ir-lirc-codec.c revision 4c8b8698053c986f5f5249878eab70cb028a1023 
1/* ir-lirc-codec.c - ir-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 <media/lirc.h>
18#include <media/lirc_dev.h>
19#include <media/rc-core.h>
20#include "rc-core-priv.h"
21
22#define LIRCBUF_SIZE 256
23
24/**
25 * ir_lirc_decode() - Send raw IR data to lirc_dev to be relayed to the
26 *		      lircd userspace daemon for decoding.
27 * @input_dev:	the struct rc_dev descriptor of the device
28 * @duration:	the struct ir_raw_event descriptor of the pulse/space
29 *
30 * This function returns -EINVAL if the lirc interfaces aren't wired up.
31 */
32static int ir_lirc_decode(struct rc_dev *dev, struct ir_raw_event ev)
33{
34	struct lirc_codec *lirc = &dev->raw->lirc;
35	int sample;
36
37	if (!(dev->raw->enabled_protocols & RC_TYPE_LIRC))
38		return 0;
39
40	if (!dev->raw->lirc.drv || !dev->raw->lirc.drv->rbuf)
41		return -EINVAL;
42
43	/* Packet start */
44	if (ev.reset)
45		return 0;
46
47	/* Carrier reports */
48	if (ev.carrier_report) {
49		sample = LIRC_FREQUENCY(ev.carrier);
50
51	/* Packet end */
52	} else if (ev.timeout) {
53
54		if (lirc->gap)
55			return 0;
56
57		lirc->gap_start = ktime_get();
58		lirc->gap = true;
59		lirc->gap_duration = ev.duration;
60
61		if (!lirc->send_timeout_reports)
62			return 0;
63
64		sample = LIRC_TIMEOUT(ev.duration / 1000);
65
66	/* Normal sample */
67	} else {
68
69		if (lirc->gap) {
70			int gap_sample;
71
72			lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
73				lirc->gap_start));
74
75			/* Convert to ms and cap by LIRC_VALUE_MASK */
76			do_div(lirc->gap_duration, 1000);
77			lirc->gap_duration = min(lirc->gap_duration,
78							(u64)LIRC_VALUE_MASK);
79
80			gap_sample = LIRC_SPACE(lirc->gap_duration);
81			lirc_buffer_write(dev->raw->lirc.drv->rbuf,
82						(unsigned char *) &gap_sample);
83			lirc->gap = false;
84		}
85
86		sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
87					LIRC_SPACE(ev.duration / 1000);
88	}
89
90	lirc_buffer_write(dev->raw->lirc.drv->rbuf,
91			  (unsigned char *) &sample);
92	wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);
93
94	return 0;
95}
96
97static ssize_t ir_lirc_transmit_ir(struct file *file, const char *buf,
98				   size_t n, loff_t *ppos)
99{
100	struct lirc_codec *lirc;
101	struct rc_dev *dev;
102	int *txbuf; /* buffer with values to transmit */
103	int ret = 0;
104	size_t count;
105
106	lirc = lirc_get_pdata(file);
107	if (!lirc)
108		return -EFAULT;
109
110	if (n % sizeof(int))
111		return -EINVAL;
112
113	count = n / sizeof(int);
114	if (count > LIRCBUF_SIZE || count % 2 == 0 || n % sizeof(int) != 0)
115		return -EINVAL;
116
117	txbuf = memdup_user(buf, n);
118	if (IS_ERR(txbuf))
119		return PTR_ERR(txbuf);
120
121	dev = lirc->dev;
122	if (!dev) {
123		ret = -EFAULT;
124		goto out;
125	}
126
127	if (dev->tx_ir)
128		ret = dev->tx_ir(dev, txbuf, (u32)n);
129
130out:
131	kfree(txbuf);
132	return ret;
133}
134
135static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
136			unsigned long __user arg)
137{
138	struct lirc_codec *lirc;
