LCD DTS configuration of ti-processor-sdk-linux-am335x-evm-06.03.00.106

user1545139

hi sir:

The software I use is the ti-processor-sdk-linux-am335x-evm-06.03.00.106.

and the hardware platform is BeagleBoneBlack. I did not find the LCD DTS configuration in the SDK. Do you have related documents?

thanks!

over 4 years ago

0 Krunal Bhargav34 over 4 years ago

TI__Mastermind 35755 points

Hello,

Unfortunately, we do not have such document. However, I recommend you to please refer to the AM335x EVM DT files. Here are the main sections that you would need to configure:
1. https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm/boot/dts/am335x-evm.dts?h=linux-4.19.y#n119
2. https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm/boot/dts/am335x-evm.dts?h=linux-4.19.y#n354
3. https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm/boot/dts/am335x-evm.dts?h=linux-4.19.y#n527

Modify the above sections based on your LCD HW parameters.

Regards,
Krunal

0 user1545139 over 4 years ago in reply to Krunal Bhargav34

Prodigy 100 points

Hi:

Thanks, I modified the dts according to evm-dts.
But I found no /dev/fb0 in my systerm.

I have enabled the following 2 options.

Device Drivers--->
Graphics support----->
<*>Direct Rendering Manager(XFree86....)
<*>DRM Support for Ti LCDC Display Controller

Is there anything else that needs to be enabled there?

thanks!

0 Krunal Bhargav34 over 4 years ago in reply to user1545139

TI__Mastermind 35755 points

Hello,

The fbdev driver is no longer supported and maintained but it is still available in the Kernel. There are flags that needs to be enabled and our default board config file, enables the required flags (file attached). Please look at the flags under "Frame buffer Devices" and CONFIG_DRM_FBDEV_EMULATION.

If you are trying to verify your LCD, I would recommend you to run modetest or kmstest in Linux. The binaries are included by default in the SDK.

Regards,
Krunal

am335x_config.txt

0 user1545139 over 4 years ago in reply to Krunal Bhargav34

Prodigy 100 points

hello:

Thanks for the information provided, LCD had bringed up.

But I met a new issue about touch.

LCD Touch is a 4-wire resistive screen. The touch calibration interface appeared when the board was first turned on. Click the 3 cross cursors in sequence.

Then LCD displayed the Matrix app launcher V2 P1 screen. I clicked on App and nothing happened.

The Touch node of DTS is as follows.

&tscadc {
    status = "okay";
    tsc {
        ti,wires = <4>;
        ti,x-plate-resistance = <200>;
        ti,coordinate-readouts = <5>;
        ti,wire-config = <0x00 0x11 0x22 0x33>;
    };
};

thsnks!

0 Krunal Bhargav34 over 4 years ago in reply to user1545139

TI__Mastermind 35755 points

Hello,

Please create another ticket for touchscreen issues.

Regards,
Krunal

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LCD DTS configuration of ti-processor-sdk-linux-am335x-evm-06.03.00.106