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 */
ir_lirc_decode(struct rc_dev * dev,struct ir_raw_event ev)33 static 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
ir_lirc_transmit_ir(struct file * file,const char __user * buf,size_t n,loff_t * ppos)108 static 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
178 out:
179 kfree(txbuf);
180 return ret;
181 }
182
ir_lirc_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)183 static 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
ir_lirc_open(void * data)315 static int ir_lirc_open(void *data)
316 {
317 return 0;
318 }
319
ir_lirc_close(void * data)320 static void ir_lirc_close(void *data)
321 {
322 return;
323 }
324
325 static 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
ir_lirc_register(struct rc_dev * dev)339 static 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
406 lirc_register_failed:
407 rbuf_init_failed:
408 kfree(rbuf);
409 rbuf_alloc_failed:
410 kfree(drv);
411
412 return rc;
413 }
414
ir_lirc_unregister(struct rc_dev * dev)415 static 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
426 static 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
ir_lirc_codec_init(void)433 static 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
ir_lirc_codec_exit(void)441 static void __exit ir_lirc_codec_exit(void)
442 {
443 ir_raw_handler_unregister(&lirc_handler);
444 }
445
446 module_init(ir_lirc_codec_init);
447 module_exit(ir_lirc_codec_exit);
448
449 MODULE_LICENSE("GPL");
450 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
451 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
452 MODULE_DESCRIPTION("LIRC IR handler bridge");
453