7 inch panel integration LT070ME05000 (panel-jdi-lt070me05000.c)

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

I plan to add this hdmi-to-mipi 7 inch ips touchscreen for a L4T Jetson Nano Dev Tablet project. The touchscreen is a LT070ME05000 and it is in our kernel source:

kernel-4.9/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c

* From internet archives, the panel for Nexus 7 2nd Gen, 2013 model is a
 * JDI model LT070ME05000, and its data sheet is at:
 * http://panelone.net/en/7-0-inch/JDI_LT070ME05000_7.0_inch-datasheet

The actual model I will be purchasing is located here: 7inch Hdmi Ips Display 1200*1920 Mipi Lcd With Driver Board Usb Touch Support Win7 8 10 Raspberry Pi 3 Lt070me05000 - Tablet Lcds & Panels - AliExpress

This model has 2 boards. 1 is an hdmi to mipi converter and 1 is an usb touch converter. Compatible with Raspberry Pi 3 so I “assume” it should be compatible with Jetson Nano.

My question is for kernel integration do i need to add this panel to nvidia drivers like so:

nvidia/drivers/video/tegra/dc/panel/

add panel-jdi-lt070me05000.c to:

Makefile

create panel board id add to:

tegra-board-id.h

/* Panel board ID */
#define    BOARD_E5000

Example dt bindings:

JDI model LT070ME05000 1200x1920 7" DSI Panel

Required properties:
- compatible: should be "jdi,lt070me05000"
- vddp-supply: phandle of the regulator that provides the supply voltage
  Power IC supply (3-5V)
- iovcc-supply: phandle of the regulator that provides the supply voltage
  IOVCC , power supply for LCM (1.8V)
- enable-gpios: phandle of gpio for enable line
  LED_EN, LED backlight enable, High active
- reset-gpios: phandle of gpio for reset line
  This should be 8mA, gpio can be configured using mux, pinctrl, pinctrl-names
  XRES, Reset, Low active
- dcdc-en-gpios: phandle of the gpio for power ic line
  Power IC supply enable, High active

Example:

	dsi0: qcom,mdss_dsi@4700000 {
		panel@0 {
			compatible = "jdi,lt070me05000";
			reg = <0>;

			vddp-supply = <&pm8921_l17>;
			iovcc-supply = <&pm8921_lvs7>;

			enable-gpios = <&pm8921_gpio 36 GPIO_ACTIVE_HIGH>;
			reset-gpios = <&tlmm_pinmux 54 GPIO_ACTIVE_LOW>;
			dcdc-en-gpios = <&pm8921_gpio 23 GPIO_ACTIVE_HIGH>;
		};
	};

Or can I just use the standard kernel drivers located at kernel-4.9/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c?

I do know USB touch support is built in as I have used Tegra boards in the past (TX1/TK1) with usb touch ie Iiyama 22 inch touchscreen works out of box on tegra.

2

In fact, we didn’t support any touch panel for forum users.

What I can tell is that the standard driver “kernel-4.9/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c” is not working since none of our driver is using it.

Please start with your option 1 → nvidia/drivers/video/tegra/dc/panel/ first.

3

Just want to confirm… does it work in mipi DSI interface? Why there is a “HDMI->mipi” converter?
Could you elaborate this as a pipeline to let us know the hardware configuration?

What under nvidia/drivers/video/tegra/dc/panel/ are only for mipi DSI or eDP panel. Tegra does not support USB panel.

4

Let me explain a bit more WayneWWW. The converter board for USB is just a touch converter to support touch over usb. The HDMI to MIPI is another converter board that converts mipi to hdmi - mipi cable to hdmi converter board - this is all separate from jetson nano hardware and runs over standard linux input drivers.

example:

I know Tegra does support standard USB touch input so the converter board should work. I have tested USB Touchscreen displays with TX1 with no issues.

Now if we wanted to use a nvidia supported panel/display in nvidia/drivers/video/tegra/dc/panel/ for DSI/SPI touch and display we would have to wire up the correct GPIOS for LCD Backlight SPI Touch correct?

Does the Jetson Nano GPIO support lcd and touch for built in supported panels in nvidia/drivers/video/tegra/dc/panel/ or would we need a special carrier board.

5

Hi Linux4all,

Thanks for clarification.
Jetson Nano supports the lcd for built-in panels. However, the functionality for touch is not verified on l4t. You will need to write that driver.

6

Thank you WayneWWW. I remember way back there was a great write up on how to interface the Jetson TK1 with a panel through GPIO so when I get this project kicked off and confirm it is working I will write up a complete how to for the nano. Thanks for your response.

7

Hi Linux4all, please keep us posted about your work progress

8

Hi! Can sombody upload DS for this panel?