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  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 (!rc_protocols_enabled(dev, 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		return 0;
 47
 48	/* Carrier reports */
 49	if (ev.carrier_report) {
 50		sample = LIRC_FREQUENCY(ev.carrier);
 51		IR_dprintk(2, "carrier report (freq: %d)\n", sample);
 52
 53	/* Packet end */
 54	} else if (ev.timeout) {
 55
 56		if (lirc->gap)
 57			return 0;
 58
 59		lirc->gap_start = ktime_get();
 60		lirc->gap = true;
 61		lirc->gap_duration = ev.duration;
 62
 63		if (!lirc->send_timeout_reports)
 64			return 0;
 65
 66		sample = LIRC_TIMEOUT(ev.duration / 1000);
 67		IR_dprintk(2, "timeout report (duration: %d)\n", sample);
 68
 69	/* Normal sample */
 70	} else {
 71
 72		if (lirc->gap) {
 73			int gap_sample;
 74
 75			lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
 76				lirc->gap_start));
 77
 78			/* Convert to ms and cap by LIRC_VALUE_MASK */
 79			do_div(lirc->gap_duration, 1000);
 80			lirc->gap_duration = min(lirc->gap_duration,
 81							(u64)LIRC_VALUE_MASK);
 82
 83			gap_sample = LIRC_SPACE(lirc->gap_duration);
 84			lirc_buffer_write(dev->raw->lirc.drv->rbuf,
 85						(unsigned char *) &gap_sample);
 86			lirc->gap = false;
 87		}
 88
 89		sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
 90					LIRC_SPACE(ev.duration / 1000);
 91		IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
 92			   TO_US(ev.duration), TO_STR(ev.pulse));
 93	}
 94
 95	lirc_buffer_write(dev->raw->lirc.drv->rbuf,
 96			  (unsigned char *) &sample);
 97	wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);
 98
 99	return 0;
100}
101
102static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
103				   size_t n, loff_t *ppos)
104{
105	struct lirc_codec *lirc;
106	struct rc_dev *dev;
107	unsigned int *txbuf; /* buffer with values to transmit */
108	ssize_t ret = -EINVAL;
109	size_t count;
110	ktime_t start;
111	s64 towait;
112	unsigned int duration = 0; /* signal duration in us */
113	int i;
114
115	start = ktime_get();
116
117	lirc = lirc_get_pdata(file);
118	if (!lirc)
119		return -EFAULT;
120
121	if (n < sizeof(unsigned) || n % sizeof(unsigned))
122		return -EINVAL;
123
124	count = n / sizeof(unsigned);
125	if (count > LIRCBUF_SIZE || count % 2 == 0)
126		return -EINVAL;
127
128	txbuf = memdup_user(buf, n);
129	if (IS_ERR(txbuf))
130		return PTR_ERR(txbuf);
131
132	dev = lirc->dev;
133	if (!dev) {
134		ret = -EFAULT;
135		goto out;
136	}
137
138	if (!dev->tx_ir) {
139		ret = -ENOSYS;
140		goto out;
141	}
142
143	for (i = 0; i < count; i++) {
144		if (txbuf[i] > IR_MAX_DURATION / 1000 - duration || !txbuf[i]) {
145			ret = -EINVAL;
146			goto out;
147		}
148
149		duration += txbuf[i];
150	}
151
152	ret = dev->tx_ir(dev, txbuf, count);
153	if (ret < 0)
154		goto out;
155
156	for (duration = i = 0; i < ret; i++)
157		duration += txbuf[i];
158
159	ret *= sizeof(unsigned int);
160
161	/*
162	 * The lircd gap calculation expects the write function to
163	 * wait for the actual IR signal to be transmitted before
164	 * returning.
