/*
 * Copyright (C) 2017 NVIDIA CORPORATION.  All rights reserved.
 *
 * 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 <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_plane_helper.h>

#include "dc.h"
#include "plane.h"

static void tegra_plane_destroy(struct drm_plane *plane)
{
        struct tegra_plane *p = to_tegra_plane(plane);

        drm_plane_cleanup(plane);
        kfree(p);
}

static void tegra_plane_reset(struct drm_plane *plane)
{
        struct tegra_plane_state *state;

        if (plane->state)
                __drm_atomic_helper_plane_destroy_state(plane->state);

        kfree(plane->state);
        plane->state = NULL;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (state) {
                plane->state = &state->base;
                plane->state->plane = plane;
        }
}

static struct drm_plane_state *
tegra_plane_atomic_duplicate_state(struct drm_plane *plane)
{
        struct tegra_plane_state *state = to_tegra_plane_state(plane->state);
        struct tegra_plane_state *copy;
        unsigned int i;

        copy = kmalloc(sizeof(*copy), GFP_KERNEL);
        if (!copy)
                return NULL;

        __drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
        copy->tiling = state->tiling;
        copy->format = state->format;
        copy->swap = state->swap;
        copy->opaque = state->opaque;

        for (i = 0; i < 3; i++)
                copy->dependent[i] = state->dependent[i];

        return &copy->base;
}

static void tegra_plane_atomic_destroy_state(struct drm_plane *plane,
                                             struct drm_plane_state *state)
{
        __drm_atomic_helper_plane_destroy_state(state);
        kfree(state);
}

static bool tegra_plane_format_mod_supported(struct drm_plane *plane,
                                             uint32_t format,
                                             uint64_t modifier)
{
        const struct drm_format_info *info = drm_format_info(format);

        if (modifier == DRM_FORMAT_MOD_LINEAR)
                return true;

        if (info->num_planes == 1)
                return true;

        return false;
}

const struct drm_plane_funcs tegra_plane_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = tegra_plane_destroy,
        .reset = tegra_plane_reset,
        .atomic_duplicate_state = tegra_plane_atomic_duplicate_state,
        .atomic_destroy_state = tegra_plane_atomic_destroy_state,
        .format_mod_supported = tegra_plane_format_mod_supported,
};

int tegra_plane_state_add(struct tegra_plane *plane,
                          struct drm_plane_state *state)
{
        struct drm_crtc_state *crtc_state;
        struct tegra_dc_state *tegra;
        int err;

        /* Propagate errors from allocation or locking failures. */
        crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
        if (IS_ERR(crtc_state))
                return PTR_ERR(crtc_state);

        /* Check plane state for visibility and calculate clipping bounds */
        err = drm_atomic_helper_check_plane_state(state, crtc_state,
                                                  0, INT_MAX, true, true);
        if (err < 0)
                return err;

        tegra = to_dc_state(crtc_state);

        tegra->planes |= WIN_A_ACT_REQ << plane->index;

        return 0;
}

int tegra_plane_format(u32 fourcc, u32 *format, u32 *swap)
{
        /* assume no swapping of fetched data */
        if (swap)
                *swap = BYTE_SWAP_NOSWAP;

        switch (fourcc) {
        case DRM_FORMAT_ARGB4444:
                *format = WIN_COLOR_DEPTH_B4G4R4A4;
                break;

        case DRM_FORMAT_ARGB1555:
                *format = WIN_COLOR_DEPTH_B5G5R5A1;
                break;

        case DRM_FORMAT_RGB565:
                *format = WIN_COLOR_DEPTH_B5G6R5;
                break;

        case DRM_FORMAT_RGBA5551:
                *format = WIN_COLOR_DEPTH_A1B5G5R5;
                break;

        case DRM_FORMAT_ARGB8888:
                *format = WIN_COLOR_DEPTH_B8G8R8A8;
                break;

        case DRM_FORMAT_ABGR8888:
                *format = WIN_COLOR_DEPTH_R8G8B8A8;
                break;

        case DRM_FORMAT_ABGR4444:
                *format = WIN_COLOR_DEPTH_R4G4B4A4;
                break;

        case DRM_FORMAT_ABGR1555:
                *format = WIN_COLOR_DEPTH_R5G5B5A;
                break;

        case DRM_FORMAT_BGRA5551:
                *format = WIN_COLOR_DEPTH_AR5G5B5;
                break;

        case DRM_FORMAT_XRGB1555:
                *format = WIN_COLOR_DEPTH_B5G5R5X1;
                break;

        case DRM_FORMAT_RGBX5551:
                *format = WIN_COLOR_DEPTH_X1B5G5R5;
                break;

        case DRM_FORMAT_XBGR1555:
                *format = WIN_COLOR_DEPTH_R5G5B5X1;
                break;

        case DRM_FORMAT_BGRX5551:
                *format = WIN_COLOR_DEPTH_X1R5G5B5;
                break;

        case DRM_FORMAT_BGR565:
                *format = WIN_COLOR_DEPTH_R5G6B5;
                break;

        case DRM_FORMAT_BGRA8888:
                *format = WIN_COLOR_DEPTH_A8R8G8B8;
                break;

        case DRM_FORMAT_RGBA8888:
                *format = WIN_COLOR_DEPTH_A8B8G8R8;
                break;

        case DRM_FORMAT_XRGB8888:
                *format = WIN_COLOR_DEPTH_B8G8R8X8;
                break;

        case DRM_FORMAT_XBGR8888:
                *format = WIN_COLOR_DEPTH_R8G8B8X8;
                break;

        case DRM_FORMAT_UYVY:
                *format = WIN_COLOR_DEPTH_YCbCr422;
                break;

        case DRM_FORMAT_YUYV:
                if (!swap)
                        return -EINVAL;

