xref: /linux/drivers/media/rc/serial_ir.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * serial_ir.c
4  *
5  * serial_ir - Device driver that records pulse- and pause-lengths
6  *	       (space-lengths) between DDCD event on a serial port.
7  *
8  * Copyright (C) 1996,97 Ralph Metzler <rjkm@thp.uni-koeln.de>
9  * Copyright (C) 1998 Trent Piepho <xyzzy@u.washington.edu>
10  * Copyright (C) 1998 Ben Pfaff <blp@gnu.org>
11  * Copyright (C) 1999 Christoph Bartelmus <lirc@bartelmus.de>
12  * Copyright (C) 2007 Andrei Tanas <andrei@tanas.ca> (suspend/resume support)
13  * Copyright (C) 2016 Sean Young <sean@mess.org> (port to rc-core)
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/kernel.h>
23 #include <linux/serial_reg.h>
24 #include <linux/types.h>
25 #include <linux/delay.h>
26 #include <linux/platform_device.h>
27 #include <linux/spinlock.h>
28 #include <media/rc-core.h>
29 
30 struct serial_ir_hw {
31 	int signal_pin;
32 	int signal_pin_change;
33 	u8 on;
34 	u8 off;
35 	unsigned set_send_carrier:1;
36 	unsigned set_duty_cycle:1;
37 	void (*send_pulse)(unsigned int length, ktime_t edge);
38 	void (*send_space)(void);
39 	spinlock_t lock;
40 };
41 
42 #define IR_HOMEBREW	0
43 #define IR_IRDEO	1
44 #define IR_IRDEO_REMOTE	2
45 #define IR_ANIMAX	3
46 #define IR_IGOR		4
47 
48 /* module parameters */
49 static int type;
50 static int io;
51 static int irq;
52 static ulong iommap;
53 static int ioshift;
54 static bool softcarrier = true;
55 static bool share_irq;
56 static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
57 static bool txsense;	/* 0 = active high, 1 = active low */
58 
59 /* forward declarations */
60 static void send_pulse_irdeo(unsigned int length, ktime_t edge);
61 static void send_space_irdeo(void);
62 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
63 static void send_pulse_homebrew(unsigned int length, ktime_t edge);
64 static void send_space_homebrew(void);
65 #endif
66 
67 static struct serial_ir_hw hardware[] = {
68 	[IR_HOMEBREW] = {
69 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_HOMEBREW].lock),
70 		.signal_pin	   = UART_MSR_DCD,
71 		.signal_pin_change = UART_MSR_DDCD,
72 		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
73 		.off = (UART_MCR_RTS | UART_MCR_OUT2),
74 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
75 		.send_pulse = send_pulse_homebrew,
76 		.send_space = send_space_homebrew,
77 		.set_send_carrier = true,
78 		.set_duty_cycle = true,
79 #endif
80 	},
81 
82 	[IR_IRDEO] = {
83 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO].lock),
84 		.signal_pin	   = UART_MSR_DSR,
85 		.signal_pin_change = UART_MSR_DDSR,
86 		.on  = UART_MCR_OUT2,
87 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
88 		.send_pulse = send_pulse_irdeo,
89 		.send_space = send_space_irdeo,
90 		.set_duty_cycle = true,
91 	},
92 
93 	[IR_IRDEO_REMOTE] = {
94 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO_REMOTE].lock),
95 		.signal_pin	   = UART_MSR_DSR,
96 		.signal_pin_change = UART_MSR_DDSR,
97 		.on  = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
98 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
