/*
 * Copyright (C) 2011 Samsung Electronics Co.Ltd
 * Authors: Joonyoung Shim <jy0922.shim@samsung.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 <drm/drmP.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/exynos_drm.h>
#include "exynos_drm_drv.h"
#include "exynos_drm_crtc.h"
#include "exynos_drm_fb.h"
#include "exynos_drm_gem.h"
#include "exynos_drm_plane.h"

/*
 * This function is to get X or Y size shown via screen. This needs length and
 * start position of CRTC.
 *
 *      <--- length --->
 * CRTC ----------------
 *      ^ start        ^ end
 *
 * There are six cases from a to f.
 *
 *             <----- SCREEN ----->
 *             0                 last
 *   ----------|------------------|----------
 * CRTCs
 * a -------
 *        b -------
 *        c --------------------------
 *                 d --------
 *                           e -------
 *                                  f -------
 */
static int exynos_plane_get_size(int start, unsigned length, unsigned last)
{
        int end = start + length;
        int size = 0;

        if (start <= 0) {
                if (end > 0)
                        size = min_t(unsigned, end, last);
        } else if (start <= last) {
                size = min_t(unsigned, last - start, length);
        }

        return size;
}

static void exynos_plane_mode_set(struct exynos_drm_plane_state *exynos_state)
{
        struct drm_plane_state *state = &exynos_state->base;
        struct drm_crtc *crtc = state->crtc;
        struct drm_crtc_state *crtc_state =
                        drm_atomic_get_existing_crtc_state(state->state, crtc);
        struct drm_display_mode *mode = &crtc_state->adjusted_mode;
        int crtc_x, crtc_y;
        unsigned int crtc_w, crtc_h;
        unsigned int src_x, src_y;
        unsigned int src_w, src_h;
        unsigned int actual_w;
        unsigned int actual_h;

        /*
         * The original src/dest coordinates are stored in exynos_state->base,
         * but we want to keep another copy internal to our driver that we can
         * clip/modify ourselves.
         */

        crtc_x = state->crtc_x;
        crtc_y = state->crtc_y;
        crtc_w = state->crtc_w;
        crtc_h = state->crtc_h;

        src_x = state->src_x >> 16;
        src_y = state->src_y >> 16;
        src_w = state->src_w >> 16;
        src_h = state->src_h >> 16;

        /* set ratio */
        exynos_state->h_ratio = (src_w << 16) / crtc_w;
        exynos_state->v_ratio = (src_h << 16) / crtc_h;

        /* clip to visible area */
        actual_w = exynos_plane_get_size(crtc_x, crtc_w, mode->hdisplay);
        actual_h = exynos_plane_get_size(crtc_y, crtc_h, mode->vdisplay);

        if (crtc_x < 0) {
                if (actual_w)
                        src_x += ((-crtc_x) * exynos_state->h_ratio) >> 16;
                crtc_x = 0;
        }

        if (crtc_y < 0) {
                if (actual_h)
                        src_y += ((-crtc_y) * exynos_state->v_ratio) >> 16;
                crtc_y = 0;
        }

        /* set drm framebuffer data. */
        exynos_state->src.x = src_x;
        exynos_state->src.y = src_y;
        exynos_state->src.w = (actual_w * exynos_state->h_ratio) >> 16;
        exynos_state->src.h = (actual_h * exynos_state->v_ratio) >> 16;

        /* set plane range to be displayed. */
        exynos_state->crtc.x = crtc_x;
        exynos_state->crtc.y = crtc_y;
        exynos_state->crtc.w = actual_w;
        exynos_state->crtc.h = actual_h;

        DRM_DEBUG_KMS("plane : offset_x/y(%d,%d), width/height(%d,%d)",
                        exynos_state->crtc.x, exynos_state->crtc.y,
                        exynos_state->crtc.w, exynos_state->crtc.h);
}

static void exynos_drm_plane_reset(struct drm_plane *plane)
{
        struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
        struct exynos_drm_plane_state *exynos_state;

        if (plane->state) {
                exynos_state = to_exynos_plane_state(plane->state);
                if (exynos_state->base.fb)
                        drm_framebuffer_unreference(exynos_state->base.fb);
                kfree(exynos_state);
                plane->state = NULL;
        }

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

static struct drm_plane_state *
exynos_drm_plane_duplicate_state(struct drm_plane *plane)
{
        struct exynos_drm_plane_state *exynos_state;
        struct exynos_drm_plane_state *copy;

        exynos_state = to_exynos_plane_state(plane->state);
        copy = kzalloc(sizeof(*exynos_state), GFP_KERNEL);
        if (!copy)
                return NULL;

        __drm_atomic_helper_plane_duplicate_state(plane, &copy->base);
        copy->zpos = exynos_state->zpos;
        return &copy->base;
}

static void exynos_drm_plane_destroy_state(struct drm_plane *plane,
                                           struct drm_plane_state *old_state)
{
        struct exynos_drm_plane_state *old_exynos_state =
                                        to_exynos_plane_state(old_state);
        __drm_atomic_helper_plane_destroy_state(plane, old_state);
        kfree(old_exynos_state);
}

static int exynos_drm_plane_atomic_set_property(struct drm_plane *plane,
                                                struct drm_plane_state *state,
                                                struct drm_property *property,
                                                uint64_t val)
{
        struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
        struct exynos_drm_plane_state *exynos_state =
                                        to_exynos_plane_state(state);
        struct exynos_drm_private *dev_priv = plane->dev->dev_private;
        const struct exynos_drm_plane_config *config = exynos_plane->config;

