drivers/media/radio/si4713/radio-platform-si4713.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/media/radio/radio-si4713.c
   4  *
   5  * Platform Driver for Silicon Labs Si4713 FM Radio Transmitter:
   6  *
   7  * Copyright (c) 2008 Instituto Nokia de Tecnologia - INdT
   8  * Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/i2c.h>
  16 #include <linux/videodev2.h>
  17 #include <linux/slab.h>
  18 #include <media/v4l2-device.h>
  19 #include <media/v4l2-common.h>
  20 #include <media/v4l2-ioctl.h>
  21 #include <media/v4l2-fh.h>
  22 #include <media/v4l2-ctrls.h>
  23 #include <media/v4l2-event.h>
  24 #include "si4713.h"
  25
  26 /* module parameters */
  27 static int radio_nr = -1;       /* radio device minor (-1 ==> auto assign) */
  28 module_param(radio_nr, int, 0);
  29 MODULE_PARM_DESC(radio_nr,
  30                  "Minor number for radio device (-1 ==> auto assign)");
  31
  32 MODULE_LICENSE("GPL v2");
  33 MODULE_AUTHOR("Eduardo Valentin <eduardo.valentin@nokia.com>");
  34 MODULE_DESCRIPTION("Platform driver for Si4713 FM Radio Transmitter");
  35 MODULE_VERSION("0.0.1");
  36 MODULE_ALIAS("platform:radio-si4713");
  37
  38 /* Driver state struct */
  39 struct radio_si4713_device {
  40         struct v4l2_device              v4l2_dev;
  41         struct video_device             radio_dev;
  42         struct mutex lock;
  43 };
  44
  45 /* radio_si4713_fops - file operations interface */
  46 static const struct v4l2_file_operations radio_si4713_fops = {
  47         .owner          = THIS_MODULE,
  48         .open = v4l2_fh_open,
  49         .release = v4l2_fh_release,
  50         .poll = v4l2_ctrl_poll,
  51         /* Note: locking is done at the subdev level in the i2c driver. */
  52         .unlocked_ioctl = video_ioctl2,
  53 };
  54
  55 /* Video4Linux Interface */
  56
  57 /* radio_si4713_querycap - query device capabilities */
  58 static int radio_si4713_querycap(struct file *file, void *priv,
  59                                         struct v4l2_capability *capability)
  60 {
  61         strscpy(capability->driver, "radio-si4713", sizeof(capability->driver));
  62         strscpy(capability->card, "Silicon Labs Si4713 Modulator",
  63                 sizeof(capability->card));
  64         strscpy(capability->bus_info, "platform:radio-si4713",
  65                 sizeof(capability->bus_info));
  66         return 0;
  67 }
  68
  69 /*
  70  * v4l2 ioctl call backs.
  71  * we are just a wrapper for v4l2_sub_devs.
  72  */
  73 static inline struct v4l2_device *get_v4l2_dev(struct file *file)
  74 {
  75         return &((struct radio_si4713_device *)video_drvdata(file))->v4l2_dev;
  76 }
  77
  78 static int radio_si4713_g_modulator(struct file *file, void *p,
  79                                     struct v4l2_modulator *vm)
  80 {
  81         return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
  82                                           g_modulator, vm);
  83 }
  84
  85 static int radio_si4713_s_modulator(struct file *file, void *p,
  86                                     const struct v4l2_modulator *vm)
  87 {
  88         return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
  89                                           s_modulator, vm);
  90 }
  91
  92 static int radio_si4713_g_frequency(struct file *file, void *p,
  93                                     struct v4l2_frequency *vf)
  94 {
  95         return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
  96                                           g_frequency, vf);
  97 }
  98
  99 static int radio_si4713_s_frequency(struct file *file, void *p,
 100                                     const struct v4l2_frequency *vf)
 101 {
 102         return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
 103                                           s_frequency, vf);
 104 }
 105
 106 static long radio_si4713_default(struct file *file, void *p,
 107                                  bool valid_prio, unsigned int cmd, void *arg)
 108 {
 109         return v4l2_device_call_until_err(get_v4l2_dev(file), 0, core,
 110                                           ioctl, cmd, arg);
 111 }
 112