99 		.send_pulse = send_pulse_irdeo,
100 		.send_space = send_space_irdeo,
101 		.set_duty_cycle = true,
102 	},
103 
104 	[IR_ANIMAX] = {
105 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_ANIMAX].lock),
106 		.signal_pin	   = UART_MSR_DCD,
107 		.signal_pin_change = UART_MSR_DDCD,
108 		.on  = 0,
109 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
110 	},
111 
112 	[IR_IGOR] = {
113 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IGOR].lock),
114 		.signal_pin	   = UART_MSR_DSR,
115 		.signal_pin_change = UART_MSR_DDSR,
116 		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
117 		.off = (UART_MCR_RTS | UART_MCR_OUT2),
118 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
119 		.send_pulse = send_pulse_homebrew,
120 		.send_space = send_space_homebrew,
121 		.set_send_carrier = true,
122 		.set_duty_cycle = true,
123 #endif
124 	},
125 };
126 
127 #define RS_ISR_PASS_LIMIT 256
128 
129 struct serial_ir {
130 	ktime_t lastkt;
131 	struct rc_dev *rcdev;
132 	struct platform_device *pdev;
133 	struct timer_list timeout_timer;
134 
135 	unsigned int carrier;
136 	unsigned int duty_cycle;
137 };
138 
139 static struct serial_ir serial_ir;
140 
141 /* fetch serial input packet (1 byte) from register offset */
142 static u8 sinp(int offset)
143 {
144 	if (iommap)
145 		/* the register is memory-mapped */
146 		offset <<= ioshift;
147 
148 	return inb(io + offset);
149 }
150 
151 /* write serial output packet (1 byte) of value to register offset */
152 static void soutp(int offset, u8 value)
153 {
154 	if (iommap)
155 		/* the register is memory-mapped */
156 		offset <<= ioshift;
157 
158 	outb(value, io + offset);
159 }
160 
161 static void on(void)
162 {
163 	if (txsense)
164 		soutp(UART_MCR, hardware[type].off);
165 	else
166 		soutp(UART_MCR, hardware[type].on);
167 }
168 
169 static void off(void)
170 {
171 	if (txsense)
172 		soutp(UART_MCR, hardware[type].on);
173 	else
174 		soutp(UART_MCR, hardware[type].off);
175 }
176 
177 static void send_pulse_irdeo(unsigned int length, ktime_t target)
178 {
179 	long rawbits;
180 	int i;
181 	unsigned char output;
182 	unsigned char chunk, shifted;
183 
184 	/* how many bits have to be sent ? */
185 	rawbits = length * 1152 / 10000;
186 	if (serial_ir.duty_cycle > 50)
187 		chunk = 3;
188 	else
189 		chunk = 1;
190 	for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
191 		shifted = chunk << (i * 3);
192 		shifted >>= 1;
193 		output &= (~shifted);
194 		i++;
195 		if (i == 3) {
196 			soutp(UART_TX, output);
197 			while (!(sinp(UART_LSR) & UART_LSR_THRE))
198 				;
199 			output = 0x7f;
200 			i = 0;
201 		}
202 	}
203 	if (i != 0) {
204 		soutp(UART_TX, output);
205 		while (!(sinp(UART_LSR) & UART_LSR_TEMT))
206 			;
207 	}
208 }
209 
210 static void send_space_irdeo(void)
211 {
212 }
213 
214 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
215 static void send_pulse_homebrew_softcarrier(unsigned int length, ktime_t edge)
216 {
217 	ktime_t now, target = ktime_add_us(edge, length);
218 	/*
219 	 * delta should never exceed 4 seconds and on m68k
220 	 * ndelay(s64) does not compile; so use s32 rather than s64.
