[RFC,3/6] drm/tilcdc: Add support for external compontised DRM encoder

diff --git a/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt b/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt
index fff10da..2136ee8 100644
--- a/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt
+++ b/Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt
@@ -18,6 +18,12 @@  Optional properties:
  - max-pixelclock: The maximum pixel clock that can be supported
    by the lcd controller in KHz.
 
+Optional nodes:
+
+ - port/ports: to describe a connection to an external encoder. The
+   binding follows Documentation/devicetree/bindings/graph.txt and
+   suppors a single port with a single endpoint.
+
 Example:
 
 	fb: fb@4830e000 {
@@ -26,4 +32,25 @@  Example:
 		interrupt-parent = <&intc>;
 		interrupts = <36>;
 		ti,hwmods = "lcdc";
+
+		port {
+			lcdc_0: endpoint@0 {
+				remote-endpoint = <&hdmi_0>;
+			};
+		};
+	};
+
+	tda19988: tda19988 {
+		compatible = "nxp,tda998x";
+		reg = <0x70>;
+
+		pinctrl-names = "default", "off";
+		pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
+		pinctrl-1 = <&nxp_hdmi_bonelt_off_pins>;
+
+		port {
+			hdmi_0: endpoint@0 {
+				remote-endpoint = <&lcdc_0>;
+			};
+		};
 	};
diff --git a/drivers/gpu/drm/tilcdc/Makefile b/drivers/gpu/drm/tilcdc/Makefile
index 44485f9..e1f738b 100644
--- a/drivers/gpu/drm/tilcdc/Makefile
+++ b/drivers/gpu/drm/tilcdc/Makefile
@@ -7,6 +7,7 @@  tilcdc-y := \
 	tilcdc_crtc.o \
 	tilcdc_tfp410.o \
 	tilcdc_panel.o \
+	tilcdc_external.o \
 	tilcdc_drv.o
 
 obj-$(CONFIG_DRM_TILCDC)	+= tilcdc.o
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index c2d5980..7d07733 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -37,6 +37,9 @@  struct tilcdc_crtc {
 
 	/* for deferred fb unref's: */
 	struct drm_flip_work unref_work;
+
+	/* Only set if an external encoder is connected */
+	bool simulate_vesa_sync;
 };
 #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
 
@@ -214,6 +217,28 @@  static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
 		const struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
 {
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+
+	if (!tilcdc_crtc->simulate_vesa_sync)
+		return true;
+
+	/*
+	 * tilcdc does not generate VESA-compliant sync but aligns
+	 * VS on the second edge of HS instead of first edge.
+	 * We use adjusted_mode, to fixup sync by aligning both rising
+	 * edges and add HSKEW offset to fix the sync.
+	 */
+	adjusted_mode->hskew = mode->hsync_end - mode->hsync_start;
+	adjusted_mode->flags |= DRM_MODE_FLAG_HSKEW;
+
+	if (mode->flags & DRM_MODE_FLAG_NHSYNC) {
+		adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
+		adjusted_mode->flags &= ~DRM_MODE_FLAG_NHSYNC;
+	} else {
+		adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC;
+		adjusted_mode->flags &= ~DRM_MODE_FLAG_PHSYNC;
+	}
+
 	return true;
 }
 
@@ -534,6 +559,14 @@  void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
 	tilcdc_crtc->info = info;
 }
 
+void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc,
+					bool simulate_vesa_sync)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+
+	tilcdc_crtc->simulate_vesa_sync = simulate_vesa_sync;
+}
+
 void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
 {
 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 0f1e099..50e1be1 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -17,10 +17,13 @@ 
 
 /* LCDC DRM driver, based on da8xx-fb */
 
+#include <linux/component.h>
+
 #include "tilcdc_drv.h"
 #include "tilcdc_regs.h"
 #include "tilcdc_tfp410.h"
 #include "tilcdc_panel.h"
+#include "tilcdc_external.h"
 
 #include "drm_fb_helper.h"
 
