kernel/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 <media/v4l2-common.h>
  26 #include <media/v4l2-event.h>
  27 #include <media/v4l2-dv-timings.h>
  28
  29 #include "vivid-core.h"
  30 #include "vivid-ctrls.h"
  31 #include "vivid-radio-common.h"
  32 #include "vivid-rds-gen.h"
  33 #include "vivid-radio-rx.h"
  34
  35 ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
  36                          size_t size, loff_t *offset)
  37 {
  38         struct vivid_dev *dev = video_drvdata(file);
  39         struct timespec ts;
  40         struct v4l2_rds_data *data = dev->rds_gen.data;
  41         bool use_alternates;
  42         unsigned blk;
  43         int perc;
  44         int i;
  45
  46         if (dev->radio_rx_rds_controls)
  47                 return -EINVAL;
  48         if (size < sizeof(*data))
  49                 return 0;
  50         size = sizeof(*data) * (size / sizeof(*data));
  51
  52         if (mutex_lock_interruptible(&dev->mutex))
  53                 return -ERESTARTSYS;
  54         if (dev->radio_rx_rds_owner &&
  55             file->private_data != dev->radio_rx_rds_owner) {
  56                 mutex_unlock(&dev->mutex);
  57                 return -EBUSY;
  58         }
  59         if (dev->radio_rx_rds_owner == NULL) {
  60                 vivid_radio_rds_init(dev);
  61                 dev->radio_rx_rds_owner = file->private_data;
  62         }
  63
  64 retry:
  65         ktime_get_ts(&ts);
  66         use_alternates = ts.tv_sec % 10 >= 5;
  67         if (dev->radio_rx_rds_last_block == 0 ||
  68             dev->radio_rx_rds_use_alternates != use_alternates) {
  69                 dev->radio_rx_rds_use_alternates = use_alternates;
  70                 /* Re-init the RDS generator */
  71                 vivid_radio_rds_init(dev);
  72         }
  73         ts = timespec_sub(ts, dev->radio_rds_init_ts);
  74         blk = ts.tv_sec * 100 + ts.tv_nsec / 10000000;
  75         blk = (blk * VIVID_RDS_GEN_BLOCKS) / 500;
  76         if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)
  77                 dev->radio_rx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
  78
  79         /*
  80          * No data is available if there hasn't been time to get new data,
  81          * or if the RDS receiver has been disabled, or if we use the data
  82          * from the RDS transmitter and that RDS transmitter has been disabled,
  83          * or if the signal quality is too weak.
  84          */
  85         if (blk == dev->radio_rx_rds_last_block || !dev->radio_rx_rds_enabled ||
  86             (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) ||
  87             abs(dev->radio_rx_sig_qual) > 200) {
  88                 mutex_unlock(&dev->mutex);
  89                 if (file->f_flags & O_NONBLOCK)
  90                         return -EWOULDBLOCK;
  91                 if (msleep_interruptible(20) && signal_pending(current))
  92                         return -EINTR;
  93                 if (mutex_lock_interruptible(&dev->mutex))
  94                         return -ERESTARTSYS;
  95                 goto retry;
  96         }
  97
  98         /* abs(dev->radio_rx_sig_qual) <= 200, map that to a 0-50% range */
  99         perc = abs(dev->radio_rx_sig_qual) / 4;
 100
 101         for (i = 0; i < size && blk > dev->radio_rx_rds_last_block;
 102                         dev->radio_rx_rds_last_block++) {
 103                 unsigned data_blk = dev->radio_rx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
 104                 struct v4l2_rds_data rds = data[data_blk];
 105
 106                 if (data_blk == 0 && dev->radio_rds_loop)
 107                         vivid_radio_rds_init(dev);
 108                 if (perc && prandom_u32_max(100) < perc) {
 109                         switch (prandom_u32_max(4)) {
 110                         case 0:
 111                                 rds.block |= V4L2_RDS_BLOCK_CORRECTED;
 112                                 break;
 113                         case 1:
 114                                 rds.block |= V4L2_RDS_BLOCK_INVALID;
 115                                 break;
 116                         case 2:
 117                                 rds.block |= V4L2_RDS_BLOCK_ERROR;
 118                                 rds.lsb = prandom_u32_max(256);
 119                                 rds.msb = prandom_u32_max(256);
 120                                 break;
 121                         case 3: /* Skip block altogether */
 122                                 if (i)
 123                                         continue;
 124                                 /*
 125                                  * Must make sure at least one block is
 126                                  * returned, otherwise the application
 127                                  * might think that end-of-file occurred.
