279 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * vivid-radio-rx.c - radio receiver 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/delay.h>11#include <linux/videodev2.h>12#include <linux/v4l2-dv-timings.h>13#include <linux/sched/signal.h>14 15#include <media/v4l2-common.h>16#include <media/v4l2-event.h>17#include <media/v4l2-dv-timings.h>18 19#include "vivid-core.h"20#include "vivid-ctrls.h"21#include "vivid-radio-common.h"22#include "vivid-rds-gen.h"23#include "vivid-radio-rx.h"24 25ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,26 size_t size, loff_t *offset)27{28 struct vivid_dev *dev = video_drvdata(file);29 struct v4l2_rds_data *data = dev->rds_gen.data;30 bool use_alternates;31 ktime_t timestamp;32 unsigned blk;33 int perc;34 int i;35 36 if (dev->radio_rx_rds_controls)37 return -EINVAL;38 if (size < sizeof(*data))39 return 0;40 size = sizeof(*data) * (size / sizeof(*data));41 42 if (mutex_lock_interruptible(&dev->mutex))43 return -ERESTARTSYS;44 if (dev->radio_rx_rds_owner &&45 file->private_data != dev->radio_rx_rds_owner) {46 mutex_unlock(&dev->mutex);47 return -EBUSY;48 }49 if (dev->radio_rx_rds_owner == NULL) {50 vivid_radio_rds_init(dev);51 dev->radio_rx_rds_owner = file->private_data;52 }53 54retry:55 timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);56 blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);57 use_alternates = (blk % VIVID_RDS_GEN_BLOCKS) & 1;58 59 if (dev->radio_rx_rds_last_block == 0 ||60 dev->radio_rx_rds_use_alternates != use_alternates) {61 dev->radio_rx_rds_use_alternates = use_alternates;62 /* Re-init the RDS generator */63 vivid_radio_rds_init(dev);64 }65 if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)66 dev->radio_rx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;67 68 /*69 * No data is available if there hasn't been time to get new data,70 * or if the RDS receiver has been disabled, or if we use the data71 * from the RDS transmitter and that RDS transmitter has been disabled,72 * or if the signal quality is too weak.73 */74 if (blk == dev->radio_rx_rds_last_block || !dev->radio_rx_rds_enabled ||75 (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) ||76 abs(dev->radio_rx_sig_qual) > 200) {77 mutex_unlock(&dev->mutex);78 if (file->f_flags & O_NONBLOCK)79 return -EWOULDBLOCK;80 if (msleep_interruptible(20) && signal_pending(current))81 return -EINTR;82 if (mutex_lock_interruptible(&dev->mutex))83 return -ERESTARTSYS;84 goto retry;85 }86 87 /* abs(dev->radio_rx_sig_qual) <= 200, map that to a 0-50% range */88 perc = abs(dev->radio_rx_sig_qual) / 4;89 90 for (i = 0; i < size && blk > dev->radio_rx_rds_last_block;91 dev->radio_rx_rds_last_block++) {92 unsigned data_blk = dev->radio_rx_rds_last_block % VIVID_RDS_GEN_BLOCKS;93 struct v4l2_rds_data rds = data[data_blk];94 95 if (data_blk == 0 && dev->radio_rds_loop)96 vivid_radio_rds_init(dev);97 if (perc && get_random_u32_below(100) < perc) {98 switch (get_random_u32_below(4)) {99 case 0:100 rds.block |= V4L2_RDS_BLOCK_CORRECTED;101 break;102 case 1:103 rds.block |= V4L2_RDS_BLOCK_INVALID;104 break;105 case 2:106 rds.block |= V4L2_RDS_BLOCK_ERROR;107 rds.lsb = get_random_u8();108 rds.msb = get_random_u8();109 break;110 case 3: /* Skip block altogether */111 if (i)112 continue;113 /*114 * Must make sure at least one block is115 * returned, otherwise the application116 * might think that end-of-file occurred.117 */118 break;119 }120 }121 if (copy_to_user(buf + i, &rds, sizeof(rds))) {122 i = -EFAULT;123 break;124 }125 i += sizeof(rds);126 }127 mutex_unlock(&dev->mutex);128 return i;129}130 131__poll_t vivid_radio_rx_poll(struct file *file, struct poll_table_struct *wait)132{133 return EPOLLIN | EPOLLRDNORM | v4l2_ctrl_poll(file, wait);134}135 136int vivid_radio_rx_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)137{138 if (band->tuner != 0)139 return -EINVAL;140 141 if (band->index >= TOT_BANDS)142 return -EINVAL;143 144 *band = vivid_radio_bands[band->index];145 return 0;146}147 148int vivid_radio_rx_s_hw_freq_seek(struct file *file, void *fh, const