@@ -73,13 +76,6 @@  static int modeset_init(struct drm_device *dev)
 		mod->funcs->modeset_init(mod, dev);
 	}
 
-	if ((priv->num_encoders == 0) || (priv->num_connectors == 0)) {
-		/* oh nos! */
-		dev_err(dev->dev, "no encoders/connectors found\n");
-		drm_mode_config_cleanup(dev);
-		return -ENXIO;
-	}
-
 	dev->mode_config.min_width = 0;
 	dev->mode_config.min_height = 0;
 	dev->mode_config.max_width = tilcdc_crtc_max_width(priv->crtc);
@@ -253,10 +249,28 @@  static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 		goto fail_cpufreq_unregister;
 	}
 
+	platform_set_drvdata(pdev, dev);
+
+	ret = component_bind_all(dev->dev, dev);
+	if (ret < 0) {
+		dev_err(dev->dev, "Binding subcomponents failed: %d\n", ret);
+		goto fail_mode_config_cleanup;
+	}
+
+	ret = tilcdc_add_external_encoders(dev, &bpp);
+	if (ret < 0)
+		goto fail_component_cleanup;
+
+	if ((priv->num_encoders == 0) || (priv->num_connectors == 0)) {
+		dev_err(dev->dev, "no encoders/connectors found\n");
+		ret = -ENXIO;
+		goto fail_component_cleanup;
+	}
+
 	ret = drm_vblank_init(dev, 1);
 	if (ret < 0) {
 		dev_err(dev->dev, "failed to initialize vblank\n");
-		goto fail_mode_config_cleanup;
+		goto fail_component_cleanup;
 	}
 
 	pm_runtime_get_sync(dev->dev);
@@ -267,9 +281,6 @@  static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 		goto fail_vblank_cleanup;
 	}
 
-	platform_set_drvdata(pdev, dev);
-
-
 	list_for_each_entry(mod, &module_list, list) {
 		DBG("%s: preferred_bpp: %d", mod->name, mod->preferred_bpp);
 		bpp = mod->preferred_bpp;
@@ -300,6 +311,9 @@  fail_vblank_cleanup:
 fail_mode_config_cleanup:
 	drm_mode_config_cleanup(dev);
 
+fail_component_cleanup:
+	component_unbind_all(dev->dev, dev);
+
 fail_cpufreq_unregister:
 	pm_runtime_disable(dev->dev);
 #ifdef CONFIG_CPU_FREQ
@@ -605,6 +619,22 @@  static const struct dev_pm_ops tilcdc_pm_ops = {
  * Platform driver:
  */
 
+static int tilcdc_bind(struct device *dev)
+{
+	return drm_platform_init(&tilcdc_driver, to_platform_device(dev));
+}
+
+static void tilcdc_unbind(struct device *dev)
+{
+	drm_put_dev(dev_get_drvdata(dev));
+}
+
+static const struct component_master_ops tilcdc_comp_ops = {
+	.add_components = tilcdc_add_external_components,
+	.bind = tilcdc_bind,
+	.unbind = tilcdc_unbind,
+};
+
 static int tilcdc_pdev_probe(struct platform_device *pdev)
 {
 	/* bail out early if no DT data: */
@@ -613,12 +643,12 @@  static int tilcdc_pdev_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
-	return drm_platform_init(&tilcdc_driver, pdev);
+	return component_master_add(&pdev->dev, &tilcdc_comp_ops);
 }
 
 static int tilcdc_pdev_remove(struct platform_device *pdev)
 {
-	drm_put_dev(platform_get_drvdata(pdev));
+	component_master_del(&pdev->dev, &tilcdc_comp_ops);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
index 6336512..70a06c7 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
@@ -165,6 +165,8 @@  irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc);
 void tilcdc_crtc_update_clk(struct drm_crtc *crtc);
 void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
 		const struct tilcdc_panel_info *info);
+void tilcdc_crtc_set_simulate_vesa_sync(struct drm_crtc *crtc,
+					bool simulate_vesa_sync);
 int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode *mode);
 int tilcdc_crtc_max_width(struct drm_crtc *crtc);
 
