&sport->port.lock);
380 	sa1100_enable_ms(&sport->port);
381 	spin_unlock_irq(&sport->port.lock);
382 
383 	return 0;
384 }
385 
sa1100_shutdown(struct uart_port * port)386 static void sa1100_shutdown(struct uart_port *port)
387 {
388 	struct sa1100_port *sport = (struct sa1100_port *)port;
389 
390 	/*
391 	 * Stop our timer.
392 	 */
393 	del_timer_sync(&sport->timer);
394 
395 	/*
396 	 * Free the interrupt
397 	 */
398 	free_irq(sport->port.irq, sport);
399 
400 	/*
401 	 * Disable all interrupts, port and break condition.
402 	 */
403 	UART_PUT_UTCR3(sport, 0);
404 }
405 
406 static void
sa1100_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)407 sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
408 		   struct ktermios *old)
409 {
410 	struct sa1100_port *sport = (struct sa1100_port *)port;
411 	unsigned long flags;
412 	unsigned int utcr0, old_utcr3, baud, quot;
413 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
414 
415 	/*
416 	 * We only support CS7 and CS8.
417 	 */
418 	while ((termios->c_cflag & CSIZE) != CS7 &&
419 	       (termios->c_cflag & CSIZE) != CS8) {
420 		termios->c_cflag &= ~CSIZE;
421 		termios->c_cflag |= old_csize;
422 		old_csize = CS8;
423 	}
424 
425 	if ((termios->c_cflag & CSIZE) == CS8)
426 		utcr0 = UTCR0_DSS;
427 	else
428 		utcr0 = 0;
429 
430 	if (termios->c_cflag & CSTOPB)
431 		utcr0 |= UTCR0_SBS;
432 	if (termios->c_cflag & PARENB) {
433 		utcr0 |= UTCR0_PE;
434 		if (!(termios->c_cflag & PARODD))
435 			utcr0 |= UTCR0_OES;
436 	}
437 
438 	/*
439 	 * Ask the core to calculate the divisor for us.
440 	 */
441 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
442 	quot = uart_get_divisor(port, baud);
443 
444 	spin_lock_irqsave(&sport->port.lock, flags);
445 
446 	sport->port.read_status_mask &= UTSR0_TO_SM(UTSR0_TFS);
447 	sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
448 	if (termios->c_iflag & INPCK)
449 		sport->port.read_status_mask |=
450 				UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
451 	if (termios->c_iflag & (BRKINT | PARMRK))
452 		sport->port.read_status_mask |=
453 				UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
454 
455 	/*
456 	 * Characters to ignore
457 	 */
458 	sport->port.ignore_status_mask = 0;
459 	if (termios->c_iflag & IGNPAR)
460 		sport->port.ignore_status_mask |=
461 				UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
462 	if (termios->c_iflag & IGNBRK) {
463 		sport->port.ignore_status_mask |=
464 				UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
465 		/*
466 		 * If we're ignoring parity and break indicators,
467 		 * ignore overruns too (for real raw support).
468 		 */
469 		if (termios->c_iflag & IGNPAR)
470 			sport->port.ignore_status_mask |=
471 				UTSR1_TO_SM(UTSR1_ROR);
472 	}
473 
474 	del_timer_sync(&sport->timer);
475 
476 	/*
477 	 * Update the per-port timeout.
