/*
 * Driver for the SH-Mobile MIPI CSI-2 unit
 *
 * Copyright (C) 2010, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
 *
 * 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.
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <linux/module.h>

#include <media/sh_mobile_ceu.h>
#include <media/sh_mobile_csi2.h>
#include <media/soc_camera.h>
#include <media/soc_mediabus.h>
#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-mediabus.h>
#include <media/v4l2-subdev.h>

#define SH_CSI2_TREF	0x00
#define SH_CSI2_SRST	0x04
#define SH_CSI2_PHYCNT	0x08
#define SH_CSI2_CHKSUM	0x0C
#define SH_CSI2_VCDT	0x10

struct sh_csi2 {
	struct v4l2_subdev		subdev;
	unsigned int			irq;
	unsigned long			mipi_flags;
	void __iomem			*base;
	struct platform_device		*pdev;
	struct sh_csi2_client_config	*client;
};

static void sh_csi2_hwinit(struct sh_csi2 *priv);

static int sh_csi2_try_fmt(struct v4l2_subdev *sd,
			   struct v4l2_mbus_framefmt *mf)
{
	struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
	struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;

	if (mf->width > 8188)
		mf->width = 8188;
	else if (mf->width & 1)
		mf->width &= ~1;

	switch (pdata->type) {
	case SH_CSI2C:
		switch (mf->code) {
		case MEDIA_BUS_FMT_UYVY8_2X8:		/* YUV422 */
		case MEDIA_BUS_FMT_YUYV8_1_5X8:		/* YUV420 */
		case MEDIA_BUS_FMT_Y8_1X8:		/* RAW8 */
		case MEDIA_BUS_FMT_SBGGR8_1X8:
		case MEDIA_BUS_FMT_SGRBG8_1X8:
			break;
		default:
			/* All MIPI CSI-2 devices must support one of primary formats */
			mf->code = MEDIA_BUS_FMT_YUYV8_2X8;
		}
		break;
	case SH_CSI2I:
		switch (mf->code) {
		case MEDIA_BUS_FMT_Y8_1X8:		/* RAW8 */
		case MEDIA_BUS_FMT_SBGGR8_1X8:
		case MEDIA_BUS_FMT_SGRBG8_1X8:
		case MEDIA_BUS_FMT_SBGGR10_1X10:	/* RAW10 */
		case MEDIA_BUS_FMT_SBGGR12_1X12:	/* RAW12 */
			break;
		default:
			/* All MIPI CSI-2 devices must support one of primary formats */
			mf->code = MEDIA_BUS_FMT_SBGGR8_1X8;
		}
		break;
	}

	return 0;
}

/*
 * We have done our best in try_fmt to try and tell the sensor, which formats
 * we support. If now the configuration is unsuitable for us we can only
 * error out.
 */
static int sh_csi2_s_fmt(struct v4l2_subdev *sd,
			 struct v4l2_mbus_framefmt *mf)
{
	struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
	u32 tmp = (priv->client->channel & 3) << 8;

	dev_dbg(sd->v4l2_dev->dev, "%s(%u)\n", __func__, mf->code);
	if (mf->width > 8188 || mf->width & 1)
		return -EINVAL;

	switch (mf->code) {
	case MEDIA_BUS_FMT_UYVY8_2X8:
		tmp |= 0x1e;	/* YUV422 8 bit */
		break;
	case MEDIA_BUS_FMT_YUYV8_1_5X8:
		tmp |= 0x18;	/* YUV420 8 bit */
		break;
	case MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE:
		tmp |= 0x21;	/* RGB555 */
		break;
	case MEDIA_BUS_FMT_RGB565_2X8_BE:
		tmp |= 0x22;	/* RGB565 */
		break;
	case MEDIA_BUS_FMT_Y8_1X8:
	case MEDIA_BUS_FMT_SBGGR8_1X8:
	case MEDIA_BUS_FMT_SGRBG8_1X8:
		tmp |= 0x2a;	/* RAW8 */
		break;
	default:
		return -EINVAL;
	}

	iowrite32(tmp, priv->base + SH_CSI2_VCDT);

	return 0;
}

static int sh_csi2_g_mbus_config(struct v4l2_subdev *sd,
				 struct v4l2_mbus_config *cfg)
{
	struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);

	if (!priv->mipi_flags) {
		struct soc_camera_device *icd = v4l2_get_subdev_hostdata(sd);
		struct v4l2_subdev *client_sd = soc_camera_to_subdev(icd);
		struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;
		unsigned long common_flags, csi2_flags;
		struct v4l2_mbus_config client_cfg = {.type = V4L2_MBUS_CSI2,};
		int ret;

