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 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 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 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 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 } 117 118 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