478 	 */
479 	uart_update_timeout(port, termios->c_cflag, baud);
480 
481 	/*
482 	 * disable interrupts and drain transmitter
483 	 */
484 	old_utcr3 = UART_GET_UTCR3(sport);
485 	UART_PUT_UTCR3(sport, old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE));
486 
487 	while (UART_GET_UTSR1(sport) & UTSR1_TBY)
488 		barrier();
489 
490 	/* then, disable everything */
491 	UART_PUT_UTCR3(sport, 0);
492 
493 	/* set the parity, stop bits and data size */
494 	UART_PUT_UTCR0(sport, utcr0);
495 
496 	/* set the baud rate */
497 	quot -= 1;
498 	UART_PUT_UTCR1(sport, ((quot & 0xf00) >> 8));
499 	UART_PUT_UTCR2(sport, (quot & 0xff));
500 
501 	UART_PUT_UTSR0(sport, -1);
502 
503 	UART_PUT_UTCR3(sport, old_utcr3);
504 
505 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
506 		sa1100_enable_ms(&sport->port);
507 
508 	spin_unlock_irqrestore(&sport->port.lock, flags);
509 }
510 
sa1100_type(struct uart_port * port)511 static const char *sa1100_type(struct uart_port *port)
512 {
513 	struct sa1100_port *sport = (struct sa1100_port *)port;
514 
515 	return sport->port.type == PORT_SA1100 ? "SA1100" : NULL;
516 }
517 
518 /*
519  * Release the memory region(s) being used by 'port'.
520  */
sa1100_release_port(struct uart_port * port)521 static void sa1100_release_port(struct uart_port *port)
522 {
523 	struct sa1100_port *sport = (struct sa1100_port *)port;
524 
525 	release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
526 }
527 
528 /*
529  * Request the memory region(s) being used by 'port'.
530  */
sa1100_request_port(struct uart_port * port)531 static int sa1100_request_port(struct uart_port *port)
532 {
533 	struct sa1100_port *sport = (struct sa1100_port *)port;
534 
535 	return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
536 			"sa11x0-uart") != NULL ? 0 : -EBUSY;
537 }
538 
539 /*
540  * Configure/autoconfigure the port.
541  */
sa1100_config_port(struct uart_port * port,int flags)542 static void sa1100_config_port(struct uart_port *port, int flags)
543 {
544 	struct sa1100_port *sport = (struct sa1100_port *)port;
545 
546 	if (flags & UART_CONFIG_TYPE &&
547 	    sa1100_request_port(&sport->port) == 0)
548 		sport->port.type = PORT_SA1100;
549 }
550 
551 /*
552  * Verify the new serial_struct (for TIOCSSERIAL).
553  * The only change we allow are to the flags and type, and
554  * even then only between PORT_SA1100 and PORT_UNKNOWN
555  */
556 static int
sa1100_verify_port(struct uart_port * port,struct serial_struct * ser)557 sa1100_verify_port(struct uart_port *port, struct serial_struct *ser)
558 {
559 	struct sa1100_port *sport = (struct sa1100_port *)port;
560 	int ret = 0;
561 
562 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SA1100)
563 		ret = -EINVAL;
564 	if (sport->port.irq != ser->irq)
565 		ret = -EINVAL;
566 	if (ser->io_type != SERIAL_IO_MEM)
567 		ret = -EINVAL;
568 	if (sport->port.uartclk / 16 != ser->baud_base)
569 		ret = -EINVAL;
570 	if ((void *)sport->port.mapbase != ser->iomem_base)
571 		ret = -EINVAL;
572 	if (sport->port.iobase != ser->port)
573 		ret = -EINVAL;
574 	if (ser->hub6 != 0)
575 		ret = -EINVAL;
576 	return ret;
577 }
578 
579 static struct uart_ops sa1100_pops = {
580 	.tx_empty	= sa1100_tx_empty,
581 	.set_mctrl	= sa1100_set_mctrl,
582 	.get_mctrl	= sa1100_get_mctrl,
583 	.stop_tx	= sa1100_stop_tx,
584 	.start_tx	= sa1100_start_tx,
585 	.stop_rx	= sa1100_stop_rx,
586 	.enable_ms	= sa1100_enable_ms,
587 	.break_ctl	= sa1100_break_ctl,
588 	.startup	= sa1100_startup,
589 	.shutdown	= sa1100_shutdown,
590 	.set_termios	= sa1100_set_termios,
591 	.type		= sa1100_type,
592 	.release_port	= sa1100_release_port,
593 	.request_port	= sa1100_request_port,
594 	.config_port	= sa1100_config_port,
595 	.verify_port	= sa1100_verify_port,
596 };
597 
598 static struct sa1100_port sa1100_ports[NR_PORTS];
599 
600 /*
601  * Setup the SA1100 serial ports.  Note that we don't include the IrDA
602  * port here since we have our own SIR/FIR driver (see drivers/net/irda)
603  *
604  * Note also that we support "console=ttySAx" where "x" is either 0 or 1.
