drm/tegra: Add DSI support

This commit adds support for both DSI outputs found on Tegra. Only very
minimal functionality is implemented, so advanced features like ganged
mode won't work.

Due to the lack of other test hardware, some sections of the driver are
hardcoded to work with Dalmore.

Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/gpu/nvidia,tegra20-host1x.txt

@@ -171,11 +171,21 @@ of the following host1x client modules:
   - clock-names: Must include the following entries:
     - dsi
       This MUST be the first entry.
+    - lp
     - parent
   - resets: Must contain an entry for each entry in reset-names.
     See ../reset/reset.txt for details.
   - reset-names: Must include the following entries:
     - dsi
+  - nvidia,mipi-calibrate: Should contain a phandle and a specifier specifying
+    which pads are used by this DSI output and need to be calibrated. See also
+    ../mipi/nvidia,tegra114-mipi.txt.
+
+  Optional properties:
+  - nvidia,ddc-i2c-bus: phandle of an I2C controller used for DDC EDID probing
+  - nvidia,hpd-gpio: specifies a GPIO used for hotplug detection
+  - nvidia,edid: supplies a binary EDID blob
+  - nvidia,panel: phandle of a display panel
 
 Example:
 

drivers/gpu/drm/tegra/Kconfig

@@ -6,6 +6,7 @@ config DRM_TEGRA
 	select TEGRA_HOST1X
 	select DRM_KMS_HELPER
 	select DRM_KMS_FB_HELPER
+	select DRM_MIPI_DSI
 	select DRM_PANEL
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA

drivers/gpu/drm/tegra/Makefile

@@ -9,6 +9,8 @@ tegra-drm-y := \
 	output.o \
 	rgb.o \
 	hdmi.o \
+	mipi-phy.o \
+	dsi.o \
 	gr2d.o \
 	gr3d.o
 

drivers/gpu/drm/tegra/dc.h

@@ -28,6 +28,7 @@
 #define DISP_CTRL_MODE_STOP (0 << 5)
 #define DISP_CTRL_MODE_C_DISPLAY (1 << 5)
 #define DISP_CTRL_MODE_NC_DISPLAY (2 << 5)
+#define DISP_CTRL_MODE_MASK (3 << 5)
 #define DC_CMD_SIGNAL_RAISE			0x033
 #define DC_CMD_DISPLAY_POWER_CONTROL		0x036
 #define PW0_ENABLE (1 <<  0)
@@ -116,6 +117,7 @@
 
 #define DC_DISP_DISP_WIN_OPTIONS		0x402
 #define HDMI_ENABLE (1 << 30)
+#define DSI_ENABLE  (1 << 29)
 
 #define DC_DISP_DISP_MEM_HIGH_PRIORITY		0x403
 #define CURSOR_THRESHOLD(x)   (((x) & 0x03) << 24)

drivers/gpu/drm/tegra/drm.c

@@ -653,6 +653,7 @@ static const struct of_device_id host1x_drm_subdevs[] = {
 	{ .compatible = "nvidia,tegra30-hdmi", },
 	{ .compatible = "nvidia,tegra30-gr2d", },
 	{ .compatible = "nvidia,tegra30-gr3d", },
+	{ .compatible = "nvidia,tegra114-dsi", },
 	{ .compatible = "nvidia,tegra114-hdmi", },
 	{ .compatible = "nvidia,tegra114-gr3d", },
 	{ /* sentinel */ }
@@ -677,10 +678,14 @@ static int __init host1x_drm_init(void)
 	if (err < 0)
 		goto unregister_host1x;
 
-	err = platform_driver_register(&tegra_hdmi_driver);
+	err = platform_driver_register(&tegra_dsi_driver);
 	if (err < 0)
 		goto unregister_dc;
 
+	err = platform_driver_register(&tegra_hdmi_driver);
+	if (err < 0)
+		goto unregister_dsi;
+
 	err = platform_driver_register(&tegra_gr2d_driver);
 	if (err < 0)
 		goto unregister_hdmi;
@@ -695,6 +700,8 @@ static int __init host1x_drm_init(void)
 	platform_driver_unregister(&tegra_gr2d_driver);
 unregister_hdmi:
 	platform_driver_unregister(&tegra_hdmi_driver);
+unregister_dsi:
+	platform_driver_unregister(&tegra_dsi_driver);
 unregister_dc:
 	platform_driver_unregister(&tegra_dc_driver);
 unregister_host1x:
@@ -708,6 +715,7 @@ static void __exit host1x_drm_exit(void)
 	platform_driver_unregister(&tegra_gr3d_driver);
 	platform_driver_unregister(&tegra_gr2d_driver);
 	platform_driver_unregister(&tegra_hdmi_driver);
+	platform_driver_unregister(&tegra_dsi_driver);
 	platform_driver_unregister(&tegra_dc_driver);
 	host1x_driver_unregister(&host1x_drm_driver);
 }

drivers/gpu/drm/tegra/drm.h

@@ -177,6 +177,7 @@ struct tegra_output_ops {
 enum tegra_output_type {
 	TEGRA_OUTPUT_RGB,
 	TEGRA_OUTPUT_HDMI,
+	TEGRA_OUTPUT_DSI,
 };
 
 struct tegra_output {
@@ -267,6 +268,7 @@ extern void tegra_drm_fb_exit(struct drm_device *drm);
 extern void tegra_fbdev_restore_mode(struct tegra_fbdev *fbdev);
 
 extern struct platform_driver tegra_dc_driver;
+extern struct platform_driver tegra_dsi_driver;
 extern struct platform_driver tegra_hdmi_driver;
 extern struct platform_driver tegra_gr2d_driver;
 extern struct platform_driver tegra_gr3d_driver;