 113 static const struct v4l2_ioctl_ops radio_si4713_ioctl_ops = {
 114         .vidioc_querycap        = radio_si4713_querycap,
 115         .vidioc_g_modulator     = radio_si4713_g_modulator,
 116         .vidioc_s_modulator     = radio_si4713_s_modulator,
 117         .vidioc_g_frequency     = radio_si4713_g_frequency,
 118         .vidioc_s_frequency     = radio_si4713_s_frequency,
 119         .vidioc_log_status      = v4l2_ctrl_log_status,
 120         .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
 121         .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
 122         .vidioc_default         = radio_si4713_default,
 123 };
 124
 125 /* radio_si4713_vdev_template - video device interface */
 126 static const struct video_device radio_si4713_vdev_template = {
 127         .fops                   = &radio_si4713_fops,
 128         .name                   = "radio-si4713",
 129         .release                = video_device_release_empty,
 130         .ioctl_ops              = &radio_si4713_ioctl_ops,
 131         .vfl_dir                = VFL_DIR_TX,
 132 };
 133
 134 /* Platform driver interface */
 135 /* radio_si4713_pdriver_probe - probe for the device */
 136 static int radio_si4713_pdriver_probe(struct platform_device *pdev)
 137 {
 138         struct radio_si4713_platform_data *pdata = pdev->dev.platform_data;
 139         struct radio_si4713_device *rsdev;
 140         struct v4l2_subdev *sd;
 141         int rval = 0;
 142
 143         if (!pdata) {
 144                 dev_err(&pdev->dev, "Cannot proceed without platform data.\n");
 145                 rval = -EINVAL;
 146                 goto exit;
 147         }
 148
 149         rsdev = devm_kzalloc(&pdev->dev, sizeof(*rsdev), GFP_KERNEL);
 150         if (!rsdev) {
 151                 dev_err(&pdev->dev, "Failed to alloc video device.\n");
 152                 rval = -ENOMEM;
 153                 goto exit;
 154         }
 155         mutex_init(&rsdev->lock);
 156
 157         rval = v4l2_device_register(&pdev->dev, &rsdev->v4l2_dev);
 158         if (rval) {
 159                 dev_err(&pdev->dev, "Failed to register v4l2 device.\n");
 160                 goto exit;
 161         }
 162
 163         sd = i2c_get_clientdata(pdata->subdev);
 164         rval = v4l2_device_register_subdev(&rsdev->v4l2_dev, sd);
 165         if (rval) {
 166                 dev_err(&pdev->dev, "Cannot get v4l2 subdevice\n");
 167                 goto unregister_v4l2_dev;
 168         }
 169
 170         rsdev->radio_dev = radio_si4713_vdev_template;
 171         rsdev->radio_dev.v4l2_dev = &rsdev->v4l2_dev;
 172         rsdev->radio_dev.ctrl_handler = sd->ctrl_handler;
 173         /* Serialize all access to the si4713 */
 174         rsdev->radio_dev.lock = &rsdev->lock;
 175         rsdev->radio_dev.device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
 176         video_set_drvdata(&rsdev->radio_dev, rsdev);
 177         if (video_register_device(&rsdev->radio_dev, VFL_TYPE_RADIO, radio_nr)) {
 178                 dev_err(&pdev->dev, "Could not register video device.\n");
 179                 rval = -EIO;
 180                 goto unregister_v4l2_dev;
 181         }
 182         dev_info(&pdev->dev, "New device successfully probed\n");
 183
 184         goto exit;
 185
 186 unregister_v4l2_dev:
 187         v4l2_device_unregister(&rsdev->v4l2_dev);
 188 exit:
 189         return rval;
 190 }
 191
 192 /* radio_si4713_pdriver_remove - remove the device */
 193 static void radio_si4713_pdriver_remove(struct platform_device *pdev)
 194 {
 195         struct v4l2_device *v4l2_dev = platform_get_drvdata(pdev);
 196         struct radio_si4713_device *rsdev;
 197
 198         rsdev = container_of(v4l2_dev, struct radio_si4713_device, v4l2_dev);
 199         video_unregister_device(&rsdev->radio_dev);
 200         v4l2_device_unregister(&rsdev->v4l2_dev);
 201 }
 202
 203 static struct platform_driver radio_si4713_pdriver = {
 204         .driver         = {
 205                 .name   = "radio-si4713",
 206         },
 207         .probe          = radio_si4713_pdriver_probe,
 208         .remove         = radio_si4713_pdriver_remove,
 209 };
 210
 211 module_platform_driver(radio_si4713_pdriver);