root/drivers/media/radio/radio-timb.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * radio-timb.c Timberdale FPGA Radio driver
 * Copyright (c) 2009 Intel Corporation
 */

#include <linux/io.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/platform_data/media/timb_radio.h>

#define DRIVER_NAME "timb-radio"

struct timbradio {
        struct timb_radio_platform_data pdata;
        struct v4l2_subdev      *sd_tuner;
        struct v4l2_subdev      *sd_dsp;
        struct video_device     video_dev;
        struct v4l2_device      v4l2_dev;
        struct mutex            lock;
};


static int timbradio_vidioc_querycap(struct file *file, void  *priv,
        struct v4l2_capability *v)
{
        strscpy(v->driver, DRIVER_NAME, sizeof(v->driver));
        strscpy(v->card, "Timberdale Radio", sizeof(v->card));
        snprintf(v->bus_info, sizeof(v->bus_info), "platform:"DRIVER_NAME);
        return 0;
}

static int timbradio_vidioc_g_tuner(struct file *file, void *priv,
        struct v4l2_tuner *v)
{
        struct timbradio *tr = video_drvdata(file);
        return v4l2_subdev_call(tr->sd_tuner, tuner, g_tuner, v);
}

static int timbradio_vidioc_s_tuner(struct file *file, void *priv,
        const struct v4l2_tuner *v)
{
        struct timbradio *tr = video_drvdata(file);
        return v4l2_subdev_call(tr->sd_tuner, tuner, s_tuner, v);
}

static int timbradio_vidioc_s_frequency(struct file *file, void *priv,
        const struct v4l2_frequency *f)
{
        struct timbradio *tr = video_drvdata(file);
        return v4l2_subdev_call(tr->sd_tuner, tuner, s_frequency, f);
}

static int timbradio_vidioc_g_frequency(struct file *file, void *priv,
        struct v4l2_frequency *f)
{
        struct timbradio *tr = video_drvdata(file);
        return v4l2_subdev_call(tr->sd_tuner, tuner, g_frequency, f);
}

static const struct v4l2_ioctl_ops timbradio_ioctl_ops = {
        .vidioc_querycap        = timbradio_vidioc_querycap,
        .vidioc_g_tuner         = timbradio_vidioc_g_tuner,
        .vidioc_s_tuner         = timbradio_vidioc_s_tuner,
        .vidioc_g_frequency     = timbradio_vidioc_g_frequency,
        .vidioc_s_frequency     = timbradio_vidioc_s_frequency,
        .vidioc_log_status      = v4l2_ctrl_log_status,
        .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct v4l2_file_operations timbradio_fops = {
        .owner          = THIS_MODULE,
        .open           = v4l2_fh_open,
        .release        = v4l2_fh_release,
        .poll           = v4l2_ctrl_poll,
        .unlocked_ioctl = video_ioctl2,
};

static int timbradio_probe(struct platform_device *pdev)
{
        struct timb_radio_platform_data *pdata = pdev->dev.platform_data;
        struct timbradio *tr;
        int err;

        if (!pdata) {
                dev_err(&pdev->dev, "Platform data missing\n");
                err = -EINVAL;
                goto err;
        }

        tr = devm_kzalloc(&pdev->dev, sizeof(*tr), GFP_KERNEL);
        if (!tr) {
                err = -ENOMEM;
                goto err;
        }

        tr->pdata = *pdata;
        mutex_init(&tr->lock);

        strscpy(tr->video_dev.name, "Timberdale Radio",
                sizeof(tr->video_dev.name));
        tr->video_dev.fops = &timbradio_fops;
        tr->video_dev.ioctl_ops = &timbradio_ioctl_ops;
        tr->video_dev.release = video_device_release_empty;
        tr->video_dev.minor = -1;
        tr->video_dev.lock = &tr->lock;
        tr->video_dev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;

        strscpy(tr->v4l2_dev.name, DRIVER_NAME, sizeof(tr->v4l2_dev.name));
        err = v4l2_device_register(NULL, &tr->v4l2_dev);
        if (err)
                goto err;

        tr->video_dev.v4l2_dev = &tr->v4l2_dev;

        tr->sd_tuner = v4l2_i2c_new_subdev_board(&tr->v4l2_dev,
                i2c_get_adapter(pdata->i2c_adapter), pdata->tuner, NULL);
        tr->sd_dsp = v4l2_i2c_new_subdev_board(&tr->v4l2_dev,
                i2c_get_adapter(pdata->i2c_adapter), pdata->dsp, NULL);
        if (tr->sd_tuner == NULL || tr->sd_dsp == NULL) {
                err = -ENODEV;
                goto err_video_req;
        }

        tr->v4l2_dev.ctrl_handler = tr->sd_dsp->ctrl_handler;

        err = video_register_device(&tr->video_dev, VFL_TYPE_RADIO, -1);
        if (err) {
                dev_err(&pdev->dev, "Error reg video\n");
                goto err_video_req;
        }

        video_set_drvdata(&tr->video_dev, tr);

        platform_set_drvdata(pdev, tr);
        return 0;

err_video_req:
        v4l2_device_unregister(&tr->v4l2_dev);
err:
        dev_err(&pdev->dev, "Failed to register: %d\n", err);

        return err;
}

static void timbradio_remove(struct platform_device *pdev)
{
        struct timbradio *tr = platform_get_drvdata(pdev);

        video_unregister_device(&tr->video_dev);
        v4l2_device_unregister(&tr->v4l2_dev);
}

static struct platform_driver timbradio_platform_driver = {
        .driver = {
                .name   = DRIVER_NAME,
        },
        .probe          = timbradio_probe,
        .remove         = timbradio_remove,
};

module_platform_driver(timbradio_platform_driver);

MODULE_DESCRIPTION("Timberdale Radio driver");
MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("0.0.2");
MODULE_ALIAS("platform:"DRIVER_NAME);