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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * drivers/media/radio/radio-si4713.c
 *
 * Platform Driver for Silicon Labs Si4713 FM Radio Transmitter:
 *
 * Copyright (c) 2008 Instituto Nokia de Tecnologia - INdT
 * Contact: Eduardo Valentin <eduardo.valentin@nokia.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <linux/slab.h>
#include <media/v4l2-device.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include "si4713.h"

/* module parameters */
static int radio_nr = -1;	/* radio device minor (-1 ==> auto assign) */
module_param(radio_nr, int, 0);
MODULE_PARM_DESC(radio_nr,
		 "Minor number for radio device (-1 ==> auto assign)");

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Eduardo Valentin <eduardo.valentin@nokia.com>");
MODULE_DESCRIPTION("Platform driver for Si4713 FM Radio Transmitter");
MODULE_VERSION("0.0.1");
MODULE_ALIAS("platform:radio-si4713");

/* Driver state struct */
struct radio_si4713_device {
	struct v4l2_device		v4l2_dev;
	struct video_device		radio_dev;
	struct mutex lock;
};

/* radio_si4713_fops - file operations interface */
static const struct v4l2_file_operations radio_si4713_fops = {
	.owner		= THIS_MODULE,
	.open = v4l2_fh_open,
	.release = v4l2_fh_release,
	.poll = v4l2_ctrl_poll,
	/* Note: locking is done at the subdev level in the i2c driver. */
	.unlocked_ioctl	= video_ioctl2,
};

/* Video4Linux Interface */

/* radio_si4713_querycap - query device capabilities */
static int radio_si4713_querycap(struct file *file, void *priv,
					struct v4l2_capability *capability)
{
	strscpy(capability->driver, "radio-si4713", sizeof(capability->driver));
	strscpy(capability->card, "Silicon Labs Si4713 Modulator",
		sizeof(capability->card));
	strscpy(capability->bus_info, "platform:radio-si4713",
		sizeof(capability->bus_info));
	return 0;
}

/*
 * v4l2 ioctl call backs.
 * we are just a wrapper for v4l2_sub_devs.
 */
static inline struct v4l2_device *get_v4l2_dev(struct file *file)
{
	return &((struct radio_si4713_device *)video_drvdata(file))->v4l2_dev;
}

static int radio_si4713_g_modulator(struct file *file, void *p,
				    struct v4l2_modulator *vm)
{
	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
					  g_modulator, vm);
}

static int radio_si4713_s_modulator(struct file *file, void *p,
				    const struct v4l2_modulator *vm)
{
	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
					  s_modulator, vm);
}

static int radio_si4713_g_frequency(struct file *file, void *p,
				    struct v4l2_frequency *vf)
{
	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
					  g_frequency, vf);
}

static int radio_si4713_s_frequency(struct file *file, void *p,
				    const struct v4l2_frequency *vf)
{
	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, tuner,
					  s_frequency, vf);
}

static long radio_si4713_default(struct file *file, void *p,
				 bool valid_prio, unsigned int cmd, void *arg)
{
	return v4l2_device_call_until_err(get_v4l2_dev(file), 0, core,
					  ioctl, cmd, arg);
}

static const struct v4l2_ioctl_ops radio_si4713_ioctl_ops = {
	.vidioc_querycap	= radio_si4713_querycap,
	.vidioc_g_modulator	= radio_si4713_g_modulator,
	.vidioc_s_modulator	= radio_si4713_s_modulator,
	.vidioc_g_frequency	= radio_si4713_g_frequency,
	.vidioc_s_frequency	= radio_si4713_s_frequency,
	.vidioc_log_status      = v4l2_ctrl_log_status,
	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
	.vidioc_default		= radio_si4713_default,
};

/* radio_si4713_vdev_template - video device interface */
static const struct video_device radio_si4713_vdev_template = {
	.fops			= &radio_si4713_fops,
	.name			= "radio-si4713",
	.release		= video_device_release_empty,
	.ioctl_ops		= &radio_si4713_ioctl_ops,
	.vfl_dir		= VFL_DIR_TX,
};

/* Platform driver interface */
/* radio_si4713_pdriver_probe - probe for the device */
static int radio_si4713_pdriver_probe(struct platform_device *pdev)
{
	struct radio_si4713_platform_data *pdata = pdev->dev.platform_data;
	struct radio_si4713_device *rsdev;
	struct v4l2_subdev *sd;
	int rval = 0;

	if (!pdata) {
		dev_err(&pdev->dev, "Cannot proceed without platform data.\n");
		rval = -EINVAL;
		goto exit;
	}

	rsdev = devm_kzalloc(&pdev->dev, sizeof(*rsdev), GFP_KERNEL);
	if (!rsdev) {
		dev_err(&pdev->dev, "Failed to alloc video device.\n");
		rval = -ENOMEM;
		goto exit;
	}
	mutex_init(&rsdev->lock);

	rval = v4l2_device_register(&pdev->dev, &rsdev->v4l2_dev);
	if (rval) {
		dev_err(&pdev->dev, "Failed to register v4l2 device.\n");
		goto exit;
	}

	sd = i2c_get_clientdata(pdata->subdev);
	rval = v4l2_device_register_subdev(&rsdev->v4l2_dev, sd);
	if (rval) {
		dev_err(&pdev->dev, "Cannot get v4l2 subdevice\n");
		goto unregister_v4l2_dev;
	}

	rsdev->radio_dev = radio_si4713_vdev_template;
	rsdev->radio_dev.v4l2_dev = &rsdev->v4l2_dev;
	rsdev->radio_dev.ctrl_handler = sd->ctrl_handler;
	/* Serialize all access to the si4713 */
	rsdev->radio_dev.lock = &rsdev->lock;
	rsdev->radio_dev.device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
	video_set_drvdata(&rsdev->radio_dev, rsdev);
	if (video_register_device(&rsdev->radio_dev, VFL_TYPE_RADIO, radio_nr)) {
		dev_err(&pdev->dev, "Could not register video device.\n");
		rval = -EIO;
		goto unregister_v4l2_dev;
	}
	dev_info(&pdev->dev, "New device successfully probed\n");

	goto exit;

unregister_v4l2_dev:
	v4l2_device_unregister(&rsdev->v4l2_dev);
exit:
	return rval;
}

/* radio_si4713_pdriver_remove - remove the device */
static void radio_si4713_pdriver_remove(struct platform_device *pdev)
{
	struct v4l2_device *v4l2_dev = platform_get_drvdata(pdev);
	struct radio_si4713_device *rsdev;

	rsdev = container_of(v4l2_dev, struct radio_si4713_device, v4l2_dev);
	video_unregister_device(&rsdev->radio_dev);
	v4l2_device_unregister(&rsdev->v4l2_dev);
}

static struct platform_driver radio_si4713_pdriver = {
	.driver		= {
		.name	= "radio-si4713",
	},
	.probe		= radio_si4713_pdriver_probe,
	.remove_new     = radio_si4713_pdriver_remove,
};

module_platform_driver(radio_si4713_pdriver);