605  * Which serial port this ends up being depends on the machine you're
606  * running this kernel on.  I'm not convinced that this is a good idea,
607  * but that's the way it traditionally works.
608  *
609  * Note that NanoEngine UART3 becomes UART2, and UART2 is no longer
610  * used here.
611  */
sa1100_init_ports(void)612 static void __init sa1100_init_ports(void)
613 {
614 	static int first = 1;
615 	int i;
616 
617 	if (!first)
618 		return;
619 	first = 0;
620 
621 	for (i = 0; i < NR_PORTS; i++) {
622 		sa1100_ports[i].port.uartclk   = 3686400;
623 		sa1100_ports[i].port.ops       = &sa1100_pops;
624 		sa1100_ports[i].port.fifosize  = 8;
625 		sa1100_ports[i].port.line      = i;
626 		sa1100_ports[i].port.iotype    = UPIO_MEM;
627 		init_timer(&sa1100_ports[i].timer);
628 		sa1100_ports[i].timer.function = sa1100_timeout;
629 		sa1100_ports[i].timer.data     = (unsigned long)&sa1100_ports[i];
630 	}
631 
632 	/*
633 	 * make transmit lines outputs, so that when the port
634 	 * is closed, the output is in the MARK state.
635 	 */
636 	PPDR |= PPC_TXD1 | PPC_TXD3;
637 	PPSR |= PPC_TXD1 | PPC_TXD3;
638 }
639 
sa1100_register_uart_fns(struct sa1100_port_fns * fns)640 void __devinit sa1100_register_uart_fns(struct sa1100_port_fns *fns)
641 {
642 	if (fns->get_mctrl)
643 		sa1100_pops.get_mctrl = fns->get_mctrl;
644 	if (fns->set_mctrl)
645 		sa1100_pops.set_mctrl = fns->set_mctrl;
646 
647 	sa1100_pops.pm       = fns->pm;
648 	sa1100_pops.set_wake = fns->set_wake;
649 }
650 
sa1100_register_uart(int idx,int port)651 void __init sa1100_register_uart(int idx, int port)
652 {
653 	if (idx >= NR_PORTS) {
654 		printk(KERN_ERR "%s: bad index number %d\n", __func__, idx);
655 		return;
656 	}
657 
658 	switch (port) {
659 	case 1:
660 		sa1100_ports[idx].port.membase = (void __iomem *)&Ser1UTCR0;
661 		sa1100_ports[idx].port.mapbase = _Ser1UTCR0;
662 		sa1100_ports[idx].port.irq     = IRQ_Ser1UART;
663 		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
664 		break;
665 
666 	case 2:
667 		sa1100_ports[idx].port.membase = (void __iomem *)&Ser2UTCR0;
668 		sa1100_ports[idx].port.mapbase = _Ser2UTCR0;
669 		sa1100_ports[idx].port.irq     = IRQ_Ser2ICP;
670 		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
671 		break;
672 
673 	case 3:
674 		sa1100_ports[idx].port.membase = (void __iomem *)&Ser3UTCR0;
675 		sa1100_ports[idx].port.mapbase = _Ser3UTCR0;
676 		sa1100_ports[idx].port.irq     = IRQ_Ser3UART;
677 		sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
678 		break;
679 
680 	default:
681 		printk(KERN_ERR "%s: bad port number %d\n", __func__, port);
682 	}
683 }
684 
685 
686 #ifdef CONFIG_SERIAL_SA1100_CONSOLE
sa1100_console_putchar(struct uart_port * port,int ch)687 static void sa1100_console_putchar(struct uart_port *port, int ch)
688 {
689 	struct sa1100_port *sport = (struct sa1100_port *)port;
690 
691 	while (!(UART_GET_UTSR1(sport) & UTSR1_TNF))
692 		barrier();
693 	UART_PUT_CHAR(sport, ch);
694 }
695 
696 /*
697  * Interrupts are disabled on entering
698  */
699 static void
sa1100_console_write(struct console * co,const char * s,unsigned int count)700 sa1100_console_write(struct console *co, const char *s, unsigned int count)
701 {
702 	struct sa1100_port *sport = &sa1100_ports[co->index];
703 	unsigned int old_utcr3, status;
704 
705 	/*
706 	 *	First, save UTCR3 and then disable interrupts
707 	 */
708 	old_utcr3 = UART_GET_UTCR3(sport);
709 	UART_PUT_UTCR3(sport, (old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE)) |
710 				UTCR3_TXE);
711 
712 	uart_console_write(&sport->port, s, count, sa1100_console_putchar);
713 
714 	/*
715 	 *	Finally, wait for transmitter to become empty
716 	 *	and restore UTCR3
717 	 */
718 	do {
719 		status = UART_GET_UTSR1(sport);
720 	} while (status & UTSR1_TBY);
721 	UART_PUT_UTCR3(sport, old_utcr3);
722 }
723 
724 /*
725  * If the port was already initialised (eg, by a boot loader),
726  * try to determine the current setup.
