/*
 * Framework for ISA radio drivers.
 * This takes care of all the V4L2 scaffolding, allowing the ISA drivers
 * to concentrate on the actual hardware operation.
 *
 * Copyright (C) 2012 Hans Verkuil <hans.verkuil@cisco.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>

#include "radio-isa.h"

MODULE_AUTHOR("Hans Verkuil");
MODULE_DESCRIPTION("A framework for ISA radio drivers.");
MODULE_LICENSE("GPL");

#define FREQ_LOW  (87U * 16000U)
#define FREQ_HIGH (108U * 16000U)

static int radio_isa_querycap(struct file *file, void  *priv,
					struct v4l2_capability *v)
{
	struct radio_isa_card *isa = video_drvdata(file);

	strlcpy(v->driver, isa->drv->driver.driver.name, sizeof(v->driver));
	strlcpy(v->card, isa->drv->card, sizeof(v->card));
	snprintf(v->bus_info, sizeof(v->bus_info), "ISA:%s", isa->v4l2_dev.name);

	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
	v->device_caps = v->capabilities | V4L2_CAP_DEVICE_CAPS;
	return 0;
}

static int radio_isa_g_tuner(struct file *file, void *priv,
				struct v4l2_tuner *v)
{
	struct radio_isa_card *isa = video_drvdata(file);
	const struct radio_isa_ops *ops = isa->drv->ops;

	if (v->index > 0)
		return -EINVAL;

	strlcpy(v->name, "FM", sizeof(v->name));
	v->type = V4L2_TUNER_RADIO;
	v->rangelow = FREQ_LOW;
	v->rangehigh = FREQ_HIGH;
	v->capability = V4L2_TUNER_CAP_LOW;
	if (isa->drv->has_stereo)
		v->capability |= V4L2_TUNER_CAP_STEREO;

	if (ops->g_rxsubchans)
		v->rxsubchans = ops->g_rxsubchans(isa);
	else
		v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
	v->audmode = isa->stereo ? V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
	if (ops->g_signal)
		v->signal = ops->g_signal(isa);
	else
		v->signal = (v->rxsubchans & V4L2_TUNER_SUB_STEREO) ?
								0xffff : 0;
	return 0;
}

static int radio_isa_s_tuner(struct file *file, void *priv,
				struct v4l2_tuner *v)
{
	struct radio_isa_card *isa = video_drvdata(file);
	const struct radio_isa_ops *ops = isa->drv->ops;

	if (v->index)
		return -EINVAL;
	if (ops->s_stereo) {
		isa->stereo = (v->audmode == V4L2_TUNER_MODE_STEREO);
		return ops->s_stereo(isa, isa->stereo);
	}
	return 0;
}

static int radio_isa_s_frequency(struct file *file, void *priv,
				struct v4l2_frequency *f)
{
	struct radio_isa_card *isa = video_drvdata(file);
	int res;

	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
		return -EINVAL;
	f->frequency = clamp(f->frequency, FREQ_LOW, FREQ_HIGH);
	res = isa->drv->ops->s_frequency(isa, f->frequency);
	if (res == 0)
		isa->freq = f->frequency;
	return res;
}

static int radio_isa_g_frequency(struct file *file, void *priv,
				struct v4l2_frequency *f)
{
	struct radio_isa_card *isa = video_drvdata(file);

	if (f->tuner != 0)
		return -EINVAL;
	f->type = V4L2_TUNER_RADIO;
	f->frequency = isa->freq;
	return 0;
}

static int radio_isa_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct radio_isa_card *isa =
		container_of(ctrl->handler, struct radio_isa_card, hdl);

	switch (ctrl->id) {
	case V4L2_CID_AUDIO_MUTE:
		return isa->drv->ops->s_mute_volume(isa, ctrl->val,
				isa->volume ? isa->volume->val : 0);
	}
	return -EINVAL;
}

static int radio_isa_log_status(struct file *file, void *priv)
{
	struct radio_isa_card *isa = video_drvdata(file);

	v4l2_info(&isa->v4l2_dev, "I/O Port = 0x%03x\n", isa->io);
	v4l2_ctrl_handler_log_status(&isa->hdl, isa->v4l2_dev.name);
	return 0;
}

static int radio_isa_subscribe_event(struct v4l2_fh *fh,
				struct v4l2_event_subscription *sub)
{
	if (sub->type == V4L2_EVENT_CTRL)
		return v4l2_event_subscribe(fh, sub, 0);
	return -EINVAL;
}

static const struct v4l2_ctrl_ops radio_isa_ctrl_ops = {
	.s_ctrl = radio_isa_s_ctrl,
};

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

static const struct v4l2_ioctl_ops radio_isa_ioctl_ops = {
	.vidioc_querycap    = radio_isa_querycap,
	.vidioc_g_tuner     = radio_isa_g_tuner,
	.vidioc_s_tuner     = radio_isa_s_tuner,
	.vidioc_g_frequency = radio_isa_g_frequency,
	.vidioc_s_frequency = radio_isa_s_frequency,
	.vidioc_log_status  = radio_isa_log_status,
	.vidioc_subscribe_event   = radio_isa_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

int radio_isa_match(struct device *pdev, unsigned int dev)
{
	struct radio_isa_driver *drv = pdev->platform_data;

	return drv->probe || drv->io_params[dev] >= 0;
}
EXPORT_SYMBOL_GPL(radio_isa_match);

static bool radio_isa_valid_io(const struct radio_isa_driver *drv, int io)
{
	int i;

