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1 /*
2  * lirc_serial.c
3  *
4  * lirc_serial - Device driver that records pulse- and pause-lengths
5  *	       (space-lengths) between DDCD event on a serial port.
6  *
7  * Copyright (C) 1996,97 Ralph Metzler <rjkm@thp.uni-koeln.de>
8  * Copyright (C) 1998 Trent Piepho <xyzzy@u.washington.edu>
9  * Copyright (C) 1998 Ben Pfaff <blp@gnu.org>
10  * Copyright (C) 1999 Christoph Bartelmus <lirc@bartelmus.de>
11  * Copyright (C) 2007 Andrei Tanas <andrei@tanas.ca> (suspend/resume support)
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or
15  *  (at your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; if not, write to the Free Software
24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  */
27 
28 /*
29  * Steve's changes to improve transmission fidelity:
30  *   - for systems with the rdtsc instruction and the clock counter, a
31  *     send_pule that times the pulses directly using the counter.
32  *     This means that the LIRC_SERIAL_TRANSMITTER_LATENCY fudge is
33  *     not needed. Measurement shows very stable waveform, even where
34  *     PCI activity slows the access to the UART, which trips up other
35  *     versions.
36  *   - For other system, non-integer-microsecond pulse/space lengths,
37  *     done using fixed point binary. So, much more accurate carrier
38  *     frequency.
39  *   - fine tuned transmitter latency, taking advantage of fractional
40  *     microseconds in previous change
41  *   - Fixed bug in the way transmitter latency was accounted for by
42  *     tuning the pulse lengths down - the send_pulse routine ignored
43  *     this overhead as it timed the overall pulse length - so the
44  *     pulse frequency was right but overall pulse length was too
45  *     long. Fixed by accounting for latency on each pulse/space
46  *     iteration.
47  *
48  * Steve Davies <steve@daviesfam.org>  July 2001
49  */
50 
51 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
52 
53 #include <linux/module.h>
54 #include <linux/errno.h>
55 #include <linux/signal.h>
56 #include <linux/sched.h>
57 #include <linux/fs.h>
58 #include <linux/interrupt.h>
59 #include <linux/ioport.h>
60 #include <linux/kernel.h>
61 #include <linux/serial_reg.h>
62 #include <linux/time.h>
63 #include <linux/string.h>
64 #include <linux/types.h>
65 #include <linux/wait.h>
66 #include <linux/mm.h>
67 #include <linux/delay.h>
68 #include <linux/poll.h>
69 #include <linux/platform_device.h>
70 #include <linux/gpio.h>
71 #include <linux/io.h>
72 #include <linux/irq.h>
73 #include <linux/fcntl.h>
74 #include <linux/spinlock.h>
75 
76 /* From Intel IXP42X Developer's Manual (#252480-005): */
77 /* ftp://download.intel.com/design/network/manuals/25248005.pdf */
78 #define UART_IE_IXP42X_UUE   0x40 /* IXP42X UART Unit enable */
79 #define UART_IE_IXP42X_RTOIE 0x10 /* IXP42X Receiver Data Timeout int.enable */
80 
81 #include <media/lirc.h>
82 #include <media/lirc_dev.h>
83 
84 #define LIRC_DRIVER_NAME "lirc_serial"
85 
86 struct lirc_serial {
87 	int signal_pin;
88 	int signal_pin_change;
89 	u8 on;
90 	u8 off;
91 	long (*send_pulse)(unsigned long length);
92 	void (*send_space)(long length);
93 	int features;
94 	spinlock_t lock;
95 };
96 
97 #define LIRC_HOMEBREW		0
98 #define LIRC_IRDEO		1
99 #define LIRC_IRDEO_REMOTE	2
100 #define LIRC_ANIMAX		3
101 #define LIRC_IGOR		4
102 #define LIRC_NSLU2		5
103 
104 /*** module parameters ***/
105 static int type;
106 static int io;
107 static int irq;
108 static bool iommap;
109 static int ioshift;
110 static bool softcarrier = 1;
111 static bool share_irq;
112 static bool debug;
113 static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
114 static bool txsense;	/* 0 = active high, 1 = active low */
115 
116 #define dprintk(fmt, args...)					\
117 	do {							\
118 		if (debug)					\
119 			printk(KERN_DEBUG LIRC_DRIVER_NAME ": "	\
120 			       fmt, ## args);			\
121 	} while (0)
122 
123 /* forward declarations */
124 static long send_pulse_irdeo(unsigned long length);
125 static long send_pulse_homebrew(unsigned long length);
126 static void send_space_irdeo(long length);
127 static void send_space_homebrew(long length);
128 
129 static struct lirc_serial hardware[] = {
130 	[LIRC_HOMEBREW] = {
131 		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_HOMEBREW].lock),
132 		.signal_pin        = UART_MSR_DCD,
133 		.signal_pin_change = UART_MSR_DDCD,
134 		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
135 		.off = (UART_MCR_RTS | UART_MCR_OUT2),
136 		.send_pulse = send_pulse_homebrew,
