/*
 * Driver for Renesas R-Car VIN
 *
 * Copyright (C) 2016 Renesas Electronics Corp.
 * Copyright (C) 2011-2013 Renesas Solutions Corp.
 * Copyright (C) 2013 Cogent Embedded, Inc., <source@cogentembedded.com>
 * Copyright (C) 2008 Magnus Damm
 *
 * Based on the soc-camera rcar_vin driver
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>

#include <media/v4l2-async.h>
#include <media/v4l2-fwnode.h>

#include "rcar-vin.h"

/* -----------------------------------------------------------------------------
 * Async notifier
 */

#define notifier_to_vin(n) container_of(n, struct rvin_dev, notifier)

static int rvin_find_pad(struct v4l2_subdev *sd, int direction)
{
	unsigned int pad;

	if (sd->entity.num_pads <= 1)
		return 0;

	for (pad = 0; pad < sd->entity.num_pads; pad++)
		if (sd->entity.pads[pad].flags & direction)
			return pad;

	return -EINVAL;
}

static bool rvin_mbus_supported(struct rvin_graph_entity *entity)
{
	struct v4l2_subdev *sd = entity->subdev;
	struct v4l2_subdev_mbus_code_enum code = {
		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
	};

	code.index = 0;
	code.pad = entity->source_pad;
	while (!v4l2_subdev_call(sd, pad, enum_mbus_code, NULL, &code)) {
		code.index++;
		switch (code.code) {
		case MEDIA_BUS_FMT_YUYV8_1X16:
		case MEDIA_BUS_FMT_UYVY8_2X8:
		case MEDIA_BUS_FMT_UYVY10_2X10:
		case MEDIA_BUS_FMT_RGB888_1X24:
			entity->code = code.code;
			return true;
		default:
			break;
		}
	}

	return false;
}

static int rvin_digital_notify_complete(struct v4l2_async_notifier *notifier)
{
	struct rvin_dev *vin = notifier_to_vin(notifier);
	int ret;

	/* Verify subdevices mbus format */
	if (!rvin_mbus_supported(vin->digital)) {
		vin_err(vin, "Unsupported media bus format for %s\n",
			vin->digital->subdev->name);
		return -EINVAL;
	}

	vin_dbg(vin, "Found media bus format for %s: %d\n",
		vin->digital->subdev->name, vin->digital->code);

	ret = v4l2_device_register_subdev_nodes(&vin->v4l2_dev);
	if (ret < 0) {
		vin_err(vin, "Failed to register subdev nodes\n");
		return ret;
	}

	return rvin_v4l2_probe(vin);
}

static void rvin_digital_notify_unbind(struct v4l2_async_notifier *notifier,
				       struct v4l2_subdev *subdev,
				       struct v4l2_async_subdev *asd)
{
	struct rvin_dev *vin = notifier_to_vin(notifier);

	vin_dbg(vin, "unbind digital subdev %s\n", subdev->name);
	rvin_v4l2_remove(vin);
	vin->digital->subdev = NULL;
}

static int rvin_digital_notify_bound(struct v4l2_async_notifier *notifier,
				     struct v4l2_subdev *subdev,
				     struct v4l2_async_subdev *asd)
{
	struct rvin_dev *vin = notifier_to_vin(notifier);
	int ret;

	v4l2_set_subdev_hostdata(subdev, vin);

	/* Find source and sink pad of remote subdevice */

	ret = rvin_find_pad(subdev, MEDIA_PAD_FL_SOURCE);
	if (ret < 0)
		return ret;
	vin->digital->source_pad = ret;

	ret = rvin_find_pad(subdev, MEDIA_PAD_FL_SINK);
	vin->digital->sink_pad = ret < 0 ? 0 : ret;

	vin->digital->subdev = subdev;

	vin_dbg(vin, "bound subdev %s source pad: %u sink pad: %u\n",
		subdev->name, vin->digital->source_pad,
		vin->digital->sink_pad);

	return 0;
}

static int rvin_digital_parse_v4l2(struct device *dev,
				   struct v4l2_fwnode_endpoint *vep,
				   struct v4l2_async_subdev *asd)
{
	struct rvin_dev *vin = dev_get_drvdata(dev);
	struct rvin_graph_entity *rvge =
		container_of(asd, struct rvin_graph_entity, asd);

	if (vep->base.port || vep->base.id)
		return -ENOTCONN;

	rvge->mbus_cfg.type = vep->bus_type;

