/*
 * TI OMAP4 ISS V4L2 Driver - ISP IPIPE module
 *
 * Copyright (C) 2012 Texas Instruments, Inc.
 *
 * Author: Sergio Aguirre <sergio.a.aguirre@gmail.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.
 */

#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/sched.h>

#include "iss.h"
#include "iss_regs.h"
#include "iss_ipipe.h"

static struct v4l2_mbus_framefmt *
__ipipe_get_format(struct iss_ipipe_device *ipipe,
		   struct v4l2_subdev_pad_config *cfg,
		   unsigned int pad,
		   enum v4l2_subdev_format_whence which);

static const unsigned int ipipe_fmts[] = {
	MEDIA_BUS_FMT_SGRBG10_1X10,
	MEDIA_BUS_FMT_SRGGB10_1X10,
	MEDIA_BUS_FMT_SBGGR10_1X10,
	MEDIA_BUS_FMT_SGBRG10_1X10,
};

/*
 * ipipe_print_status - Print current IPIPE Module register values.
 * @ipipe: Pointer to ISS ISP IPIPE device.
 *
 * Also prints other debug information stored in the IPIPE module.
 */
#define IPIPE_PRINT_REGISTER(iss, name)\
	dev_dbg(iss->dev, "###IPIPE " #name "=0x%08x\n", \
		iss_reg_read(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_##name))

static void ipipe_print_status(struct iss_ipipe_device *ipipe)
{
	struct iss_device *iss = to_iss_device(ipipe);

	dev_dbg(iss->dev, "-------------IPIPE Register dump-------------\n");

	IPIPE_PRINT_REGISTER(iss, SRC_EN);
	IPIPE_PRINT_REGISTER(iss, SRC_MODE);
	IPIPE_PRINT_REGISTER(iss, SRC_FMT);
	IPIPE_PRINT_REGISTER(iss, SRC_COL);
	IPIPE_PRINT_REGISTER(iss, SRC_VPS);
	IPIPE_PRINT_REGISTER(iss, SRC_VSZ);
	IPIPE_PRINT_REGISTER(iss, SRC_HPS);
	IPIPE_PRINT_REGISTER(iss, SRC_HSZ);
	IPIPE_PRINT_REGISTER(iss, GCK_MMR);
	IPIPE_PRINT_REGISTER(iss, YUV_PHS);

	dev_dbg(iss->dev, "-----------------------------------------------\n");
}

/*
 * ipipe_enable - Enable/Disable IPIPE.
 * @enable: enable flag
 *
 */
static void ipipe_enable(struct iss_ipipe_device *ipipe, u8 enable)
{
	struct iss_device *iss = to_iss_device(ipipe);

	iss_reg_update(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_EN,
		       IPIPE_SRC_EN_EN, enable ? IPIPE_SRC_EN_EN : 0);
}

/* -----------------------------------------------------------------------------
 * Format- and pipeline-related configuration helpers
 */

static void ipipe_configure(struct iss_ipipe_device *ipipe)
{
	struct iss_device *iss = to_iss_device(ipipe);
	struct v4l2_mbus_framefmt *format;

	/* IPIPE_PAD_SINK */
	format = &ipipe->formats[IPIPE_PAD_SINK];

	/* NOTE: Currently just supporting pipeline IN: RGB, OUT: YUV422 */
	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_FMT,
		      IPIPE_SRC_FMT_RAW2YUV);

	/* Enable YUV444 -> YUV422 conversion */
	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_YUV_PHS,
		      IPIPE_YUV_PHS_LPF);

	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_VPS, 0);
	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_HPS, 0);
	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_VSZ,
		      (format->height - 2) & IPIPE_SRC_VSZ_MASK);
	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_HSZ,
		      (format->width - 1) & IPIPE_SRC_HSZ_MASK);

	/* Ignore ipipeif_wrt signal, and operate on-the-fly.  */
	iss_reg_clr(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_MODE,
		    IPIPE_SRC_MODE_WRT | IPIPE_SRC_MODE_OST);

