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
vivid_radio_tx_write(struct file * file,const char __user * buf,size_t size,loff_t * offset)34 ssize_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
59 retry:
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
vivid_radio_tx_poll(struct file * file,struct poll_table_struct * wait)107 unsigned 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
vidioc_g_modulator(struct file * file,void * fh,struct v4l2_modulator * a)112 int 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
vidioc_s_modulator(struct file * file,void * fh,const struct v4l2_modulator * a)131 int 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