// SPDX-License-Identifier: GPL-2.0-only
/*
* vivid-radio-rx.c - radio receiver support functions.
*
* Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <linux/v4l2-dv-timings.h>
#include <linux/sched/signal.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-rds-gen.h"
#include "vivid-radio-rx.h"
ssize_t vivid_radio_rx_read(struct file *file, 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;
bool use_alternates;
ktime_t timestamp;
unsigned blk;
int perc;
int i;
if (dev->radio_rx_rds_controls)
return -EINVAL;
if (size < sizeof(*data))
return 0;
size = sizeof(*data) * (size / sizeof(*data));
if (mutex_lock_interruptible(&dev->mutex))
return -ERESTARTSYS;
if (dev->radio_rx_rds_owner &&
file->private_data != dev->radio_rx_rds_owner) {
mutex_unlock(&dev->mutex);
return -EBUSY;
}
if (dev->radio_rx_rds_owner == NULL) {
vivid_radio_rds_init(dev);
dev->radio_rx_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);
use_alternates = (blk % VIVID_RDS_GEN_BLOCKS) & 1;
if (dev->radio_rx_rds_last_block == 0 ||
dev->radio_rx_rds_use_alternates != use_alternates) {
dev->radio_rx_rds_use_alternates = use_alternates;
/* Re-init the RDS generator */
vivid_radio_rds_init(dev);
}
if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)
dev->radio_rx_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_rx_rds_last_block || !dev->radio_rx_rds_enabled ||
(dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) ||
abs(dev->radio_rx_sig_qual) > 200) {
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;
}
/* abs(dev->radio_rx_sig_qual) <= 200, map that to a 0-50% range */
perc = abs(dev->radio_rx_sig_qual) / 4;
for (i = 0; i < size && blk > dev->radio_rx_rds_last_block;
dev->radio_rx_rds_last_block++) {
unsigned data_blk = dev->radio_rx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
struct v4l2_rds_data rds = data[data_blk];
if (data_blk == 0 && dev->radio_rds_loop)
vivid_radio_rds_init(dev);
if (perc && get_random_u32_below(100) < perc) {
switch (get_random_u32_below(4)) {
case 0:
rds.block |= V4L2_RDS_BLOCK_CORRECTED;
break;
case 1:
rds.block |= V4L2_RDS_BLOCK_INVALID;
break;
case 2:
rds.block |= V4L2_RDS_BLOCK_ERROR;
rds.lsb = get_random_u8();
rds.msb = get_random_u8();
break;
case 3: /* Skip block altogether */
if (i)
continue;
/*
* Must make sure at least one block is
* returned, otherwise the application
* might think that end-of-file occurred.
*/
break;
}
}
if (copy_to_user(buf + i, &rds, sizeof(rds))) {
i = -EFAULT;
break;
}
i += sizeof(rds);
}
mutex_unlock(&dev->mutex);
return i;
}
__poll_t vivid_radio_rx_poll(struct file *file, struct poll_table_struct *wait)
{
return EPOLLIN | EPOLLRDNORM | v4l2_ctrl_poll(file, wait);
}
int vivid_radio_rx_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)
{
if (band->tuner != 0)
return -EINVAL;
if (band->index >= TOT_BANDS)
return -EINVAL;
*band = vivid_radio_bands[band->index];
return 0;
}
int vivid_radio_rx_s_hw_freq_seek(struct file *file, void *fh, const struct v4l2_hw_freq_seek *a)
{
struct vivid_dev *dev = video_drvdata(file);
unsigned low, high;
unsigned freq;
unsigned spacing;
unsigned band;
if (a->tuner)
return -EINVAL;
if (a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_BOUNDED)
return -EINVAL;
if (!a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_WRAP)
return -EINVAL;
if (!a->rangelow ^ !a->rangehigh)