		/* Check if we can support this camera */
		csi2_flags = V4L2_MBUS_CSI2_CONTINUOUS_CLOCK |
			V4L2_MBUS_CSI2_1_LANE;

		switch (pdata->type) {
		case SH_CSI2C:
			if (priv->client->lanes != 1)
				csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
			break;
		case SH_CSI2I:
			switch (priv->client->lanes) {
			default:
				csi2_flags |= V4L2_MBUS_CSI2_4_LANE;
			case 3:
				csi2_flags |= V4L2_MBUS_CSI2_3_LANE;
			case 2:
				csi2_flags |= V4L2_MBUS_CSI2_2_LANE;
			}
		}

		ret = v4l2_subdev_call(client_sd, video, g_mbus_config, &client_cfg);
		if (ret == -ENOIOCTLCMD)
			common_flags = csi2_flags;
		else if (!ret)
			common_flags = soc_mbus_config_compatible(&client_cfg,
								  csi2_flags);
		else
			common_flags = 0;

		if (!common_flags)
			return -EINVAL;

		/* All good: camera MIPI configuration supported */
		priv->mipi_flags = common_flags;
	}

	if (cfg) {
		cfg->flags = V4L2_MBUS_PCLK_SAMPLE_RISING |
			V4L2_MBUS_HSYNC_ACTIVE_HIGH | V4L2_MBUS_VSYNC_ACTIVE_HIGH |
			V4L2_MBUS_MASTER | V4L2_MBUS_DATA_ACTIVE_HIGH;
		cfg->type = V4L2_MBUS_PARALLEL;
	}

	return 0;
}

static int sh_csi2_s_mbus_config(struct v4l2_subdev *sd,
				 const struct v4l2_mbus_config *cfg)
{
	struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);
	struct soc_camera_device *icd = v4l2_get_subdev_hostdata(sd);
	struct v4l2_subdev *client_sd = soc_camera_to_subdev(icd);
	struct v4l2_mbus_config client_cfg = {.type = V4L2_MBUS_CSI2,};
	int ret = sh_csi2_g_mbus_config(sd, NULL);

	if (ret < 0)
		return ret;

	pm_runtime_get_sync(&priv->pdev->dev);

	sh_csi2_hwinit(priv);

	client_cfg.flags = priv->mipi_flags;

	return v4l2_subdev_call(client_sd, video, s_mbus_config, &client_cfg);
}

static struct v4l2_subdev_video_ops sh_csi2_subdev_video_ops = {
	.s_mbus_fmt	= sh_csi2_s_fmt,
	.try_mbus_fmt	= sh_csi2_try_fmt,
	.g_mbus_config	= sh_csi2_g_mbus_config,
	.s_mbus_config	= sh_csi2_s_mbus_config,
};

static void sh_csi2_hwinit(struct sh_csi2 *priv)
{
	struct sh_csi2_pdata *pdata = priv->pdev->dev.platform_data;
	__u32 tmp = 0x10; /* Enable MIPI CSI clock lane */

	/* Reflect registers immediately */
	iowrite32(0x00000001, priv->base + SH_CSI2_TREF);
	/* reset CSI2 harware */
	iowrite32(0x00000001, priv->base + SH_CSI2_SRST);
	udelay(5);
	iowrite32(0x00000000, priv->base + SH_CSI2_SRST);

	switch (pdata->type) {
	case SH_CSI2C:
		if (priv->client->lanes == 1)
			tmp |= 1;
		else
			/* Default - both lanes */
			tmp |= 3;
		break;
	case SH_CSI2I:
		if (!priv->client->lanes || priv->client->lanes > 4)
			/* Default - all 4 lanes */
			tmp |= 0xf;
		else
			tmp |= (1 << priv->client->lanes) - 1;
	}

	if (priv->client->phy == SH_CSI2_PHY_MAIN)
		tmp |= 0x8000;

	iowrite32(tmp, priv->base + SH_CSI2_PHYCNT);

	tmp = 0;
	if (pdata->flags & SH_CSI2_ECC)
		tmp |= 2;
	if (pdata->flags & SH_CSI2_CRC)
		tmp |= 1;
	iowrite32(tmp, priv->base + SH_CSI2_CHKSUM);
}