	/* HACK: Values tuned for Ducati SW (OV) */
	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_SRC_COL,
		      IPIPE_SRC_COL_EE_B | IPIPE_SRC_COL_EO_GB |
		      IPIPE_SRC_COL_OE_GR | IPIPE_SRC_COL_OO_R);

	/* IPIPE_PAD_SOURCE_VP */
	format = &ipipe->formats[IPIPE_PAD_SOURCE_VP];
	/* Do nothing? */
}

/* -----------------------------------------------------------------------------
 * V4L2 subdev operations
 */

/*
 * ipipe_set_stream - Enable/Disable streaming on the IPIPE module
 * @sd: ISP IPIPE V4L2 subdevice
 * @enable: Enable/disable stream
 */
static int ipipe_set_stream(struct v4l2_subdev *sd, int enable)
{
	struct iss_ipipe_device *ipipe = v4l2_get_subdevdata(sd);
	struct iss_device *iss = to_iss_device(ipipe);
	int ret = 0;

	if (ipipe->state == ISS_PIPELINE_STREAM_STOPPED) {
		if (enable == ISS_PIPELINE_STREAM_STOPPED)
			return 0;

		omap4iss_isp_subclk_enable(iss, OMAP4_ISS_ISP_SUBCLK_IPIPE);

		/* Enable clk_arm_g0 */
		iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_GCK_MMR,
			      IPIPE_GCK_MMR_REG);

		/* Enable clk_pix_g[3:0] */
		iss_reg_write(iss, OMAP4_ISS_MEM_ISP_IPIPE, IPIPE_GCK_PIX,
			      IPIPE_GCK_PIX_G3 | IPIPE_GCK_PIX_G2 |
			      IPIPE_GCK_PIX_G1 | IPIPE_GCK_PIX_G0);
	}

	switch (enable) {
	case ISS_PIPELINE_STREAM_CONTINUOUS:

		ipipe_configure(ipipe);
		ipipe_print_status(ipipe);

		atomic_set(&ipipe->stopping, 0);
		ipipe_enable(ipipe, 1);
		break;

	case ISS_PIPELINE_STREAM_STOPPED:
		if (ipipe->state == ISS_PIPELINE_STREAM_STOPPED)
			return 0;
		if (omap4iss_module_sync_idle(&sd->entity, &ipipe->wait,
					      &ipipe->stopping))
			ret = -ETIMEDOUT;

		ipipe_enable(ipipe, 0);
		omap4iss_isp_subclk_disable(iss, OMAP4_ISS_ISP_SUBCLK_IPIPE);
		break;
	}

	ipipe->state = enable;
	return ret;
}

static struct v4l2_mbus_framefmt *
__ipipe_get_format(struct iss_ipipe_device *ipipe,
		   struct v4l2_subdev_pad_config *cfg,
		   unsigned int pad,
		   enum v4l2_subdev_format_whence which)
{
	if (which == V4L2_SUBDEV_FORMAT_TRY)
		return v4l2_subdev_get_try_format(&ipipe->subdev, cfg, pad);

	return &ipipe->formats[pad];
}

/*
 * ipipe_try_format - Try video format on a pad
 * @ipipe: ISS IPIPE device
 * @cfg: V4L2 subdev pad config
 * @pad: Pad number
 * @fmt: Format
 */
static void
ipipe_try_format(struct iss_ipipe_device *ipipe,
		 struct v4l2_subdev_pad_config *cfg,
		 unsigned int pad,
		 struct v4l2_mbus_framefmt *fmt,
		 enum v4l2_subdev_format_whence which)
{
	struct v4l2_mbus_framefmt *format;
	unsigned int width = fmt->width;
	unsigned int height = fmt->height;
	unsigned int i;

	switch (pad) {
	case IPIPE_PAD_SINK:
		for (i = 0; i < ARRAY_SIZE(ipipe_fmts); i++) {
			if (fmt->code == ipipe_fmts[i])
				break;
		}

