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

   1 /*
   2  * vivid-radio-rx.c - radio receiver support functions.
   3  *
   4  * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5  *
   6  * This program is free software; you may redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  11  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  12  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  13  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  14  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  15  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  16  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  17  * SOFTWARE.
  18  */
  19
  20 #include <linux/errno.h>
  21 #include <linux/kernel.h>
  22 #include <linux/delay.h>
  23 #include <linux/videodev2.h>
  24 #include <linux/v4l2-dv-timings.h>
  25 #include <linux/sched/signal.h>
  26
  27 #include <media/v4l2-common.h>
  28 #include <media/v4l2-event.h>
  29 #include <media/v4l2-dv-timings.h>
  30
  31 #include "vivid-core.h"
  32 #include "vivid-ctrls.h"
  33 #include "vivid-radio-common.h"
  34 #include "vivid-rds-gen.h"
  35 #include "vivid-radio-rx.h"
  36
  37 ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
  38                          size_t size, loff_t *offset)
  39 {
  40         struct vivid_dev *dev = video_drvdata(file);
  41         struct v4l2_rds_data *data = dev->rds_gen.data;
  42         bool use_alternates;
  43         ktime_t timestamp;
  44         unsigned blk;
  45         int perc;
  46         int i;
  47
  48         if (dev->radio_rx_rds_controls)
  49                 return -EINVAL;
  50         if (size < sizeof(*data))
  51                 return 0;
  52         size = sizeof(*data) * (size / sizeof(*data));
  53
  54         if (mutex_lock_interruptible(&dev->mutex))
  55                 return -ERESTARTSYS;
  56         if (dev->radio_rx_rds_owner &&
  57             file->private_data != dev->radio_rx_rds_owner) {
  58                 mutex_unlock(&dev->mutex);
  59                 return -EBUSY;
  60         }
  61         if (dev->radio_rx_rds_owner == NULL) {
  62                 vivid_radio_rds_init(dev);
  63                 dev->radio_rx_rds_owner = file->private_data;
  64         }
  65
  66 retry:
  67         timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
  68         blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
  69         use_alternates = (blk % VIVID_RDS_GEN_BLOCKS) & 1;
  70
  71         if (dev->radio_rx_rds_last_block == 0 ||
  72             dev->radio_rx_rds_use_alternates != use_alternates) {
  73                 dev->radio_rx_rds_use_alternates = use_alternates;
  74                 /* Re-init the RDS generator */
  75                 vivid_radio_rds_init(dev);
  76         }
  77         if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)
  78                 dev->radio_rx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
  79
  80         /*
  81          * No data is available if there hasn't been time to get new data,
  82          * or if the RDS receiver has been disabled, or if we use the data
  83          * from the RDS transmitter and that RDS transmitter has been disabled,
  84          * or if the signal quality is too weak.
  85          */
  86         if (blk == dev->radio_rx_rds_last_block || !dev->radio_rx_rds_enabled ||
  87             (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) ||
  88             abs(dev->radio_rx_sig_qual) > 200) {
  89                 mutex_unlock(&dev->mutex);
  90                 if (file->f_flags & O_NONBLOCK)
  91                         return -EWOULDBLOCK;
  92                 if (msleep_interruptible(20) && signal_pending(current))
  93                         return -EINTR;
  94                 if (mutex_lock_interruptible(&dev->mutex))
  95                         return -ERESTARTSYS;
  96                 goto retry;
  97         }
  98
  99         /* abs(dev->radio_rx_sig_qual) <= 200, map that to a 0-50% range */
 100         perc = abs(dev->radio_rx_sig_qual) / 4;
 101
 102         for (i = 0; i < size && blk > dev->radio_rx_rds_last_block;
 103                         dev->radio_rx_rds_last_block++) {
 104                 unsigned data_blk = dev->radio_rx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
 105                 struct v4l2_rds_data rds = data[data_blk];
 106
 107                 if (data_blk == 0 && dev->radio_rds_loop)
 108                         vivid_radio_rds_init(dev);
 109                 if (perc && prandom_u32_max(100) < perc) {
 110                         switch (prandom_u32_max(4)) {
 111                         case 0:
 112                                 rds.block |= V4L2_RDS_BLOCK_CORRECTED;
 113                                 break;
 114                         case 1:
 115                                 rds.block |= V4L2_RDS_BLOCK_INVALID;
 116                                 break;
 117                         case 2:
 118                                 rds.block |= V4L2_RDS_BLOCK_ERROR;
 119                                 rds.lsb = prandom_u32_max(256);
 120                                 rds.msb = prandom_u32_max(256);
 121                                 break;
 122                         case 3: /* Skip block altogether */
 123                                 if (i)
 124                                         continue;
 125                                 /*
 126                                  * Must make sure at least one block is
 127                                  * returned, otherwise the application
 128                                  * might think that end-of-file occurred.