137 		.send_space = send_space_homebrew,
138 #ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
139 		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
140 				LIRC_CAN_SET_SEND_CARRIER |
141 				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
142 #else
143 		.features    = LIRC_CAN_REC_MODE2
144 #endif
145 	},
146 
147 	[LIRC_IRDEO] = {
148 		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_IRDEO].lock),
149 		.signal_pin        = UART_MSR_DSR,
150 		.signal_pin_change = UART_MSR_DDSR,
151 		.on  = UART_MCR_OUT2,
152 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
153 		.send_pulse  = send_pulse_irdeo,
154 		.send_space  = send_space_irdeo,
155 		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
156 				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
157 	},
158 
159 	[LIRC_IRDEO_REMOTE] = {
160 		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_IRDEO_REMOTE].lock),
161 		.signal_pin        = UART_MSR_DSR,
162 		.signal_pin_change = UART_MSR_DDSR,
163 		.on  = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
164 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
165 		.send_pulse  = send_pulse_irdeo,
166 		.send_space  = send_space_irdeo,
167 		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
168 				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
169 	},
170 
171 	[LIRC_ANIMAX] = {
172 		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_ANIMAX].lock),
173 		.signal_pin        = UART_MSR_DCD,
174 		.signal_pin_change = UART_MSR_DDCD,
175 		.on  = 0,
176 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
177 		.send_pulse = NULL,
178 		.send_space = NULL,
179 		.features   = LIRC_CAN_REC_MODE2
180 	},
181 
182 	[LIRC_IGOR] = {
183 		.lock = __SPIN_LOCK_UNLOCKED(hardware[LIRC_IGOR].lock),
184 		.signal_pin        = UART_MSR_DSR,
185 		.signal_pin_change = UART_MSR_DDSR,
186 		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
187 		.off = (UART_MCR_RTS | UART_MCR_OUT2),
188 		.send_pulse = send_pulse_homebrew,
189 		.send_space = send_space_homebrew,
190 #ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
191 		.features    = (LIRC_CAN_SET_SEND_DUTY_CYCLE |
192 				LIRC_CAN_SET_SEND_CARRIER |
193 				LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2)
194 #else
195 		.features    = LIRC_CAN_REC_MODE2
196 #endif
197 	},
198 };
199 
200 #define RS_ISR_PASS_LIMIT 256
201 
202 /*
203  * A long pulse code from a remote might take up to 300 bytes.  The
204  * daemon should read the bytes as soon as they are generated, so take
205  * the number of keys you think you can push before the daemon runs
206  * and multiply by 300.  The driver will warn you if you overrun this
207  * buffer.  If you have a slow computer or non-busmastering IDE disks,
208  * maybe you will need to increase this.
209  */
210 
211 /* This MUST be a power of two!  It has to be larger than 1 as well. */
212 
213 #define RBUF_LEN 256
214 
215 static struct timeval lasttv = {0, 0};
216 
217 static struct lirc_buffer rbuf;
218 
219 static unsigned int freq = 38000;
220 static unsigned int duty_cycle = 50;
221 
222 /* Initialized in init_timing_params() */
223 static unsigned long period;
224 static unsigned long pulse_width;
225 static unsigned long space_width;
226 
227 #if defined(__i386__)
228 /*
229  * From:
230  * Linux I/O port programming mini-HOWTO
231  * Author: Riku Saikkonen <Riku.Saikkonen@hut.fi>
232  * v, 28 December 1997
233  *
234  * [...]
235  * Actually, a port I/O instruction on most ports in the 0-0x3ff range
236  * takes almost exactly 1 microsecond, so if you're, for example, using
237  * the parallel port directly, just do additional inb()s from that port
238  * to delay.
239  * [...]
240  */
241 /* transmitter latency 1.5625us 0x1.90 - this figure arrived at from
242  * comment above plus trimming to match actual measured frequency.
243  * This will be sensitive to cpu speed, though hopefully most of the 1.5us
244  * is spent in the uart access.  Still - for reference test machine was a
245  * 1.13GHz Athlon system - Steve
246  */
247 
248 /*
249  * changed from 400 to 450 as this works better on slower machines;
250  * faster machines will use the rdtsc code anyway
251  */
252 #define LIRC_SERIAL_TRANSMITTER_LATENCY 450
253 
254 #else
255 
256 /* does anybody have information on other platforms ? */
257 /* 256 = 1<<8 */
258 #define LIRC_SERIAL_TRANSMITTER_LATENCY 256
259 
260 #endif  /* __i386__ */
261 /*
262  * FIXME: should we be using hrtimers instead of this
263  * LIRC_SERIAL_TRANSMITTER_LATENCY nonsense?