        if (property == dev_priv->plane_zpos_property &&
            (config->capabilities & EXYNOS_DRM_PLANE_CAP_ZPOS))
                exynos_state->zpos = val;
        else
                return -EINVAL;

        return 0;
}

static int exynos_drm_plane_atomic_get_property(struct drm_plane *plane,
                                          const struct drm_plane_state *state,
                                          struct drm_property *property,
                                          uint64_t *val)
{
        const struct exynos_drm_plane_state *exynos_state =
                container_of(state, const struct exynos_drm_plane_state, base);
        struct exynos_drm_private *dev_priv = plane->dev->dev_private;

        if (property == dev_priv->plane_zpos_property)
                *val = exynos_state->zpos;
        else
                return -EINVAL;

        return 0;
}

static struct drm_plane_funcs exynos_plane_funcs = {
        .update_plane   = drm_atomic_helper_update_plane,
        .disable_plane  = drm_atomic_helper_disable_plane,
        .destroy        = drm_plane_cleanup,
        .set_property   = drm_atomic_helper_plane_set_property,
        .reset          = exynos_drm_plane_reset,
        .atomic_duplicate_state = exynos_drm_plane_duplicate_state,
        .atomic_destroy_state = exynos_drm_plane_destroy_state,
        .atomic_set_property = exynos_drm_plane_atomic_set_property,
        .atomic_get_property = exynos_drm_plane_atomic_get_property,
};

static int
exynos_drm_plane_check_size(const struct exynos_drm_plane_config *config,
                            struct exynos_drm_plane_state *state)
{
        bool width_ok = false, height_ok = false;

        if (config->capabilities & EXYNOS_DRM_PLANE_CAP_SCALE)
                return 0;

        if (state->src.w == state->crtc.w)
                width_ok = true;

        if (state->src.h == state->crtc.h)
                height_ok = true;

        if ((config->capabilities & EXYNOS_DRM_PLANE_CAP_DOUBLE) &&
            state->h_ratio == (1 << 15))
                width_ok = true;

        if ((config->capabilities & EXYNOS_DRM_PLANE_CAP_DOUBLE) &&
            state->v_ratio == (1 << 15))
                height_ok = true;

        if (width_ok & height_ok)
                return 0;

        DRM_DEBUG_KMS("scaling mode is not supported");
        return -ENOTSUPP;
}

static int exynos_plane_atomic_check(struct drm_plane *plane,
                                     struct drm_plane_state *state)
{
        struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
        struct exynos_drm_plane_state *exynos_state =
                                                to_exynos_plane_state(state);
        int ret = 0;

        if (!state->crtc || !state->fb)
                return 0;

        /* translate state into exynos_state */
        exynos_plane_mode_set(exynos_state);

        ret = exynos_drm_plane_check_size(exynos_plane->config, exynos_state);
        return ret;
}

static void exynos_plane_atomic_update(struct drm_plane *plane,
                                       struct drm_plane_state *old_state)
{
        struct drm_plane_state *state = plane->state;
        struct exynos_drm_crtc *exynos_crtc = to_exynos_crtc(state->crtc);
        struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);

        if (!state->crtc)
                return;

        plane->crtc = state->crtc;
        exynos_plane->pending_fb = state->fb;

        if (exynos_crtc->ops->update_plane)
                exynos_crtc->ops->update_plane(exynos_crtc, exynos_plane);
}

static void exynos_plane_atomic_disable(struct drm_plane *plane,
                                        struct drm_plane_state *old_state)
{
        struct exynos_drm_plane *exynos_plane = to_exynos_plane(plane);
        struct exynos_drm_crtc *exynos_crtc = to_exynos_crtc(old_state->crtc);

        if (!old_state->crtc)
                return;

        if (exynos_crtc->ops->disable_plane)
                exynos_crtc->ops->disable_plane(exynos_crtc, exynos_plane);
}

static const struct drm_plane_helper_funcs plane_helper_funcs = {
        .atomic_check = exynos_plane_atomic_check,
        .atomic_update = exynos_plane_atomic_update,
        .atomic_disable = exynos_plane_atomic_disable,
};

static void exynos_plane_attach_zpos_property(struct drm_plane *plane,
                                              unsigned int zpos)
{
        struct drm_device *dev = plane->dev;
        struct exynos_drm_private *dev_priv = dev->dev_private;
        struct drm_property *prop;

        prop = dev_priv->plane_zpos_property;
        if (!prop) {
                prop = drm_property_create_range(dev, 0, "zpos",
                                                 0, MAX_PLANE - 1);
                if (!prop)
                        return;

                dev_priv->plane_zpos_property = prop;
        }

        drm_object_attach_property(&plane->base, prop, zpos);
}

int exynos_plane_init(struct drm_device *dev,
                      struct exynos_drm_plane *exynos_plane,
                      unsigned int index, unsigned long possible_crtcs,
                      const struct exynos_drm_plane_config *config)
{
        int err;

        err = drm_universal_plane_init(dev, &exynos_plane->base,
                                       possible_crtcs,
                                       &exynos_plane_funcs,
                                       config->pixel_formats,
                                       config->num_pixel_formats,
                                       config->type, NULL);
        if (err) {
                DRM_ERROR("failed to initialize plane\n");
                return err;
        }

        drm_plane_helper_add(&exynos_plane->base, &plane_helper_funcs);

        exynos_plane->index = index;
        exynos_plane->config = config;

        exynos_plane_attach_zpos_property(&exynos_plane->base, config->zpos);

        return 0;
}