1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * vivid-radio-tx.c - radio transmitter support functions.
4 *
5 * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6 */
7
8 #include <linux/errno.h>
9 #include <linux/kernel.h>
10 #include <linux/sched/signal.h>
11 #include <linux/delay.h>
12 #include <linux/videodev2.h>
13 #include <linux/v4l2-dv-timings.h>
14 #include <media/v4l2-common.h>
15 #include <media/v4l2-event.h>
16 #include <media/v4l2-dv-timings.h>
17
18 #include "vivid-core.h"
19 #include "vivid-ctrls.h"
20 #include "vivid-radio-common.h"
21 #include "vivid-radio-tx.h"
22
vivid_radio_tx_write(struct file * file,const char __user * buf,size_t size,loff_t * offset)23 ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
24 size_t size, loff_t *offset)
25 {
26 struct vivid_dev *dev = video_drvdata(file);
27 struct v4l2_rds_data *data = dev->rds_gen.data;
28 ktime_t timestamp;
29 unsigned blk;
30 int i;
31
32 if (dev->radio_tx_rds_controls)
33 return -EINVAL;
34
35 if (size < sizeof(*data))
36 return -EINVAL;
37 size = sizeof(*data) * (size / sizeof(*data));
38
39 if (mutex_lock_interruptible(&dev->mutex))
40 return -ERESTARTSYS;
41 if (dev->radio_tx_rds_owner &&
42 file->private_data != dev->radio_tx_rds_owner) {
43 mutex_unlock(&dev->mutex);
44 return -EBUSY;
45 }
46 dev->radio_tx_rds_owner = file->private_data;
47
48 retry:
49 timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
50 blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
51 if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
52 dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
53
54 /*
55 * No data is available if there hasn't been time to get new data,
56 * or if the RDS receiver has been disabled, or if we use the data
57 * from the RDS transmitter and that RDS transmitter has been disabled,
58 * or if the signal quality is too weak.
59 */
60 if (blk == dev->radio_tx_rds_last_block ||
61 !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) {
62 mutex_unlock(&dev->mutex);
63 if (file->f_flags & O_NONBLOCK)
64 return -EWOULDBLOCK;
65 if (msleep_interruptible(20) && signal_pending(current))
66 return -EINTR;
67 if (mutex_lock_interruptible(&dev->mutex))
68 return -ERESTARTSYS;
69 goto retry;
70 }
71
72 for (i = 0; i < size && blk > dev->radio_tx_rds_last_block;
73 dev->radio_tx_rds_last_block++) {
74 unsigned data_blk = dev->radio_tx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
75 struct v4l2_rds_data rds;
76
77 if (copy_from_user(&rds, buf + i, sizeof(rds))) {
78 i = -EFAULT;
79 break;
80 }
81 i += sizeof(rds);
82 if (!dev->radio_rds_loop)
83 continue;
84 if ((rds.block & V4L2_RDS_BLOCK_MSK) == V4L2_RDS_BLOCK_INVALID ||
85 (rds.block & V4L2_RDS_BLOCK_ERROR))
86 continue;
87 rds.block &= V4L2_RDS_BLOCK_MSK;
88 data[data_blk] = rds;
89 }
90 mutex_unlock(&dev->mutex);
91 return i;
92 }
93
vivid_radio_tx_poll(struct file * file,struct poll_table_struct * wait)94 __poll_t vivid_radio_tx_poll(struct file *file, struct poll_table_struct *wait)
95 {
96 return EPOLLOUT | EPOLLWRNORM | v4l2_ctrl_poll(file, wait);
97 }
98
vidioc_g_modulator(struct file * file,void * fh,struct v4l2_modulator * a)99 int vidioc_g_modulator(struct file *file, void *fh, struct v4l2_modulator *a)
100 {
101 struct vivid_dev *dev = video_drvdata(file);
102
103 if (a->index > 0)
104 return -EINVAL;
105
106 strlcpy(a->name, "AM/FM/SW Transmitter", sizeof(a->name));
107 a->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
108 V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
109 (dev->radio_tx_rds_controls ?
110 V4L2_TUNER_CAP_RDS_CONTROLS :
111 V4L2_TUNER_CAP_RDS_BLOCK_IO);
112 a->rangelow = AM_FREQ_RANGE_LOW;
113 a->rangehigh = FM_FREQ_RANGE_HIGH;
114 a->txsubchans = dev->radio_tx_subchans;
115 return 0;
116 }
117
vidioc_s_modulator(struct file * file,void * fh,const struct v4l2_modulator * a)118 int vidioc_s_modulator(struct file *file, void *fh, const struct v4l2_modulator *a)
119 {
120 struct vivid_dev *dev = video_drvdata(file);
121
122 if (a->index)
123 return -EINVAL;
124 if (a->txsubchans & ~0x13)
125 return -EINVAL;
126 dev->radio_tx_subchans = a->txsubchans;
127 return 0;
128 }
129
