1/* ir-lirc-codec.c - rc-core to classic lirc interface bridge
2 *
3 * Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 *  it under the terms of the GNU General Public License as published by
7 *  the Free Software Foundation version 2 of the License.
8 *
9 *  This program is distributed in the hope that it will be useful,
10 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
11 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 *  GNU General Public License for more details.
13 */
14
15#include <linux/sched.h>
16#include <linux/wait.h>
17#include <linux/module.h>
18#include <media/lirc.h>
19#include <media/lirc_dev.h>
20#include <media/rc-core.h>
21#include "rc-core-priv.h"
22
23#define LIRCBUF_SIZE 256
24
25/**
26 * ir_lirc_decode() - Send raw IR data to lirc_dev to be relayed to the
27 *		      lircd userspace daemon for decoding.
28 * @input_dev:	the struct rc_dev descriptor of the device
29 * @duration:	the struct ir_raw_event descriptor of the pulse/space
30 *
31 * This function returns -EINVAL if the lirc interfaces aren't wired up.
32 */
33static int ir_lirc_decode(struct rc_dev *dev, struct ir_raw_event ev)
34{
35	struct lirc_codec *lirc = &dev->raw->lirc;
36	int sample;
37
38	if (!(dev->enabled_protocols & RC_BIT_LIRC))
39		return 0;
40
41	if (!dev->raw->lirc.drv || !dev->raw->lirc.drv->rbuf)
42		return -EINVAL;
43
44	/* Packet start */
45	if (ev.reset) {
46		/* Userspace expects a long space event before the start of
47		 * the signal to use as a sync.  This may be done with repeat
48		 * packets and normal samples.  But if a reset has been sent
49		 * then we assume that a long time has passed, so we send a
50		 * space with the maximum time value. */
51		sample = LIRC_SPACE(LIRC_VALUE_MASK);
52		IR_dprintk(2, "delivering reset sync space to lirc_dev\n");
53
54	/* Carrier reports */
55	} else if (ev.carrier_report) {
56		sample = LIRC_FREQUENCY(ev.carrier);
57		IR_dprintk(2, "carrier report (freq: %d)\n", sample);
58
59	/* Packet end */
60	} else if (ev.timeout) {
61
62		if (lirc->gap)
63			return 0;
64
65		lirc->gap_start = ktime_get();
66		lirc->gap = true;
67		lirc->gap_duration = ev.duration;
68
69		if (!lirc->send_timeout_reports)
70			return 0;
71
72		sample = LIRC_TIMEOUT(ev.duration / 1000);
73		IR_dprintk(2, "timeout report (duration: %d)\n", sample);
74
75	/* Normal sample */
76	} else {
77
78		if (lirc->gap) {
79			int gap_sample;
80
81			lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
82				lirc->gap_start));
83
84			/* Convert to ms and cap by LIRC_VALUE_MASK */
85			do_div(lirc->gap_duration, 1000);
86			lirc->gap_duration = min(lirc->gap_duration,
87							(u64)LIRC_VALUE_MASK);
88
89			gap_sample = LIRC_SPACE(lirc->gap_duration);
90			lirc_buffer_write(dev->raw->lirc.drv->rbuf,
91						(unsigned char *) &gap_sample);
92			lirc->gap = false;
93		}
94
95		sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
96					LIRC_SPACE(ev.duration / 1000);
97		IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
98			   TO_US(ev.duration), TO_STR(ev.pulse));
99	}
100
101	lirc_buffer_write(dev->raw->lirc.drv->rbuf,
102			  (unsigned char *) &sample);
103	wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);
104
105	return 0;
106}
107
108static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
109				   size_t n, loff_t *ppos)
110{
111	struct lirc_codec *lirc;
112	struct rc_dev *dev;
113	unsigned int *txbuf; /* buffer with values to transmit */
114	ssize_t ret = -EINVAL;
115	size_t count;
116	ktime_t start;
117	s64 towait;
118	unsigned int duration = 0; /* signal duration in us */
119	int i;
120
121	start = ktime_get();
122
123	lirc = lirc_get_pdata(file);
124	if (!lirc)
125		return -EFAULT;
126
127	if (n < sizeof(unsigned) || n % sizeof(unsigned))
128		return -EINVAL;
129
130	count = n / sizeof(unsigned);
131	if (count > LIRCBUF_SIZE || count % 2 == 0)
132		return -EINVAL;
133
134	txbuf = memdup_user(buf, n);
135	if (IS_ERR(txbuf))
136		return PTR_ERR(txbuf);
137
138	dev = lirc->dev;
139	if (!dev) {
140		ret = -EFAULT;
141		goto out;
142	}
143
144	if (!dev->tx_ir) {
145		ret = -ENOSYS;
146		goto out;
147	}
148
149	for (i = 0; i < count; i++) {
150		if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
151			ret = -EINVAL;
152			goto out;
153		}
154
155		duration += txbuf[i];
156	}
157
158	ret = dev->tx_ir(dev, txbuf, count);
159	if (ret < 0)
160		goto out;
161
162	for (duration = i = 0; i < ret; i++)
163		duration += txbuf[i];
164
165	ret *= sizeof(unsigned int);
166
167	/*
168	 * The lircd gap calculation expects the write function to
169	 * wait for the actual IR signal to be transmitted before
170	 * returning.
