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

   1 /*
   2  * vivid-radio-tx.c - radio transmitter 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/sched/signal.h>
  23 #include <linux/delay.h>
  24 #include <linux/videodev2.h>
  25 #include <linux/v4l2-dv-timings.h>
  26 #include <media/v4l2-common.h>
  27 #include <media/v4l2-event.h>
  28 #include <media/v4l2-dv-timings.h>
  29
  30 #include "vivid-core.h"
  31 #include "vivid-ctrls.h"
  32 #include "vivid-radio-common.h"
  33 #include "vivid-radio-tx.h"
  34
  35 ssize_t vivid_radio_tx_write(struct file *file, const char __user *buf,
  36                           size_t size, loff_t *offset)
  37 {
  38         struct vivid_dev *dev = video_drvdata(file);
  39         struct v4l2_rds_data *data = dev->rds_gen.data;
  40         ktime_t timestamp;
  41         unsigned blk;
  42         int i;
  43
  44         if (dev->radio_tx_rds_controls)
  45                 return -EINVAL;
  46
  47         if (size < sizeof(*data))
  48                 return -EINVAL;
  49         size = sizeof(*data) * (size / sizeof(*data));
  50
  51         if (mutex_lock_interruptible(&dev->mutex))
  52                 return -ERESTARTSYS;
  53         if (dev->radio_tx_rds_owner &&
  54             file->private_data != dev->radio_tx_rds_owner) {
  55                 mutex_unlock(&dev->mutex);
  56                 return -EBUSY;
  57         }
  58         dev->radio_tx_rds_owner = file->private_data;
  59
  60 retry:
  61         timestamp = ktime_sub(ktime_get(), dev->radio_rds_init_time);
  62         blk = ktime_divns(timestamp, VIVID_RDS_NSEC_PER_BLK);
  63         if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
  64                 dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
  65
  66         /*
  67          * No data is available if there hasn't been time to get new data,
  68          * or if the RDS receiver has been disabled, or if we use the data
  69          * from the RDS transmitter and that RDS transmitter has been disabled,
  70          * or if the signal quality is too weak.
  71          */
  72         if (blk == dev->radio_tx_rds_last_block ||
  73             !(dev->radio_tx_subchans & V4L2_TUNER_SUB_RDS)) {
  74                 mutex_unlock(&dev->mutex);
  75                 if (file->f_flags & O_NONBLOCK)
  76                         return -EWOULDBLOCK;
  77                 if (msleep_interruptible(20) && signal_pending(current))
  78                         return -EINTR;
  79                 if (mutex_lock_interruptible(&dev->mutex))
  80                         return -ERESTARTSYS;
  81                 goto retry;
  82         }
  83
  84         for (i = 0; i < size && blk > dev->radio_tx_rds_last_block;
  85                         dev->radio_tx_rds_last_block++) {
  86                 unsigned data_blk = dev->radio_tx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
  87                 struct v4l2_rds_data rds;
  88
  89                 if (copy_from_user(&rds, buf + i, sizeof(rds))) {
  90                         i = -EFAULT;
  91                         break;
  92                 }
  93                 i += sizeof(rds);
  94                 if (!dev->radio_rds_loop)
  95                         continue;
  96                 if ((rds.block & V4L2_RDS_BLOCK_MSK) == V4L2_RDS_BLOCK_INVALID ||
  97                     (rds.block & V4L2_RDS_BLOCK_ERROR))
  98                         continue;
  99                 rds.block &= V4L2_RDS_BLOCK_MSK;
 100                 data[data_blk] = rds;
 101         }
 102         mutex_unlock(&dev->mutex);
 103         return i;
 104 }
 105
 106 __poll_t vivid_radio_tx_poll(struct file *file, struct poll_table_struct *wait)
 107 {
 108         return POLLOUT | POLLWRNORM | v4l2_ctrl_poll(file, wait);
 109 }
 110
 111 int vidioc_g_modulator(struct file *file, void *fh, struct v4l2_modulator *a)
 112 {
 113         struct vivid_dev *dev = video_drvdata(file);
 114
 115         if (a->index > 0)
 116                 return -EINVAL;
 117
 118         strlcpy(a->name, "AM/FM/SW Transmitter", sizeof(a->name));
 119         a->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
 120                         V4L2_TUNER_CAP_FREQ_BANDS | V4L2_TUNER_CAP_RDS |
 121                         (dev->radio_tx_rds_controls ?
 122                                 V4L2_TUNER_CAP_RDS_CONTROLS :
 123                                 V4L2_TUNER_CAP_RDS_BLOCK_IO);
 124         a->rangelow = AM_FREQ_RANGE_LOW;
 125         a->rangehigh = FM_FREQ_RANGE_HIGH;
 126         a->txsubchans = dev->radio_tx_subchans;
 127         return 0;
 128 }
 129
 130 int vidioc_s_modulator(struct file *file, void *fh, const struct v4l2_modulator *a)
 131 {
 132         struct vivid_dev *dev = video_drvdata(file);
 133
 134         if (a->index)
 135                 return -EINVAL;
 136         if (a->txsubchans & ~0x13)
 137                 return -EINVAL;
 138         dev->radio_tx_subchans = a->txsubchans;
 139         return 0;
 140 }