727  */
728 static void __init
sa1100_console_get_options(struct sa1100_port * sport,int * baud,int * parity,int * bits)729 sa1100_console_get_options(struct sa1100_port *sport, int *baud,
730 			   int *parity, int *bits)
731 {
732 	unsigned int utcr3;
733 
734 	utcr3 = UART_GET_UTCR3(sport) & (UTCR3_RXE | UTCR3_TXE);
735 	if (utcr3 == (UTCR3_RXE | UTCR3_TXE)) {
736 		/* ok, the port was enabled */
737 		unsigned int utcr0, quot;
738 
739 		utcr0 = UART_GET_UTCR0(sport);
740 
741 		*parity = 'n';
742 		if (utcr0 & UTCR0_PE) {
743 			if (utcr0 & UTCR0_OES)
744 				*parity = 'e';
745 			else
746 				*parity = 'o';
747 		}
748 
749 		if (utcr0 & UTCR0_DSS)
750 			*bits = 8;
751 		else
752 			*bits = 7;
753 
754 		quot = UART_GET_UTCR2(sport) | UART_GET_UTCR1(sport) << 8;
755 		quot &= 0xfff;
756 		*baud = sport->port.uartclk / (16 * (quot + 1));
757 	}
758 }
759 
760 static int __init
sa1100_console_setup(struct console * co,char * options)761 sa1100_console_setup(struct console *co, char *options)
762 {
763 	struct sa1100_port *sport;
764 	int baud = 9600;
765 	int bits = 8;
766 	int parity = 'n';
767 	int flow = 'n';
768 
769 	/*
770 	 * Check whether an invalid uart number has been specified, and
771 	 * if so, search for the first available port that does have
772 	 * console support.