struct v4l2_hw_freq_seek *a)149{150 struct vivid_dev *dev = video_drvdata(file);151 unsigned low, high;152 unsigned freq;153 unsigned spacing;154 unsigned band;155 156 if (a->tuner)157 return -EINVAL;158 if (a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_BOUNDED)159 return -EINVAL;160 161 if (!a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_WRAP)162 return -EINVAL;163 if (!a->rangelow ^ !a->rangehigh)164 return -EINVAL;165 166 if (file->f_flags & O_NONBLOCK)167 return -EWOULDBLOCK;168 169 if (a->rangelow) {170 for (band = 0; band < TOT_BANDS; band++)171 if (a->rangelow >= vivid_radio_bands[band].rangelow &&172 a->rangehigh <= vivid_radio_bands[band].rangehigh)173 break;174 if (band == TOT_BANDS)175 return -EINVAL;176 if (!dev->radio_rx_hw_seek_prog_lim &&177 (a->rangelow != vivid_radio_bands[band].rangelow ||178 a->rangehigh != vivid_radio_bands[band].rangehigh))179 return -EINVAL;180 low = a->rangelow;181 high = a->rangehigh;182 } else {183 for (band = 0; band < TOT_BANDS; band++)184 if (dev->radio_rx_freq >= vivid_radio_bands[band].rangelow &&185 dev->radio_rx_freq <= vivid_radio_bands[band].rangehigh)186 break;187 if (band == TOT_BANDS)188 return -EINVAL;189 low = vivid_radio_bands[band].rangelow;190 high = vivid_radio_bands[band].rangehigh;191 }192 spacing = band == BAND_AM ? 1600 : 16000;193 freq = clamp(dev->radio_rx_freq, low, high);194 195 if (a->seek_upward) {196 freq = spacing * (freq / spacing) + spacing;197 if (freq > high) {198 if (!a->wrap_around)199 return -ENODATA;200 freq = spacing * (low / spacing) + spacing;201 if (freq >= dev->radio_rx_freq)202 return -ENODATA;203 }204 } else {205 freq = spacing * ((freq + spacing - 1) / spacing) - spacing;206 if (freq < low) {207 if (!a->wrap_around)208 return -ENODATA;209 freq = spacing * ((high + spacing - 1) / spacing) - spacing;210 if (freq <= dev->radio_rx_freq)211 return -ENODATA;212 }213 }214 return 0;215}216 217int vivid_radio_rx_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)218{219 struct vivid_dev *dev = video_drvdata(file);220 int delta = 800;221 int sig_qual;222 223 if (vt->index > 0)224 return -EINVAL;225 226 strscpy(vt->name, "AM/FM/SW Receiver", sizeof(vt->name));227 vt->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |228 V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |229 (dev->radio_rx_rds_controls ?230 V4L2_TUNER_CAP_RDS_CONTROLS :231 V4L2_TUNER_CAP_RDS_BLOCK_IO) |232 (dev->radio_rx_hw_seek_prog_lim ?233 V4L2_TUNER_CAP_HWSEEK_PROG_LIM : 0);234 switch (dev->radio_rx_hw_seek_mode) {235 case VIVID_HW_SEEK_BOUNDED:236 vt->capability |= V4L2_TUNER_CAP_HWSEEK_BOUNDED;237 break;238 case VIVID_HW_SEEK_WRAP:239 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP;240 break;241 case VIVID_HW_SEEK_BOTH:242 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP |243 V4L2_TUNER_CAP_HWSEEK_BOUNDED;244 break;245 }246 vt->rangelow = AM_FREQ_RANGE_LOW;247 vt->rangehigh = FM_FREQ_RANGE_HIGH;248 sig_qual = dev->radio_rx_sig_qual;249 vt->signal = abs(sig_qual) > delta ? 0 :250 0xffff - ((unsigned)abs(sig_qual) * 0xffff) / delta;251 vt->afc = sig_qual > delta ? 0 : sig_qual;252 if (abs(sig_qual) > delta)253 vt->rxsubchans = 0;254 else if (dev->radio_rx_freq < FM_FREQ_RANGE_LOW || vt->signal < 0x8000)255 vt->rxsubchans = V4L2_TUNER_SUB_MONO;256 else if (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_STEREO))257 vt->rxsubchans = V4L2_TUNER_SUB_MONO;258 else259 vt->rxsubchans = V4L2_TUNER_SUB_STEREO;260 if (dev->radio_rx_rds_enabled &&261 (!dev->radio_rds_loop || (dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) &&262 dev->radio_rx_freq >= FM_FREQ_RANGE_LOW && vt->signal >= 0xc000)263 vt->rxsubchans |= V4L2_TUNER_SUB_RDS;264 if (dev->radio_rx_rds_controls)265 vivid_radio_rds_init(dev);266 vt->audmode = dev->radio_rx_audmode;267 return 0;268}269 270int vivid_radio_rx_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)271{272 struct vivid_dev *dev = video_drvdata(file);273 274 if (vt->index)275 return -EINVAL;276 dev->radio_rx_audmode = vt->audmode >= V4L2_TUNER_MODE_STEREO;277 return 0;278}279