		/* If not found, use SGRBG10 as default */
		if (i >= ARRAY_SIZE(ipipe_fmts))
			fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;

		/* Clamp the input size. */
		fmt->width = clamp_t(u32, width, 1, 8192);
		fmt->height = clamp_t(u32, height, 1, 8192);
		fmt->colorspace = V4L2_COLORSPACE_SRGB;
		break;

	case IPIPE_PAD_SOURCE_VP:
		format = __ipipe_get_format(ipipe, cfg, IPIPE_PAD_SINK, which);
		memcpy(fmt, format, sizeof(*fmt));

		fmt->code = MEDIA_BUS_FMT_UYVY8_1X16;
		fmt->width = clamp_t(u32, width, 32, fmt->width);
		fmt->height = clamp_t(u32, height, 32, fmt->height);
		fmt->colorspace = V4L2_COLORSPACE_JPEG;
		break;
	}

	fmt->field = V4L2_FIELD_NONE;
}

/*
 * ipipe_enum_mbus_code - Handle pixel format enumeration
 * @sd     : pointer to v4l2 subdev structure
 * @cfg    : V4L2 subdev pad config
 * @code   : pointer to v4l2_subdev_mbus_code_enum structure
 * return -EINVAL or zero on success
 */
static int ipipe_enum_mbus_code(struct v4l2_subdev *sd,
				struct v4l2_subdev_pad_config *cfg,
				struct v4l2_subdev_mbus_code_enum *code)
{
	switch (code->pad) {
	case IPIPE_PAD_SINK:
		if (code->index >= ARRAY_SIZE(ipipe_fmts))
			return -EINVAL;

		code->code = ipipe_fmts[code->index];
		break;

	case IPIPE_PAD_SOURCE_VP:
		/* FIXME: Forced format conversion inside IPIPE ? */
		if (code->index != 0)
			return -EINVAL;

		code->code = MEDIA_BUS_FMT_UYVY8_1X16;
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static int ipipe_enum_frame_size(struct v4l2_subdev *sd,
				 struct v4l2_subdev_pad_config *cfg,
				 struct v4l2_subdev_frame_size_enum *fse)
{
	struct iss_ipipe_device *ipipe = v4l2_get_subdevdata(sd);
	struct v4l2_mbus_framefmt format;

	if (fse->index != 0)
		return -EINVAL;

	format.code = fse->code;
	format.width = 1;
	format.height = 1;
	ipipe_try_format(ipipe, cfg, fse->pad, &format, fse->which);
	fse->min_width = format.width;
	fse->min_height = format.height;

	if (format.code != fse->code)
		return -EINVAL;

	format.code = fse->code;
	format.width = -1;
	format.height = -1;
	ipipe_try_format(ipipe, cfg, fse->pad, &format, fse->which);
	fse->max_width = format.width;
	fse->max_height = format.height;

	return 0;
}

/*
 * ipipe_get_format - Retrieve the video format on a pad
 * @sd : ISP IPIPE V4L2 subdevice
 * @cfg: V4L2 subdev pad config
 * @fmt: Format
 *
 * Return 0 on success or -EINVAL if the pad is invalid or doesn't correspond
 * to the format type.
 */
static int ipipe_get_format(struct v4l2_subdev *sd,
			    struct v4l2_subdev_pad_config *cfg,
			    struct v4l2_subdev_format *fmt)
{
	struct iss_ipipe_device *ipipe = v4l2_get_subdevdata(sd);
	struct v4l2_mbus_framefmt *format;

	format = __ipipe_get_format(ipipe, cfg, fmt->pad, fmt->which);
	if (!format)
		return -EINVAL;

	fmt->format = *format;
	return 0;
}

/*
 * ipipe_set_format - Set the video format on a pad
 * @sd : ISP IPIPE V4L2 subdevice
 * @cfg: V4L2 subdev pad config
 * @fmt: Format
 *
 * Return 0 on success or -EINVAL if the pad is invalid or doesn't correspond
 * to the format type.
 */
static int ipipe_set_format(struct v4l2_subdev *sd,
			    struct v4l2_subdev_pad_config *cfg,
			    struct v4l2_subdev_format *fmt)
{
	struct iss_ipipe_device *ipipe = v4l2_get_subdevdata(sd);
	struct v4l2_mbus_framefmt *format;

	format = __ipipe_get_format(ipipe, cfg, fmt->pad, fmt->which);
	if (!format)
		return -EINVAL;

	ipipe_try_format(ipipe, cfg, fmt->pad, &fmt->format, fmt->which);
	*format = fmt->format;