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_external.c b/drivers/gpu/drm/tilcdc/tilcdc_external.c
new file mode 100644
index 0000000..7254151
--- /dev/null
+++ b/drivers/gpu/drm/tilcdc/tilcdc_external.c
@@ -0,0 +1,105 @@ 
+/*
+ * Copyright (C) 2015 Texas Instruments
+ * Author: Jyri Sarha <jsarha@ti.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.
+ *
+ */
+#define DEBUG 1
+
+#include <linux/component.h>
+#include <linux/of_graph.h>
+
+#include "tilcdc_drv.h"
+#include "tilcdc_external.h"
+
+static const struct tilcdc_panel_info panel_info_defaults = {
+		.ac_bias                = 255,
+		.ac_bias_intrpt         = 0,
+		.dma_burst_sz           = 16,
+		.bpp                    = 16,
+		.fdd                    = 0x80,
+		.tft_alt_mode           = 0,
+		.invert_pxl_clk		= 1,
+		.sync_edge              = 1,
+		.sync_ctrl              = 1,
+		.raster_order           = 0,
+};
+
+static int tilcdc_add_external_encoder(struct drm_device *dev, int *bpp,
+				       struct drm_connector *connector)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+
+	priv->connectors[priv->num_connectors++] = connector;
+	priv->encoders[priv->num_encoders++] = connector->encoder;
+
+	tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
+	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_defaults);
+	*bpp = panel_info_defaults.bpp;
+
+	dev_info(dev->dev, "External encoder '%s' connected\n",
+		 connector->encoder->name);
+
+	return 0;
+}
+
+
+int tilcdc_add_external_encoders(struct drm_device *dev, int *bpp)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	struct drm_connector *connector;
+	int num_internal_connectors = priv->num_connectors;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		bool found = false;
+		int i, ret;
+
+		for (i = 0; i < num_internal_connectors; i++)
+			if (connector == priv->connectors[i])
+				found = true;
+		if (!found) {
+			ret = tilcdc_add_external_encoder(dev, bpp, connector);
+			if (ret)
+				return ret;
+		}
+	}
+	if (priv->num_connectors - num_internal_connectors > 1) {
+		dev_err(dev->dev, "Only one external encoder is supported.");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int of_dev_node_match(struct device *dev, void *data)
+{
+	return dev->of_node == data;
+}
+
+int tilcdc_add_external_components(struct device *master,
+				   struct master *m)
+{
+	struct device_node *ep = NULL;
+
+	while ((ep = of_graph_get_next_endpoint(master->of_node, ep))) {
+		struct device_node *node;
+		int ret;
+
+		node = of_graph_get_remote_port_parent(ep);
+		of_node_put(ep);
+		if (!node || !of_device_is_available(node))
+			continue;
+
+		dev_info(master, "Subdevice node '%s' found\n", node->name);
+		ret = component_master_add_child(m, of_dev_node_match, node);
+		of_node_put(node);
+		if (ret) {
+			dev_err(master, "Adding component failed: %d\n", ret);
+			of_node_put(ep);
+			return ret;
+		}
+	}
+	return 0;
+}
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_external.h b/drivers/gpu/drm/tilcdc/tilcdc_external.h
new file mode 100644
index 0000000..8acf3a1
--- /dev/null
+++ b/drivers/gpu/drm/tilcdc/tilcdc_external.h
@@ -0,0 +1,24 @@ 
+/*
+ * Copyright (C) 2015 Texas Instruments
+ * Author: Jyri Sarha <jsarha@gmail.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/>.
+ */
+
+#ifndef __TILCDC_EXTERNAL_H__
+#define __TILCDC_EXTERNAL_H__
+
+int tilcdc_add_external_encoders(struct drm_device *dev, int *bpp);
+int tilcdc_add_external_components(struct device *master, struct master *m);
+
+#endif /* __TILCDC_SLAVE_H__ */