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->raw->lirc.drv || !dev->raw->lirc.drv->rbuf)
39 return -EINVAL;
40
41 /* Packet start */
42 if (ev.reset) {
43 /* Userspace expects a long space event before the start of
44 * the signal to use as a sync. This may be done with repeat
45 * packets and normal samples. But if a reset has been sent
46 * then we assume that a long time has passed, so we send a
47 * space with the maximum time value. */
48 sample = LIRC_SPACE(LIRC_VALUE_MASK);
49 IR_dprintk(2, "delivering reset sync space to lirc_dev\n");
50
51 /* Carrier reports */
52 } else if (ev.carrier_report) {
53 sample = LIRC_FREQUENCY(ev.carrier);
54 IR_dprintk(2, "carrier report (freq: %d)\n", sample);
55
56 /* Packet end */
57 } else if (ev.timeout) {
58
59 if (lirc->gap)
60 return 0;
61
62 lirc->gap_start = ktime_get();
63 lirc->gap = true;
64 lirc->gap_duration = ev.duration;
65
66 if (!lirc->send_timeout_reports)
67 return 0;
68
69 sample = LIRC_TIMEOUT(ev.duration / 1000);
70 IR_dprintk(2, "timeout report (duration: %d)\n", sample);
71
72 /* Normal sample */
73 } else {
74
75 if (lirc->gap) {
76 int gap_sample;
77
78 lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
79 lirc->gap_start));
80
81 /* Convert to ms and cap by LIRC_VALUE_MASK */
82 do_div(lirc->gap_duration, 1000);
83 lirc->gap_duration = min(lirc->gap_duration,
84 (u64)LIRC_VALUE_MASK);
85
86 gap_sample = LIRC_SPACE(lirc->gap_duration);
87 lirc_buffer_write(dev->raw->lirc.drv->rbuf,
88 (unsigned char *) &gap_sample);
89 lirc->gap = false;
90 }
91
92 sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
93 LIRC_SPACE(ev.duration / 1000);
94 IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
95 TO_US(ev.duration), TO_STR(ev.pulse));
96 }
97
98 lirc_buffer_write(dev->raw->lirc.drv->rbuf,
99 (unsigned char *) &sample);
100 wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);
101
102 return 0;
103 }
104
ir_lirc_transmit_ir(struct file * file,const char __user * buf,size_t n,loff_t * ppos)105 static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
106 size_t n, loff_t *ppos)
107 {
108 struct lirc_codec *lirc;
109 struct rc_dev *dev;
110 unsigned int *txbuf; /* buffer with values to transmit */
111 ssize_t ret = -EINVAL;
112 size_t count;
113 ktime_t start;
114 s64 towait;
115 unsigned int duration = 0; /* signal duration in us */
116 int i;
117
118 start = ktime_get();
119
120 lirc = lirc_get_pdata(file);
121 if (!lirc)
122 return -EFAULT;
123
124 if (n < sizeof(unsigned) || n % sizeof(unsigned))
125 return -EINVAL;
126
127 count = n / sizeof(unsigned);
128 if (count > LIRCBUF_SIZE || count % 2 == 0)
129 return -EINVAL;
130
131 txbuf = memdup_user(buf, n);
132 if (IS_ERR(txbuf))
133 return PTR_ERR(txbuf);
134
135 dev = lirc->dev;
136 if (!dev) {
137 ret = -EFAULT;
138 goto out;
139 }
140
141 if (!dev->tx_ir) {
142 ret = -EINVAL;
143 goto out;
144 }
145
146 for (i = 0; i < count; i++) {
147 if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
148 ret = -EINVAL;
149 goto out;
150 }
151
152 duration += txbuf[i];
153 }
154
155 ret = dev->tx_ir(dev, txbuf, count);
156 if (ret < 0)
157 goto out;
158
159 for (duration = i = 0; i < ret; i++)
160 duration += txbuf[i];
161
162 ret *= sizeof(unsigned int);
163
164 /*
165 * The lircd gap calculation expects the write function to
166 * wait for the actual IR signal to be transmitted before
167 * returning.