221 	 */
222 	s32 delta;
223 	unsigned int pulse, space;
224 
225 	/* Ensure the dividend fits into 32 bit */
226 	pulse = DIV_ROUND_CLOSEST(serial_ir.duty_cycle * (NSEC_PER_SEC / 100),
227 				  serial_ir.carrier);
228 	space = DIV_ROUND_CLOSEST((100 - serial_ir.duty_cycle) *
229 				  (NSEC_PER_SEC / 100), serial_ir.carrier);
230 
231 	for (;;) {
232 		now = ktime_get();
233 		if (ktime_compare(now, target) >= 0)
234 			break;
235 		on();
236 		edge = ktime_add_ns(edge, pulse);
237 		delta = ktime_to_ns(ktime_sub(edge, now));
238 		if (delta > 0)
239 			ndelay(delta);
240 		now = ktime_get();
241 		off();
242 		if (ktime_compare(now, target) >= 0)
243 			break;
244 		edge = ktime_add_ns(edge, space);
245 		delta = ktime_to_ns(ktime_sub(edge, now));
246 		if (delta > 0)
247 			ndelay(delta);
248 	}
249 }
250 
251 static void send_pulse_homebrew(unsigned int length, ktime_t edge)
252 {
253 	if (softcarrier)
254 		send_pulse_homebrew_softcarrier(length, edge);
255 	else
256 		on();
257 }
258 
259 static void send_space_homebrew(void)
260 {
261 	off();
262 }
263 #endif
264 
265 static void frbwrite(unsigned int l, bool is_pulse)
266 {
267 	/* simple noise filter */
268 	static unsigned int ptr, pulse, space;
269 	struct ir_raw_event ev = {};
270 
271 	if (ptr > 0 && is_pulse) {
272 		pulse += l;
273 		if (pulse > 250) {
274 			ev.duration = space;
275 			ev.pulse = false;
276 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
277 			ev.duration = pulse;
278 			ev.pulse = true;
279 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
280 			ptr = 0;
281 			pulse = 0;
282 		}
283 		return;
284 	}
285 	if (!is_pulse) {
286 		if (ptr == 0) {
287 			if (l > 20000) {
288 				space = l;
289 				ptr++;
290 				return;
291 			}
292 		} else {
293 			if (l > 20000) {
294 				space += pulse;
295 				if (space > IR_MAX_DURATION)
296 					space = IR_MAX_DURATION;
297 				space += l;
298 				if (space > IR_MAX_DURATION)
299 					space = IR_MAX_DURATION;
300 				pulse = 0;
301 				return;
302 			}
303 
304 			ev.duration = space;
305 			ev.pulse = false;
306 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
307 			ev.duration = pulse;
308 			ev.pulse = true;
309 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
310 			ptr = 0;
311 			pulse = 0;
312 		}
313 	}
314 
315 	ev.duration = l;
316 	ev.pulse = is_pulse;
317 	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
318 }
319 
320 static irqreturn_t serial_ir_irq_handler(int i, void *blah)
321 {
322 	ktime_t kt;
323 	int counter, dcd;
324 	u8 status;
325 	ktime_t delkt;
326 	unsigned int data;
327 	static int last_dcd = -1;
328 
329 	if ((sinp(UART_IIR) & UART_IIR_NO_INT)) {
330 		/* not our interrupt */
331 		return IRQ_NONE;
332 	}
333 
334 	counter = 0;
335 	do {
336 		counter++;
337 		status = sinp(UART_MSR);
338 		if (counter > RS_ISR_PASS_LIMIT) {
339 			dev_err(&serial_ir.pdev->dev, "Trapped in interrupt");
340 			break;
341 		}
342 		if ((status & hardware[type].signal_pin_change) &&
343 		    sense != -1) {
344 			/* get current time */
345 			kt = ktime_get();
346 
347 			/*
348 			 * The driver needs to know if your receiver is
349 			 * active high or active low, or the space/pulse
350 			 * sense could be inverted.
351 			 */
352 
353 			/* calc time since last interrupt in nanoseconds */
354 			dcd = (status & hardware[type].signal_pin) ? 1 : 0;
355 
356 			if (dcd == last_dcd) {
357 				dev_dbg(&serial_ir.pdev->dev,
358 					"ignoring spike: %d %d %lldns %lldns\n",
359 					dcd, sense, ktime_to_ns(kt),
360 					ktime_to_ns(serial_ir.lastkt));
361 				continue;
362 			}
363 
364 			delkt = ktime_sub(kt, serial_ir.lastkt);
365 			if (ktime_compare(delkt, ktime_set(15, 0)) > 0) {
366 				data = IR_MAX_DURATION; /* really long time */
367 				if (!(dcd ^ sense)) {
368 					/* sanity check */
369 					dev_err(&serial_ir.pdev->dev,
370 						"dcd unexpected: %d %d %lldns %lldns\n",
371 						dcd, sense, ktime_to_ns(kt),
372 						ktime_to_ns(serial_ir.lastkt));
373 					/*
374 					 * detecting pulse while this
375 					 * MUST be a space!