	/* Propagate the format from sink to source */
	if (fmt->pad == IPIPE_PAD_SINK) {
		format = __ipipe_get_format(ipipe, cfg, IPIPE_PAD_SOURCE_VP,
					    fmt->which);
		*format = fmt->format;
		ipipe_try_format(ipipe, cfg, IPIPE_PAD_SOURCE_VP, format,
				 fmt->which);
	}

	return 0;
}

static int ipipe_link_validate(struct v4l2_subdev *sd, struct media_link *link,
			       struct v4l2_subdev_format *source_fmt,
			       struct v4l2_subdev_format *sink_fmt)
{
	/* Check if the two ends match */
	if (source_fmt->format.width != sink_fmt->format.width ||
	    source_fmt->format.height != sink_fmt->format.height)
		return -EPIPE;

	if (source_fmt->format.code != sink_fmt->format.code)
		return -EPIPE;

	return 0;
}

/*
 * ipipe_init_formats - Initialize formats on all pads
 * @sd: ISP IPIPE V4L2 subdevice
 * @fh: V4L2 subdev file handle
 *
 * Initialize all pad formats with default values. If fh is not NULL, try
 * formats are initialized on the file handle. Otherwise active formats are
 * initialized on the device.
 */
static int ipipe_init_formats(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
	struct v4l2_subdev_format format;

	memset(&format, 0, sizeof(format));
	format.pad = IPIPE_PAD_SINK;
	format.which = fh ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
	format.format.code = MEDIA_BUS_FMT_SGRBG10_1X10;
	format.format.width = 4096;
	format.format.height = 4096;
	ipipe_set_format(sd, fh ? fh->pad : NULL, &format);

	return 0;
}

/* V4L2 subdev video operations */
static const struct v4l2_subdev_video_ops ipipe_v4l2_video_ops = {
	.s_stream = ipipe_set_stream,
};

/* V4L2 subdev pad operations */
static const struct v4l2_subdev_pad_ops ipipe_v4l2_pad_ops = {
	.enum_mbus_code = ipipe_enum_mbus_code,
	.enum_frame_size = ipipe_enum_frame_size,
	.get_fmt = ipipe_get_format,
	.set_fmt = ipipe_set_format,
	.link_validate = ipipe_link_validate,
};

/* V4L2 subdev operations */
static const struct v4l2_subdev_ops ipipe_v4l2_ops = {
	.video = &ipipe_v4l2_video_ops,
	.pad = &ipipe_v4l2_pad_ops,
};

/* V4L2 subdev internal operations */
static const struct v4l2_subdev_internal_ops ipipe_v4l2_internal_ops = {
	.open = ipipe_init_formats,
};

/* -----------------------------------------------------------------------------
 * Media entity operations
 */

/*
 * ipipe_link_setup - Setup IPIPE connections
 * @entity: IPIPE media entity
 * @local: Pad at the local end of the link
 * @remote: Pad at the remote end of the link
 * @flags: Link flags
 *
 * return -EINVAL or zero on success
 */
static int ipipe_link_setup(struct media_entity *entity,
			    const struct media_pad *local,
			    const struct media_pad *remote, u32 flags)
{
	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
	struct iss_ipipe_device *ipipe = v4l2_get_subdevdata(sd);
	struct iss_device *iss = to_iss_device(ipipe);

	if (!is_media_entity_v4l2_subdev(remote->entity))
		return -EINVAL;