139	struct rc_dev *dev;
140	int ret = 0;
141	__u32 val = 0, tmp;
142
143	lirc = lirc_get_pdata(filep);
144	if (!lirc)
145		return -EFAULT;
146
147	dev = lirc->dev;
148	if (!dev)
149		return -EFAULT;
150
151	if (_IOC_DIR(cmd) & _IOC_WRITE) {
152		ret = get_user(val, (__u32 *)arg);
153		if (ret)
154			return ret;
155	}
156
157	switch (cmd) {
158
159	/* legacy support */
160	case LIRC_GET_SEND_MODE:
161		val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
162		break;
163
164	case LIRC_SET_SEND_MODE:
165		if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
166			return -EINVAL;
167		return 0;
168
169	/* TX settings */
170	case LIRC_SET_TRANSMITTER_MASK:
171		if (!dev->s_tx_mask)
172			return -EINVAL;
173
174		return dev->s_tx_mask(dev, val);
175
176	case LIRC_SET_SEND_CARRIER:
177		if (!dev->s_tx_carrier)
178			return -EINVAL;
179
180		return dev->s_tx_carrier(dev, val);
181
182	case LIRC_SET_SEND_DUTY_CYCLE:
183		if (!dev->s_tx_duty_cycle)
184			return -ENOSYS;
185
186		if (val <= 0 || val >= 100)
187			return -EINVAL;
188
189		return dev->s_tx_duty_cycle(dev, val);
190
191	/* RX settings */
192	case LIRC_SET_REC_CARRIER:
193		if (!dev->s_rx_carrier_range)
194			return -ENOSYS;
195
196		if (val <= 0)
197			return -EINVAL;
198
199		return dev->s_rx_carrier_range(dev,
200					       dev->raw->lirc.carrier_low,
201					       val);
202
203	case LIRC_SET_REC_CARRIER_RANGE:
204		if (val <= 0)
205			return -EINVAL;
206
207		dev->raw->lirc.carrier_low = val;
208		return 0;
209
210	case LIRC_GET_REC_RESOLUTION:
211		val = dev->rx_resolution;
212		break;
213
214	case LIRC_SET_WIDEBAND_RECEIVER:
215		if (!dev->s_learning_mode)
216			return -ENOSYS;
217
218		return dev->s_learning_mode(dev, !!val);
219
220	case LIRC_SET_MEASURE_CARRIER_MODE:
221		if (!dev->s_carrier_report)
222			return -ENOSYS;
223
224		return dev->s_carrier_report(dev, !!val);
225
226	/* Generic timeout support */
227	case LIRC_GET_MIN_TIMEOUT:
228		if (!dev->max_timeout)
229			return -ENOSYS;
230		val = dev->min_timeout / 1000;
231		break;
232
233	case LIRC_GET_MAX_TIMEOUT:
234		if (!dev->max_timeout)
235			return -ENOSYS;
236		val = dev->max_timeout / 1000;
237		break;
238
239	case LIRC_SET_REC_TIMEOUT:
240		if (!dev->max_timeout)
241			return -ENOSYS;
242
243		tmp = val * 1000;
244
245		if (tmp < dev->min_timeout ||
246		    tmp > dev->max_timeout)
247				return -EINVAL;
248
249		dev->timeout = tmp;
250		break;
251
252	case LIRC_SET_REC_TIMEOUT_REPORTS:
253		lirc->send_timeout_reports = !!val;
254		break;
255
256	default:
257		return lirc_dev_fop_ioctl(filep, cmd, arg);
258	}
259
260	if (_IOC_DIR(cmd) & _IOC_READ)
261		ret = put_user(val, (__u32 *)arg);
262
263	return ret;
264}
265
266static int ir_lirc_open(void *data)
267{
268	return 0;
269}
270
271static void ir_lirc_close(void *data)
272{
273	return;
274}
275
276static struct file_operations lirc_fops = {
277	.owner		= THIS_MODULE,
278	.write		= ir_lirc_transmit_ir,
279	.unlocked_ioctl	= ir_lirc_ioctl,
280#ifdef CONFIG_COMPAT
281	.compat_ioctl	= ir_lirc_ioctl,
282#endif
283	.read		= lirc_dev_fop_read,
