/*
 * Copyright 2016 Linaro Ltd.
 * Copyright 2016 ZTE Corporation.
 *
 * 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_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_plane_helper.h>
#include <drm/drmP.h>

#include "zx_drm_drv.h"
#include "zx_plane.h"
#include "zx_plane_regs.h"
#include "zx_vou.h"

struct zx_plane {
	struct drm_plane plane;
	void __iomem *layer;
	void __iomem *csc;
	void __iomem *hbsc;
	void __iomem *rsz;
};

#define to_zx_plane(plane)	container_of(plane, struct zx_plane, plane)

static const uint32_t gl_formats[] = {
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_RGB888,
	DRM_FORMAT_RGB565,
	DRM_FORMAT_ARGB1555,
	DRM_FORMAT_ARGB4444,
};

static int zx_gl_plane_atomic_check(struct drm_plane *plane,
				    struct drm_plane_state *plane_state)
{
	struct drm_framebuffer *fb = plane_state->fb;
	struct drm_crtc *crtc = plane_state->crtc;
	struct drm_crtc_state *crtc_state;
	struct drm_rect clip;

	if (!crtc || !fb)
		return 0;

	crtc_state = drm_atomic_get_existing_crtc_state(plane_state->state,
							crtc);
	if (WARN_ON(!crtc_state))
		return -EINVAL;

	/* nothing to check when disabling or disabled */
	if (!crtc_state->enable)
		return 0;

	/* plane must be enabled */
	if (!plane_state->crtc)
		return -EINVAL;

	clip.x1 = 0;
	clip.y1 = 0;
	clip.x2 = crtc_state->adjusted_mode.hdisplay;
	clip.y2 = crtc_state->adjusted_mode.vdisplay;

	return drm_plane_helper_check_state(plane_state, &clip,
					    DRM_PLANE_HELPER_NO_SCALING,
					    DRM_PLANE_HELPER_NO_SCALING,
					    false, true);
}

static int zx_gl_get_fmt(uint32_t format)
{
	switch (format) {
	case DRM_FORMAT_ARGB8888:
	case DRM_FORMAT_XRGB8888:
		return GL_FMT_ARGB8888;
	case DRM_FORMAT_RGB888:
		return GL_FMT_RGB888;
	case DRM_FORMAT_RGB565:
		return GL_FMT_RGB565;
	case DRM_FORMAT_ARGB1555:
		return GL_FMT_ARGB1555;
	case DRM_FORMAT_ARGB4444:
		return GL_FMT_ARGB4444;
	default:
		WARN_ONCE(1, "invalid pixel format %d\n", format);
		return -EINVAL;
	}
}

static inline void zx_gl_set_update(struct zx_plane *zplane)
{
	void __iomem *layer = zplane->layer;

	zx_writel_mask(layer + GL_CTRL0, GL_UPDATE, GL_UPDATE);
}

static inline void zx_gl_rsz_set_update(struct zx_plane *zplane)
{
	zx_writel(zplane->rsz + RSZ_ENABLE_CFG, 1);
}

void zx_plane_set_update(struct drm_plane *plane)
{
	struct zx_plane *zplane = to_zx_plane(plane);

	zx_gl_rsz_set_update(zplane);
	zx_gl_set_update(zplane);
}

static void zx_gl_rsz_setup(struct zx_plane *zplane, u32 src_w, u32 src_h,
			    u32 dst_w, u32 dst_h)
{
	void __iomem *rsz = zplane->rsz;

	zx_writel(rsz + RSZ_SRC_CFG, RSZ_VER(src_h - 1) | RSZ_HOR(src_w - 1));
	zx_writel(rsz + RSZ_DEST_CFG, RSZ_VER(dst_h - 1) | RSZ_HOR(dst_w - 1));

	zx_gl_rsz_set_update(zplane);
}

static void zx_gl_plane_atomic_update(struct drm_plane *plane,
				      struct drm_plane_state *old_state)
{
	struct zx_plane *zplane = to_zx_plane(plane);
	struct drm_framebuffer *fb = plane->state->fb;
	struct drm_gem_cma_object *cma_obj;
	void __iomem *layer = zplane->layer;
	void __iomem *csc = zplane->csc;
	void __iomem *hbsc = zplane->hbsc;
	u32 src_x, src_y, src_w, src_h;
	u32 dst_x, dst_y, dst_w, dst_h;
	unsigned int bpp;
	uint32_t format;
	dma_addr_t paddr;
	u32 stride;
	int fmt;

	if (!fb)
		return;

	format = fb->pixel_format;
	stride = fb->pitches[0];

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

	dst_x = plane->state->crtc_x;
	dst_y = plane->state->crtc_y;
	dst_w = plane->state->crtc_w;
	dst_h = plane->state->crtc_h;

	bpp = drm_format_plane_cpp(format, 0);

	cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
	paddr = cma_obj->paddr + fb->offsets[0];
	paddr += src_y * stride + src_x * bpp / 8;
	zx_writel(layer + GL_ADDR, paddr);

	/* Set up source height/width register */
	zx_writel(layer + GL_SRC_SIZE, GL_SRC_W(src_w) | GL_SRC_H(src_h));

