LVDS - Revision history

Jacob at 07:37, 11 October 2017

2017-10-11T07:37:47Z

Jacob at 02:50, 11 October 2017

2017-10-11T02:50:41Z

Jacob at 02:50, 11 October 2017

2017-10-11T02:50:16Z

Jacob: Created page with " === * How to Enable LVDS Module === ---- '''1. Driver Compile'''
Ensure below configures have been selected:

CONFIG_ROCKCHIP_LVDS=y

Bellow dr..."

2017-10-11T02:32:41Z

Created page with " === * How to Enable LVDS Module === ---- '''1. Driver Compile'''<br/> Ensure below configures have been selected: <pre><code>CONFIG_ROCKCHIP_LVDS=y</code> </pre> Bellow dr..."

New page

=== * How to Enable LVDS Module ===

----

'''1. Driver Compile'''<br/> Ensure below configures have been selected:
<pre><code>CONFIG_ROCKCHIP_LVDS=y</code>
</pre>

Bellow drivers have been compiled:
<pre><code>drivers/gpu/drm/rockchip/rockchip_lvds.c</code>
</pre>

'''2. DTS Setting'''<br/> 2.1 Enable LVDS Device Node：

*Include the SoC DTS 'rk3288.dtsi' file.
*Set the LVDS device node state to 'okay'.
<pre><code>include "rk3288.dtsi"
&lvds {
status = "okay";
};</code>
</pre>

2.2 LVDS device node parameters, there're four properties for LVDS device:

*"rockchip,data-mapping": stand for the output data mapping, avaliable values "jeida" or "vesa".
*"rockchip,data-width": stand for the output data width, avaliable values "<24>" or "<18>". ("<24>" means RGB888, "<18>" means RGB666)
*"rockchip,ouput": stand for the output connector type, avaliable values "rgb", "lvds" or "duallvds".
*"rockchip,panel": pointed to panel device node (more panel detail, please see link: xxxx )
<pre><code>rockchip,data-mapping = "jeida";
rockchip,data-width = <24>;
rockchip,output = "lvds";
rockchip,panel = <&lvds_panel>;</code>
</pre>

----

=== * How To Debug LVDS Module ===

'''3. Whether LVDS display card has been registered successfully'''

If the LVDS display card has been created, it would create a sysfs debug directory.
<pre><code>$ ls /sys/class/drm/card0-LVDS-1</code>
</pre>

So you just need to check that directory. If that directory is missing in your machine board, please check:

*Whether LVDS have been enabled in DTS files.
*Whether LVDS panel have been registered successfully.
*Whether you have available VOP module for LVDS.
*Check the kernel log for more detail (dmesg | grep lvds)

'''4. Check LVDS display card status: status, enabled, modes'''
<pre><code>$ cd /sys/class/drm/card0-LVDS-1
$ cat status # should printed "connected" or "disconnected"
$ cat enabled # should printed "enabled" or "disabled"
$ cat modes # should printed the available mode list, like 1536x2048</code>
</pre>

'''5. If you still have no picture on LVDS panel, please check bellow information:'''

*Check the LVDS panel power supply.
*Check the panel datasheet, ensure you have configured the timing and data format rightly.
*Check the hardware connected status, or test the panel on workable board.

----

=== * Reference LVDS DTS Configure： ===
<pre><code>include "rk3288.dtsi"

lvds_panel: lvds_panel {
compatible ="auo,b101ew05","simple-panel";
backlight = <&backlight>;
enable-gpios = <&gpio7 4 GPIO_ACTIVE_HIGH>;
pinctrl-0 = <&lcd_cs>;
status = "okay";

ports {
panel_in_lvds: endpoint {
remote-endpoint = <&lvds_out_panel>;
};
};
};

&lvds {
rockchip,data-mapping = "jeida";
rockchip,data-width = <24>;
rockchip,output = "lvds";
status = "okay";

ports {
lvds_out: port@1 {
reg = <1>;
#address-cells = <1>;
#size-cells = <0>;

lvds_out_panel: endpoint@0 {
reg = <0>;
remote-endpoint = <&panel_in_lvds>;
};
};
};
};</code></pre>

@@ Line 13: / Line 13: @@
 If the LVDS display card has been created, it would create a sysfs debug directory.
-<pre><code>$ ls /sys/class/drm/card0-LVDS-1</code>
+<pre>$ ls /sys/class/drm/card0-LVDS-1</code>
 </pre>
@@ Line 24: / Line 24: @@
 == Check LVDS display card status: status, enabled, modes ==
-<pre><code>$ cd /sys/class/drm/card0-LVDS-1
+<pre>$ cd /sys/class/drm/card0-LVDS-1
 $ cat status  # should printed "connected" or "disconnected"
 $ cat enabled # should printed "enabled" or "disabled"

@@ Line 34: / Line 34: @@
 *Check the LVDS panel power supply.
 *Check the panel datasheet, ensure you have configured the timing and data format rightly.
 *Check the hardware connected status, or test the panel on workable board.

@@ Line 1: / Line 1: @@
-=== * How to Enable LVDS Module ===
+= References =
-----
+[https://github.com/rockchip-linux/kernel/tree/release-4.4/drivers/media/platform/rockchip-rga source code]
-'''1. Driver Compile'''<br/> Ensure below configures have been selected:
+[https://github.com/rockchip-linux/kernel/blob/release-4.4/Documentation/devicetree/bindings/display/rockchip/rockchip-lvds.txt device-tree document]
-*"rockchip,data-mapping": stand for the output data mapping, avaliable values "jeida" or "vesa".
+&nbsp;
-----
+= Tips =
-=== * How To Debug LVDS Module ===
+== Whether LVDS display card has been registered successfully ==
 If the LVDS display card has been created, it would create a sysfs debug directory.
@@ Line 51: / Line 23: @@
 *Check the kernel log for more detail (dmesg | grep lvds)
-'''4. Check LVDS display card status: status, enabled, modes'''
+== Check LVDS display card status: status, enabled, modes ==
 <pre><code>$ cd /sys/class/drm/card0-LVDS-1
 $ cat status  # should printed "connected" or "disconnected"
@@ Line 58: / Line 30: @@
 </pre>
-'''5. If you still have no picture on LVDS panel, please check bellow information:'''
+== If you still have no picture on LVDS panel, please check bellow information: ==
 *Check the LVDS panel power supply.
@@ Line 64: / Line 36: @@
 *Check the hardware connected status, or test the panel on workable board.
-----
+=== &nbsp; ===

LVDS - Revision history

Jacob at 07:37, 11 October 2017

Jacob at 02:50, 11 October 2017

Jacob at 02:50, 11 October 2017

Jacob: Created page with " === * How to Enable LVDS Module === ---- '''1. Driver Compile''' Ensure below configures have been selected: CONFIG_ROCKCHIP_LVDS=y Bellow dr..."

Jacob: Created page with " === * How to Enable LVDS Module === ---- '''1. Driver Compile'''
Ensure below configures have been selected:
`CONFIG_ROCKCHIP_LVDS=y`
Bellow dr..."