	switch (rvge->mbus_cfg.type) {
	case V4L2_MBUS_PARALLEL:
		vin_dbg(vin, "Found PARALLEL media bus\n");
		rvge->mbus_cfg.flags = vep->bus.parallel.flags;
		break;
	case V4L2_MBUS_BT656:
		vin_dbg(vin, "Found BT656 media bus\n");
		rvge->mbus_cfg.flags = 0;
		break;
	default:
		vin_err(vin, "Unknown media bus type\n");
		return -EINVAL;
	}

	vin->digital = rvge;

	return 0;
}

static int rvin_digital_graph_init(struct rvin_dev *vin)
{
	int ret;

	ret = v4l2_async_notifier_parse_fwnode_endpoints(
		vin->dev, &vin->notifier,
		sizeof(struct rvin_graph_entity), rvin_digital_parse_v4l2);
	if (ret)
		return ret;

	if (!vin->digital)
		return -ENODEV;

	vin_dbg(vin, "Found digital subdevice %pOF\n",
		to_of_node(vin->digital->asd.match.fwnode.fwnode));

	vin->notifier.bound = rvin_digital_notify_bound;
	vin->notifier.unbind = rvin_digital_notify_unbind;
	vin->notifier.complete = rvin_digital_notify_complete;
	ret = v4l2_async_notifier_register(&vin->v4l2_dev, &vin->notifier);
	if (ret < 0) {
		vin_err(vin, "Notifier registration failed\n");
		return ret;
	}

	return 0;
}

/* -----------------------------------------------------------------------------
 * Platform Device Driver
 */

static const struct of_device_id rvin_of_id_table[] = {
	{ .compatible = "renesas,vin-r8a7794", .data = (void *)RCAR_GEN2 },
	{ .compatible = "renesas,vin-r8a7793", .data = (void *)RCAR_GEN2 },
	{ .compatible = "renesas,vin-r8a7791", .data = (void *)RCAR_GEN2 },
	{ .compatible = "renesas,vin-r8a7790", .data = (void *)RCAR_GEN2 },
	{ .compatible = "renesas,vin-r8a7779", .data = (void *)RCAR_H1 },
	{ .compatible = "renesas,vin-r8a7778", .data = (void *)RCAR_M1 },
	{ .compatible = "renesas,rcar-gen2-vin", .data = (void *)RCAR_GEN2 },
	{ },
};
MODULE_DEVICE_TABLE(of, rvin_of_id_table);

static int rcar_vin_probe(struct platform_device *pdev)
{
	const struct of_device_id *match;
	struct rvin_dev *vin;
	struct resource *mem;
	int irq, ret;

	vin = devm_kzalloc(&pdev->dev, sizeof(*vin), GFP_KERNEL);
	if (!vin)
		return -ENOMEM;

	match = of_match_device(of_match_ptr(rvin_of_id_table), &pdev->dev);
	if (!match)
		return -ENODEV;

	vin->dev = &pdev->dev;
	vin->chip = (enum chip_id)match->data;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (mem == NULL)
		return -EINVAL;

	vin->base = devm_ioremap_resource(vin->dev, mem);
	if (IS_ERR(vin->base))
		return PTR_ERR(vin->base);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	ret = rvin_dma_probe(vin, irq);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, vin);

	ret = rvin_digital_graph_init(vin);
	if (ret < 0)
		goto error;

	pm_suspend_ignore_children(&pdev->dev, true);
	pm_runtime_enable(&pdev->dev);

	return 0;
error:
	rvin_dma_remove(vin);
	v4l2_async_notifier_cleanup(&vin->notifier);

	return ret;
}

static int rcar_vin_remove(struct platform_device *pdev)
{
	struct rvin_dev *vin = platform_get_drvdata(pdev);

	pm_runtime_disable(&pdev->dev);

	v4l2_async_notifier_unregister(&vin->notifier);
	v4l2_async_notifier_cleanup(&vin->notifier);

	rvin_dma_remove(vin);

	return 0;
}

static struct platform_driver rcar_vin_driver = {
	.driver = {
		.name = "rcar-vin",
		.of_match_table = rvin_of_id_table,
	},
	.probe = rcar_vin_probe,
	.remove = rcar_vin_remove,
};

module_platform_driver(rcar_vin_driver);

MODULE_AUTHOR("Niklas Söderlund <niklas.soderlund@ragnatech.se>");
MODULE_DESCRIPTION("Renesas R-Car VIN camera host driver");
MODULE_LICENSE("GPL v2");