	/* Set up start position register */
	zx_writel(layer + GL_POS_START, GL_POS_X(dst_x) | GL_POS_Y(dst_y));

	/* Set up end position register */
	zx_writel(layer + GL_POS_END,
		  GL_POS_X(dst_x + dst_w) | GL_POS_Y(dst_y + dst_h));

	/* Set up stride register */
	zx_writel(layer + GL_STRIDE, stride & 0xffff);

	/* Set up graphic layer data format */
	fmt = zx_gl_get_fmt(format);
	if (fmt >= 0)
		zx_writel_mask(layer + GL_CTRL1, GL_DATA_FMT_MASK,
			       fmt << GL_DATA_FMT_SHIFT);

	/* Initialize global alpha with a sane value */
	zx_writel_mask(layer + GL_CTRL2, GL_GLOBAL_ALPHA_MASK,
		       0xff << GL_GLOBAL_ALPHA_SHIFT);

	/* Setup CSC for the GL */
	if (dst_h > 720)
		zx_writel_mask(csc + CSC_CTRL0, CSC_COV_MODE_MASK,
			       CSC_BT709_IMAGE_RGB2YCBCR << CSC_COV_MODE_SHIFT);
	else
		zx_writel_mask(csc + CSC_CTRL0, CSC_COV_MODE_MASK,
			       CSC_BT601_IMAGE_RGB2YCBCR << CSC_COV_MODE_SHIFT);
	zx_writel_mask(csc + CSC_CTRL0, CSC_WORK_ENABLE, CSC_WORK_ENABLE);

	/* Always use scaler since it exists (set for not bypass) */
	zx_writel_mask(layer + GL_CTRL3, GL_SCALER_BYPASS_MODE,
		       GL_SCALER_BYPASS_MODE);

	zx_gl_rsz_setup(zplane, src_w, src_h, dst_w, dst_h);

	/* Enable HBSC block */
	zx_writel_mask(hbsc + HBSC_CTRL0, HBSC_CTRL_EN, HBSC_CTRL_EN);

	zx_gl_set_update(zplane);
}

static const struct drm_plane_helper_funcs zx_gl_plane_helper_funcs = {
	.atomic_check = zx_gl_plane_atomic_check,
	.atomic_update = zx_gl_plane_atomic_update,
};

static void zx_plane_destroy(struct drm_plane *plane)
{
	drm_plane_helper_disable(plane);
	drm_plane_cleanup(plane);
}

static const struct drm_plane_funcs zx_plane_funcs = {
	.update_plane = drm_atomic_helper_update_plane,
	.disable_plane = drm_atomic_helper_disable_plane,
	.destroy = zx_plane_destroy,
	.reset = drm_atomic_helper_plane_reset,
	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
};

static void zx_plane_hbsc_init(struct zx_plane *zplane)
{
	void __iomem *hbsc = zplane->hbsc;

	/*
	 *  Initialize HBSC block with a sane configuration per recommedation
	 *  from ZTE BSP code.
	 */
	zx_writel(hbsc + HBSC_SATURATION, 0x200);
	zx_writel(hbsc + HBSC_HUE, 0x0);
	zx_writel(hbsc + HBSC_BRIGHT, 0x0);
	zx_writel(hbsc + HBSC_CONTRAST, 0x200);

	zx_writel(hbsc + HBSC_THRESHOLD_COL1, (0x3ac << 16) | 0x40);
	zx_writel(hbsc + HBSC_THRESHOLD_COL2, (0x3c0 << 16) | 0x40);
	zx_writel(hbsc + HBSC_THRESHOLD_COL3, (0x3c0 << 16) | 0x40);
}

struct drm_plane *zx_plane_init(struct drm_device *drm, struct device *dev,
				struct zx_layer_data *data,
				enum drm_plane_type type)
{
	const struct drm_plane_helper_funcs *helper;
	struct zx_plane *zplane;
	struct drm_plane *plane;
	const uint32_t *formats;
	unsigned int format_count;
	int ret;

	zplane = devm_kzalloc(dev, sizeof(*zplane), GFP_KERNEL);
	if (!zplane)
		return ERR_PTR(-ENOMEM);

	plane = &zplane->plane;

	zplane->layer = data->layer;
	zplane->hbsc = data->hbsc;
	zplane->csc = data->csc;
	zplane->rsz = data->rsz;

	zx_plane_hbsc_init(zplane);

	switch (type) {
	case DRM_PLANE_TYPE_PRIMARY:
		helper = &zx_gl_plane_helper_funcs;
		formats = gl_formats;
		format_count = ARRAY_SIZE(gl_formats);
		break;
	case DRM_PLANE_TYPE_OVERLAY:
		/* TODO: add video layer (vl) support */
		break;
	default:
		return ERR_PTR(-ENODEV);
	}

	ret = drm_universal_plane_init(drm, plane, VOU_CRTC_MASK,
				       &zx_plane_funcs, formats, format_count,
				       type, NULL);
	if (ret) {
		DRM_DEV_ERROR(dev, "failed to init universal plane: %d\n", ret);
		return ERR_PTR(ret);
	}

	drm_plane_helper_add(plane, helper);

	return plane;
}