264  */
265 
266 /* fetch serial input packet (1 byte) from register offset */
sinp(int offset)267 static u8 sinp(int offset)
268 {
269 	if (iommap != 0)
270 		/* the register is memory-mapped */
271 		offset <<= ioshift;
272 
273 	return inb(io + offset);
274 }
275 
276 /* write serial output packet (1 byte) of value to register offset */
soutp(int offset,u8 value)277 static void soutp(int offset, u8 value)
278 {
279 	if (iommap != 0)
280 		/* the register is memory-mapped */
281 		offset <<= ioshift;
282 
283 	outb(value, io + offset);
284 }
285 
on(void)286 static void on(void)
287 {
288 	if (txsense)
289 		soutp(UART_MCR, hardware[type].off);
290 	else
291 		soutp(UART_MCR, hardware[type].on);
292 }
293 
off(void)294 static void off(void)
295 {
296 	if (txsense)
297 		soutp(UART_MCR, hardware[type].on);
298 	else
299 		soutp(UART_MCR, hardware[type].off);
300 }
301 
302 #ifndef MAX_UDELAY_MS
303 #define MAX_UDELAY_US 5000
304 #else
305 #define MAX_UDELAY_US (MAX_UDELAY_MS*1000)
306 #endif
307 
safe_udelay(unsigned long usecs)308 static void safe_udelay(unsigned long usecs)
309 {
310 	while (usecs > MAX_UDELAY_US) {
311 		udelay(MAX_UDELAY_US);
312 		usecs -= MAX_UDELAY_US;
313 	}
314 	udelay(usecs);
315 }
316 
317 #ifdef USE_RDTSC
318 /*
319  * This is an overflow/precision juggle, complicated in that we can't
320  * do long long divide in the kernel
321  */
322 
323 /*
324  * When we use the rdtsc instruction to measure clocks, we keep the
325  * pulse and space widths as clock cycles.  As this is CPU speed
326  * dependent, the widths must be calculated in init_port and ioctl
327  * time
328  */
329 
330 /* So send_pulse can quickly convert microseconds to clocks */
331 static unsigned long conv_us_to_clocks;
332 
init_timing_params(unsigned int new_duty_cycle,unsigned int new_freq)333 static int init_timing_params(unsigned int new_duty_cycle,
334 		unsigned int new_freq)
335 {
336 	__u64 loops_per_sec, work;
337 
338 	duty_cycle = new_duty_cycle;
339 	freq = new_freq;
340 
341 	loops_per_sec = __this_cpu_read(cpu.info.loops_per_jiffy);
342 	loops_per_sec *= HZ;
343 
344 	/* How many clocks in a microsecond?, avoiding long long divide */
345 	work = loops_per_sec;
346 	work *= 4295;  /* 4295 = 2^32 / 1e6 */
347 	conv_us_to_clocks = (work >> 32);
348 
349 	/*
350 	 * Carrier period in clocks, approach good up to 32GHz clock,
351 	 * gets carrier frequency within 8Hz
352 	 */
353 	period = loops_per_sec >> 3;
354 	period /= (freq >> 3);
355 
356 	/* Derive pulse and space from the period */
357 	pulse_width = period * duty_cycle / 100;
358 	space_width = period - pulse_width;
359 	dprintk("in init_timing_params, freq=%d, duty_cycle=%d, "
360 		"clk/jiffy=%ld, pulse=%ld, space=%ld, "
361 		"conv_us_to_clocks=%ld\n",
362 		freq, duty_cycle, __this_cpu_read(cpu_info.loops_per_jiffy),
363 		pulse_width, space_width, conv_us_to_clocks);
364 	return 0;
365 }
366 #else /* ! USE_RDTSC */
init_timing_params(unsigned int new_duty_cycle,unsigned int new_freq)367 static int init_timing_params(unsigned int new_duty_cycle,
368 		unsigned int new_freq)
369 {
370 /*
371  * period, pulse/space width are kept with 8 binary places -
372  * IE multiplied by 256.
373  */
374 	if (256 * 1000000L / new_freq * new_duty_cycle / 100 <=
375 	    LIRC_SERIAL_TRANSMITTER_LATENCY)
376 		return -EINVAL;
377 	if (256 * 1000000L / new_freq * (100 - new_duty_cycle) / 100 <=
378 	    LIRC_SERIAL_TRANSMITTER_LATENCY)
379 		return -EINVAL;
380 	duty_cycle = new_duty_cycle;
381 	freq = new_freq;
382 	period = 256 * 1000000L / freq;
383 	pulse_width = period * duty_cycle / 100;
384 	space_width = period - pulse_width;
385 	dprintk("in init_timing_params, freq=%d pulse=%ld, space=%ld\n",
386 		freq, pulse_width, space_width);
387 	return 0;
388 }
389 #endif /* USE_RDTSC */
390 
391 
392 /* return value: space length delta */
393 
send_pulse_irdeo(unsigned long length)394 static long send_pulse_irdeo(unsigned long length)
395 {
396 	long rawbits, ret;
397 	int i;
398 	unsigned char output;
399 	unsigned char chunk, shifted;
400 
401 	/* how many bits have to be sent ? */
402 	rawbits = length * 1152 / 10000;
403 	if (duty_cycle > 50)
404 		chunk = 3;
405 	else
406 		chunk = 1;
407 	for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
408 		shifted = chunk << (i * 3);
409 		shifted >>= 1;
410 		output &= (~shifted);
411 		i++;
412 		if (i == 3) {
413 			soutp(UART_TX, output);
414 			while (!(sinp(UART_LSR) & UART_LSR_THRE))
415 				;
416 			output = 0x7f;
417 			i = 0;
418 		}
419 	}
420 	if (i != 0) {
421 		soutp(UART_TX, output);
422 		while (!(sinp(UART_LSR) & UART_LSR_TEMT))
423 			;
424 	}
425 
426 	if (i == 0)
427 		ret = (-rawbits) * 10000 / 1152;
428 	else
429 		ret = (3 - i) * 3 * 10000 / 1152 + (-rawbits) * 10000 / 1152;
430 
431 	return ret;
432 }
433 
434 #ifdef USE_RDTSC
435 /* Version that uses Pentium rdtsc instruction to measure clocks */
436 
437 /*
438  * This version does sub-microsecond timing using rdtsc instruction,
439  * and does away with the fudged LIRC_SERIAL_TRANSMITTER_LATENCY
440  * Implicitly i586 architecture...  - Steve
441  */
442 
send_pulse_homebrew_softcarrier(unsigned long length)443 static long send_pulse_homebrew_softcarrier(unsigned long length)
444 {
445 	int flag;
446 	unsigned long target, start, now;
447 
448 	/* Get going quick as we can */
449 	rdtscl(start);
450 	on();
451 	/* Convert length from microseconds to clocks */
452 	length *= conv_us_to_clocks;
453 	/* And loop till time is up - flipping at right intervals */
454 	now = start;
455 	target = pulse_width;
456 	flag = 1;
457 	/*
458 	 * FIXME: This looks like a hard busy wait, without even an occasional,
459 	 * polite, cpu_relax() call.  There's got to be a better way?