165	 */
166	towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
167	if (towait > 0) {
168		set_current_state(TASK_INTERRUPTIBLE);
169		schedule_timeout(usecs_to_jiffies(towait));
170	}
171
172out:
173	kfree(txbuf);
174	return ret;
175}
176
177static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
178			unsigned long arg)
179{
180	struct lirc_codec *lirc;
181	struct rc_dev *dev;
182	u32 __user *argp = (u32 __user *)(arg);
183	int ret = 0;
184	__u32 val = 0, tmp;
185
186	lirc = lirc_get_pdata(filep);
187	if (!lirc)
188		return -EFAULT;
189
190	dev = lirc->dev;
191	if (!dev)
192		return -EFAULT;
193
194	if (_IOC_DIR(cmd) & _IOC_WRITE) {
195		ret = get_user(val, argp);
196		if (ret)
197			return ret;
198	}
199
200	switch (cmd) {
201
202	/* legacy support */
203	case LIRC_GET_SEND_MODE:
204		val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
205		break;
206
207	case LIRC_SET_SEND_MODE:
208		if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
209			return -EINVAL;
210		return 0;
211
212	/* TX settings */
213	case LIRC_SET_TRANSMITTER_MASK:
214		if (!dev->s_tx_mask)
215			return -ENOSYS;
216
217		return dev->s_tx_mask(dev, val);
218
219	case LIRC_SET_SEND_CARRIER:
220		if (!dev->s_tx_carrier)
221			return -ENOSYS;
222
223		return dev->s_tx_carrier(dev, val);
224
225	case LIRC_SET_SEND_DUTY_CYCLE:
226		if (!dev->s_tx_duty_cycle)
227			return -ENOSYS;
228
229		if (val <= 0 || val >= 100)
230			return -EINVAL;
231
232		return dev->s_tx_duty_cycle(dev, val);
233
234	/* RX settings */
235	case LIRC_SET_REC_CARRIER:
236		if (!dev->s_rx_carrier_range)
237			return -ENOSYS;
238
239		if (val <= 0)
240			return -EINVAL;
241
242		return dev->s_rx_carrier_range(dev,
243					       dev->raw->lirc.carrier_low,
244					       val);
245
246	case LIRC_SET_REC_CARRIER_RANGE:
247		if (val <= 0)
248			return -EINVAL;
249
250		dev->raw->lirc.carrier_low = val;
251		return 0;
252
253	case LIRC_GET_REC_RESOLUTION:
254		val = dev->rx_resolution;
255		break;
256
257	case LIRC_SET_WIDEBAND_RECEIVER:
258		if (!dev->s_learning_mode)
259			return -ENOSYS;
260
261		return dev->s_learning_mode(dev, !!val);
262
263	case LIRC_SET_MEASURE_CARRIER_MODE:
264		if (!dev->s_carrier_report)
265			return -ENOSYS;
266
267		return dev->s_carrier_report(dev, !!val);
268
269	/* Generic timeout support */
270	case LIRC_GET_MIN_TIMEOUT:
271		if (!dev->max_timeout)
272			return -ENOSYS;
273		val = dev->min_timeout / 1000;
274		break;
275
276	case LIRC_GET_MAX_TIMEOUT:
277		if (!dev->max_timeout)
278			return -ENOSYS;
279		val = dev->max_timeout / 1000;
280		break;
281
282	case LIRC_SET_REC_TIMEOUT:
283		if (!dev->max_timeout)
284			return -ENOSYS;
285
286		tmp = val * 1000;
287
288		if (tmp < dev->min_timeout ||
289		    tmp > dev->max_timeout)
290				return -EINVAL;
291
292		dev->timeout = tmp;
293		break;
294
295	case LIRC_SET_REC_TIMEOUT_REPORTS:
296		lirc->send_timeout_reports = !!val;
297		break;
298
299	default:
300		return lirc_dev_fop_ioctl(filep, cmd, arg);
301	}
302
303	if (_IOC_DIR(cmd) & _IOC_READ)
304		ret = put_user(val, argp);
305
306	return ret;
307}
308
309static int ir_lirc_open(void *data)
310{
311	return 0;
312}
313
314static void ir_lirc_close(void *data)
315{
316	return;
317}
318
319static const struct file_operations lirc_fops = {