376 					 */
377 					sense = sense ? 0 : 1;
378 				}
379 			} else {
380 				data = ktime_to_us(delkt);
381 			}
382 			frbwrite(data, !(dcd ^ sense));
383 			serial_ir.lastkt = kt;
384 			last_dcd = dcd;
385 		}
386 	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */
387 
388 	mod_timer(&serial_ir.timeout_timer,
389 		  jiffies + usecs_to_jiffies(serial_ir.rcdev->timeout));
390 
391 	ir_raw_event_handle(serial_ir.rcdev);
392 
393 	return IRQ_HANDLED;
394 }
395 
396 static int hardware_init_port(void)
397 {
398 	u8 scratch, scratch2, scratch3;
399 
400 	/*
401 	 * This is a simple port existence test, borrowed from the autoconfig
402 	 * function in drivers/tty/serial/8250/8250_port.c
403 	 */
404 	scratch = sinp(UART_IER);
405 	soutp(UART_IER, 0);
406 #ifdef __i386__
407 	outb(0xff, 0x080);
408 #endif
409 	scratch2 = sinp(UART_IER) & 0x0f;
410 	soutp(UART_IER, 0x0f);
411 #ifdef __i386__
412 	outb(0x00, 0x080);
413 #endif
414 	scratch3 = sinp(UART_IER) & 0x0f;
415 	soutp(UART_IER, scratch);
416 	if (scratch2 != 0 || scratch3 != 0x0f) {
417 		/* we fail, there's nothing here */
418 		pr_err("port existence test failed, cannot continue\n");
419 		return -ENODEV;
420 	}
421 
422 	/* Set DLAB 0. */
423 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
424 
425 	/* First of all, disable all interrupts */
426 	soutp(UART_IER, sinp(UART_IER) &
427 	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
428 
429 	/* Clear registers. */
430 	sinp(UART_LSR);
431 	sinp(UART_RX);
432 	sinp(UART_IIR);
433 	sinp(UART_MSR);
434 
435 	/* Set line for power source */
436 	off();
437 
438 	/* Clear registers again to be sure. */
439 	sinp(UART_LSR);
440 	sinp(UART_RX);
441 	sinp(UART_IIR);
442 	sinp(UART_MSR);
443 
444 	switch (type) {
445 	case IR_IRDEO:
446 	case IR_IRDEO_REMOTE:
447 		/* setup port to 7N1 @ 115200 Baud */
448 		/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */
449 
450 		/* Set DLAB 1. */
451 		soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
452 		/* Set divisor to 1 => 115200 Baud */
453 		soutp(UART_DLM, 0);
454 		soutp(UART_DLL, 1);
455 		/* Set DLAB 0 +  7N1 */
456 		soutp(UART_LCR, UART_LCR_WLEN7);
457 		/* THR interrupt already disabled at this point */
458 		break;
459 	default:
460 		break;
461 	}
462 
463 	return 0;
464 }
465 
466 static void serial_ir_timeout(struct timer_list *unused)
467 {
468 	struct ir_raw_event ev = {
469 		.timeout = true,
470 		.duration = serial_ir.rcdev->timeout
471 	};
472 	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
473 	ir_raw_event_handle(serial_ir.rcdev);
474 }
475 
476 /* Needed by serial_ir_probe() */
477 static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
478 			unsigned int count);
479 static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle);
480 static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier);
481 static int serial_ir_open(struct rc_dev *rcdev);
482 static void serial_ir_close(struct rc_dev *rcdev);
483 
484 static int serial_ir_probe(struct platform_device *dev)
485 {
486 	struct rc_dev *rcdev;
487 	int i, nlow, nhigh, result;
488 
489 	rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW);
490 	if (!rcdev)
491 		return -ENOMEM;
492 
493 	if (hardware[type].send_pulse && hardware[type].send_space)
494 		rcdev->tx_ir = serial_ir_tx;
495 	if (hardware[type].set_send_carrier)