 128                                  */
 129                                 break;
 130                         }
 131                 }
 132                 if (copy_to_user(buf + i, &rds, sizeof(rds))) {
 133                         i = -EFAULT;
 134                         break;
 135                 }
 136                 i += sizeof(rds);
 137         }
 138         mutex_unlock(&dev->mutex);
 139         return i;
 140 }
 141
 142 unsigned int vivid_radio_rx_poll(struct file *file, struct poll_table_struct *wait)
 143 {
 144         return POLLIN | POLLRDNORM | v4l2_ctrl_poll(file, wait);
 145 }
 146
 147 int vivid_radio_rx_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)
 148 {
 149         if (band->tuner != 0)
 150                 return -EINVAL;
 151
 152         if (band->index >= TOT_BANDS)
 153                 return -EINVAL;
 154
 155         *band = vivid_radio_bands[band->index];
 156         return 0;
 157 }
 158
 159 int vivid_radio_rx_s_hw_freq_seek(struct file *file, void *fh, const struct v4l2_hw_freq_seek *a)
 160 {
 161         struct vivid_dev *dev = video_drvdata(file);
 162         unsigned low, high;
 163         unsigned freq;
 164         unsigned spacing;
 165         unsigned band;
 166
 167         if (a->tuner)
 168                 return -EINVAL;
 169         if (a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_BOUNDED)
 170                 return -EINVAL;
 171
 172         if (!a->wrap_around && dev->radio_rx_hw_seek_mode == VIVID_HW_SEEK_WRAP)
 173                 return -EINVAL;
 174         if (!a->rangelow ^ !a->rangehigh)
 175                 return -EINVAL;
 176
 177         if (file->f_flags & O_NONBLOCK)
 178                 return -EWOULDBLOCK;
 179
 180         if (a->rangelow) {
 181                 for (band = 0; band < TOT_BANDS; band++)
 182                         if (a->rangelow >= vivid_radio_bands[band].rangelow &&
 183                             a->rangehigh <= vivid_radio_bands[band].rangehigh)
 184                                 break;
 185                 if (band == TOT_BANDS)
 186                         return -EINVAL;
 187                 if (!dev->radio_rx_hw_seek_prog_lim &&
 188                     (a->rangelow != vivid_radio_bands[band].rangelow ||
 189                      a->rangehigh != vivid_radio_bands[band].rangehigh))
 190                         return -EINVAL;
 191                 low = a->rangelow;
 192                 high = a->rangehigh;
 193         } else {
 194                 for (band = 0; band < TOT_BANDS; band++)
 195                         if (dev->radio_rx_freq >= vivid_radio_bands[band].rangelow &&
 196                             dev->radio_rx_freq <= vivid_radio_bands[band].rangehigh)
 197                                 break;
 198                 low = vivid_radio_bands[band].rangelow;
 199                 high = vivid_radio_bands[band].rangehigh;
 200         }
 201         spacing = band == BAND_AM ? 1600 : 16000;
 202         freq = clamp(dev->radio_rx_freq, low, high);
 203
 204         if (a->seek_upward) {
 205                 freq = spacing * (freq / spacing) + spacing;
 206                 if (freq > high) {
 207                         if (!a->wrap_around)
 208                                 return -ENODATA;
 209                         freq = spacing * (low / spacing) + spacing;
 210                         if (freq >= dev->radio_rx_freq)
 211                                 return -ENODATA;
 212                 }
 213         } else {
 214                 freq = spacing * ((freq + spacing - 1) / spacing) - spacing;
 215                 if (freq < low) {
 216                         if (!a->wrap_around)
 217                                 return -ENODATA;
 218                         freq = spacing * ((high + spacing - 1) / spacing) - spacing;
 219                         if (freq <= dev->radio_rx_freq)
 220                                 return -ENODATA;
 221                 }
 222         }
 223         return 0;
 224 }
 225
 226 int vivid_radio_rx_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
 227 {
 228         struct vivid_dev *dev = video_drvdata(file);
 229         int delta = 800;
 230         int sig_qual;
 231
 232         if (vt->index > 0)
 233                 return -EINVAL;
 234
 235         strlcpy(vt->name, "AM/FM/SW Receiver", sizeof(vt->name));
 236         vt->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
 237                          V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
 238                          (dev->radio_rx_rds_controls ?