460 	 *
461 	 * The i2c code has the result of a lot of bit-banging work, I wonder if
462 	 * there's something there which could be helpful here.
463 	 */
464 	while ((now - start) < length) {
465 		/* Delay till flip time */
466 		do {
467 			rdtscl(now);
468 		} while ((now - start) < target);
469 
470 		/* flip */
471 		if (flag) {
472 			rdtscl(now);
473 			off();
474 			target += space_width;
475 		} else {
476 			rdtscl(now); on();
477 			target += pulse_width;
478 		}
479 		flag = !flag;
480 	}
481 	rdtscl(now);
482 	return ((now - start) - length) / conv_us_to_clocks;
483 }
484 #else /* ! USE_RDTSC */
485 /* Version using udelay() */
486 
487 /*
488  * here we use fixed point arithmetic, with 8
489  * fractional bits.  that gets us within 0.1% or so of the right average
490  * frequency, albeit with some jitter in pulse length - Steve
491  */
492 
493 /* To match 8 fractional bits used for pulse/space length */
494 
send_pulse_homebrew_softcarrier(unsigned long length)495 static long send_pulse_homebrew_softcarrier(unsigned long length)
496 {
497 	int flag;
498 	unsigned long actual, target, d;
499 
500 	length <<= 8;
501 
502 	actual = 0; target = 0; flag = 0;
503 	while (actual < length) {
504 		if (flag) {
505 			off();
506 			target += space_width;
507 		} else {
508 			on();
509 			target += pulse_width;
510 		}
511 		d = (target - actual -
512 		     LIRC_SERIAL_TRANSMITTER_LATENCY + 128) >> 8;
513 		/*
514 		 * Note - we've checked in ioctl that the pulse/space
515 		 * widths are big enough so that d is > 0
516 		 */
517 		udelay(d);
518 		actual += (d << 8) + LIRC_SERIAL_TRANSMITTER_LATENCY;
519 		flag = !flag;
520 	}
521 	return (actual-length) >> 8;
522 }
523 #endif /* USE_RDTSC */
524 
send_pulse_homebrew(unsigned long length)525 static long send_pulse_homebrew(unsigned long length)
526 {
527 	if (length <= 0)
528 		return 0;
529 
530 	if (softcarrier)
531 		return send_pulse_homebrew_softcarrier(length);
532 
533 	on();
534 	safe_udelay(length);
535 	return 0;
536 }
537 
send_space_irdeo(long length)538 static void send_space_irdeo(long length)
539 {
540 	if (length <= 0)
541 		return;
542 
543 	safe_udelay(length);
544 }
545 
send_space_homebrew(long length)546 static void send_space_homebrew(long length)
547 {
548 	off();
549 	if (length <= 0)
550 		return;
551 	safe_udelay(length);
552 }
553 
rbwrite(int l)554 static void rbwrite(int l)
555 {
556 	if (lirc_buffer_full(&rbuf)) {
557 		/* no new signals will be accepted */
558 		dprintk("Buffer overrun\n");
559 		return;
560 	}
561 	lirc_buffer_write(&rbuf, (void *)&l);
562 }
563 
frbwrite(int l)564 static void frbwrite(int l)
565 {
566 	/* simple noise filter */
567 	static int pulse, space;
568 	static unsigned int ptr;
569 
570 	if (ptr > 0 && (l & PULSE_BIT)) {
571 		pulse += l & PULSE_MASK;
572 		if (pulse > 250) {
573 			rbwrite(space);
574 			rbwrite(pulse | PULSE_BIT);
575 			ptr = 0;
576 			pulse = 0;
577 		}
578 		return;
579 	}
580 	if (!(l & PULSE_BIT)) {
581 		if (ptr == 0) {
582 			if (l > 20000) {
583 				space = l;
584 				ptr++;
585 				return;
586 			}
587 		} else {
588 			if (l > 20000) {
589 				space += pulse;
590 				if (space > PULSE_MASK)
591 					space = PULSE_MASK;
592 				space += l;
593 				if (space > PULSE_MASK)
594 					space = PULSE_MASK;
595 				pulse = 0;
596 				return;
597 			}
598 			rbwrite(space);
599 			rbwrite(pulse | PULSE_BIT);
600 			ptr = 0;
601 			pulse = 0;
602 		}
603 	}
604 	rbwrite(l);
605 }
606 
lirc_irq_handler(int i,void * blah)607 static irqreturn_t lirc_irq_handler(int i, void *blah)
608 {
609 	struct timeval tv;
610 	int counter, dcd;
611 	u8 status;
612 	long deltv;
613 	int data;
614 	static int last_dcd = -1;
615 
616 	if ((sinp(UART_IIR) & UART_IIR_NO_INT)) {
617 		/* not our interrupt */
618 		return IRQ_NONE;
619 	}
620 
621 	counter = 0;
622 	do {
623 		counter++;
624 		status = sinp(UART_MSR);
625 		if (counter > RS_ISR_PASS_LIMIT) {
626 			pr_warn("AIEEEE: We're caught!\n");
627 			break;
628 		}
629 		if ((status & hardware[type].signal_pin_change)
630 		    && sense != -1) {
631 			/* get current time */
632 			do_gettimeofday(&tv);
633 
634 			/* New mode, written by Trent Piepho
635 			   <xyzzy@u.washington.edu>. */
636 
637 			/*
638 			 * The old format was not very portable.
