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Commit 751e2676 authored by Philipp Zabel's avatar Philipp Zabel
Browse files

drm/imx: imx-ldb: add drm_panel support 



This patch allows to optionally attach the lvds-channel to a panel
supported by a drm_panel driver using of-graph bindings, instead of
supplying the modes via display-timings in the device tree.

This depends on of_graph_get_port_by_id and uses the OF graph to
link the optional DRM panel to the LDB lvds-channel. The output
port number is 1 on devices without the 4-port input multiplexer
(i.MX5) and 4 on devices with the mux (i.MX6).

Before:

	ldb {
		...

		lvds-channel@0 {
			...

			display-timings {
				native-timing = <&timing1>;
				timing1: etm0700g0dh6 {
					hactive = <800>;
					vactive = <480>;
					clock-frequency = <33260000>;
					hsync-len = <128>;
					hback-porch = <88>;
					hfront-porch = <40>;
					vsync-len = <2>;
					vback-porch = <33>;
					vfront-porch = <10>;
					hsync-active = <0>;
					vsync-active = <0>;
					...
				};
			};
			...
		};
	};

After:
	ldb {
		...

		lvds-channel@0 {
			...

			port@4 {
				reg = <4>;

				lvds_out: endpoint {
					remote_endpoint = <&panel_in>;
				};
			};
		};
	};

	panel {
		compatible = "edt,etm0700g0dh6", "simple-panel";
		...

		port {
			panel_in: endpoint {
				remote-endpoint = <&lvds_out>;
			};
		};
	};

[Fixed build error due to missing select on DRM_PANEL --rmk]
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent 2872c807

Documentation/devicetree/bindings/drm/imx/ldb.txt

+43 −19
Original line number Diff line number Diff line
@@ -44,23 +44,30 @@ Optional properties: 
LVDS Channel

============



Each LVDS Channel has to contain a display-timings node that describes the

video timings for the connected LVDS display. For detailed information, also

have a look at Documentation/devicetree/bindings/video/display-timing.txt.

Each LVDS Channel has to contain either an of graph link to a panel device node

or a display-timings node that describes the video timings for the connected

LVDS display as well as the fsl,data-mapping and fsl,data-width properties.



Required properties:

 - reg : should be <0> or <1>

 - port: Input and output port nodes with endpoint definitions as defined in

   Documentation/devicetree/bindings/graph.txt.

   On i.MX5, the internal two-input-multiplexer is used. Due to hardware

   limitations, only one input port (port@[0,1]) can be used for each channel

   (lvds-channel@[0,1], respectively).

   On i.MX6, there should be four input ports (port@[0-3]) that correspond

   to the four LVDS multiplexer inputs.

   A single output port (port@2 on i.MX5, port@4 on i.MX6) must be connected

   to a panel input port. Optionally, the output port can be left out if

   display-timings are used instead.



Optional properties (required if display-timings are used):

 - display-timings : A node that describes the display timings as defined in

   Documentation/devicetree/bindings/video/display-timing.txt.

 - fsl,data-mapping : should be "spwg" or "jeida"

                      This describes how the color bits are laid out in the

                      serialized LVDS signal.

 - fsl,data-width : should be <18> or <24>

 - port: A port node with endpoint definitions as defined in

   Documentation/devicetree/bindings/media/video-interfaces.txt.

   On i.MX5, the internal two-input-multiplexer is used.

   Due to hardware limitations, only one port (port@[0,1])

   can be used for each channel (lvds-channel@[0,1], respectively)

   On i.MX6, there should be four ports (port@[0-3]) that correspond

   to the four LVDS multiplexer inputs.



example:
@@ -73,23 +80,21 @@ ldb: ldb@53fa8008 { 
	#size-cells = <0>;

	compatible = "fsl,imx53-ldb";

	gpr = <&gpr>;

	clocks = <&clks 122>, <&clks 120>,

		 <&clks 115>, <&clks 116>,

		 <&clks 123>, <&clks 85>;

	clocks = <&clks IMX5_CLK_LDB_DI0_SEL>,

		 <&clks IMX5_CLK_LDB_DI1_SEL>,

		 <&clks IMX5_CLK_IPU_DI0_SEL>,

		 <&clks IMX5_CLK_IPU_DI1_SEL>,

		 <&clks IMX5_CLK_LDB_DI0_GATE>,

		 <&clks IMX5_CLK_LDB_DI1_GATE>;

	clock-names = "di0_pll", "di1_pll",

		      "di0_sel", "di1_sel",

		      "di0", "di1";



	/* Using an of-graph endpoint link to connect the panel */

	lvds-channel@0 {

		#address-cells = <1>;

		#size-cells = <0>;

		reg = <0>;

		fsl,data-mapping = "spwg";

		fsl,data-width = <24>;



		display-timings {

			/* ... */

		};



		port@0 {

			reg = <0>;
@@ -98,8 +103,17 @@ ldb: ldb@53fa8008 { 
				remote-endpoint = <&ipu_di0_lvds0>;

			};

		};



		port@2 {

			reg = <2>;



			lvds0_out: endpoint {

				remote-endpoint = <&panel_in>;

			};

		};

	};



	/* Using display-timings and fsl,data-mapping/width instead */

	lvds-channel@1 {

		#address-cells = <1>;

		#size-cells = <0>;
@@ -120,3 +134,13 @@ ldb: ldb@53fa8008 { 
		};