                *format = WIN_COLOR_DEPTH_YCbCr422;
                *swap = BYTE_SWAP_SWAP2;
                break;

        case DRM_FORMAT_YUV420:
                *format = WIN_COLOR_DEPTH_YCbCr420P;
                break;

        case DRM_FORMAT_YUV422:
                *format = WIN_COLOR_DEPTH_YCbCr422P;
                break;

        default:
                return -EINVAL;
        }

        return 0;
}

bool tegra_plane_format_is_yuv(unsigned int format, bool *planar)
{
        switch (format) {
        case WIN_COLOR_DEPTH_YCbCr422:
        case WIN_COLOR_DEPTH_YUV422:
                if (planar)
                        *planar = false;

                return true;

        case WIN_COLOR_DEPTH_YCbCr420P:
        case WIN_COLOR_DEPTH_YUV420P:
        case WIN_COLOR_DEPTH_YCbCr422P:
        case WIN_COLOR_DEPTH_YUV422P:
        case WIN_COLOR_DEPTH_YCbCr422R:
        case WIN_COLOR_DEPTH_YUV422R:
        case WIN_COLOR_DEPTH_YCbCr422RA:
        case WIN_COLOR_DEPTH_YUV422RA:
                if (planar)
                        *planar = true;

                return true;
        }

        if (planar)
                *planar = false;

        return false;
}

static bool __drm_format_has_alpha(u32 format)
{
        switch (format) {
        case DRM_FORMAT_ARGB1555:
        case DRM_FORMAT_RGBA5551:
        case DRM_FORMAT_ABGR8888:
        case DRM_FORMAT_ARGB8888:
                return true;
        }

        return false;
}

/*
 * This is applicable to Tegra20 and Tegra30 only where the opaque formats can
 * be emulated using the alpha formats and alpha blending disabled.
 */
bool tegra_plane_format_has_alpha(unsigned int format)
{
        switch (format) {
        case WIN_COLOR_DEPTH_B5G5R5A1:
        case WIN_COLOR_DEPTH_A1B5G5R5:
        case WIN_COLOR_DEPTH_R8G8B8A8:
        case WIN_COLOR_DEPTH_B8G8R8A8:
                return true;
        }

        return false;
}

int tegra_plane_format_get_alpha(unsigned int opaque, unsigned int *alpha)
{
        if (tegra_plane_format_is_yuv(opaque, NULL)) {
                *alpha = opaque;
                return 0;
        }

        switch (opaque) {
        case WIN_COLOR_DEPTH_B5G5R5X1:
                *alpha = WIN_COLOR_DEPTH_B5G5R5A1;
                return 0;

        case WIN_COLOR_DEPTH_X1B5G5R5:
                *alpha = WIN_COLOR_DEPTH_A1B5G5R5;
                return 0;

        case WIN_COLOR_DEPTH_R8G8B8X8:
                *alpha = WIN_COLOR_DEPTH_R8G8B8A8;
                return 0;

        case WIN_COLOR_DEPTH_B8G8R8X8:
                *alpha = WIN_COLOR_DEPTH_B8G8R8A8;
                return 0;

        case WIN_COLOR_DEPTH_B5G6R5:
                *alpha = opaque;
                return 0;
        }

        return -EINVAL;
}

static unsigned int tegra_plane_get_overlap_index(struct tegra_plane *plane,
                                                  struct tegra_plane *other)
{
        unsigned int index = 0, i;

        WARN_ON(plane == other);

        for (i = 0; i < 3; i++) {
                if (i == plane->index)
                        continue;

                if (i == other->index)
                        break;

                index++;
        }

        return index;
}

void tegra_plane_check_dependent(struct tegra_plane *tegra,
                                 struct tegra_plane_state *state)
{
        struct drm_plane_state *old, *new;
        struct drm_plane *plane;
        unsigned int zpos[2];
        unsigned int i;

        for (i = 0; i < 2; i++)
                zpos[i] = 0;

        for_each_oldnew_plane_in_state(state->base.state, plane, old, new, i) {
                struct tegra_plane *p = to_tegra_plane(plane);
                unsigned index;

                /* skip this plane and planes on different CRTCs */
                if (p == tegra || new->crtc != state->base.crtc)
                        continue;

                index = tegra_plane_get_overlap_index(tegra, p);

                state->dependent[index] = false;

                /*
                 * If any of the other planes is on top of this plane and uses
                 * a format with an alpha component, mark this plane as being
                 * dependent, meaning it's alpha value will be 1 minus the sum
                 * of alpha components of the overlapping planes.
                 */
                if (p->index > tegra->index) {
                        if (__drm_format_has_alpha(new->fb->format->format))
                                state->dependent[index] = true;

                        /* keep track of the Z position */
                        zpos[index] = p->index;
                }
        }

        /*
         * The region where three windows overlap is the intersection of the
         * two regions where two windows overlap. It contributes to the area
         * if any of the windows on top of it have an alpha component.
         */
        for (i = 0; i < 2; i++)
                state->dependent[2] = state->dependent[2] ||
                                      state->dependent[i];

        /*
         * However, if any of the windows on top of this window is opaque, it
         * will completely conceal this window within that area, so avoid the
         * window from contributing to the area.
         */
        for (i = 0; i < 2; i++) {
                if (zpos[i] > tegra->index)
                        state->dependent[2] = state->dependent[2] &&
                                              state->dependent[i];
        }
}