/*
   * Exynos DRM Parallel output support.
   *
   * Copyright (c) 2014 Samsung Electronics Co., Ltd
   *
   * Contacts: Andrzej Hajda <a.hajda@samsung.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.
  */
  
  #include <drm/drmP.h>
  #include <drm/drm_crtc_helper.h>
  #include <drm/drm_panel.h>
  
  #include <linux/regulator/consumer.h>
  
  #include <video/of_videomode.h>
  #include <video/videomode.h>
  
  #include "exynos_drm_drv.h"
  
  struct exynos_dpi {
  	struct device *dev;
  	struct device_node *panel_node;
  
  	struct drm_panel *panel;
  	struct drm_connector connector;
  	struct drm_encoder *encoder;
  
  	struct videomode *vm;
  	int dpms_mode;
  };
  
  #define connector_to_dpi(c) container_of(c, struct exynos_dpi, connector)
  
  static enum drm_connector_status
  exynos_dpi_detect(struct drm_connector *connector, bool force)
  {
  	struct exynos_dpi *ctx = connector_to_dpi(connector);

  	if (ctx->panel && !ctx->panel->connector)

  		drm_panel_attach(ctx->panel, &ctx->connector);

  	return connector_status_connected;

  }
  
  static void exynos_dpi_connector_destroy(struct drm_connector *connector)
  {

  	drm_connector_unregister(connector);

  	drm_connector_cleanup(connector);
  }
  
  static struct drm_connector_funcs exynos_dpi_connector_funcs = {
  	.dpms = drm_helper_connector_dpms,
  	.detect = exynos_dpi_detect,
  	.fill_modes = drm_helper_probe_single_connector_modes,
  	.destroy = exynos_dpi_connector_destroy,
  };
  
  static int exynos_dpi_get_modes(struct drm_connector *connector)
  {
  	struct exynos_dpi *ctx = connector_to_dpi(connector);
  
  	/* fimd timings gets precedence over panel modes */
  	if (ctx->vm) {
  		struct drm_display_mode *mode;
  
  		mode = drm_mode_create(connector->dev);
  		if (!mode) {
  			DRM_ERROR("failed to create a new display mode
  ");
  			return 0;
  		}
  		drm_display_mode_from_videomode(ctx->vm, mode);
  		mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
  		drm_mode_probed_add(connector, mode);
  		return 1;
  	}
  
  	if (ctx->panel)
  		return ctx->panel->funcs->get_modes(ctx->panel);
  
  	return 0;
  }

  static struct drm_encoder *
  exynos_dpi_best_encoder(struct drm_connector *connector)
  {
  	struct exynos_dpi *ctx = connector_to_dpi(connector);
  
  	return ctx->encoder;
  }
  
  static struct drm_connector_helper_funcs exynos_dpi_connector_helper_funcs = {
  	.get_modes = exynos_dpi_get_modes,

  	.best_encoder = exynos_dpi_best_encoder,
  };
  
  static int exynos_dpi_create_connector(struct exynos_drm_display *display,
  				       struct drm_encoder *encoder)
  {
  	struct exynos_dpi *ctx = display->ctx;
  	struct drm_connector *connector = &ctx->connector;
  	int ret;
  
  	ctx->encoder = encoder;

  	connector->polled = DRM_CONNECTOR_POLL_HPD;

  
  	ret = drm_connector_init(encoder->dev, connector,
  				 &exynos_dpi_connector_funcs,
  				 DRM_MODE_CONNECTOR_VGA);
  	if (ret) {
  		DRM_ERROR("failed to initialize connector with drm
  ");
  		return ret;
  	}
  
  	drm_connector_helper_add(connector, &exynos_dpi_connector_helper_funcs);

  	drm_connector_register(connector);

  	drm_mode_connector_attach_encoder(connector, encoder);
  
  	return 0;
  }
  
  static void exynos_dpi_poweron(struct exynos_dpi *ctx)
  {

  	if (ctx->panel) {
  		drm_panel_prepare(ctx->panel);

  		drm_panel_enable(ctx->panel);

  	}

  }
  
  static void exynos_dpi_poweroff(struct exynos_dpi *ctx)
  {

  	if (ctx->panel) {

  		drm_panel_disable(ctx->panel);

  		drm_panel_unprepare(ctx->panel);
  	}

  }
  
  static void exynos_dpi_dpms(struct exynos_drm_display *display, int mode)
  {
  	struct exynos_dpi *ctx = display->ctx;
  
  	switch (mode) {
  	case DRM_MODE_DPMS_ON:
  		if (ctx->dpms_mode != DRM_MODE_DPMS_ON)
  				exynos_dpi_poweron(ctx);
  			break;
  	case DRM_MODE_DPMS_STANDBY:
  	case DRM_MODE_DPMS_SUSPEND:
  	case DRM_MODE_DPMS_OFF:
  		if (ctx->dpms_mode == DRM_MODE_DPMS_ON)
  			exynos_dpi_poweroff(ctx);
  		break;
  	default:
  		break;

  	}

  	ctx->dpms_mode = mode;
  }
  
  static struct exynos_drm_display_ops exynos_dpi_display_ops = {
  	.create_connector = exynos_dpi_create_connector,
  	.dpms = exynos_dpi_dpms
  };
  
  static struct exynos_drm_display exynos_dpi_display = {
  	.type = EXYNOS_DISPLAY_TYPE_LCD,
  	.ops = &exynos_dpi_display_ops,
  };
  