	};

};



panel: lvds-panel {

	/* ... */



	port {

		panel_in: endpoint {

			remote-endpoint = <&lvds0_out>;

		};

	};

};

drivers/gpu/drm/imx/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ config DRM_IMX_TVE 
config DRM_IMX_LDB

	tristate "Support for LVDS displays"

	depends on DRM_IMX && MFD_SYSCON

	select DRM_PANEL

	help

	  Choose this to enable the internal LVDS Display Bridge (LDB)

	  found on i.MX53 and i.MX6 processors.

drivers/gpu/drm/imx/imx-ldb.c

+46 −2
Original line number Diff line number Diff line
@@ -19,10 +19,11 @@ 
#include <drm/drmP.h>

#include <drm/drm_fb_helper.h>

#include <drm/drm_crtc_helper.h>

#include <drm/drm_panel.h>

#include <linux/mfd/syscon.h>

#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>

#include <linux/of_address.h>

#include <linux/of_device.h>

#include <linux/of_graph.h>

#include <video/of_videomode.h>

#include <linux/regmap.h>

#include <linux/videodev2.h>
@@ -55,6 +56,7 @@ struct imx_ldb_channel { 
	struct imx_ldb *ldb;

	struct drm_connector connector;

	struct drm_encoder encoder;

	struct drm_panel *panel;

	struct device_node *child;

	int chno;

	void *edid;
@@ -91,6 +93,13 @@ static int imx_ldb_connector_get_modes(struct drm_connector *connector) 
	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);

	int num_modes = 0;



	if (imx_ldb_ch->panel && imx_ldb_ch->panel->funcs &&

	    imx_ldb_ch->panel->funcs->get_modes) {

		num_modes = imx_ldb_ch->panel->funcs->get_modes(imx_ldb_ch->panel);

		if (num_modes > 0)

			return num_modes;

	}



	if (imx_ldb_ch->edid) {

		drm_mode_connector_update_edid_property(connector,

							imx_ldb_ch->edid);
@@ -190,6 +199,8 @@ static void imx_ldb_encoder_commit(struct drm_encoder *encoder) 
	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;

	int mux = imx_drm_encoder_get_mux_id(imx_ldb_ch->child, encoder);



	drm_panel_prepare(imx_ldb_ch->panel);



	if (dual) {

		clk_prepare_enable(ldb->clk[0]);

		clk_prepare_enable(ldb->clk[1]);
@@ -223,6 +234,8 @@ static void imx_ldb_encoder_commit(struct drm_encoder *encoder) 
	}



	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);



	drm_panel_enable(imx_ldb_ch->panel);

}



static void imx_ldb_encoder_mode_set(struct drm_encoder *encoder,
@@ -287,6 +300,8 @@ static void imx_ldb_encoder_disable(struct drm_encoder *encoder) 
		 (ldb->ldb_ctrl & LDB_CH1_MODE_EN_MASK) == 0)

		return;



	drm_panel_disable(imx_ldb_ch->panel);



	if (imx_ldb_ch == &ldb->channel[0])

		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;

	else if (imx_ldb_ch == &ldb->channel[1])
@@ -298,6 +313,8 @@ static void imx_ldb_encoder_disable(struct drm_encoder *encoder) 
		clk_disable_unprepare(ldb->clk[0]);

		clk_disable_unprepare(ldb->clk[1]);

	}



	drm_panel_unprepare(imx_ldb_ch->panel);

}



static struct drm_connector_funcs imx_ldb_connector_funcs = {
@@ -371,6 +388,9 @@ static int imx_ldb_register(struct drm_device *drm, 
	drm_connector_init(drm, &imx_ldb_ch->connector,

			   &imx_ldb_connector_funcs, DRM_MODE_CONNECTOR_LVDS);



	if (imx_ldb_ch->panel)

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



	drm_mode_connector_attach_encoder(&imx_ldb_ch->connector,

			&imx_ldb_ch->encoder);
@@ -485,6 +505,7 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data) 


	for_each_child_of_node(np, child) {

		struct imx_ldb_channel *channel;

		struct device_node *port;



		ret = of_property_read_u32(child, "reg", &i);

		if (ret || i < 0 || i > 1)
@@ -503,11 +524,34 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data) 
		channel->chno = i;

		channel->child = child;



		/*

		 * The output port is port@4 with an external 4-port mux or

		 * port@2 with the internal 2-port mux.

		 */

		port = of_graph_get_port_by_id(child, imx_ldb->lvds_mux ? 4 : 2);

		if (port) {

			struct device_node *endpoint, *remote;



			endpoint = of_get_child_by_name(port, "endpoint");

			if (endpoint) {

				remote = of_graph_get_remote_port_parent(endpoint);

				if (remote)

					channel->panel = of_drm_find_panel(remote);

				else

					return -EPROBE_DEFER;

				if (!channel->panel) {

					dev_err(dev, "panel not found: %s\n",

						remote->full_name);

					return -EPROBE_DEFER;

				}

			}

		}



		edidp = of_get_property(child, "edid", &channel->edid_len);

		if (edidp) {

			channel->edid = kmemdup(edidp, channel->edid_len,

						GFP_KERNEL);

		} else {

		} else if (!channel->panel) {

			ret = of_get_drm_display_mode(child, &channel->mode, 0);

			if (!ret)

				channel->mode_valid = 1;