/*
 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
 * Copyright (c) 2014, Inforce Computing. All rights reserved.
 *
 * Author: Vinay Simha <vinaysimha@inforcecomputing.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.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <drm/drm_crtc.h>
#include <drm/drm_probe_helper.h>

#include "mdp4_kms.h"

struct mdp4_dsi_encoder {
	struct drm_encoder base;
	struct drm_panel *panel;
	bool enabled;
};
#define to_mdp4_dsi_encoder(x) container_of(x, struct mdp4_dsi_encoder, base)

static struct mdp4_kms *get_kms(struct drm_encoder *encoder)
{
	struct msm_drm_private *priv = encoder->dev->dev_private;
	return to_mdp4_kms(to_mdp_kms(priv->kms));
}

static void mdp4_dsi_encoder_destroy(struct drm_encoder *encoder)
{
	struct mdp4_dsi_encoder *mdp4_dsi_encoder = to_mdp4_dsi_encoder(encoder);

	drm_encoder_cleanup(encoder);
	kfree(mdp4_dsi_encoder);
}

static const struct drm_encoder_funcs mdp4_dsi_encoder_funcs = {
	.destroy = mdp4_dsi_encoder_destroy,
};

static void mdp4_dsi_encoder_mode_set(struct drm_encoder *encoder,
				      struct drm_display_mode *mode,
				      struct drm_display_mode *adjusted_mode)
{
	struct mdp4_kms *mdp4_kms = get_kms(encoder);
	uint32_t dsi_hsync_skew, vsync_period, vsync_len, ctrl_pol;
	uint32_t display_v_start, display_v_end;
	uint32_t hsync_start_x, hsync_end_x;

	mode = adjusted_mode;

	DBG("set mode: " DRM_MODE_FMT, DRM_MODE_ARG(mode));

	ctrl_pol = 0;
	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
		ctrl_pol |= MDP4_DSI_CTRL_POLARITY_HSYNC_LOW;
	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
		ctrl_pol |= MDP4_DSI_CTRL_POLARITY_VSYNC_LOW;
	/* probably need to get DATA_EN polarity from panel.. */

	dsi_hsync_skew = 0;  /* get this from panel? */

	hsync_start_x = (mode->htotal - mode->hsync_start);
	hsync_end_x = mode->htotal - (mode->hsync_start - mode->hdisplay) - 1;

	vsync_period = mode->vtotal * mode->htotal;
	vsync_len = (mode->vsync_end - mode->vsync_start) * mode->htotal;
	display_v_start = (mode->vtotal - mode->vsync_start) * mode->htotal + dsi_hsync_skew;
	display_v_end = vsync_period - ((mode->vsync_start - mode->vdisplay) * mode->htotal) + dsi_hsync_skew - 1;

	mdp4_write(mdp4_kms, REG_MDP4_DSI_HSYNC_CTRL,
			MDP4_DSI_HSYNC_CTRL_PULSEW(mode->hsync_end - mode->hsync_start) |
			MDP4_DSI_HSYNC_CTRL_PERIOD(mode->htotal));
	mdp4_write(mdp4_kms, REG_MDP4_DSI_VSYNC_PERIOD, vsync_period);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_VSYNC_LEN, vsync_len);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_DISPLAY_HCTRL,
			MDP4_DSI_DISPLAY_HCTRL_START(hsync_start_x) |
			MDP4_DSI_DISPLAY_HCTRL_END(hsync_end_x));
	mdp4_write(mdp4_kms, REG_MDP4_DSI_DISPLAY_VSTART, display_v_start);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_DISPLAY_VEND, display_v_end);