496 		rcdev->s_tx_carrier = serial_ir_tx_carrier;
497 	if (hardware[type].set_duty_cycle)
498 		rcdev->s_tx_duty_cycle = serial_ir_tx_duty_cycle;
499 
500 	switch (type) {
501 	case IR_HOMEBREW:
502 		rcdev->device_name = "Serial IR type home-brew";
503 		break;
504 	case IR_IRDEO:
505 		rcdev->device_name = "Serial IR type IRdeo";
506 		break;
507 	case IR_IRDEO_REMOTE:
508 		rcdev->device_name = "Serial IR type IRdeo remote";
509 		break;
510 	case IR_ANIMAX:
511 		rcdev->device_name = "Serial IR type AnimaX";
512 		break;
513 	case IR_IGOR:
514 		rcdev->device_name = "Serial IR type IgorPlug";
515 		break;
516 	}
517 
518 	rcdev->input_phys = KBUILD_MODNAME "/input0";
519 	rcdev->input_id.bustype = BUS_HOST;
520 	rcdev->input_id.vendor = 0x0001;
521 	rcdev->input_id.product = 0x0001;
522 	rcdev->input_id.version = 0x0100;
523 	rcdev->open = serial_ir_open;
524 	rcdev->close = serial_ir_close;
525 	rcdev->dev.parent = &serial_ir.pdev->dev;
526 	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
527 	rcdev->driver_name = KBUILD_MODNAME;
528 	rcdev->map_name = RC_MAP_RC6_MCE;
529 	rcdev->min_timeout = 1;
530 	rcdev->timeout = IR_DEFAULT_TIMEOUT;
531 	rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
532 	rcdev->rx_resolution = 250;
533 
534 	serial_ir.rcdev = rcdev;
535 
536 	timer_setup(&serial_ir.timeout_timer, serial_ir_timeout, 0);
537 
538 	result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
539 				  share_irq ? IRQF_SHARED : 0,
540 				  KBUILD_MODNAME, &hardware);
541 	if (result < 0) {
542 		if (result == -EBUSY)
543 			dev_err(&dev->dev, "IRQ %d busy\n", irq);
544 		else if (result == -EINVAL)
545 			dev_err(&dev->dev, "Bad irq number or handler\n");
546 		return result;
547 	}
548 
549 	/* Reserve io region. */
550 	if ((iommap &&
551 	     (devm_request_mem_region(&dev->dev, iommap, 8UL << ioshift,
552 				      KBUILD_MODNAME) == NULL)) ||
553 	     (!iommap && (devm_request_region(&dev->dev, io, 8,
554 			  KBUILD_MODNAME) == NULL))) {
555 		dev_err(&dev->dev, "port %04x already in use\n", io);
556 		dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
557 		dev_warn(&dev->dev,
558 			 "or compile the serial port driver as module and\n");
559 		dev_warn(&dev->dev, "make sure this module is loaded first\n");
560 		return -EBUSY;
561 	}
562 
563 	result = hardware_init_port();
564 	if (result < 0)
565 		return result;
566 
567 	/* Initialize pulse/space widths */
568 	serial_ir.duty_cycle = 50;
569 	serial_ir.carrier = 38000;
570 
571 	/* If pin is high, then this must be an active low receiver. */
572 	if (sense == -1) {
573 		/* wait 1/2 sec for the power supply */
574 		msleep(500);
575 
576 		/*
577 		 * probe 9 times every 0.04s, collect "votes" for
578 		 * active high/low
579 		 */
580 		nlow = 0;
581 		nhigh = 0;
582 		for (i = 0; i < 9; i++) {
583 			if (sinp(UART_MSR) & hardware[type].signal_pin)
584 				nlow++;
585 			else
586 				nhigh++;
587 			msleep(40);
588 		}
589 		sense = nlow >= nhigh ? 1 : 0;
590 		dev_info(&dev->dev, "auto-detected active %s receiver\n",
591 			 sense ? "low" : "high");
592 	} else
593 		dev_info(&dev->dev, "Manually using active %s receiver\n",
594 			 sense ? "low" : "high");
595 
596 	dev_dbg(&dev->dev, "Interrupt %d, port %04x obtained\n", irq, io);
597 
598 	return devm_rc_register_device(&dev->dev, rcdev);
599 }
600 