639 			 * We now use an int to pass pulses
640 			 * and spaces to user space.
641 			 *
642 			 * If PULSE_BIT is set a pulse has been
643 			 * received, otherwise a space has been
644 			 * received.  The driver needs to know if your
645 			 * receiver is active high or active low, or
646 			 * the space/pulse sense could be
647 			 * inverted. The bits denoted by PULSE_MASK are
648 			 * the length in microseconds. Lengths greater
649 			 * than or equal to 16 seconds are clamped to
650 			 * PULSE_MASK.  All other bits are unused.
651 			 * This is a much simpler interface for user
652 			 * programs, as well as eliminating "out of
653 			 * phase" errors with space/pulse
654 			 * autodetection.
655 			 */
656 
657 			/* calc time since last interrupt in microseconds */
658 			dcd = (status & hardware[type].signal_pin) ? 1 : 0;
659 
660 			if (dcd == last_dcd) {
661 				pr_warn("ignoring spike: %d %d %lx %lx %lx %lx\n",
662 					dcd, sense,
663 					tv.tv_sec, lasttv.tv_sec,
664 					(unsigned long)tv.tv_usec,
665 					(unsigned long)lasttv.tv_usec);
666 				continue;
667 			}
668 
669 			deltv = tv.tv_sec-lasttv.tv_sec;
670 			if (tv.tv_sec < lasttv.tv_sec ||
671 			    (tv.tv_sec == lasttv.tv_sec &&
672 			     tv.tv_usec < lasttv.tv_usec)) {
673 				pr_warn("AIEEEE: your clock just jumped backwards\n");
674 				pr_warn("%d %d %lx %lx %lx %lx\n",
675 					dcd, sense,
676 					tv.tv_sec, lasttv.tv_sec,
677 					(unsigned long)tv.tv_usec,
678 					(unsigned long)lasttv.tv_usec);
679 				data = PULSE_MASK;
680 			} else if (deltv > 15) {
681 				data = PULSE_MASK; /* really long time */
682 				if (!(dcd^sense)) {
683 					/* sanity check */
684 					pr_warn("AIEEEE: %d %d %lx %lx %lx %lx\n",
685 						dcd, sense,
686 						tv.tv_sec, lasttv.tv_sec,
687 						(unsigned long)tv.tv_usec,
688 						(unsigned long)lasttv.tv_usec);
689 					/*
690 					 * detecting pulse while this
691 					 * MUST be a space!
692 					 */
693 					sense = sense ? 0 : 1;
694 				}
695 			} else
696 				data = (int) (deltv*1000000 +
697 					       tv.tv_usec -
698 					       lasttv.tv_usec);
699 			frbwrite(dcd^sense ? data : (data|PULSE_BIT));
700 			lasttv = tv;
701 			last_dcd = dcd;
702 			wake_up_interruptible(&rbuf.wait_poll);
703 		}
704 	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */
705 	return IRQ_HANDLED;
706 }
707 
708 
hardware_init_port(void)709 static int hardware_init_port(void)
710 {
711 	u8 scratch, scratch2, scratch3;
712 
713 	/*
714 	 * This is a simple port existence test, borrowed from the autoconfig
715 	 * function in drivers/serial/8250.c
716 	 */
717 	scratch = sinp(UART_IER);
718 	soutp(UART_IER, 0);
719 #ifdef __i386__
720 	outb(0xff, 0x080);
721 #endif
722 	scratch2 = sinp(UART_IER) & 0x0f;
723 	soutp(UART_IER, 0x0f);
724 #ifdef __i386__
725 	outb(0x00, 0x080);
726 #endif
727 	scratch3 = sinp(UART_IER) & 0x0f;
728 	soutp(UART_IER, scratch);
729 	if (scratch2 != 0 || scratch3 != 0x0f) {
730 		/* we fail, there's nothing here */
731 		pr_err("port existence test failed, cannot continue\n");
732 		return -ENODEV;
733 	}
734 
735 
736 
737 	/* Set DLAB 0. */
738 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
739 
740 	/* First of all, disable all interrupts */
741 	soutp(UART_IER, sinp(UART_IER) &
742 	      (~(UART_IER_MSI|UART_IER_RLSI|UART_IER_THRI|UART_IER_RDI)));
743 
744 	/* Clear registers. */
745 	sinp(UART_LSR);
746 	sinp(UART_RX);
747 	sinp(UART_IIR);
748 	sinp(UART_MSR);
749 
750 	/* Set line for power source */
751 	off();
752 
753 	/* Clear registers again to be sure. */
754 	sinp(UART_LSR);
755 	sinp(UART_RX);
756 	sinp(UART_IIR);
757 	sinp(UART_MSR);
758 
759 	switch (type) {
760 	case LIRC_IRDEO:
761 	case LIRC_IRDEO_REMOTE:
762 		/* setup port to 7N1 @ 115200 Baud */
763 		/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */
764 
765 		/* Set DLAB 1. */
766 		soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
767 		/* Set divisor to 1 => 115200 Baud */
768 		soutp(UART_DLM, 0);
769 		soutp(UART_DLL, 1);
770 		/* Set DLAB 0 +  7N1 */
771 		soutp(UART_LCR, UART_LCR_WLEN7);
772 		/* THR interrupt already disabled at this point */
773 		break;
774 	default:
775 		break;
776 	}
777 
778 	return 0;
779 }
780 
lirc_serial_probe(struct platform_device * dev)781 static int lirc_serial_probe(struct platform_device *dev)
782 {
783 	int i, nlow, nhigh, result;
784 
785 	result = devm_request_irq(&dev->dev, irq, lirc_irq_handler,
786 			     (share_irq ? IRQF_SHARED : 0),
787 			     LIRC_DRIVER_NAME, (void *)&hardware);
788 	if (result < 0) {
789 		if (result == -EBUSY)
790 			dev_err(&dev->dev, "IRQ %d busy\n", irq);
791 		else if (result == -EINVAL)
792 			dev_err(&dev->dev, "Bad irq number or handler\n");
793 		return result;
794 	}
795 
796 	/* Reserve io region. */
797 	/*
798 	 * Future MMAP-Developers: Attention!