	switch (local->index) {
	case IPIPE_PAD_SINK:
		/* Read from IPIPEIF. */
		if (!(flags & MEDIA_LNK_FL_ENABLED)) {
			ipipe->input = IPIPE_INPUT_NONE;
			break;
		}

		if (ipipe->input != IPIPE_INPUT_NONE)
			return -EBUSY;

		if (remote->entity == &iss->ipipeif.subdev.entity)
			ipipe->input = IPIPE_INPUT_IPIPEIF;

		break;

	case IPIPE_PAD_SOURCE_VP:
		/* Send to RESIZER */
		if (flags & MEDIA_LNK_FL_ENABLED) {
			if (ipipe->output & ~IPIPE_OUTPUT_VP)
				return -EBUSY;
			ipipe->output |= IPIPE_OUTPUT_VP;
		} else {
			ipipe->output &= ~IPIPE_OUTPUT_VP;
		}
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

/* media operations */
static const struct media_entity_operations ipipe_media_ops = {
	.link_setup = ipipe_link_setup,
	.link_validate = v4l2_subdev_link_validate,
};

/*
 * ipipe_init_entities - Initialize V4L2 subdev and media entity
 * @ipipe: ISS ISP IPIPE module
 *
 * Return 0 on success and a negative error code on failure.
 */
static int ipipe_init_entities(struct iss_ipipe_device *ipipe)
{
	struct v4l2_subdev *sd = &ipipe->subdev;
	struct media_pad *pads = ipipe->pads;
	struct media_entity *me = &sd->entity;
	int ret;

	ipipe->input = IPIPE_INPUT_NONE;

	v4l2_subdev_init(sd, &ipipe_v4l2_ops);
	sd->internal_ops = &ipipe_v4l2_internal_ops;
	strlcpy(sd->name, "OMAP4 ISS ISP IPIPE", sizeof(sd->name));
	sd->grp_id = BIT(16);	/* group ID for iss subdevs */
	v4l2_set_subdevdata(sd, ipipe);
	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

	pads[IPIPE_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
	pads[IPIPE_PAD_SOURCE_VP].flags = MEDIA_PAD_FL_SOURCE;

	me->ops = &ipipe_media_ops;
	ret = media_entity_pads_init(me, IPIPE_PADS_NUM, pads);
	if (ret < 0)
		return ret;

	ipipe_init_formats(sd, NULL);

	return 0;
}

void omap4iss_ipipe_unregister_entities(struct iss_ipipe_device *ipipe)
{
	v4l2_device_unregister_subdev(&ipipe->subdev);
}

int omap4iss_ipipe_register_entities(struct iss_ipipe_device *ipipe,
				     struct v4l2_device *vdev)
{
	int ret;

	/* Register the subdev and video node. */
	ret = v4l2_device_register_subdev(vdev, &ipipe->subdev);
	if (ret < 0)
		goto error;

	return 0;

error:
	omap4iss_ipipe_unregister_entities(ipipe);
	return ret;
}

/* -----------------------------------------------------------------------------
 * ISP IPIPE initialisation and cleanup
 */

/*
 * omap4iss_ipipe_init - IPIPE module initialization.
 * @iss: Device pointer specific to the OMAP4 ISS.
 *
 * TODO: Get the initialisation values from platform data.
 *
 * Return 0 on success or a negative error code otherwise.
 */
int omap4iss_ipipe_init(struct iss_device *iss)
{
	struct iss_ipipe_device *ipipe = &iss->ipipe;

	ipipe->state = ISS_PIPELINE_STREAM_STOPPED;
	init_waitqueue_head(&ipipe->wait);

	return ipipe_init_entities(ipipe);
}

/*
 * omap4iss_ipipe_cleanup - IPIPE module cleanup.
 * @iss: Device pointer specific to the OMAP4 ISS.
 */
void omap4iss_ipipe_cleanup(struct iss_device *iss)
{
	struct iss_ipipe_device *ipipe = &iss->ipipe;

	media_entity_cleanup(&ipipe->subdev.entity);
}