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// SPDX-License-Identifier: GPL-2.0-only
/*
* vivid-radio-tx.c - radio transmitter support functions.
*
* Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <linux/v4l2-dv-timings.h>
#include <media/v4l2-common.h>
#include <media/v4l2-event.h>
#include <media/v4l2-dv-timings.h>
#include "vivid-core.h"
#include "vivid-ctrls.h"
#include "vivid-radio-common.h"
#include "vivid-radio-tx.h"
ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
size_t size, loff_t *offset)
{
struct vivid_dev *dev = video_drvdata(file);
struct v4l2_rds_data *data = dev->rds_gen.data;
ktime_t timestamp;
unsigned blk;
int i;
if (dev->radio_tx_rds_controls)
return -EINVAL;
if (size < sizeof(*data))
return -EINVAL;
size = sizeof(*data) * (size / sizeof(*data));
if (mutex_lock_interruptible(&dev->mutex))
return -ERESTARTSYS;
if (dev->radio_tx_rds_owner &&
file->private_data != dev->radio_tx_rds_owner) {
mutex_unlock(&dev->mutex);
return -EBUSY;
}
dev->radio_tx_rds_owner = file->private_data;
retry:
timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
/*
* No data is available if there hasn't been time to get new data,
* or if the RDS receiver has been disabled, or if we use the data
* from the RDS transmitter and that RDS transmitter has been disabled,
* or if the signal quality is too weak.
*/
if (blk == dev->radio_tx_rds_last_block ||
!(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) {
mutex_unlock(&dev->mutex);
if (file->f_flags & O_NONBLOCK)
return -EWOULDBLOCK;
if (msleep_interruptible(20) && signal_pending(current))
return -EINTR;
if (mutex_lock_interruptible(&dev->mutex))
return -ERESTARTSYS;
goto retry;
}
for (i = 0; i < size && blk > dev->radio_tx_rds_last_block;
dev->radio_tx_rds_last_block++) {
unsigned data_blk = dev->radio_tx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
struct v4l2_rds_data rds;
if (copy_from_user(&rds, buf + i, sizeof(rds))) {
i = -EFAULT;
break;
}
i += sizeof(rds);
if (!dev->radio_rds_loop)
continue;
if ((rds.block & V4L2_RDS_BLOCK_MSK) == V4L2_RDS_BLOCK_INVALID ||
(rds.block & V4L2_RDS_BLOCK_ERROR))
continue;
rds.block &= V4L2_RDS_BLOCK_MSK;
data[data_blk] = rds;
}
mutex_unlock(&dev->mutex);
return i;
}
__poll_t vivid_radio_tx_poll(struct file *file, struct poll_table_struct *wait)
{
return EPOLLOUT | EPOLLWRNORM | v4l2_ctrl_poll(file, wait);
}
int vidioc_g_modulator(struct file *file, void *fh, struct v4l2_modulator *a)
{
struct vivid_dev *dev = video_drvdata(file);
if (a->index > 0)
return -EINVAL;
strscpy(a->name, "AM/FM/SW Transmitter", sizeof(a->name));
a->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
(dev->radio_tx_rds_controls ?
V4L2_TUNER_CAP_RDS_CONTROLS :
V4L2_TUNER_CAP_RDS_BLOCK_IO);
a->rangelow = AM_FREQ_RANGE_LOW;
a->rangehigh = FM_FREQ_RANGE_HIGH;
a->txsubchans = dev->radio_tx_subchans;
return 0;
}
int vidioc_s_modulator(struct file *file, void *fh, const struct v4l2_modulator *a)
{
struct vivid_dev *dev = video_drvdata(file);
if (a->index)
return -EINVAL;
if (a->txsubchans & ~0x13)
return -EINVAL;
dev->radio_tx_subchans = a->txsubchans;
return 0;
}
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