	mdp4_write(mdp4_kms, REG_MDP4_DSI_CTRL_POLARITY, ctrl_pol);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_UNDERFLOW_CLR,
			MDP4_DSI_UNDERFLOW_CLR_ENABLE_RECOVERY |
			MDP4_DSI_UNDERFLOW_CLR_COLOR(0xff));
	mdp4_write(mdp4_kms, REG_MDP4_DSI_ACTIVE_HCTL,
			MDP4_DSI_ACTIVE_HCTL_START(0) |
			MDP4_DSI_ACTIVE_HCTL_END(0));
	mdp4_write(mdp4_kms, REG_MDP4_DSI_HSYNC_SKEW, dsi_hsync_skew);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_BORDER_CLR, 0);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_ACTIVE_VSTART, 0);
	mdp4_write(mdp4_kms, REG_MDP4_DSI_ACTIVE_VEND, 0);
}

static void mdp4_dsi_encoder_disable(struct drm_encoder *encoder)
{
	struct mdp4_dsi_encoder *mdp4_dsi_encoder = to_mdp4_dsi_encoder(encoder);
	struct mdp4_kms *mdp4_kms = get_kms(encoder);

	if (!mdp4_dsi_encoder->enabled)
		return;

	mdp4_write(mdp4_kms, REG_MDP4_DSI_ENABLE, 0);

	/*
	 * Wait for a vsync so we know the ENABLE=0 latched before
	 * the (connector) source of the vsync's gets disabled,
	 * otherwise we end up in a funny state if we re-enable
	 * before the disable latches, which results that some of
	 * the settings changes for the new modeset (like new
	 * scanout buffer) don't latch properly..
	 */
	mdp_irq_wait(&mdp4_kms->base, MDP4_IRQ_PRIMARY_VSYNC);

	mdp4_dsi_encoder->enabled = false;
}

static void mdp4_dsi_encoder_enable(struct drm_encoder *encoder)
{
	struct mdp4_dsi_encoder *mdp4_dsi_encoder = to_mdp4_dsi_encoder(encoder);
	struct mdp4_kms *mdp4_kms = get_kms(encoder);

	if (mdp4_dsi_encoder->enabled)
		return;

	 mdp4_crtc_set_config(encoder->crtc,
			MDP4_DMA_CONFIG_PACK_ALIGN_MSB |
			MDP4_DMA_CONFIG_DEFLKR_EN |
			MDP4_DMA_CONFIG_DITHER_EN |
			MDP4_DMA_CONFIG_R_BPC(BPC8) |
			MDP4_DMA_CONFIG_G_BPC(BPC8) |
			MDP4_DMA_CONFIG_B_BPC(BPC8) |
			MDP4_DMA_CONFIG_PACK(0x21));

	mdp4_crtc_set_intf(encoder->crtc, INTF_DSI_VIDEO, 0);

	mdp4_write(mdp4_kms, REG_MDP4_DSI_ENABLE, 1);

	mdp4_dsi_encoder->enabled = true;
}

static const struct drm_encoder_helper_funcs mdp4_dsi_encoder_helper_funcs = {
	.mode_set = mdp4_dsi_encoder_mode_set,
	.disable = mdp4_dsi_encoder_disable,
	.enable = mdp4_dsi_encoder_enable,
};

/* initialize encoder */
struct drm_encoder *mdp4_dsi_encoder_init(struct drm_device *dev)
{
	struct drm_encoder *encoder = NULL;
	struct mdp4_dsi_encoder *mdp4_dsi_encoder;
	int ret;

	mdp4_dsi_encoder = kzalloc(sizeof(*mdp4_dsi_encoder), GFP_KERNEL);
	if (!mdp4_dsi_encoder) {
		ret = -ENOMEM;
		goto fail;
	}

	encoder = &mdp4_dsi_encoder->base;

	drm_encoder_init(dev, encoder, &mdp4_dsi_encoder_funcs,
			 DRM_MODE_ENCODER_DSI, NULL);
	drm_encoder_helper_add(encoder, &mdp4_dsi_encoder_helper_funcs);

	return encoder;

fail:
	if (encoder)
		mdp4_dsi_encoder_destroy(encoder);

	return ERR_PTR(ret);
}