AM6548: AM6548 supports both LVDS and MIPI DPI display under linux

shenghui.james

Part Number: AM6548
Other Parts Discussed in Thread: TFP410

Dear TI

Customer is asking how to set the lvds and mipi dpi correctly in the DTS.I tried to modify the k3-am654-evm-oldi-lcd1evm.dtso file,

but I am not sure if it is correct, please help me to check it out. Customers need to support both lvds and mipi dpi display.

// SPDX-License-Identifier: GPL-2.0
/**
 * OLDI-LCD1EVM Rocktech integrated panel and touch DT overlay for AM654-EVM.
 *
 * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
 */

/dts-v1/;
/plugin/;

#include <dt-bindings/pwm/pwm.h>
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>

/ {
  fragment@101 {
	target-path = "/";

	__overlay__ {
		display0 {
			compatible = "rocktech,rk101ii01d-ct";
			backlight = <&lcd_bl>;
			enable-gpios = <&pca9555 8 GPIO_ACTIVE_HIGH>;

			port@0 {
				lcd_in0: endpoint {
					remote-endpoint = <&oldi_out0>;
				};
			};
			port@1 {
				lcd_in1: endpoint {
					remote-endpoint = <&oldi_out1>;
				};
			};
		};

		lcd_bl: backlight {
			compatible = "pwm-backlight";
			pwms = <&ecap0 0 50000 PWM_POLARITY_INVERTED>;
			brightness-levels = <0 32 64 96 128 160 192 224 255>;
			default-brightness-level = <8>;
		};
	};
  };
};

&dss {
	status = "ok";
};

&dss_ports {
	#address-cells = <1>;
	#size-cells = <0>;
	port@0 {
		reg = <0>;

		oldi_out0: endpoint {
			remote-endpoint = <&lcd_in0>;
		};
	};
	port@1 {
		reg = <1>;

		oldi_out1: endpoint {
			remote-endpoint = <&lcd_in1>;
		};
	};
};

&main_i2c1 {
	#address-cells = <1>;
	#size-cells = <0>;
	gt928: touchscreen@14 {
		status = "okay";
		compatible = "goodix,gt928";
		reg = <0x14>;

		interrupt-parent = <&pca9554>;
		interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
		touchscreen-size-x = <1280>;
		touchscreen-size-y = <800>;

		reset-gpios = <&pca9555 9 GPIO_ACTIVE_HIGH>;
		irq-gpios = <&pca9554 3 GPIO_ACTIVE_HIGH>;
	};
};

over 4 years ago

0 shenghui.james over 4 years ago

Prodigy 180 points

Are there any updates?

0 jian35385 over 4 years ago in reply to shenghui.james

TI__Mastermind 23125 points

James,

your dss port configuration does not seem right, as port 1 need to be dpi_out0. I saw we have an example:

k3-am654-evm-hdmi.dtso

k3-am654-evm-oldi-lcd1evm.dtso

where you can reference and combine. there are also pinmux entries in the HDIMI overlay file. To make dual display work, you may also tune the clock divider configurations around DSS to make sure the resolutions on both displays does not conflict using one PLL.

Sorry for the delay. pls reopen as you run into more questions. This is beyond standard SDK so debug may be needed.

Jian

0 Tony Tang over 4 years ago in reply to jian35385

TI__Mastermind 28922 points

Jian,

I think we only need to modify last node of k3-am654-evm-oldi-lcd1evm.dtso to support DPI display, would you please tell us how to modify the yellow portion of below?

&dss_ports {
#address-cells = <1>;
#size-cells = <0>;
port@1 {
reg = <1>;

dpi_out0: endpoint {
remote-endpoint = <&tfp410_in>;
};
};
};

0 jian35385 over 4 years ago in reply to Tony Tang

TI__Mastermind 23125 points

Tony,

k3-am654-evm-oldi-lcd1evm.dtso seems configuring touch screen ports for either LCD or OLDI panels, so I am not sure simply adding the code block there will be recognized.

To enable dual display, we need to:

1. setup pinmux for the VOUT pins (match to the panel) as in the HDMI dtso

2. setup both port@0 and port@1

3. setup corresponding clock mux and devices.

so I would expect most of the code blocks in the HDMI overlay file is needed.

If you have access to the customer hardware that has both interfaces, we can have a work session to test some tries. We will need to check clock devider and mux registers to see if the dts are taking effect.

regards

Jian

Processors

Processors forum

AM6548: AM6548 supports both LVDS and MIPI DPI display under linux