168 */
169 towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
170 if (towait > 0) {
171 set_current_state(TASK_INTERRUPTIBLE);
172 schedule_timeout(usecs_to_jiffies(towait));
173 }
174
175 out:
176 kfree(txbuf);
177 return ret;
178 }
179
ir_lirc_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)180 static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
181 unsigned long arg)
182 {
183 struct lirc_codec *lirc;
184 struct rc_dev *dev;
185 u32 __user *argp = (u32 __user *)(arg);
186 int ret = 0;
187 __u32 val = 0, tmp;
188
189 lirc = lirc_get_pdata(filep);
190 if (!lirc)
191 return -EFAULT;
192
193 dev = lirc->dev;
194 if (!dev)
195 return -EFAULT;
196
197 if (_IOC_DIR(cmd) & _IOC_WRITE) {
198 ret = get_user(val, argp);
199 if (ret)
200 return ret;
201 }
202
203 switch (cmd) {
204
205 /* legacy support */
206 case LIRC_GET_SEND_MODE:
207 if (!dev->tx_ir)
208 return -ENOTTY;
209
210 val = LIRC_MODE_PULSE;
211 break;
212
213 case LIRC_SET_SEND_MODE:
214 if (!dev->tx_ir)
215 return -ENOTTY;
216
217 if (val != LIRC_MODE_PULSE)
218 return -EINVAL;
219 return 0;
220
221 /* TX settings */
222 case LIRC_SET_TRANSMITTER_MASK:
223 if (!dev->s_tx_mask)
224 return -ENOTTY;
225
226 return dev->s_tx_mask(dev, val);
227
228 case LIRC_SET_SEND_CARRIER:
229 if (!dev->s_tx_carrier)
230 return -ENOTTY;
231
232 return dev->s_tx_carrier(dev, val);
233
234 case LIRC_SET_SEND_DUTY_CYCLE:
235 if (!dev->s_tx_duty_cycle)
236 return -ENOTTY;
237
238 if (val <= 0 || val >= 100)
239 return -EINVAL;
240
241 return dev->s_tx_duty_cycle(dev, val);
242
243 /* RX settings */
244 case LIRC_SET_REC_CARRIER:
245 if (!dev->s_rx_carrier_range)
246 return -ENOTTY;
247
248 if (val <= 0)
249 return -EINVAL;
250
251 return dev->s_rx_carrier_range(dev,
252 dev->raw->lirc.carrier_low,
253 val);
254
255 case LIRC_SET_REC_CARRIER_RANGE:
256 if (!dev->s_rx_carrier_range)
257 return -ENOTTY;
258
259 if (val <= 0)
260 return -EINVAL;
261
262 dev->raw->lirc.carrier_low = val;
263 return 0;
264
265 case LIRC_GET_REC_RESOLUTION:
266 if (!dev->rx_resolution)
267 return -ENOTTY;
268
269 val = dev->rx_resolution / 1000;
270 break;
271
272 case LIRC_SET_WIDEBAND_RECEIVER:
273 if (!dev->s_learning_mode)
274 return -ENOTTY;
275
276 return dev->s_learning_mode(dev, !!val);
277
278 case LIRC_SET_MEASURE_CARRIER_MODE:
279 if (!dev->s_carrier_report)
280 return -ENOTTY;
281
282 return dev->s_carrier_report(dev, !!val);
283
284 /* Generic timeout support */
285 case LIRC_GET_MIN_TIMEOUT:
286 if (!dev->max_timeout)
287 return -ENOTTY;
288 val = DIV_ROUND_UP(dev->min_timeout, 1000);
289 break;
290
291 case LIRC_GET_MAX_TIMEOUT:
292 if (!dev->max_timeout)
293 return -ENOTTY;
294 val = dev->max_timeout / 1000;
295 break;
296
297 case LIRC_SET_REC_TIMEOUT:
298 if (!dev->max_timeout)
299 return -ENOTTY;
300
301 /* Check for multiply overflow */
302 if (val > U32_MAX / 1000)
303 return -EINVAL;
304
305 tmp = val * 1000;