171	 */
172	towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
173	if (towait > 0) {
174		set_current_state(TASK_INTERRUPTIBLE);
175		schedule_timeout(usecs_to_jiffies(towait));
176	}
177
178out:
179	kfree(txbuf);
180	return ret;
181}
182
183static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
184			unsigned long arg)
185{
186	struct lirc_codec *lirc;
187	struct rc_dev *dev;
188	u32 __user *argp = (u32 __user *)(arg);
189	int ret = 0;
190	__u32 val = 0, tmp;
191
192	lirc = lirc_get_pdata(filep);
193	if (!lirc)
194		return -EFAULT;
195
196	dev = lirc->dev;
197	if (!dev)
198		return -EFAULT;
199
200	if (_IOC_DIR(cmd) & _IOC_WRITE) {
201		ret = get_user(val, argp);
202		if (ret)
203			return ret;
204	}
205
206	switch (cmd) {
207
208	/* legacy support */
209	case LIRC_GET_SEND_MODE:
210		val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
211		break;
212
213	case LIRC_SET_SEND_MODE:
214		if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
215			return -EINVAL;
216		return 0;
217
218	/* TX settings */
219	case LIRC_SET_TRANSMITTER_MASK:
220		if (!dev->s_tx_mask)
221			return -ENOSYS;
222
223		return dev->s_tx_mask(dev, val);
224
225	case LIRC_SET_SEND_CARRIER:
226		if (!dev->s_tx_carrier)
227			return -ENOSYS;
228
229		return dev->s_tx_carrier(dev, val);
230
231	case LIRC_SET_SEND_DUTY_CYCLE:
232		if (!dev->s_tx_duty_cycle)
233			return -ENOSYS;
234
235		if (val <= 0 || val >= 100)
236			return -EINVAL;
237
238		return dev->s_tx_duty_cycle(dev, val);
239
240	/* RX settings */
241	case LIRC_SET_REC_CARRIER:
242		if (!dev->s_rx_carrier_range)
243			return -ENOSYS;
244
245		if (val <= 0)
246			return -EINVAL;
247
248		return dev->s_rx_carrier_range(dev,
249					       dev->raw->lirc.carrier_low,
250					       val);
251
252	case LIRC_SET_REC_CARRIER_RANGE:
253		if (val <= 0)
254			return -EINVAL;
255
256		dev->raw->lirc.carrier_low = val;
257		return 0;
258
259	case LIRC_GET_REC_RESOLUTION:
260		val = dev->rx_resolution;
261		break;
262
263	case LIRC_SET_WIDEBAND_RECEIVER:
264		if (!dev->s_learning_mode)
265			return -ENOSYS;
266
267		return dev->s_learning_mode(dev, !!val);
268
269	case LIRC_SET_MEASURE_CARRIER_MODE:
270		if (!dev->s_carrier_report)
271			return -ENOSYS;
272
273		return dev->s_carrier_report(dev, !!val);
274
275	/* Generic timeout support */
276	case LIRC_GET_MIN_TIMEOUT:
277		if (!dev->max_timeout)
278			return -ENOSYS;
279		val = dev->min_timeout / 1000;
280		break;
281
282	case LIRC_GET_MAX_TIMEOUT:
283		if (!dev->max_timeout)
284			return -ENOSYS;
285		val = dev->max_timeout / 1000;
286		break;
287
288	case LIRC_SET_REC_TIMEOUT:
289		if (!dev->max_timeout)
290			return -ENOSYS;
291
292		tmp = val * 1000;
293
294		if (tmp < dev->min_timeout ||
295		    tmp > dev->max_timeout)
296				return -EINVAL;
297
298		dev->timeout = tmp;
299		break;
300
301	case LIRC_SET_REC_TIMEOUT_REPORTS:
302		lirc->send_timeout_reports = !!val;
303		break;
304
305	default:
306		return lirc_dev_fop_ioctl(filep, cmd, arg);
307	}
308
309	if (_IOC_DIR(cmd) & _IOC_READ)
310		ret = put_user(val, argp);
311
312	return ret;
313}
314
315static int ir_lirc_open(void *data)
316{
317	return 0;
318}
319
320static void ir_lirc_close(void *data)
321{
322	return;
323}
324
325static const struct file_operations lirc_fops = {
