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/sched/signal.h>
23 #include <linux/delay.h>
24 #include <linux/videodev2.h>
25 #include <linux/v4l2-dv-timings.h>
26 #include <media/v4l2-common.h>
27 #include <media/v4l2-event.h>
28 #include <media/v4l2-dv-timings.h>
29
30 #include "vivid-core.h"
31 #include "vivid-ctrls.h"
32 #include "vivid-radio-common.h"
33 #include "vivid-radio-tx.h"
34
vivid_radio_tx_write(struct file * file,const char __user * buf,size_t size,loff_t * offset)35 ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
36 size_t size, loff_t *offset)
37 {
38 struct vivid_dev *dev = video_drvdata(file);
39 struct v4l2_rds_data *data = dev->rds_gen.data;
40 struct timespec ts;
41 unsigned blk;
42 int i;
43
44 if (dev->radio_tx_rds_controls)
45 return -EINVAL;
46
47 if (size < sizeof(*data))
48 return -EINVAL;
49 size = sizeof(*data) * (size / sizeof(*data));
50
51 if (mutex_lock_interruptible(&dev->mutex))
52 return -ERESTARTSYS;
53 if (dev->radio_tx_rds_owner &&
54 file->private_data != dev->radio_tx_rds_owner) {
55 mutex_unlock(&dev->mutex);
56 return -EBUSY;
57 }
58 dev->radio_tx_rds_owner = file->private_data;
59
60 retry:
61 ktime_get_ts(&ts);
62 ts = timespec_sub(ts, dev->radio_rds_init_ts);
63 blk = ts.tv_sec * 100 + ts.tv_nsec / 10000000;
64 blk = (blk * VIVID_RDS_GEN_BLOCKS) / 500;
65 if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
66 dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
67
68 /*
69 * No data is available if there hasn't been time to get new data,
70 * or if the RDS receiver has been disabled, or if we use the data
71 * from the RDS transmitter and that RDS transmitter has been disabled,
72 * or if the signal quality is too weak.
73 */
74 if (blk == dev->radio_tx_rds_last_block ||
75 !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) {
76 mutex_unlock(&dev->mutex);
77 if (file->f_flags & O_NONBLOCK)
78 return -EWOULDBLOCK;
79 if (msleep_interruptible(20) && signal_pending(current))
80 return -EINTR;
81 if (mutex_lock_interruptible(&dev->mutex))
82 return -ERESTARTSYS;
83 goto retry;
84 }
85
86 for (i = 0; i < size && blk > dev->radio_tx_rds_last_block;
87 dev->radio_tx_rds_last_block++) {
88 unsigned data_blk = dev->radio_tx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
89 struct v4l2_rds_data rds;
90
91 if (copy_from_user(&rds, buf + i, sizeof(rds))) {
92 i = -EFAULT;
93 break;
94 }
95 i += sizeof(rds);
96 if (!dev->radio_rds_loop)
97 continue;
98 if ((rds.block & V4L2_RDS_BLOCK_MSK) == V4L2_RDS_BLOCK_INVALID ||
99 (rds.block & V4L2_RDS_BLOCK_ERROR))
100 continue;
101 rds.block &= V4L2_RDS_BLOCK_MSK;
102 data[data_blk] = rds;
103 }
104 mutex_unlock(&dev->mutex);
105 return i;
106 }
107
vivid_radio_tx_poll(struct file * file,struct poll_table_struct * wait)108 unsigned int vivid_radio_tx_poll(struct file *file, struct poll_table_struct *wait)
109 {
110 return POLLOUT | POLLWRNORM | v4l2_ctrl_poll(file, wait);
111 }
112
vidioc_g_modulator(struct file * file,void * fh,struct v4l2_modulator * a)113 int vidioc_g_modulator(struct file *file, void *fh, struct v4l2_modulator *a)
114 {
115 struct vivid_dev *dev = video_drvdata(file);
116
117 if (a->index > 0)
118 return -EINVAL;
119
120 strlcpy(a->name, "AM/FM/SW Transmitter", sizeof(a->name));
121 a->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
122 V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
123 (dev->radio_tx_rds_controls ?
124 V4L2_TUNER_CAP_RDS_CONTROLS :
125 V4L2_TUNER_CAP_RDS_BLOCK_IO);
126 a->rangelow = AM_FREQ_RANGE_LOW;
127 a->rangehigh = FM_FREQ_RANGE_HIGH;
128 a->txsubchans = dev->radio_tx_subchans;
129 return 0;
130 }
131
vidioc_s_modulator(struct file * file,void * fh,const struct v4l2_modulator * a)132 int vidioc_s_modulator(struct file *file, void *fh, const struct v4l2_modulator *a)
133 {
134 struct vivid_dev *dev = video_drvdata(file);
135
136 if (a->index)
137 return -EINVAL;
138 if (a->txsubchans & ~0x13)
139 return -EINVAL;
140 dev->radio_tx_subchans = a->txsubchans;
141 return 0;
142 }
143