306
307 if (tmp < dev->min_timeout || tmp > dev->max_timeout)
308 return -EINVAL;
309
310 if (dev->s_timeout)
311 ret = dev->s_timeout(dev, tmp);
312 if (!ret)
313 dev->timeout = tmp;
314 break;
315
316 case LIRC_SET_REC_TIMEOUT_REPORTS:
317 if (!dev->timeout)
318 return -ENOTTY;
319
320 lirc->send_timeout_reports = !!val;
321 break;
322
323 default:
324 return lirc_dev_fop_ioctl(filep, cmd, arg);
325 }
326
327 if (_IOC_DIR(cmd) & _IOC_READ)
328 ret = put_user(val, argp);
329
330 return ret;
331 }
332
333 static const struct file_operations lirc_fops = {
334 .owner = THIS_MODULE,
335 .write = ir_lirc_transmit_ir,
336 .unlocked_ioctl = ir_lirc_ioctl,
337 #ifdef CONFIG_COMPAT
338 .compat_ioctl = ir_lirc_ioctl,
339 #endif
340 .read = lirc_dev_fop_read,
341 .poll = lirc_dev_fop_poll,
342 .open = lirc_dev_fop_open,
343 .release = lirc_dev_fop_close,
344 .llseek = no_llseek,
345 };
346
ir_lirc_register(struct rc_dev * dev)347 static int ir_lirc_register(struct rc_dev *dev)
348 {
349 struct lirc_driver *drv;
350 int rc = -ENOMEM;
351 unsigned long features = 0;
352
353 drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
354 if (!drv)
355 return rc;
356
357 if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
358 features |= LIRC_CAN_REC_MODE2;
359 if (dev->rx_resolution)
360 features |= LIRC_CAN_GET_REC_RESOLUTION;
361 }
362
363 if (dev->tx_ir) {
364 features |= LIRC_CAN_SEND_PULSE;
365 if (dev->s_tx_mask)
366 features |= LIRC_CAN_SET_TRANSMITTER_MASK;
367 if (dev->s_tx_carrier)
368 features |= LIRC_CAN_SET_SEND_CARRIER;
369 if (dev->s_tx_duty_cycle)
370 features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
371 }
372
373 if (dev->s_rx_carrier_range)
374 features |= LIRC_CAN_SET_REC_CARRIER |
375 LIRC_CAN_SET_REC_CARRIER_RANGE;
376
377 if (dev->s_learning_mode)
378 features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
379
380 if (dev->s_carrier_report)
381 features |= LIRC_CAN_MEASURE_CARRIER;
382
383 if (dev->max_timeout)
384 features |= LIRC_CAN_SET_REC_TIMEOUT;
385
386 snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
387 dev->driver_name);
388 drv->minor = -1;
389 drv->features = features;
390 drv->data = &dev->raw->lirc;
391 drv->rbuf = NULL;
392 drv->code_length = sizeof(struct ir_raw_event) * 8;
393 drv->chunk_size = sizeof(int);
394 drv->buffer_size = LIRCBUF_SIZE;
395 drv->fops = &lirc_fops;
396 drv->dev = &dev->dev;
397 drv->rdev = dev;
398 drv->owner = THIS_MODULE;
399
400 drv->minor = lirc_register_driver(drv);
401 if (drv->minor < 0) {
402 rc = -ENODEV;
403 goto out;
404 }
405
406 dev->raw->lirc.drv = drv;
407 dev->raw->lirc.dev = dev;
408 return 0;
409
410 out:
411 kfree(drv);
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 kfree(lirc->drv);
421 lirc->drv = NULL;
422
423 return 0;
424 }
425
426 static struct ir_raw_handler lirc_handler = {
427 .protocols = 0,
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