129 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*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 23ssize_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 48retry: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 data57 * 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 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 99int 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 strscpy(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 118int 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