799 	 * For memory mapped I/O you *might* need to use ioremap() first,
800 	 * for the NSLU2 it's done in boot code.
801 	 */
802 	if (((iommap != 0)
803 	     && (devm_request_mem_region(&dev->dev, iommap, 8 << ioshift,
804 					 LIRC_DRIVER_NAME) == NULL))
805 	   || ((iommap == 0)
806 	       && (devm_request_region(&dev->dev, io, 8,
807 				       LIRC_DRIVER_NAME) == NULL))) {
808 		dev_err(&dev->dev, "port %04x already in use\n", io);
809 		dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
810 		dev_warn(&dev->dev,
811 			 "or compile the serial port driver as module and\n");
812 		dev_warn(&dev->dev, "make sure this module is loaded first\n");
813 		return -EBUSY;
814 	}
815 
816 	result = hardware_init_port();
817 	if (result < 0)
818 		return result;
819 
820 	/* Initialize pulse/space widths */
821 	init_timing_params(duty_cycle, freq);
822 
823 	/* If pin is high, then this must be an active low receiver. */
824 	if (sense == -1) {
825 		/* wait 1/2 sec for the power supply */
826 		msleep(500);
827 
828 		/*
829 		 * probe 9 times every 0.04s, collect "votes" for
830 		 * active high/low
831 		 */
832 		nlow = 0;
833 		nhigh = 0;
834 		for (i = 0; i < 9; i++) {
835 			if (sinp(UART_MSR) & hardware[type].signal_pin)
836 				nlow++;
837 			else
838 				nhigh++;
839 			msleep(40);
840 		}
841 		sense = (nlow >= nhigh ? 1 : 0);
842 		dev_info(&dev->dev, "auto-detected active %s receiver\n",
843 			 sense ? "low" : "high");
844 	} else
845 		dev_info(&dev->dev, "Manually using active %s receiver\n",
846 			 sense ? "low" : "high");
847 
848 	dprintk("Interrupt %d, port %04x obtained\n", irq, io);
849 	return 0;
850 }
851 
set_use_inc(void * data)852 static int set_use_inc(void *data)
853 {
854 	unsigned long flags;
855 
856 	/* initialize timestamp */
857 	do_gettimeofday(&lasttv);
858 
859 	spin_lock_irqsave(&hardware[type].lock, flags);
860 
861 	/* Set DLAB 0. */
862 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
863 
864 	soutp(UART_IER, sinp(UART_IER)|UART_IER_MSI);
865 
866 	spin_unlock_irqrestore(&hardware[type].lock, flags);
867 
868 	return 0;
869 }
870 
set_use_dec(void * data)871 static void set_use_dec(void *data)
872 {	unsigned long flags;
873 
874 	spin_lock_irqsave(&hardware[type].lock, flags);
875 
876 	/* Set DLAB 0. */
877 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
878 
879 	/* First of all, disable all interrupts */
880 	soutp(UART_IER, sinp(UART_IER) &
881 	      (~(UART_IER_MSI|UART_IER_RLSI|UART_IER_THRI|UART_IER_RDI)));
882 	spin_unlock_irqrestore(&hardware[type].lock, flags);
883 }
884 
lirc_write(struct file * file,const char __user * buf,size_t n,loff_t * ppos)885 static ssize_t lirc_write(struct file *file, const char __user *buf,
886 			 size_t n, loff_t *ppos)
887 {
888 	int i, count;
889 	unsigned long flags;
890 	long delta = 0;
891 	int *wbuf;
892 
893 	if (!(hardware[type].features & LIRC_CAN_SEND_PULSE))
894 		return -EPERM;
895 
896 	count = n / sizeof(int);
897 	if (n % sizeof(int) || count % 2 == 0)
898 		return -EINVAL;
899 	wbuf = memdup_user(buf, n);
900 	if (IS_ERR(wbuf))
901 		return PTR_ERR(wbuf);
902 	spin_lock_irqsave(&hardware[type].lock, flags);
903 	if (type == LIRC_IRDEO) {
904 		/* DTR, RTS down */
905 		on();
906 	}
907 	for (i = 0; i < count; i++) {
908 		if (i%2)
909 			hardware[type].send_space(wbuf[i] - delta);
910 		else
911 			delta = hardware[type].send_pulse(wbuf[i]);
912 	}
913 	off();
914 	spin_unlock_irqrestore(&hardware[type].lock, flags);
915 	kfree(wbuf);
916 	return n;
917 }
918 
lirc_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)919 static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
920 {
921 	int result;
922 	u32 __user *uptr = (u32 __user *)arg;
923 	u32 value;
924 
925 	switch (cmd) {
926 	case LIRC_GET_SEND_MODE:
927 		if (!(hardware[type].features&LIRC_CAN_SEND_MASK))
928 			return -ENOIOCTLCMD;
929 
930 		result = put_user(LIRC_SEND2MODE
931 				  (hardware[type].features&LIRC_CAN_SEND_MASK),
932 				  uptr);
933 		if (result)
934 			return result;