284	.poll		= lirc_dev_fop_poll,
285	.open		= lirc_dev_fop_open,
286	.release	= lirc_dev_fop_close,
287	.llseek		= no_llseek,
288};
289
290static int ir_lirc_register(struct rc_dev *dev)
291{
292	struct lirc_driver *drv;
293	struct lirc_buffer *rbuf;
294	int rc = -ENOMEM;
295	unsigned long features;
296
297	drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
298	if (!drv)
299		return rc;
300
301	rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
302	if (!rbuf)
303		goto rbuf_alloc_failed;
304
305	rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
306	if (rc)
307		goto rbuf_init_failed;
308
309	features = LIRC_CAN_REC_MODE2;
310	if (dev->tx_ir) {
311		features |= LIRC_CAN_SEND_PULSE;
312		if (dev->s_tx_mask)
313			features |= LIRC_CAN_SET_TRANSMITTER_MASK;
314		if (dev->s_tx_carrier)
315			features |= LIRC_CAN_SET_SEND_CARRIER;
316		if (dev->s_tx_duty_cycle)
317			features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
318	}
319
320	if (dev->s_rx_carrier_range)
321		features |= LIRC_CAN_SET_REC_CARRIER |
322			LIRC_CAN_SET_REC_CARRIER_RANGE;
323
324	if (dev->s_learning_mode)
325		features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
326
327	if (dev->s_carrier_report)
328		features |= LIRC_CAN_MEASURE_CARRIER;
329
330	if (dev->max_timeout)
331		features |= LIRC_CAN_SET_REC_TIMEOUT;
332
333	snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
334		 dev->driver_name);
335	drv->minor = -1;
336	drv->features = features;
337	drv->data = &dev->raw->lirc;
338	drv->rbuf = rbuf;
339	drv->set_use_inc = &ir_lirc_open;
340	drv->set_use_dec = &ir_lirc_close;
341	drv->code_length = sizeof(struct ir_raw_event) * 8;
342	drv->fops = &lirc_fops;
343	drv->dev = &dev->dev;
344	drv->owner = THIS_MODULE;
345
346	drv->minor = lirc_register_driver(drv);
347	if (drv->minor < 0) {
348		rc = -ENODEV;
349		goto lirc_register_failed;
350	}
351
352	dev->raw->lirc.drv = drv;
353	dev->raw->lirc.dev = dev;
354	return 0;
355
356lirc_register_failed:
357rbuf_init_failed:
358	kfree(rbuf);
359rbuf_alloc_failed:
360	kfree(drv);
361
362	return rc;
363}
364
365static int ir_lirc_unregister(struct rc_dev *dev)
366{
367	struct lirc_codec *lirc = &dev->raw->lirc;
368
369	lirc_unregister_driver(lirc->drv->minor);
370	lirc_buffer_free(lirc->drv->rbuf);
371	kfree(lirc->drv);
372
373	return 0;
374}
375
376static struct ir_raw_handler lirc_handler = {
377	.protocols	= RC_TYPE_LIRC,
378	.decode		= ir_lirc_decode,
379	.raw_register	= ir_lirc_register,
380	.raw_unregister	= ir_lirc_unregister,
381};
382
383static int __init ir_lirc_codec_init(void)
384{
385	ir_raw_handler_register(&lirc_handler);
386
387	printk(KERN_INFO "IR LIRC bridge handler initialized\n");
388	return 0;
389}
390
391static void __exit ir_lirc_codec_exit(void)
392{
393	ir_raw_handler_unregister(&lirc_handler);
394}
395
396module_init(ir_lirc_codec_init);
397module_exit(ir_lirc_codec_exit);
398
399MODULE_LICENSE("GPL");
400MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
401MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
402MODULE_DESCRIPTION("LIRC IR handler bridge");
403