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question about stm32mp1 LTDC PIN configuration

zqizh.1
Associate II

Hi,

My LCD display format is RGB666, I removed the "LCD_R0,LCDR1, LCD_G0,LCD_G1,LCD_B0,LCD_B1" in file "stm32mp15-pinctrl.dtsi", and recompile my device tree, then upload to my board.

I tried to use the LCD_R0 as GPIO with command:

gpioset gpiochip7 2=1

But get error:

"

[  52.329202] stm32mp157-pinctrl soc:pin-controller@50002000: pin PH2 already requested by panel; cannot claim for GPIOH:114

[  52.348561] stm32mp157-pinctrl soc:pin-controller@50002000: pin-114 (GPIOH:114) status -22

gpioset: error setting the GPIO line values: Invalid argument

"

Please advise how to reuse the unused LTDC pin as GPIO.

Thanks,

QiZhang

ltdc_pins_a: ltdc-a-0 {

pins {

pinmux = <STM32_PINMUX('G', 7, AF14)>, /* LCD_CLK */

<STM32_PINMUX('I', 10, AF14)>, /* LCD_HSYNC */

<STM32_PINMUX('I', 9, AF14)>, /* LCD_VSYNC */

<STM32_PINMUX('E', 13, AF14)>, /* LCD_DE */

<STM32_PINMUX('H', 8, AF14)>, /* LCD_R2 */

<STM32_PINMUX('H', 9, AF14)>, /* LCD_R3 */

<STM32_PINMUX('H', 10, AF14)>, /* LCD_R4 */

<STM32_PINMUX('H', 11, AF14)>, /* LCD_R5 */

<STM32_PINMUX('H', 12, AF14)>, /* LCD_R6 */

<STM32_PINMUX('E', 15, AF14)>, /* LCD_R7 */

<STM32_PINMUX('H', 13, AF14)>, /* LCD_G2 */

<STM32_PINMUX('H', 14, AF14)>, /* LCD_G3 */

<STM32_PINMUX('H', 15, AF14)>, /* LCD_G4 */

<STM32_PINMUX('I', 0, AF14)>, /* LCD_G5 */

<STM32_PINMUX('I', 1, AF14)>, /* LCD_G6 */

<STM32_PINMUX('I', 2, AF14)>, /* LCD_G7 */

<STM32_PINMUX('G', 10, AF14)>, /* LCD_B2 */

<STM32_PINMUX('D', 10, AF14)>, /* LCD_B3 */

<STM32_PINMUX('I', 4, AF14)>, /* LCD_B4 */

<STM32_PINMUX('I', 5, AF14)>, /* LCD_B5 */

<STM32_PINMUX('I', 6, AF14)>, /* LCD_B6 */

<STM32_PINMUX('I', 7, AF14)>; /* LCD_B7 */

bias-disable;

drive-push-pull;

slew-rate = <1>;

};

};

ltdc_pins_sleep_a: ltdc-a-1 {

pins {

pinmux = <STM32_PINMUX('G', 7, ANALOG)>, /* LCD_CLK */

<STM32_PINMUX('I', 10, ANALOG)>, /* LCD_HSYNC */

<STM32_PINMUX('I', 9, ANALOG)>, /* LCD_VSYNC */

<STM32_PINMUX('E', 13, ANALOG)>, /* LCD_DE */

<STM32_PINMUX('H', 8, ANALOG)>, /* LCD_R2 */

<STM32_PINMUX('H', 9, ANALOG)>, /* LCD_R3 */

<STM32_PINMUX('H', 10, ANALOG)>, /* LCD_R4 */

<STM32_PINMUX('H', 11, ANALOG)>, /* LCD_R5 */

<STM32_PINMUX('H', 12, ANALOG)>, /* LCD_R6 */

<STM32_PINMUX('E', 15, ANALOG)>, /* LCD_R7 */

<STM32_PINMUX('H', 13, ANALOG)>, /* LCD_G2 */

<STM32_PINMUX('H', 14, ANALOG)>, /* LCD_G3 */

<STM32_PINMUX('H', 15, ANALOG)>, /* LCD_G4 */

<STM32_PINMUX('I', 0, ANALOG)>, /* LCD_G5 */

<STM32_PINMUX('I', 1, ANALOG)>, /* LCD_G6 */

<STM32_PINMUX('I', 2, ANALOG)>, /* LCD_G7 */

<STM32_PINMUX('G', 10, ANALOG)>, /* LCD_B2 */

<STM32_PINMUX('D', 10, ANALOG)>, /* LCD_B3 */

<STM32_PINMUX('I', 4, ANALOG)>, /* LCD_B4 */

<STM32_PINMUX('I', 5, ANALOG)>, /* LCD_B5 */

<STM32_PINMUX('I', 6, ANALOG)>, /* LCD_B6 */

<STM32_PINMUX('I', 7, ANALOG)>; /* LCD_B7 */

};

};

1 ACCEPTED SOLUTION

Accepted Solutions
Kevin HUBER
ST Employee

Hello,

Sorry for the late reply.

I don't know if you still have the problem, but I tried on my 157C-DK2 board and I am able to set the PIN.

I edited "stm32mp15-pinctrl.dtsi" and removed the two lines "LCD_R0", rebuild, then scp of the new DTB.

root@stm32mp1:~# gpioset gpiochip7 2=1
root@stm32mp1:~# 

And I no longer have the error.

Can you please send me your "stm32mp15-pinctrl.dtsi" and your complete DTB file?

Regards,

Kevin

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.

View solution in original post

3 REPLIES 3
Kevin HUBER
ST Employee

Hello,

Sorry for the late reply.

I don't know if you still have the problem, but I tried on my 157C-DK2 board and I am able to set the PIN.

I edited "stm32mp15-pinctrl.dtsi" and removed the two lines "LCD_R0", rebuild, then scp of the new DTB.

root@stm32mp1:~# gpioset gpiochip7 2=1
root@stm32mp1:~# 

And I no longer have the error.

Can you please send me your "stm32mp15-pinctrl.dtsi" and your complete DTB file?

Regards,

Kevin

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.
Kevin HUBER
ST Employee

Hello @zqizh.1​ ,

Do you still have the problem?

Regards,

Kévin

In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.
debugging
Lead

I  have s similar problem with pin already requested by panel" see: Link