320	.owner		= THIS_MODULE,
321	.write		= ir_lirc_transmit_ir,
322	.unlocked_ioctl	= ir_lirc_ioctl,
323#ifdef CONFIG_COMPAT
324	.compat_ioctl	= ir_lirc_ioctl,
325#endif
326	.read		= lirc_dev_fop_read,
327	.poll		= lirc_dev_fop_poll,
328	.open		= lirc_dev_fop_open,
329	.release	= lirc_dev_fop_close,
330	.llseek		= no_llseek,
331};
332
333static int ir_lirc_register(struct rc_dev *dev)
334{
335	struct lirc_driver *drv;
336	struct lirc_buffer *rbuf;
337	int rc = -ENOMEM;
338	unsigned long features;
339
340	drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
341	if (!drv)
342		return rc;
343
344	rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
345	if (!rbuf)
346		goto rbuf_alloc_failed;
347
348	rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
349	if (rc)
350		goto rbuf_init_failed;
351
352	features = LIRC_CAN_REC_MODE2;
353	if (dev->tx_ir) {
354		features |= LIRC_CAN_SEND_PULSE;
355		if (dev->s_tx_mask)
356			features |= LIRC_CAN_SET_TRANSMITTER_MASK;
357		if (dev->s_tx_carrier)
358			features |= LIRC_CAN_SET_SEND_CARRIER;
359		if (dev->s_tx_duty_cycle)
360			features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
361	}
362
363	if (dev->s_rx_carrier_range)
364		features |= LIRC_CAN_SET_REC_CARRIER |
365			LIRC_CAN_SET_REC_CARRIER_RANGE;
366
367	if (dev->s_learning_mode)
368		features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;
369
370	if (dev->s_carrier_report)
371		features |= LIRC_CAN_MEASURE_CARRIER;
372
373	if (dev->max_timeout)
374		features |= LIRC_CAN_SET_REC_TIMEOUT;
375
376	snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
377		 dev->driver_name);
378	drv->minor = -1;
379	drv->features = features;
380	drv->data = &dev->raw->lirc;
381	drv->rbuf = rbuf;
382	drv->set_use_inc = &ir_lirc_open;
383	drv->set_use_dec = &ir_lirc_close;
384	drv->code_length = sizeof(struct ir_raw_event) * 8;
385	drv->fops = &lirc_fops;
386	drv->dev = &dev->dev;
387	drv->rdev = dev;
388	drv->owner = THIS_MODULE;
389
390	drv->minor = lirc_register_driver(drv);
391	if (drv->minor < 0) {
392		rc = -ENODEV;
393		goto lirc_register_failed;
394	}
395
396	dev->raw->lirc.drv = drv;
397	dev->raw->lirc.dev = dev;
398	return 0;
399
400lirc_register_failed:
401rbuf_init_failed:
402	kfree(rbuf);
403rbuf_alloc_failed:
404	kfree(drv);
405
406	return rc;
407}
408
409static int ir_lirc_unregister(struct rc_dev *dev)
410{
411	struct lirc_codec *lirc = &dev->raw->lirc;
412
413	lirc_unregister_driver(lirc->drv->minor);
414	lirc_buffer_free(lirc->drv->rbuf);
415	kfree(lirc->drv);
416
417	return 0;
418}
419
420static struct ir_raw_handler lirc_handler = {
421	.protocols	= RC_BIT_LIRC,
422	.decode		= ir_lirc_decode,
423	.raw_register	= ir_lirc_register,
424	.raw_unregister	= ir_lirc_unregister,
425};
426
427static int __init ir_lirc_codec_init(void)
428{
429	ir_raw_handler_register(&lirc_handler);
430
431	printk(KERN_INFO "IR LIRC bridge handler initialized\n");
432	return 0;
433}
434
435static void __exit ir_lirc_codec_exit(void)
436{
437	ir_raw_handler_unregister(&lirc_handler);
438}
439
440module_init(ir_lirc_codec_init);
441module_exit(ir_lirc_codec_exit);
442
443MODULE_LICENSE("GPL");
444MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
445MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
446MODULE_DESCRIPTION("LIRC IR handler bridge");