935 		break;
936 
937 	case LIRC_SET_SEND_MODE:
938 		if (!(hardware[type].features&LIRC_CAN_SEND_MASK))
939 			return -ENOIOCTLCMD;
940 
941 		result = get_user(value, uptr);
942 		if (result)
943 			return result;
944 		/* only LIRC_MODE_PULSE supported */
945 		if (value != LIRC_MODE_PULSE)
946 			return -EINVAL;
947 		break;
948 
949 	case LIRC_GET_LENGTH:
950 		return -ENOIOCTLCMD;
951 
952 	case LIRC_SET_SEND_DUTY_CYCLE:
953 		dprintk("SET_SEND_DUTY_CYCLE\n");
954 		if (!(hardware[type].features&LIRC_CAN_SET_SEND_DUTY_CYCLE))
955 			return -ENOIOCTLCMD;
956 
957 		result = get_user(value, uptr);
958 		if (result)
959 			return result;
960 		if (value <= 0 || value > 100)
961 			return -EINVAL;
962 		return init_timing_params(value, freq);
963 
964 	case LIRC_SET_SEND_CARRIER:
965 		dprintk("SET_SEND_CARRIER\n");
966 		if (!(hardware[type].features&LIRC_CAN_SET_SEND_CARRIER))
967 			return -ENOIOCTLCMD;
968 
969 		result = get_user(value, uptr);
970 		if (result)
971 			return result;
972 		if (value > 500000 || value < 20000)
973 			return -EINVAL;
974 		return init_timing_params(duty_cycle, value);
975 
976 	default:
977 		return lirc_dev_fop_ioctl(filep, cmd, arg);
978 	}
979 	return 0;
980 }
981 
982 static const struct file_operations lirc_fops = {
983 	.owner		= THIS_MODULE,
984 	.write		= lirc_write,
985 	.unlocked_ioctl	= lirc_ioctl,
986 #ifdef CONFIG_COMPAT
987 	.compat_ioctl	= lirc_ioctl,
988 #endif
989 	.read		= lirc_dev_fop_read,
990 	.poll		= lirc_dev_fop_poll,
991 	.open		= lirc_dev_fop_open,
992 	.release	= lirc_dev_fop_close,
993 	.llseek		= no_llseek,
994 };
995 
996 static struct lirc_driver driver = {
997 	.name		= LIRC_DRIVER_NAME,
998 	.minor		= -1,
999 	.code_length	= 1,
1000 	.sample_rate	= 0,
1001 	.data		= NULL,
1002 	.add_to_buf	= NULL,
1003 	.rbuf		= &rbuf,
1004 	.set_use_inc	= set_use_inc,
1005 	.set_use_dec	= set_use_dec,
1006 	.fops		= &lirc_fops,
1007 	.dev		= NULL,
1008 	.owner		= THIS_MODULE,
1009 };
1010 
1011 static struct platform_device *lirc_serial_dev;
1012 
lirc_serial_suspend(struct platform_device * dev,pm_message_t state)1013 static int lirc_serial_suspend(struct platform_device *dev,
1014 			       pm_message_t state)
1015 {
1016 	/* Set DLAB 0. */
1017 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
1018 
1019 	/* Disable all interrupts */
1020 	soutp(UART_IER, sinp(UART_IER) &
1021 	      (~(UART_IER_MSI|UART_IER_RLSI|UART_IER_THRI|UART_IER_RDI)));
1022 
1023 	/* Clear registers. */
1024 	sinp(UART_LSR);
1025 	sinp(UART_RX);
1026 	sinp(UART_IIR);
1027 	sinp(UART_MSR);
1028 
1029 	return 0;
1030 }
1031 
1032 /* twisty maze... need a forward-declaration here... */
1033 static void lirc_serial_exit(void);
1034 
lirc_serial_resume(struct platform_device * dev)1035 static int lirc_serial_resume(struct platform_device *dev)
1036 {
1037 	unsigned long flags;
1038 	int result;
1039 
1040 	result = hardware_init_port();
1041 	if (result < 0)
1042 		return result;
1043 
1044 	spin_lock_irqsave(&hardware[type].lock, flags);
1045 	/* Enable Interrupt */
1046 	do_gettimeofday(&lasttv);
1047 	soutp(UART_IER, sinp(UART_IER)|UART_IER_MSI);
1048 	off();
1049 
1050 	lirc_buffer_clear(&rbuf);
1051 
1052 	spin_unlock_irqrestore(&hardware[type].lock, flags);
1053 
1054 	return 0;
1055 }
1056 
1057 static struct platform_driver lirc_serial_driver = {
1058 	.probe		= lirc_serial_probe,
1059 	.suspend	= lirc_serial_suspend,
1060 	.resume		= lirc_serial_resume,
1061 	.driver		= {
1062 		.name	= "lirc_serial",
1063 		.owner	= THIS_MODULE,
1064 	},
1065 };
1066 
lirc_serial_init(void)1067 static int __init lirc_serial_init(void)
1068 {
1069 	int result;
1070 
1071 	/* Init read buffer. */
1072 	result = lirc_buffer_init(&rbuf, sizeof(int), RBUF_LEN);
1073 	if (result < 0)
1074 		return result;
1075 
1076 	result = platform_driver_register(&lirc_serial_driver);
1077 	if (result) {
1078 		printk("lirc register returned %d\n", result);
1079 		goto exit_buffer_free;
1080 	}
1081 
1082 	lirc_serial_dev = platform_device_alloc("lirc_serial", 0);
