/*
 * Color space converter library
 *
 * Copyright (c) 2013 Texas Instruments Inc.
 *
 * David Griego, <dagriego@biglakesoftware.com>
 * Dale Farnsworth, <dale@farnsworth.org>
 * Archit Taneja, <archit@ti.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.
 */

#include <linux/err.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/videodev2.h>

#include "csc.h"

/*
 * 16 coefficients in the order:
 * a0, b0, c0, a1, b1, c1, a2, b2, c2, d0, d1, d2
 * (we may need to pass non-default values from user space later on, we might
 * need to make the coefficient struct more easy to populate)
 */
struct colorspace_coeffs {
        u16     sd[12];
        u16     hd[12];
};

/* VIDEO_RANGE: limited range, GRAPHICS_RANGE: full range */
#define CSC_COEFFS_VIDEO_RANGE_Y2R      0
#define CSC_COEFFS_GRAPHICS_RANGE_Y2R   1
#define CSC_COEFFS_VIDEO_RANGE_R2Y      2
#define CSC_COEFFS_GRAPHICS_RANGE_R2Y   3

/* default colorspace coefficients */
static struct colorspace_coeffs colorspace_coeffs[4] = {
        [CSC_COEFFS_VIDEO_RANGE_Y2R] = {
                {
                        /* SDTV */
                        0x0400, 0x0000, 0x057D, 0x0400, 0x1EA7, 0x1D35,
                        0x0400, 0x06EF, 0x1FFE, 0x0D40, 0x0210, 0x0C88,
                },
                {
                        /* HDTV */
                        0x0400, 0x0000, 0x0629, 0x0400, 0x1F45, 0x1E2B,
                        0x0400, 0x0742, 0x0000, 0x0CEC, 0x0148, 0x0C60,
                },
        },
        [CSC_COEFFS_GRAPHICS_RANGE_Y2R] = {
                {
                        /* SDTV */
                        0x04A8, 0x1FFE, 0x0662, 0x04A8, 0x1E6F, 0x1CBF,
                        0x04A8, 0x0812, 0x1FFF, 0x0C84, 0x0220, 0x0BAC,
                },
                {
                        /* HDTV */
                        0x04A8, 0x0000, 0x072C, 0x04A8, 0x1F26, 0x1DDE,
                        0x04A8, 0x0873, 0x0000, 0x0C20, 0x0134, 0x0B7C,
                },
        },
        [CSC_COEFFS_VIDEO_RANGE_R2Y] = {
                {
                        /* SDTV */
                        0x0132, 0x0259, 0x0075, 0x1F50, 0x1EA5, 0x020B,
                        0x020B, 0x1E4A, 0x1FAB, 0x0000, 0x0200, 0x0200,
                },
                {
                        /* HDTV */
                        0x00DA, 0x02DC, 0x004A, 0x1F88, 0x1E6C, 0x020C,
                        0x020C, 0x1E24, 0x1FD0, 0x0000, 0x0200, 0x0200,
                },
        },
        [CSC_COEFFS_GRAPHICS_RANGE_R2Y] = {
                {
                        /* SDTV */
                        0x0107, 0x0204, 0x0064, 0x1F68, 0x1ED6, 0x01C2,
                        0x01C2, 0x1E87, 0x1FB7, 0x0040, 0x0200, 0x0200,
                },
                {
                        /* HDTV */
                        0x04A8, 0x0000, 0x072C, 0x04A8, 0x1F26, 0x1DDE,
                        0x04A8, 0x0873, 0x0000, 0x0C20, 0x0134, 0x0B7C,
                },
        },
};

void csc_dump_regs(struct csc_data *csc)
{
        struct device *dev = &csc->pdev->dev;

#define DUMPREG(r) dev_dbg(dev, "%-35s %08x\n", #r, \
        ioread32(csc->base + CSC_##r))

        DUMPREG(CSC00);
        DUMPREG(CSC01);
        DUMPREG(CSC02);
        DUMPREG(CSC03);
        DUMPREG(CSC04);
        DUMPREG(CSC05);

#undef DUMPREG
}

void csc_set_coeff_bypass(struct csc_data *csc, u32 *csc_reg5)
{
        *csc_reg5 |= CSC_BYPASS;
}

/*
 * set the color space converter coefficient shadow register values
 */
void csc_set_coeff(struct csc_data *csc, u32 *csc_reg0,
                enum v4l2_colorspace src_colorspace,
                enum v4l2_colorspace dst_colorspace)
{
        u32 *csc_reg5 = csc_reg0 + 5;
        u32 *shadow_csc = csc_reg0;
        struct colorspace_coeffs *sd_hd_coeffs;
        u16 *coeff, *end_coeff;
        enum v4l2_colorspace yuv_colorspace;
        int sel = 0;

        /*
         * support only graphics data range(full range) for now, a control ioctl
         * would be nice here
         */
        /* Y2R */
        if (dst_colorspace == V4L2_COLORSPACE_SRGB &&
                        (src_colorspace == V4L2_COLORSPACE_SMPTE170M ||
                        src_colorspace == V4L2_COLORSPACE_REC709)) {
                /* Y2R */
                sel = 1;
                yuv_colorspace = src_colorspace;
        } else if ((dst_colorspace == V4L2_COLORSPACE_SMPTE170M ||
                        dst_colorspace == V4L2_COLORSPACE_REC709) &&
                        src_colorspace == V4L2_COLORSPACE_SRGB) {
                /* R2Y */
                sel = 3;
                yuv_colorspace = dst_colorspace;
        } else {
                *csc_reg5 |= CSC_BYPASS;
                return;
        }

        sd_hd_coeffs = &colorspace_coeffs[sel];

        /* select between SD or HD coefficients */
        if (yuv_colorspace == V4L2_COLORSPACE_SMPTE170M)
                coeff = sd_hd_coeffs->sd;
        else
                coeff = sd_hd_coeffs->hd;

        end_coeff = coeff + 12;

        for (; coeff < end_coeff; coeff += 2)
                *shadow_csc++ = (*(coeff + 1) << 16) | *coeff;
}

struct csc_data *csc_create(struct platform_device *pdev)
{
        struct csc_data *csc;

        dev_dbg(&pdev->dev, "csc_create\n");

        csc = devm_kzalloc(&pdev->dev, sizeof(*csc), GFP_KERNEL);
        if (!csc) {
                dev_err(&pdev->dev, "couldn't alloc csc_data\n");
                return ERR_PTR(-ENOMEM);
        }

        csc->pdev = pdev;

        csc->res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                        "csc");
        if (csc->res == NULL) {
                dev_err(&pdev->dev, "missing platform resources data\n");
                return ERR_PTR(-ENODEV);
        }

        csc->base = devm_ioremap_resource(&pdev->dev, csc->res);
        if (IS_ERR(csc->base)) {
                dev_err(&pdev->dev, "failed to ioremap\n");
                return ERR_CAST(csc->base);
        }

        return csc;
}