// SPDX-License-Identifier: GPL-2.0-only
/*
 * ARC PGU DRM driver.
 *
 * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_device.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
#include <linux/clk.h>
#include <linux/platform_data/simplefb.h>

#include "arcpgu.h"
#include "arcpgu_regs.h"

#define ENCODE_PGU_XY(x, y)	((((x) - 1) << 16) | ((y) - 1))

static const u32 arc_pgu_supported_formats[] = {
	DRM_FORMAT_RGB565,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_ARGB8888,
};

static void arc_pgu_set_pxl_fmt(struct drm_crtc *crtc)
{
	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
	const struct drm_framebuffer *fb = crtc->primary->state->fb;
	uint32_t pixel_format = fb->format->format;
	u32 format = DRM_FORMAT_INVALID;
	int i;
	u32 reg_ctrl;

	for (i = 0; i < ARRAY_SIZE(arc_pgu_supported_formats); i++) {
		if (arc_pgu_supported_formats[i] == pixel_format)
			format = arc_pgu_supported_formats[i];
	}

	if (WARN_ON(format == DRM_FORMAT_INVALID))
		return;

	reg_ctrl = arc_pgu_read(arcpgu, ARCPGU_REG_CTRL);
	if (format == DRM_FORMAT_RGB565)
		reg_ctrl &= ~ARCPGU_MODE_XRGB8888;
	else
		reg_ctrl |= ARCPGU_MODE_XRGB8888;
	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL, reg_ctrl);
}

static const struct drm_crtc_funcs arc_pgu_crtc_funcs = {
	.destroy = drm_crtc_cleanup,
	.set_config = drm_atomic_helper_set_config,
	.page_flip = drm_atomic_helper_page_flip,
	.reset = drm_atomic_helper_crtc_reset,
	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
};

static enum drm_mode_status arc_pgu_crtc_mode_valid(struct drm_crtc *crtc,
						    const struct drm_display_mode *mode)
{
	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
	long rate, clk_rate = mode->clock * 1000;
	long diff = clk_rate / 200; /* +-0.5% allowed by HDMI spec */

	rate = clk_round_rate(arcpgu->clk, clk_rate);
	if ((max(rate, clk_rate) - min(rate, clk_rate) < diff) && (rate > 0))
		return MODE_OK;

	return MODE_NOCLOCK;
}

static void arc_pgu_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
	struct drm_display_mode *m = &crtc->state->adjusted_mode;
	u32 val;

	arc_pgu_write(arcpgu, ARCPGU_REG_FMT,
		      ENCODE_PGU_XY(m->crtc_htotal, m->crtc_vtotal));

	arc_pgu_write(arcpgu, ARCPGU_REG_HSYNC,
		      ENCODE_PGU_XY(m->crtc_hsync_start - m->crtc_hdisplay,
				    m->crtc_hsync_end - m->crtc_hdisplay));

	arc_pgu_write(arcpgu, ARCPGU_REG_VSYNC,
		      ENCODE_PGU_XY(m->crtc_vsync_start - m->crtc_vdisplay,
				    m->crtc_vsync_end - m->crtc_vdisplay));

	arc_pgu_write(arcpgu, ARCPGU_REG_ACTIVE,
		      ENCODE_PGU_XY(m->crtc_hblank_end - m->crtc_hblank_start,
				    m->crtc_vblank_end - m->crtc_vblank_start));

	val = arc_pgu_read(arcpgu, ARCPGU_REG_CTRL);

	if (m->flags & DRM_MODE_FLAG_PVSYNC)
		val |= ARCPGU_CTRL_VS_POL_MASK << ARCPGU_CTRL_VS_POL_OFST;
	else
		val &= ~(ARCPGU_CTRL_VS_POL_MASK << ARCPGU_CTRL_VS_POL_OFST);

	if (m->flags & DRM_MODE_FLAG_PHSYNC)
		val |= ARCPGU_CTRL_HS_POL_MASK << ARCPGU_CTRL_HS_POL_OFST;
	else
		val &= ~(ARCPGU_CTRL_HS_POL_MASK << ARCPGU_CTRL_HS_POL_OFST);