1083 	if (!lirc_serial_dev) {
1084 		result = -ENOMEM;
1085 		goto exit_driver_unregister;
1086 	}
1087 
1088 	result = platform_device_add(lirc_serial_dev);
1089 	if (result)
1090 		goto exit_device_put;
1091 
1092 	return 0;
1093 
1094 exit_device_put:
1095 	platform_device_put(lirc_serial_dev);
1096 exit_driver_unregister:
1097 	platform_driver_unregister(&lirc_serial_driver);
1098 exit_buffer_free:
1099 	lirc_buffer_free(&rbuf);
1100 	return result;
1101 }
1102 
lirc_serial_exit(void)1103 static void lirc_serial_exit(void)
1104 {
1105 	platform_device_unregister(lirc_serial_dev);
1106 	platform_driver_unregister(&lirc_serial_driver);
1107 	lirc_buffer_free(&rbuf);
1108 }
1109 
lirc_serial_init_module(void)1110 static int __init lirc_serial_init_module(void)
1111 {
1112 	int result;
1113 
1114 	switch (type) {
1115 	case LIRC_HOMEBREW:
1116 	case LIRC_IRDEO:
1117 	case LIRC_IRDEO_REMOTE:
1118 	case LIRC_ANIMAX:
1119 	case LIRC_IGOR:
1120 		/* if nothing specified, use ttyS0/com1 and irq 4 */
1121 		io = io ? io : 0x3f8;
1122 		irq = irq ? irq : 4;
1123 		break;
1124 	default:
1125 		return -EINVAL;
1126 	}
1127 	if (!softcarrier) {
1128 		switch (type) {
1129 		case LIRC_HOMEBREW:
1130 		case LIRC_IGOR:
1131 			hardware[type].features &=
1132 				~(LIRC_CAN_SET_SEND_DUTY_CYCLE|
1133 				  LIRC_CAN_SET_SEND_CARRIER);
1134 			break;
1135 		}
1136 	}
1137 
1138 	/* make sure sense is either -1, 0, or 1 */
1139 	if (sense != -1)
1140 		sense = !!sense;
1141 
1142 	result = lirc_serial_init();
1143 	if (result)
1144 		return result;
1145 
1146 	driver.features = hardware[type].features;
1147 	driver.dev = &lirc_serial_dev->dev;
1148 	driver.minor = lirc_register_driver(&driver);
1149 	if (driver.minor < 0) {
1150 		pr_err("register_chrdev failed!\n");
1151 		lirc_serial_exit();
1152 		return driver.minor;
1153 	}
1154 	return 0;
1155 }
1156 
lirc_serial_exit_module(void)1157 static void __exit lirc_serial_exit_module(void)
1158 {
1159 	lirc_unregister_driver(driver.minor);
1160 	lirc_serial_exit();
1161 	dprintk("cleaned up module\n");
1162 }
1163 
1164 
1165 module_init(lirc_serial_init_module);
1166 module_exit(lirc_serial_exit_module);
1167 
1168 MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
1169 MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, "
1170 	      "Christoph Bartelmus, Andrei Tanas");
1171 MODULE_LICENSE("GPL");
1172 
1173 module_param(type, int, S_IRUGO);
1174 MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo,"
1175 		 " 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug,"
1176 		 " 5 = NSLU2 RX:CTS2/TX:GreenLED)");
1177 
1178 module_param(io, int, S_IRUGO);
1179 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
1180 
1181 /* some architectures (e.g. intel xscale) have memory mapped registers */
1182 module_param(iommap, bool, S_IRUGO);
1183 MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O"
1184 		" (0 = no memory mapped io)");
1185 
1186 /*
1187  * some architectures (e.g. intel xscale) align the 8bit serial registers
1188  * on 32bit word boundaries.
1189  * See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
1190  */
1191 module_param(ioshift, int, S_IRUGO);
1192 MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
1193 
1194 module_param(irq, int, S_IRUGO);
1195 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
1196 
1197 module_param(share_irq, bool, S_IRUGO);
1198 MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
1199 
1200 module_param(sense, int, S_IRUGO);
1201 MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit"
1202 		 " (0 = active high, 1 = active low )");
1203 
1204 #ifdef CONFIG_LIRC_SERIAL_TRANSMITTER
1205 module_param(txsense, bool, S_IRUGO);
1206 MODULE_PARM_DESC(txsense, "Sense of transmitter circuit"
1207 		 " (0 = active high, 1 = active low )");
1208 #endif
1209 
1210 module_param(softcarrier, bool, S_IRUGO);
1211 MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");
1212 
1213 module_param(debug, bool, S_IRUGO | S_IWUSR);
1214 MODULE_PARM_DESC(debug, "Enable debugging messages");
1215