static int sh_csi2_client_connect(struct sh_csi2 *priv)
{
	struct device *dev = v4l2_get_subdevdata(&priv->subdev);
	struct sh_csi2_pdata *pdata = dev->platform_data;
	struct soc_camera_device *icd = v4l2_get_subdev_hostdata(&priv->subdev);
	int i;

	if (priv->client)
		return -EBUSY;

	for (i = 0; i < pdata->num_clients; i++)
		if ((pdata->clients[i].pdev &&
		     &pdata->clients[i].pdev->dev == icd->pdev) ||
		    (icd->control &&
		     strcmp(pdata->clients[i].name, dev_name(icd->control))))
			break;

	dev_dbg(dev, "%s(%p): found #%d\n", __func__, dev, i);

	if (i == pdata->num_clients)
		return -ENODEV;

	priv->client = pdata->clients + i;

	return 0;
}

static void sh_csi2_client_disconnect(struct sh_csi2 *priv)
{
	if (!priv->client)
		return;

	priv->client = NULL;

	pm_runtime_put(v4l2_get_subdevdata(&priv->subdev));
}

static int sh_csi2_s_power(struct v4l2_subdev *sd, int on)
{
	struct sh_csi2 *priv = container_of(sd, struct sh_csi2, subdev);

	if (on)
		return sh_csi2_client_connect(priv);

	sh_csi2_client_disconnect(priv);
	return 0;
}

static struct v4l2_subdev_core_ops sh_csi2_subdev_core_ops = {
	.s_power	= sh_csi2_s_power,
};

static struct v4l2_subdev_ops sh_csi2_subdev_ops = {
	.core	= &sh_csi2_subdev_core_ops,
	.video	= &sh_csi2_subdev_video_ops,
};

static int sh_csi2_probe(struct platform_device *pdev)
{
	struct resource *res;
	unsigned int irq;
	int ret;
	struct sh_csi2 *priv;
	/* Platform data specify the PHY, lanes, ECC, CRC */
	struct sh_csi2_pdata *pdata = pdev->dev.platform_data;

	if (!pdata)
		return -EINVAL;

	priv = devm_kzalloc(&pdev->dev, sizeof(struct sh_csi2), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	/* Interrupt unused so far */
	irq = platform_get_irq(pdev, 0);

	if (!res || (int)irq <= 0) {
		dev_err(&pdev->dev, "Not enough CSI2 platform resources.\n");
		return -ENODEV;
	}

	/* TODO: Add support for CSI2I. Careful: different register layout! */
	if (pdata->type != SH_CSI2C) {
		dev_err(&pdev->dev, "Only CSI2C supported ATM.\n");
		return -EINVAL;
	}

	priv->irq = irq;

	priv->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(priv->base))
		return PTR_ERR(priv->base);

	priv->pdev = pdev;
	priv->subdev.owner = THIS_MODULE;
	priv->subdev.dev = &pdev->dev;
	platform_set_drvdata(pdev, &priv->subdev);

	v4l2_subdev_init(&priv->subdev, &sh_csi2_subdev_ops);
	v4l2_set_subdevdata(&priv->subdev, &pdev->dev);

	snprintf(priv->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s.mipi-csi",
		 dev_name(&pdev->dev));

	ret = v4l2_async_register_subdev(&priv->subdev);
	if (ret < 0)
		return ret;

	pm_runtime_enable(&pdev->dev);

	dev_dbg(&pdev->dev, "CSI2 probed.\n");

	return 0;
}

static int sh_csi2_remove(struct platform_device *pdev)
{
	struct v4l2_subdev *subdev = platform_get_drvdata(pdev);
	struct sh_csi2 *priv = container_of(subdev, struct sh_csi2, subdev);

	v4l2_async_unregister_subdev(&priv->subdev);
	v4l2_device_unregister_subdev(subdev);
	pm_runtime_disable(&pdev->dev);

	return 0;
}

static struct platform_driver __refdata sh_csi2_pdrv = {
	.remove	= sh_csi2_remove,
	.probe	= sh_csi2_probe,
	.driver	= {
		.name	= "sh-mobile-csi2",
	},
};

module_platform_driver(sh_csi2_pdrv);

MODULE_DESCRIPTION("SH-Mobile MIPI CSI-2 driver");
MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:sh-mobile-csi2");