question about stm32mp1 LTDC PIN configuration

[zqizh.1]

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 */

};

};

[Kevin HUBER · Accepted solution]

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

[Kevin HUBER]

Hello @zqizh.1​ ,

Do you still have the problem?

Regards,

Kévin

[debugging]

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