773 	 */
774 	if (co->index == -1 || co->index >= NR_PORTS)
775 		co->index = 0;
776 	sport = &sa1100_ports[co->index];
777 
778 	if (options)
779 		uart_parse_options(options, &baud, &parity, &bits, &flow);
780 	else
781 		sa1100_console_get_options(sport, &baud, &parity, &bits);
782 
783 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
784 }
785 
786 static struct uart_driver sa1100_reg;
787 static struct console sa1100_console = {
788 	.name		= "ttySA",
789 	.write		= sa1100_console_write,
790 	.device		= uart_console_device,
791 	.setup		= sa1100_console_setup,
792 	.flags		= CON_PRINTBUFFER,
793 	.index		= -1,
794 	.data		= &sa1100_reg,
795 };
796 
sa1100_rs_console_init(void)797 static int __init sa1100_rs_console_init(void)
798 {
799 	sa1100_init_ports();
800 	register_console(&sa1100_console);
801 	return 0;
802 }
803 console_initcall(sa1100_rs_console_init);
804 
805 #define SA1100_CONSOLE	&sa1100_console
806 #else
807 #define SA1100_CONSOLE	NULL
808 #endif
809 
810 static struct uart_driver sa1100_reg = {
811 	.owner			= THIS_MODULE,
812 	.driver_name		= "ttySA",
813 	.dev_name		= "ttySA",
814 	.major			= SERIAL_SA1100_MAJOR,
815 	.minor			= MINOR_START,
816 	.nr			= NR_PORTS,
817 	.cons			= SA1100_CONSOLE,
818 };
819 
sa1100_serial_suspend(struct platform_device * dev,pm_message_t state)820 static int sa1100_serial_suspend(struct platform_device *dev, pm_message_t state)
821 {
822 	struct sa1100_port *sport = platform_get_drvdata(dev);
823 
824 	if (sport)
825 		uart_suspend_port(&sa1100_reg, &sport->port);
826 
827 	return 0;
828 }
829 
sa1100_serial_resume(struct platform_device * dev)830 static int sa1100_serial_resume(struct platform_device *dev)
831 {
832 	struct sa1100_port *sport = platform_get_drvdata(dev);
833 
834 	if (sport)
835 		uart_resume_port(&sa1100_reg, &sport->port);
836 
837 	return 0;
838 }
839 
sa1100_serial_probe(struct platform_device * dev)840 static int sa1100_serial_probe(struct platform_device *dev)
841 {
842 	struct resource *res = dev->resource;
843 	int i;
844 
845 	for (i = 0; i < dev->num_resources; i++, res++)
846 		if (res->flags & IORESOURCE_MEM)
847 			break;
848 
849 	if (i < dev->num_resources) {
850 		for (i = 0; i < NR_PORTS; i++) {
851 			if (sa1100_ports[i].port.mapbase != res->start)
852 				continue;
853 
854 			sa1100_ports[i].port.dev = &dev->dev;
855 			uart_add_one_port(&sa1100_reg, &sa1100_ports[i].port);
856 			platform_set_drvdata(dev, &sa1100_ports[i]);
857 			break;
858 		}
859 	}
860 
861 	return 0;
862 }
863 
sa1100_serial_remove(struct platform_device * pdev)864 static int sa1100_serial_remove(struct platform_device *pdev)
865 {
866 	struct sa1100_port *sport = platform_get_drvdata(pdev);
867 
868 	platform_set_drvdata(pdev, NULL);
869 
870 	if (sport)
871 		uart_remove_one_port(&sa1100_reg, &sport->port);
872 
873 	return 0;
874 }
875 
876 static struct platform_driver sa11x0_serial_driver = {
877 	.probe		= sa1100_serial_probe,
878 	.remove		= sa1100_serial_remove,
879 	.suspend	= sa1100_serial_suspend,
880 	.resume		= sa1100_serial_resume,
881 	.driver		= {
882 		.name	= "sa11x0-uart",
883 		.owner	= THIS_MODULE,
884 	},
885 };
886 
sa1100_serial_init(void)887 static int __init sa1100_serial_init(void)
888 {
889 	int ret;
890 
891 	printk(KERN_INFO "Serial: SA11x0 driver\n");
892 
893 	sa1100_init_ports();
894 
895 	ret = uart_register_driver(&sa1100_reg);
896 	if (ret == 0) {
897 		ret = platform_driver_register(&sa11x0_serial_driver);
898 		if (ret)
899 			uart_unregister_driver(&sa1100_reg);
900 	}
901 	return ret;
902 }
903 
sa1100_serial_exit(void)904 static void __exit sa1100_serial_exit(void)
905 {
906 	platform_driver_unregister(&sa11x0_serial_driver);
907 	uart_unregister_driver(&sa1100_reg);
908 }
909 
910 module_init(sa1100_serial_init);
911 module_exit(sa1100_serial_exit);
912 
913 MODULE_AUTHOR("Deep Blue Solutions Ltd");
914 MODULE_DESCRIPTION("SA1100 generic serial port driver");
915 MODULE_LICENSE("GPL");
916 MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_SA1100_MAJOR);
917 MODULE_ALIAS("platform:sa11x0-uart");
918