	for (i = 0; i < drv->num_of_io_ports; i++)
		if (drv->io_ports[i] == io)
			return true;
	return false;
}

int radio_isa_probe(struct device *pdev, unsigned int dev)
{
	struct radio_isa_driver *drv = pdev->platform_data;
	const struct radio_isa_ops *ops = drv->ops;
	struct v4l2_device *v4l2_dev;
	struct radio_isa_card *isa;
	int res;

	isa = drv->ops->alloc();
	if (isa == NULL)
		return -ENOMEM;
	dev_set_drvdata(pdev, isa);
	isa->drv = drv;
	isa->io = drv->io_params[dev];
	v4l2_dev = &isa->v4l2_dev;
	strlcpy(v4l2_dev->name, dev_name(pdev), sizeof(v4l2_dev->name));

	if (drv->probe && ops->probe) {
		int i;

		for (i = 0; i < drv->num_of_io_ports; ++i) {
			int io = drv->io_ports[i];

			if (request_region(io, drv->region_size, v4l2_dev->name)) {
				bool found = ops->probe(isa, io);

				release_region(io, drv->region_size);
				if (found) {
					isa->io = io;
					break;
				}
			}
		}
	}

	if (!radio_isa_valid_io(drv, isa->io)) {
		int i;

		if (isa->io < 0)
			return -ENODEV;
		v4l2_err(v4l2_dev, "you must set an I/O address with io=0x%03x",
				drv->io_ports[0]);
		for (i = 1; i < drv->num_of_io_ports; i++)
			printk(KERN_CONT "/0x%03x", drv->io_ports[i]);
		printk(KERN_CONT ".\n");
		kfree(isa);
		return -EINVAL;
	}

	if (!request_region(isa->io, drv->region_size, v4l2_dev->name)) {
		v4l2_err(v4l2_dev, "port 0x%x already in use\n", isa->io);
		kfree(isa);
		return -EBUSY;
	}

	res = v4l2_device_register(pdev, v4l2_dev);
	if (res < 0) {
		v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
		goto err_dev_reg;
	}

	v4l2_ctrl_handler_init(&isa->hdl, 1);
	isa->mute = v4l2_ctrl_new_std(&isa->hdl, &radio_isa_ctrl_ops,
				V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
	if (drv->max_volume)
		isa->volume = v4l2_ctrl_new_std(&isa->hdl, &radio_isa_ctrl_ops,
			V4L2_CID_AUDIO_VOLUME, 0, drv->max_volume, 1,
			drv->max_volume);
	v4l2_dev->ctrl_handler = &isa->hdl;
	if (isa->hdl.error) {
		res = isa->hdl.error;
		v4l2_err(v4l2_dev, "Could not register controls\n");
		goto err_hdl;
	}
	if (drv->max_volume)
		v4l2_ctrl_cluster(2, &isa->mute);
	v4l2_dev->ctrl_handler = &isa->hdl;

	mutex_init(&isa->lock);
	isa->vdev.lock = &isa->lock;
	strlcpy(isa->vdev.name, v4l2_dev->name, sizeof(isa->vdev.name));
	isa->vdev.v4l2_dev = v4l2_dev;
	isa->vdev.fops = &radio_isa_fops;
	isa->vdev.ioctl_ops = &radio_isa_ioctl_ops;
	isa->vdev.release = video_device_release_empty;
	set_bit(V4L2_FL_USE_FH_PRIO, &isa->vdev.flags);
	video_set_drvdata(&isa->vdev, isa);
	isa->freq = FREQ_LOW;
	isa->stereo = drv->has_stereo;

	if (ops->init)
		res = ops->init(isa);
	if (!res)
		res = v4l2_ctrl_handler_setup(&isa->hdl);
	if (!res)
		res = ops->s_frequency(isa, isa->freq);
	if (!res && ops->s_stereo)
		res = ops->s_stereo(isa, isa->stereo);
	if (res < 0) {
		v4l2_err(v4l2_dev, "Could not setup card\n");
		goto err_node_reg;
	}
	res = video_register_device(&isa->vdev, VFL_TYPE_RADIO,
					drv->radio_nr_params[dev]);
	if (res < 0) {
		v4l2_err(v4l2_dev, "Could not register device node\n");
		goto err_node_reg;
	}

	v4l2_info(v4l2_dev, "Initialized radio card %s on port 0x%03x\n",
			drv->card, isa->io);
	return 0;

err_node_reg:
	v4l2_ctrl_handler_free(&isa->hdl);
err_hdl:
	v4l2_device_unregister(&isa->v4l2_dev);
err_dev_reg:
	release_region(isa->io, drv->region_size);
	kfree(isa);
	return res;
}
EXPORT_SYMBOL_GPL(radio_isa_probe);

int radio_isa_remove(struct device *pdev, unsigned int dev)
{
	struct radio_isa_card *isa = dev_get_drvdata(pdev);
	const struct radio_isa_ops *ops = isa->drv->ops;

	ops->s_mute_volume(isa, true, isa->volume ? isa->volume->cur.val : 0);
	video_unregister_device(&isa->vdev);
	v4l2_ctrl_handler_free(&isa->hdl);
	v4l2_device_unregister(&isa->v4l2_dev);
	release_region(isa->io, isa->drv->region_size);
	v4l2_info(&isa->v4l2_dev, "Removed radio card %s\n", isa->drv->card);
	kfree(isa);
	return 0;
}
EXPORT_SYMBOL_GPL(radio_isa_remove);