/*
 * 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>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#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));
        capability->device_caps = V4L2_CAP_MODULATOR | V4L2_CAP_RDS_OUTPUT;
        capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS;

        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 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;
        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 int 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);

        return 0;
}

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

module_platform_driver(radio_si4713_pdriver);