601 static int serial_ir_open(struct rc_dev *rcdev)
602 {
603 	unsigned long flags;
604 
605 	/* initialize timestamp */
606 	serial_ir.lastkt = ktime_get();
607 
608 	spin_lock_irqsave(&hardware[type].lock, flags);
609 
610 	/* Set DLAB 0. */
611 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
612 
613 	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
614 
615 	spin_unlock_irqrestore(&hardware[type].lock, flags);
616 
617 	return 0;
618 }
619 
620 static void serial_ir_close(struct rc_dev *rcdev)
621 {
622 	unsigned long flags;
623 
624 	spin_lock_irqsave(&hardware[type].lock, flags);
625 
626 	/* Set DLAB 0. */
627 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
628 
629 	/* First of all, disable all interrupts */
630 	soutp(UART_IER, sinp(UART_IER) &
631 	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
632 	spin_unlock_irqrestore(&hardware[type].lock, flags);
633 }
634 
635 static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
636 			unsigned int count)
637 {
638 	unsigned long flags;
639 	ktime_t edge;
640 	s64 delta;
641 	int i;
642 
643 	spin_lock_irqsave(&hardware[type].lock, flags);
644 	if (type == IR_IRDEO) {
645 		/* DTR, RTS down */
646 		on();
647 	}
648 
649 	edge = ktime_get();
650 	for (i = 0; i < count; i++) {
651 		if (i % 2)
652 			hardware[type].send_space();
653 		else
654 			hardware[type].send_pulse(txbuf[i], edge);
655 
656 		edge = ktime_add_us(edge, txbuf[i]);
657 		delta = ktime_us_delta(edge, ktime_get());
658 		if (delta > 25) {
659 			spin_unlock_irqrestore(&hardware[type].lock, flags);
660 			usleep_range(delta - 25, delta + 25);
661 			spin_lock_irqsave(&hardware[type].lock, flags);
662 		} else if (delta > 0) {
663 			udelay(delta);
664 		}
665 	}
666 	off();
667 	spin_unlock_irqrestore(&hardware[type].lock, flags);
668 	return count;
669 }
670 
671 static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
672 {
673 	serial_ir.duty_cycle = cycle;
674 	return 0;
675 }
676 
677 static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
678 {
679 	if (carrier > 500000 || carrier < 20000)
680 		return -EINVAL;
681 
682 	serial_ir.carrier = carrier;
683 	return 0;
684 }
685 
686 static int serial_ir_suspend(struct platform_device *dev,
687 			     pm_message_t state)
688 {
689 	/* Set DLAB 0. */
690 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
691 
692 	/* Disable all interrupts */
693 	soutp(UART_IER, sinp(UART_IER) &
694 	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
695 
696 	/* Clear registers. */
697 	sinp(UART_LSR);
698 	sinp(UART_RX);
699 	sinp(UART_IIR);
700 	sinp(UART_MSR);
701 
702 	return 0;
703 }
704 
705 static int serial_ir_resume(struct platform_device *dev)
706 {
707 	unsigned long flags;
708 	int result;
709 
710 	result = hardware_init_port();
711 	if (result < 0)
712 		return result;
713 
714 	spin_lock_irqsave(&hardware[type].lock, flags);
715 	/* Enable Interrupt */
716 	serial_ir.lastkt = ktime_get();
717 	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
718 	off();
719 
720 	spin_unlock_irqrestore(&hardware[type].lock, flags);
721 
722 	return 0;
723 }
724 
725 static struct platform_driver serial_ir_driver = {
726 	.probe		= serial_ir_probe,
727 	.suspend	= serial_ir_suspend,
728 	.resume		= serial_ir_resume,
729 	.driver		= {
730 		.name	= "serial_ir",
731 	},
732 };
733 
734 static int __init serial_ir_init(void)
