drivers/media/test-drivers/vivid/vivid-radio-rx.c

   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
  25 ssize_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
  54 retry:
  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 = 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 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
 136 int 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
 148 int 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
 217 int 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
 270 int 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 }