 129                                  */
 130                                 break;
 131                         }
 132                 }
 133                 if (copy_to_user(buf + i, &rds, sizeof(rds))) {
 134                         i = -EFAULT;
 135                         break;
 136                 }
 137                 i += sizeof(rds);
 138         }
 139         mutex_unlock(&dev->mutex);
 140         return i;
 141 }
 142
 143 __poll_t vivid_radio_rx_poll(struct file *file, struct poll_table_struct *wait)
 144 {
 145         return EPOLLIN | EPOLLRDNORM | v4l2_ctrl_poll(file, wait);
 146 }
 147
 148 int vivid_radio_rx_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)
 149 {
 150         if (band->tuner != 0)
 151                 return -EINVAL;
 152
 153         if (band->index >= TOT_BANDS)
 154                 return -EINVAL;
 155
 156         *band = vivid_radio_bands[band->index];
 157         return 0;
 158 }
 159
 160 int vivid_radio_rx_s_hw_freq_seek(struct file *file, void *fh, const struct v4l2_hw_freq_seek *a)
 161 {
 162         struct vivid_dev *dev = video_drvdata(file);
 163         unsigned low, high;
 164         unsigned freq;
 165         unsigned spacing;
 166         unsigned band;
 167
 168         if (a->tuner)
 169                 return -EINVAL;
 170         if (a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_BOUNDED)
 171                 return -EINVAL;
 172
 173         if (!a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_WRAP)
 174                 return -EINVAL;
 175         if (!a->rangelow ^ !a->rangehigh)
 176                 return -EINVAL;
 177
 178         if (file->f_flags & O_NONBLOCK)
 179                 return -EWOULDBLOCK;
 180
 181         if (a->rangelow) {
 182                 for (band = 0; band < TOT_BANDS; band++)
 183                         if (a->rangelow >= vivid_radio_bands[band].rangelow &&
 184                             a->rangehigh <= vivid_radio_bands[band].rangehigh)
 185                                 break;
 186                 if (band == TOT_BANDS)
 187                         return -EINVAL;
 188                 if (!dev->radio_rx_hw_seek_prog_lim &&
 189                     (a->rangelow != vivid_radio_bands[band].rangelow ||
 190                      a->rangehigh != vivid_radio_bands[band].rangehigh))
 191                         return -EINVAL;
 192                 low = a->rangelow;
 193                 high = a->rangehigh;
 194         } else {
 195                 for (band = 0; band < TOT_BANDS; band++)
 196                         if (dev->radio_rx_freq >= vivid_radio_bands[band].rangelow &&
 197                             dev->radio_rx_freq <= vivid_radio_bands[band].rangehigh)
 198                                 break;
 199                 if (band == TOT_BANDS)
 200                         return -EINVAL;
 201                 low = vivid_radio_bands[band].rangelow;
 202                 high = vivid_radio_bands[band].rangehigh;
 203         }
 204         spacing = band == BAND_AM ? 1600 : 16000;
 205         freq = clamp(dev->radio_rx_freq, low, high);
 206
 207         if (a->seek_upward) {
 208                 freq = spacing * (freq / spacing) + spacing;
 209                 if (freq > high) {
 210                         if (!a->wrap_around)
 211                                 return -ENODATA;
 212                         freq = spacing * (low / spacing) + spacing;
 213                         if (freq >= dev->radio_rx_freq)
 214                                 return -ENODATA;