	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL, val);
	arc_pgu_write(arcpgu, ARCPGU_REG_STRIDE, 0);
	arc_pgu_write(arcpgu, ARCPGU_REG_START_SET, 1);

	arc_pgu_set_pxl_fmt(crtc);

	clk_set_rate(arcpgu->clk, m->crtc_clock * 1000);
}

static void arc_pgu_crtc_atomic_enable(struct drm_crtc *crtc,
				       struct drm_atomic_state *state)
{
	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);

	clk_prepare_enable(arcpgu->clk);
	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL,
		      arc_pgu_read(arcpgu, ARCPGU_REG_CTRL) |
		      ARCPGU_CTRL_ENABLE_MASK);
}

static void arc_pgu_crtc_atomic_disable(struct drm_crtc *crtc,
					struct drm_atomic_state *state)
{
	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);

	clk_disable_unprepare(arcpgu->clk);
	arc_pgu_write(arcpgu, ARCPGU_REG_CTRL,
			      arc_pgu_read(arcpgu, ARCPGU_REG_CTRL) &
			      ~ARCPGU_CTRL_ENABLE_MASK);
}

static const struct drm_crtc_helper_funcs arc_pgu_crtc_helper_funcs = {
	.mode_valid	= arc_pgu_crtc_mode_valid,
	.mode_set_nofb	= arc_pgu_crtc_mode_set_nofb,
	.atomic_enable	= arc_pgu_crtc_atomic_enable,
	.atomic_disable	= arc_pgu_crtc_atomic_disable,
};

static void arc_pgu_plane_atomic_update(struct drm_plane *plane,
					struct drm_atomic_state *state)
{
	struct drm_plane_state *new_plane_state = plane->state;
	struct arcpgu_drm_private *arcpgu;
	struct drm_gem_cma_object *gem;

	if (!new_plane_state->crtc || !new_plane_state->fb)
		return;

	arcpgu = crtc_to_arcpgu_priv(new_plane_state->crtc);
	gem = drm_fb_cma_get_gem_obj(new_plane_state->fb, 0);
	arc_pgu_write(arcpgu, ARCPGU_REG_BUF0_ADDR, gem->paddr);
}

static const struct drm_plane_helper_funcs arc_pgu_plane_helper_funcs = {
	.atomic_update = arc_pgu_plane_atomic_update,
};

static const struct drm_plane_funcs arc_pgu_plane_funcs = {
	.update_plane		= drm_atomic_helper_update_plane,
	.disable_plane		= drm_atomic_helper_disable_plane,
	.destroy		= drm_plane_cleanup,
	.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 struct drm_plane *arc_pgu_plane_init(struct drm_device *drm)
{
	struct arcpgu_drm_private *arcpgu = drm->dev_private;
	struct drm_plane *plane = NULL;
	int ret;

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

	ret = drm_universal_plane_init(drm, plane, 0xff, &arc_pgu_plane_funcs,
				       arc_pgu_supported_formats,
				       ARRAY_SIZE(arc_pgu_supported_formats),
				       NULL,
				       DRM_PLANE_TYPE_PRIMARY, NULL);
	if (ret)
		return ERR_PTR(ret);

	drm_plane_helper_add(plane, &arc_pgu_plane_helper_funcs);
	arcpgu->plane = plane;

	return plane;
}

int arc_pgu_setup_crtc(struct drm_device *drm)
{
	struct arcpgu_drm_private *arcpgu = drm->dev_private;
	struct drm_plane *primary;
	int ret;

	primary = arc_pgu_plane_init(drm);
	if (IS_ERR(primary))
		return PTR_ERR(primary);

	ret = drm_crtc_init_with_planes(drm, &arcpgu->crtc, primary, NULL,
					&arc_pgu_crtc_funcs, NULL);
	if (ret) {
		drm_plane_cleanup(primary);
		return ret;
	}

	drm_crtc_helper_add(&arcpgu->crtc, &arc_pgu_crtc_helper_funcs);
	return 0;
}