drm: tegra: Add HDMI support

This commit adds support for the HDMI output on the Tegra20 SoC. Only
one such output is available, but it can be driven by either of the two
display controllers.

A lot of work on this patch has been contributed by NVIDIA's Mark Zhang
<markz@nvidia.com> and many other people at NVIDIA were very helpful in
getting the HDMI support and surrounding infrastructure to work.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Zhang <markz@nvidia.com>
Reviewed-by: Mark Zhang <markz@nvidia.com>
Tested-by: Mark Zhang <markz@nvidia.com>
Tested-and-acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/tegra/Makefile

@@ -2,6 +2,6 @@ ccflags-y := -Iinclude/drm
 ccflags-$(CONFIG_DRM_TEGRA_DEBUG) += -DDEBUG
 
 tegra-drm-y := drm.o fb.o dc.o host1x.o
-tegra-drm-y += output.o rgb.o
+tegra-drm-y += output.o rgb.o hdmi.o
 
 obj-$(CONFIG_DRM_TEGRA) += tegra-drm.o

drivers/gpu/drm/tegra/drm.h

@@ -130,6 +130,7 @@ struct tegra_output_ops {
 
 enum tegra_output_type {
 	TEGRA_OUTPUT_RGB,
+	TEGRA_OUTPUT_HDMI,
 };
 
 struct tegra_output {
@@ -226,6 +227,7 @@ extern int tegra_drm_fb_init(struct drm_device *drm);
 extern void tegra_drm_fb_exit(struct drm_device *drm);
 
 extern struct platform_driver tegra_host1x_driver;
+extern struct platform_driver tegra_hdmi_driver;
 extern struct platform_driver tegra_dc_driver;
 extern struct drm_driver tegra_drm_driver;
 

drivers/gpu/drm/tegra/host1x.c

@@ -67,6 +67,7 @@ static int host1x_parse_dt(struct host1x *host1x)
 {
 	static const char * const compat[] = {
 		"nvidia,tegra20-dc",
+		"nvidia,tegra20-hdmi",
 	};
 	unsigned int i;
 	int err;
@@ -294,8 +295,14 @@ static int __init tegra_host1x_init(void)
 	if (err < 0)
 		goto unregister_host1x;
 
+	err = platform_driver_register(&tegra_hdmi_driver);
+	if (err < 0)
+		goto unregister_dc;
+
 	return 0;
 
+unregister_dc:
+	platform_driver_unregister(&tegra_dc_driver);
 unregister_host1x:
 	platform_driver_unregister(&tegra_host1x_driver);
 	return err;
@@ -304,6 +311,7 @@ module_init(tegra_host1x_init);
 
 static void __exit tegra_host1x_exit(void)
 {
+	platform_driver_unregister(&tegra_hdmi_driver);
 	platform_driver_unregister(&tegra_dc_driver);
 	platform_driver_unregister(&tegra_host1x_driver);
 }

drivers/gpu/drm/tegra/output.c

@@ -227,6 +227,11 @@ int tegra_output_init(struct drm_device *drm, struct tegra_output *output)
 		encoder = DRM_MODE_ENCODER_LVDS;
 		break;
 
+	case TEGRA_OUTPUT_HDMI:
+		connector = DRM_MODE_CONNECTOR_HDMIA;
+		encoder = DRM_MODE_ENCODER_TMDS;
+		break;
+
 	default:
 		connector = DRM_MODE_CONNECTOR_Unknown;
 		encoder = DRM_MODE_ENCODER_NONE;