 215                 }
 216         } else {
 217                 freq = spacing * ((freq + spacing - 1) / spacing) - spacing;
 218                 if (freq < low) {
 219                         if (!a->wrap_around)
 220                                 return -ENODATA;
 221                         freq = spacing * ((high + spacing - 1) / spacing) - spacing;
 222                         if (freq <= dev->radio_rx_freq)
 223                                 return -ENODATA;
 224                 }
 225         }
 226         return 0;
 227 }
 228
 229 int vivid_radio_rx_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
 230 {
 231         struct vivid_dev *dev = video_drvdata(file);
 232         int delta = 800;
 233         int sig_qual;
 234
 235         if (vt->index > 0)
 236                 return -EINVAL;
 237
 238         strlcpy(vt->name, "AM/FM/SW Receiver", sizeof(vt->name));
 239         vt->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
 240                          V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
 241                          (dev->radio_rx_rds_controls ?
 242                                 V4L2_TUNER_CAP_RDS_CONTROLS :
 243                                 V4L2_TUNER_CAP_RDS_BLOCK_IO) |
 244                          (dev->radio_rx_hw_seek_prog_lim ?
 245                                 V4L2_TUNER_CAP_HWSEEK_PROG_LIM : 0);
 246         switch (dev->radio_rx_hw_seek_mode) {
 247         case VIVID_HW_SEEK_BOUNDED:
 248                 vt->capability |= V4L2_TUNER_CAP_HWSEEK_BOUNDED;
 249                 break;
 250         case VIVID_HW_SEEK_WRAP:
 251                 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP;
 252                 break;
 253         case VIVID_HW_SEEK_BOTH:
 254                 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP |
 255                                   V4L2_TUNER_CAP_HWSEEK_BOUNDED;
 256                 break;
 257         }
 258         vt->rangelow = AM_FREQ_RANGE_LOW;
 259         vt->rangehigh = FM_FREQ_RANGE_HIGH;
 260         sig_qual = dev->radio_rx_sig_qual;
 261         vt->signal = abs(sig_qual) > delta ? 0 :
 262                      0xffff - (abs(sig_qual) * 0xffff) / delta;
 263         vt->afc = sig_qual > delta ? 0 : sig_qual;
 264         if (abs(sig_qual) > delta)
 265                 vt->rxsubchans = 0;
 266         else if (dev->radio_rx_freq < FM_FREQ_RANGE_LOW || vt->signal < 0x8000)
 267                 vt->rxsubchans = V4L2_TUNER_SUB_MONO;
 268         else if (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_STEREO))
 269                 vt->rxsubchans = V4L2_TUNER_SUB_MONO;
 270         else
 271                 vt->rxsubchans = V4L2_TUNER_SUB_STEREO;
 272         if (dev->radio_rx_rds_enabled &&
 273             (!dev->radio_rds_loop || (dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) &&
 274             dev->radio_rx_freq >= FM_FREQ_RANGE_LOW && vt->signal >= 0xc000)
 275                 vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
 276         if (dev->radio_rx_rds_controls)
 277                 vivid_radio_rds_init(dev);
 278         vt->audmode = dev->radio_rx_audmode;
 279         return 0;
 280 }
 281
 282 int vivid_radio_rx_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
 283 {
 284         struct vivid_dev *dev = video_drvdata(file);
 285
 286         if (vt->index)
 287                 return -EINVAL;
 288         dev->radio_rx_audmode = vt->audmode >= V4L2_TUNER_MODE_STEREO;
 289         return 0;
 290 }