1/*
2 * vivid-radio-tx.c - radio transmitter support functions.
3 *
4 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
5 *
6 * This program is free software; you may redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 */
19
20#include <linux/errno.h>
21#include <linux/kernel.h>
22#include <linux/delay.h>
23#include <linux/videodev2.h>
24#include <linux/v4l2-dv-timings.h>
25#include <media/v4l2-common.h>
26#include <media/v4l2-event.h>
27#include <media/v4l2-dv-timings.h>
28
29#include "vivid-core.h"
30#include "vivid-ctrls.h"
31#include "vivid-radio-common.h"
32#include "vivid-radio-tx.h"
33
34ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
35			  size_t size, loff_t *offset)
36{
37	struct vivid_dev *dev = video_drvdata(file);
38	struct v4l2_rds_data *data = dev->rds_gen.data;
39	struct timespec ts;
40	unsigned blk;
41	int i;
42
43	if (dev->radio_tx_rds_controls)
44		return -EINVAL;
45
46	if (size < sizeof(*data))
47		return -EINVAL;
48	size = sizeof(*data) * (size / sizeof(*data));
49
50	if (mutex_lock_interruptible(&dev->mutex))
51		return -ERESTARTSYS;
52	if (dev->radio_tx_rds_owner &&
53	    file->private_data != dev->radio_tx_rds_owner) {
54		mutex_unlock(&dev->mutex);
55		return -EBUSY;
56	}
57	dev->radio_tx_rds_owner = file->private_data;
58
59retry:
60	ktime_get_ts(&ts);
61	ts = timespec_sub(ts, dev->radio_rds_init_ts);
62	blk = ts.tv_sec * 100 + ts.tv_nsec / 10000000;
63	blk = (blk * VIVID_RDS_GEN_BLOCKS) / 500;
64	if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
65		dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
66
67	/*
68	 * No data is available if there hasn't been time to get new data,
69	 * or if the RDS receiver has been disabled, or if we use the data
70	 * from the RDS transmitter and that RDS transmitter has been disabled,
71	 * or if the signal quality is too weak.
72	 */
73	if (blk == dev->radio_tx_rds_last_block ||
74	    !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) {
75		mutex_unlock(&dev->mutex);
76		if (file->f_flags & O_NONBLOCK)
77			return -EWOULDBLOCK;
78		if (msleep_interruptible(20) && signal_pending(current))
79			return -EINTR;
80		if (mutex_lock_interruptible(&dev->mutex))
81			return -ERESTARTSYS;
82		goto retry;
83	}
84
85	for (i = 0; i < size && blk > dev->radio_tx_rds_last_block;
86			dev->radio_tx_rds_last_block++) {
87		unsigned data_blk = dev->radio_tx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
88		struct v4l2_rds_data rds;
89
90		if (copy_from_user(&rds, buf + i, sizeof(rds))) {
91			i = -EFAULT;
92			break;
93		}
94		i += sizeof(rds);
95		if (!dev->radio_rds_loop)
96			continue;
97		if ((rds.block & V4L2_RDS_BLOCK_MSK) == V4L2_RDS_BLOCK_INVALID ||
98		    (rds.block & V4L2_RDS_BLOCK_ERROR))
99			continue;
100		rds.block &= V4L2_RDS_BLOCK_MSK;
101		data[data_blk] = rds;
102	}
103	mutex_unlock(&dev->mutex);
104	return i;
105}
106
107unsigned int vivid_radio_tx_poll(struct file *file, struct poll_table_struct *wait)
108{
109	return POLLOUT | POLLWRNORM | v4l2_ctrl_poll(file, wait);
110}
111
112int vidioc_g_modulator(struct file *file, void *fh, struct v4l2_modulator *a)
113{
114	struct vivid_dev *dev = video_drvdata(file);
115
116	if (a->index > 0)
117		return -EINVAL;
118
119	strlcpy(a->name, "AM/FM/SW Transmitter", sizeof(a->name));
120	a->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
121			V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
122			(dev->radio_tx_rds_controls ?
123				V4L2_TUNER_CAP_RDS_CONTROLS :
124				V4L2_TUNER_CAP_RDS_BLOCK_IO);
125	a->rangelow = AM_FREQ_RANGE_LOW;
126	a->rangehigh = FM_FREQ_RANGE_HIGH;
127	a->txsubchans = dev->radio_tx_subchans;
128	return 0;
129}
130
131int vidioc_s_modulator(struct file *file, void *fh, const struct v4l2_modulator *a)
132{
133	struct vivid_dev *dev = video_drvdata(file);
134
135	if (a->index)
136		return -EINVAL;
137	if (a->txsubchans & ~0x13)
138		return -EINVAL;
139	dev->radio_tx_subchans = a->txsubchans;
140	return 0;
141}
142