 239                                 V4L2_TUNER_CAP_RDS_CONTROLS :
 240                                 V4L2_TUNER_CAP_RDS_BLOCK_IO) |
 241                          (dev->radio_rx_hw_seek_prog_lim ?
 242                                 V4L2_TUNER_CAP_HWSEEK_PROG_LIM : 0);
 243         switch (dev->radio_rx_hw_seek_mode) {
 244         case VIVID_HW_SEEK_BOUNDED:
 245                 vt->capability |= V4L2_TUNER_CAP_HWSEEK_BOUNDED;
 246                 break;
 247         case VIVID_HW_SEEK_WRAP:
 248                 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP;
 249                 break;
 250         case VIVID_HW_SEEK_BOTH:
 251                 vt->capability |= V4L2_TUNER_CAP_HWSEEK_WRAP |
 252                                   V4L2_TUNER_CAP_HWSEEK_BOUNDED;
 253                 break;
 254         }
 255         vt->rangelow = AM_FREQ_RANGE_LOW;
 256         vt->rangehigh = FM_FREQ_RANGE_HIGH;
 257         sig_qual = dev->radio_rx_sig_qual;
 258         vt->signal = abs(sig_qual) > delta ? 0 :
 259                      0xffff - (abs(sig_qual) * 0xffff) / delta;
 260         vt->afc = sig_qual > delta ? 0 : sig_qual;
 261         if (abs(sig_qual) > delta)
 262                 vt->rxsubchans = 0;
 263         else if (dev->radio_rx_freq < FM_FREQ_RANGE_LOW || vt->signal < 0x8000)
 264                 vt->rxsubchans = V4L2_TUNER_SUB_MONO;
 265         else if (dev->radio_rds_loop && !(dev->radio_tx_subchans & V4L2_TUNER_SUB_STEREO))
 266                 vt->rxsubchans = V4L2_TUNER_SUB_MONO;
 267         else
 268                 vt->rxsubchans = V4L2_TUNER_SUB_STEREO;
 269         if (dev->radio_rx_rds_enabled &&
 270             (!dev->radio_rds_loop || (dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) &&
 271             dev->radio_rx_freq >= FM_FREQ_RANGE_LOW && vt->signal >= 0xc000)
 272                 vt->rxsubchans |= V4L2_TUNER_SUB_RDS;
 273         if (dev->radio_rx_rds_controls)
 274                 vivid_radio_rds_init(dev);
 275         vt->audmode = dev->radio_rx_audmode;
 276         return 0;
 277 }
 278
 279 int vivid_radio_rx_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
 280 {
 281         struct vivid_dev *dev = video_drvdata(file);
 282
 283         if (vt->index)
 284                 return -EINVAL;
 285         dev->radio_rx_audmode = vt->audmode >= V4L2_TUNER_MODE_STEREO;
 286         return 0;
 287 }