linux/drivers/media/test-drivers/vivid/vivid-radio-rx.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   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 data
  71         * 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 && prandom_u32_max(100) < perc) {
  98                        switch (prandom_u32_max(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 = prandom_u32_max(256);
 108                                rds.msb = prandom_u32_max(256);
 109                                break;
 110                        case 3: /* Skip block altogether */
 111                                if (i)
 112                                        continue;
 113                                /*
 114                                 * Must make sure at least one block is
 115                                 * returned, otherwise the application
 116                                 * 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        else
 259                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