return -EINVAL;
if (file->f_flags & O_NONBLOCK)
return -EWOULDBLOCK;
if (a->rangelow) {
for (band = 0; band < TOT_BANDS; band++)
if (a->rangelow >= vivid_radio_bands[band].rangelow &&
a->rangehigh <= vivid_radio_bands[band].rangehigh)
break;
if (band == TOT_BANDS)
return -EINVAL;
if (!dev->radio_rx_hw_seek_prog_lim &&
(a->rangelow != vivid_radio_bands[band].rangelow ||
a->rangehigh != vivid_radio_bands[band].rangehigh))
return -EINVAL;
low = a->rangelow;
high = a->rangehigh;
} else {
for (band = 0; band < TOT_BANDS; band++)
if (dev->radio_rx_freq >= vivid_radio_bands[band].rangelow &&
dev->radio_rx_freq <= vivid_radio_bands[band].rangehigh)
break;
if (band == TOT_BANDS)
return -EINVAL;
low = vivid_radio_bands[band].rangelow;
high = vivid_radio_bands[band].rangehigh;
}
spacing = band == BAND_AM ? 1600 : 16000;
freq = clamp(dev->radio_rx_freq, low, high);
if (a->seek_upward) {
freq = spacing * (freq / spacing) + spacing;
if (freq > high) {
if (!a->wrap_around)
return -ENODATA;
freq = spacing * (low / spacing) + spacing;
if (freq >= dev->radio_rx_freq)
return -ENODATA;
}
} else {
freq = spacing * ((freq + spacing - 1) / spacing) - spacing;
if (freq < low) {
if (!a->wrap_around)
return -ENODATA;
freq = spacing * ((high + spacing - 1) / spacing) - spacing;
if (freq <= dev->radio_rx_freq)
return -ENODATA;
}
}
return 0;
}
int vivid_radio_rx_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
{
struct vivid_dev *dev = video_drvdata(file);
int delta = 800;
int sig_qual;
if (vt->index > 0)
return -EINVAL;
strscpy(vt->name, "AM/FM/SW Receiver", sizeof(vt->name));
vt->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
(dev->radio_rx_rds_controls ?
V4L2_TUNER_CAP_RDS_CONTROLS :
V4L2_TUNER_CAP_RDS_BLOCK_IO) |
(dev->radio_rx_hw_seek_prog_lim ?
V4L2_TUNER_CAP_HWSEEK_PROG_LIM : 0);
switch (dev->radio_rx_hw_seek_mode) {
case VIVID_HW_SEEK_BOUNDED:
vt->capability |= V4L2_TUNER_CAP_HWSEEK_BOUNDED;
break;
case VIVID_HW_SEEK_WRAP:
vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP;
break;
case VIVID_HW_SEEK_BOTH:
vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP |
V4L2_TUNER_CAP_HWSEEK_BOUNDED;
break;
}
vt->rangelow = AM_FREQ_RANGE_LOW;
vt->rangehigh = FM_FREQ_RANGE_HIGH;
sig_qual = dev->radio_rx_sig_qual;
vt->signal = abs(sig_qual) > delta ? 0 :
0xffff - ((unsigned)abs(sig_qual) * 0xffff) / delta;
vt->afc = sig_qual > delta ? 0 : sig_qual;
if (abs(sig_qual) > delta)
vt->rxsubchans = 0;
else if (dev->radio_rx_freq < FM_FREQ_RANGE_LOW || vt->signal < 0x8000)
vt->rxsubchans = V4L2_TUNER_SUB_MONO;
else if (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_STEREO))
vt->rxsubchans = V4L2_TUNER_SUB_MONO;
else
vt->rxsubchans = V4L2_TUNER_SUB_STEREO;
if (dev->radio_rx_rds_enabled &&
(!dev->radio_rds_loop || (dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) &&
dev->radio_rx_freq >= FM_FREQ_RANGE_LOW && vt->signal >= 0xc000)
vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
if (dev->radio_rx_rds_controls)
vivid_radio_rds_init(dev);
vt->audmode = dev->radio_rx_audmode;
return 0;
}
int vivid_radio_rx_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
{
struct vivid_dev *dev = video_drvdata(file);
if (vt->index)
return -EINVAL;
dev->radio_rx_audmode = vt->audmode >= V4L2_TUNER_MODE_STEREO;
return 0;
}
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