326	.owner		= THIS_MODULE,
327	.write		= ir_lirc_transmit_ir,
328	.unlocked_ioctl	= ir_lirc_ioctl,
329#ifdef CONFIG_COMPAT
330	.compat_ioctl	= ir_lirc_ioctl,
331#endif
332	.read		= lirc_dev_fop_read,
333	.poll		= lirc_dev_fop_poll,
334	.open		= lirc_dev_fop_open,
335	.release	= lirc_dev_fop_close,
336	.llseek		= no_llseek,
337};
338
339static int ir_lirc_register(struct rc_dev *dev)
340{
341	struct lirc_driver *drv;
342	struct lirc_buffer *rbuf;
343	int rc = -ENOMEM;
344	unsigned long features;
345
346	drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
347	if (!drv)
348		return rc;
349
350	rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
351	if (!rbuf)
352		goto rbuf_alloc_failed;
353
354	rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
355	if (rc)
356		goto rbuf_init_failed;
357
358	features = LIRC_CAN_REC_MODE2;
359	if (dev->tx_ir) {
360		features |= LIRC_CAN_SEND_PULSE;
361		if (dev->s_tx_mask)
362			features |= LIRC_CAN_SET_TRANSMITTER_MASK;
363		if (dev->s_tx_carrier)
364			features |= LIRC_CAN_SET_SEND_CARRIER;
365		if (dev->s_tx_duty_cycle)
366			features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
367	}
368
369	if (dev->s_rx_carrier_range)
370		features |= LIRC_CAN_SET_REC_CARRIER |
371			LIRC_CAN_SET_REC_CARRIER_RANGE;
372
373	if (dev->s_learning_mode)
374		features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
375
376	if (dev->s_carrier_report)
377		features |= LIRC_CAN_MEASURE_CARRIER;
378
379	if (dev->max_timeout)
380		features |= LIRC_CAN_SET_REC_TIMEOUT;
381
382	snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
383		 dev->driver_name);
384	drv->minor = -1;
385	drv->features = features;
386	drv->data = &dev->raw->lirc;
387	drv->rbuf = rbuf;
388	drv->set_use_inc = &ir_lirc_open;
389	drv->set_use_dec = &ir_lirc_close;
390	drv->code_length = sizeof(struct ir_raw_event) * 8;
391	drv->fops = &lirc_fops;
392	drv->dev = &dev->dev;
393	drv->rdev = dev;
394	drv->owner = THIS_MODULE;
395
396	drv->minor = lirc_register_driver(drv);
397	if (drv->minor < 0) {
398		rc = -ENODEV;
399		goto lirc_register_failed;
400	}
401
402	dev->raw->lirc.drv = drv;
403	dev->raw->lirc.dev = dev;
404	return 0;
405
406lirc_register_failed:
407rbuf_init_failed:
408	kfree(rbuf);
409rbuf_alloc_failed:
410	kfree(drv);
411
412	return rc;
413}
414
415static int ir_lirc_unregister(struct rc_dev *dev)
416{
417	struct lirc_codec *lirc = &dev->raw->lirc;
418
419	lirc_unregister_driver(lirc->drv->minor);
420	lirc_buffer_free(lirc->drv->rbuf);
421	kfree(lirc->drv);
422
423	return 0;
424}
425
426static struct ir_raw_handler lirc_handler = {
427	.protocols	= RC_BIT_LIRC,
428	.decode		= ir_lirc_decode,
429	.raw_register	= ir_lirc_register,
430	.raw_unregister	= ir_lirc_unregister,
431};
432
433static int __init ir_lirc_codec_init(void)
434{
435	ir_raw_handler_register(&lirc_handler);
436
437	printk(KERN_INFO "IR LIRC bridge handler initialized\n");
438	return 0;
439}
440
441static void __exit ir_lirc_codec_exit(void)
442{
443	ir_raw_handler_unregister(&lirc_handler);
444}
445
446module_init(ir_lirc_codec_init);
447module_exit(ir_lirc_codec_exit);
448
449MODULE_LICENSE("GPL");
450MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
451MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
452MODULE_DESCRIPTION("LIRC IR handler bridge");
453