735 {
736 	int result;
737 
738 	result = platform_driver_register(&serial_ir_driver);
739 	if (result)
740 		return result;
741 
742 	serial_ir.pdev = platform_device_alloc("serial_ir", 0);
743 	if (!serial_ir.pdev) {
744 		result = -ENOMEM;
745 		goto exit_driver_unregister;
746 	}
747 
748 	result = platform_device_add(serial_ir.pdev);
749 	if (result)
750 		goto exit_device_put;
751 
752 	return 0;
753 
754 exit_device_put:
755 	platform_device_put(serial_ir.pdev);
756 exit_driver_unregister:
757 	platform_driver_unregister(&serial_ir_driver);
758 	return result;
759 }
760 
761 static void serial_ir_exit(void)
762 {
763 	platform_device_unregister(serial_ir.pdev);
764 	platform_driver_unregister(&serial_ir_driver);
765 }
766 
767 static int __init serial_ir_init_module(void)
768 {
769 	switch (type) {
770 	case IR_HOMEBREW:
771 	case IR_IRDEO:
772 	case IR_IRDEO_REMOTE:
773 	case IR_ANIMAX:
774 	case IR_IGOR:
775 		/* if nothing specified, use ttyS0/com1 and irq 4 */
776 		io = io ? io : 0x3f8;
777 		irq = irq ? irq : 4;
778 		break;
779 	default:
780 		return -EINVAL;
781 	}
782 	if (!softcarrier) {
783 		switch (type) {
784 		case IR_HOMEBREW:
785 		case IR_IGOR:
786 			hardware[type].set_send_carrier = false;
787 			hardware[type].set_duty_cycle = false;
788 			break;
789 		}
790 	}
791 
792 	/* make sure sense is either -1, 0, or 1 */
793 	if (sense != -1)
794 		sense = !!sense;
795 
796 	return serial_ir_init();
797 }
798 
799 static void __exit serial_ir_exit_module(void)
800 {
801 	del_timer_sync(&serial_ir.timeout_timer);
802 	serial_ir_exit();
803 }
804 
805 module_init(serial_ir_init_module);
806 module_exit(serial_ir_exit_module);
807 
808 MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
809 MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, Christoph Bartelmus, Andrei Tanas");
810 MODULE_LICENSE("GPL");
811 
812 module_param(type, int, 0444);
813 MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo, 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug");
814 
815 module_param_hw(io, int, ioport, 0444);
816 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
817 
818 /* some architectures (e.g. intel xscale) have memory mapped registers */
819 module_param_hw(iommap, ulong, other, 0444);
820 MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O (0 = no memory mapped io)");
821 
822 /*
823  * some architectures (e.g. intel xscale) align the 8bit serial registers
824  * on 32bit word boundaries.
825  * See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
826  */
827 module_param_hw(ioshift, int, other, 0444);
828 MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
829 
830 module_param_hw(irq, int, irq, 0444);
831 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
832 
833 module_param_hw(share_irq, bool, other, 0444);
834 MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
835 
836 module_param(sense, int, 0444);
837 MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit (0 = active high, 1 = active low )");
838 
839 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
840 module_param(txsense, bool, 0444);
841 MODULE_PARM_DESC(txsense, "Sense of transmitter circuit (0 = active high, 1 = active low )");
842 #endif
843 
844 module_param(softcarrier, bool, 0444);
845 MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");
846