  /* of_* functions will be removed after merge of of_graph patches */
  static struct device_node *
  of_get_child_by_name_reg(struct device_node *parent, const char *name, u32 reg)
  {
  	struct device_node *np;
  
  	for_each_child_of_node(parent, np) {
  		u32 r;
  
  		if (!np->name || of_node_cmp(np->name, name))
  			continue;
  
  		if (of_property_read_u32(np, "reg", &r) < 0)
  			r = 0;
  
  		if (reg == r)
  			break;
  	}
  
  	return np;
  }
  
  static struct device_node *of_graph_get_port_by_reg(struct device_node *parent,
  						    u32 reg)
  {
  	struct device_node *ports, *port;
  
  	ports = of_get_child_by_name(parent, "ports");
  	if (ports)
  		parent = ports;
  
  	port = of_get_child_by_name_reg(parent, "port", reg);
  
  	of_node_put(ports);
  
  	return port;
  }
  
  static struct device_node *
  of_graph_get_endpoint_by_reg(struct device_node *port, u32 reg)
  {
  	return of_get_child_by_name_reg(port, "endpoint", reg);
  }
  
  static struct device_node *
  of_graph_get_remote_port_parent(const struct device_node *node)
  {
  	struct device_node *np;
  	unsigned int depth;
  
  	np = of_parse_phandle(node, "remote-endpoint", 0);
  
  	/* Walk 3 levels up only if there is 'ports' node. */
  	for (depth = 3; depth && np; depth--) {
  		np = of_get_next_parent(np);
  		if (depth == 2 && of_node_cmp(np->name, "ports"))
  			break;
  	}
  	return np;
  }
  
  enum {
  	FIMD_PORT_IN0,
  	FIMD_PORT_IN1,
  	FIMD_PORT_IN2,
  	FIMD_PORT_RGB,
  	FIMD_PORT_WRB,
  };

  static struct device_node *exynos_dpi_of_find_panel_node(struct device *dev)

  {
  	struct device_node *np, *ep;
  
  	np = of_graph_get_port_by_reg(dev->of_node, FIMD_PORT_RGB);
  	if (!np)
  		return NULL;
  
  	ep = of_graph_get_endpoint_by_reg(np, 0);
  	of_node_put(np);
  	if (!ep)
  		return NULL;
  
  	np = of_graph_get_remote_port_parent(ep);
  	of_node_put(ep);
  
  	return np;
  }
  
  static int exynos_dpi_parse_dt(struct exynos_dpi *ctx)
  {
  	struct device *dev = ctx->dev;
  	struct device_node *dn = dev->of_node;
  	struct device_node *np;
  
  	ctx->panel_node = exynos_dpi_of_find_panel_node(dev);
  
  	np = of_get_child_by_name(dn, "display-timings");
  	if (np) {
  		struct videomode *vm;
  		int ret;
  
  		of_node_put(np);
  
  		vm = devm_kzalloc(dev, sizeof(*ctx->vm), GFP_KERNEL);
  		if (!vm)
  			return -ENOMEM;
  
  		ret = of_get_videomode(dn, vm, 0);

  		if (ret < 0) {
  			devm_kfree(dev, vm);

  			return ret;

  		}

  
  		ctx->vm = vm;
  
  		return 0;
  	}
  
  	if (!ctx->panel_node)
  		return -EINVAL;
  
  	return 0;
  }

  struct exynos_drm_display *exynos_dpi_probe(struct device *dev)

  {
  	struct exynos_dpi *ctx;
  	int ret;

  	ret = exynos_drm_component_add(dev,
  					EXYNOS_DEVICE_TYPE_CONNECTOR,
  					exynos_dpi_display.type);
  	if (ret)
  		return ERR_PTR(ret);

  	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
  	if (!ctx)

  		goto err_del_component;

  
  	ctx->dev = dev;
  	exynos_dpi_display.ctx = ctx;
  	ctx->dpms_mode = DRM_MODE_DPMS_OFF;
  
  	ret = exynos_dpi_parse_dt(ctx);

  	if (ret < 0) {
  		devm_kfree(dev, ctx);

  		goto err_del_component;

  	}
  
  	if (ctx->panel_node) {
  		ctx->panel = of_drm_find_panel(ctx->panel_node);

  		if (!ctx->panel) {
  			exynos_drm_component_del(dev,
  						EXYNOS_DEVICE_TYPE_CONNECTOR);

  			return ERR_PTR(-EPROBE_DEFER);

  		}

  	}

  	return &exynos_dpi_display;

  
  err_del_component:
  	exynos_drm_component_del(dev, EXYNOS_DEVICE_TYPE_CONNECTOR);
  
  	return NULL;

  }

  int exynos_dpi_remove(struct device *dev)

  {

  	struct exynos_dpi *ctx = exynos_dpi_display.ctx;

  	exynos_dpi_dpms(&exynos_dpi_display, DRM_MODE_DPMS_OFF);

  	if (ctx->panel)
  		drm_panel_detach(ctx->panel);

  	exynos_drm_component_del(dev, EXYNOS_DEVICE_TYPE_CONNECTOR);

  	return 0;
  }