linux/drivers/media/radio/si4713/radio-platform-si4713.c
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   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 */
  27static int radio_nr = -1;       /* radio device minor (-1 ==> auto assign) */
  28module_param(radio_nr, int, 0);
  29MODULE_PARM_DESC(radio_nr,
  30                 "Minor number for radio device (-1 ==> auto assign)");
  31
  32MODULE_LICENSE("GPL v2");
  33MODULE_AUTHOR("Eduardo Valentin <eduardo.valentin@nokia.com>");
  34MODULE_DESCRIPTION("Platform driver for Si4713 FM Radio Transmitter");
  35MODULE_VERSION("0.0.1");
  36MODULE_ALIAS("platform:radio-si4713");
  37
  38/* Driver state struct */
  39struct 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 */
  46static 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 */
  58static 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 */
  73static inline struct v4l2_device *get_v4l2_dev(struct file *file)
  74{
  75        return &((struct radio_si4713_device *)video_drvdata(file))->v4l2_dev;
  76}
  77
  78static 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
  85static 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
  92static 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
  99static 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
 106static 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
 113static 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 */
 126static 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 */
 136static 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
 186unregister_v4l2_dev:
 187        v4l2_device_unregister(&rsdev->v4l2_dev);
 188exit:
 189        return rval;
 190}
 191
 192/* radio_si4713_pdriver_remove - remove the device */
 193static int 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        return 0;
 203}
 204
 205static struct platform_driver radio_si4713_pdriver = {
 206        .driver         = {
 207                .name   = "radio-si4713",
 208        },
 209        .probe          = radio_si4713_pdriver_probe,
 210        .remove         = radio_si4713_pdriver_remove,
 211};
 212
 213module_platform_driver(radio_si4713_pdriver);
 214