AM625: Interrupt and pin setting for external Touch IC

1, how to set/use it MCU_GPIO0_10 as reset pin

2, how to set/use MCU_GPIO0_9 as interrupt pion and where could i find out its interrupt parent?

Hi Paul,

Can you explain why the compatible field has xx (compatible = "goodix,gt9xx";)? Are you using a custom driver? TI is unable to provide support for custom Linux drivers and applications.

Looking through the device tree documentation, the compatible field is compatible = "goodix,gt911";

Can you share the MCU GPIO pinmux and reference node used by this?

Best Regards,

Anshu

Hello Anshu, 

"goodix,gt9xx" is a customized version of  "goodix,gt911". 

I just found a reference dts in SDK 9.0 "k3-am654-evm-oldi-lcd1evm.dtso" but it is just another diff version of external touch IC and it connects to diff pins of AM62x.

&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>;
};
};

Here for AM62x SoC as in our HW schematic, we want to use 

1, MCU_GPIO0_10 as reset pin

2, MCU_GPIO0_9 as interrupt pin

"Can you share the MCU GPIO pinmux and reference node used by this?"

We try to config the pimux as below, but we don't know how to use and fill in the driver node:

May you help for this dts?

goodix_ts@5d {
compatible = "goodix,gt9xx";
reg = <0x5d>;
interrupt-parent = <?>;   
goodix,rst-gpio = <?>;    //MCU_GPIO0_10, Pin C5
goodix,irq-gpio = <?>;    //MCU_GPIO0_9, Pin B4

}

Hi Paul,

You are calling "&mcugpio0" in the IRQ and reset parameters. Where is &mcugpio0 defined? Can you try &mcu_gpio0?

hello Anshu, 

yes, it should be mcu_gpio0, we are trying.

1) We use MCU_GPIO0_9 as interrupt pin, what its interrupt-parent?

2) Could we use them directly (e.g < &mcu_gpio0 9 GPIO_ACTIVE_LOW>) ?

or we need to do use their pinmuxing?

< &mcugpio0_mcu_gpio_9_irq_pins_default 9 GPIO_ACTIVE_LOW>

< &mcugpio0_mcu_gpio_10_reset_pins_default 9 GPIO_ACTIVE_LOW>

&mcu_pmx0 {

mcugpio0_mcu_gpio_9_irq_pins_default: mcugpio0-default-pins {
pinctrl-single,pins = <
AM62X_MCU_IOPAD(0x0024, PIN_INPUT_PULLDOWN, 7) /* (B4) WKUP_UART0_RXD.MCU_GPIO0_9 */
>;
};

mcugpio0_mcu_gpio_10_reset_pins_default: mcugpio0-default-pins {
pinctrl-single,pins = <
AM62X_MCU_IOPAD(0x0028, PIN_OUTPUT_PULLDOWN, 7) /* (C5) WKUP_UART0_TXD.MCU_GPIO0_10 */
>;
};

};

Hello Anshu, 

May you check our irq and reset pin setting? It still does not work.

Could you guide how to verify this irq  ("mcu_gpio0 9") and reset pin ("mcu_gpio0 10")?

touchscreen@5d {
compatible = "goodix,gt911";
reg = <0x5d>;
//pinctrl-names = "default";
//pinctrl-0 = <&touchscreen_pins_default>;
interrupt-parent = <&mcu_gpio0>;
interrupts = <9 IRQ_TYPE_EDGE_RISING>;
irq-gpios = <&mcu_gpio0 9 GPIO_ACTIVE_LOW>;
reset-gpios = <&mcu_gpio0 10 GPIO_ACTIVE_LOW>;

}

FYI, We also try   interrupts = <9 IRQ_TYPE_EDGE_FALLING>;

"mcu_gpio0 9" we use it as irq, do we need to set direction (INPUT) of this gpio?

Hi Paul,

Paul Minh said:

May you check our irq and reset pin setting?

Nothing seems wrong.

Paul Minh said:

do we need to set direction (INPUT) of this gpio?

Yes it needs to be input.

To debug further, you can check the output of 'cat /proc/interrupts' & also decompile the dtb to see if there any issues how the node was compiled.

Thanks,

Anshu

Hello Anshu

Because reset pin does not work, we want to control (LOW or HIGH) "mcu_gpio0 10"  (reset pin) mannually but I could not.

May you guide?

root@am62xx-evm:~# cat /sys/kernel/debug/gpio
gpiochip2: GPIOs 344-395, parent: platform/601000.gpio, 601000.gpio:

gpiochip1: GPIOs 396-487, parent: platform/600000.gpio, 600000.gpio:
gpio-427 ( |tlv71033 ) out lo

gpiochip0: GPIOs 488-511, parent: platform/4201000.gpio, 4201000.gpio:

==================

gpiochip0: GPIOs 488

488 + 10 = 498

==================

root@am62xx-evm:~# echo 498 > /sys/class/gpio/export
root@am62xx-evm:~# echo out > /sys/class/gpio/gpio498/direction
root@am62xx-evm:~# echo 0 > /sys/class/gpio/gpio498/value      /* On Scope: Signal is Not LOW */
root@am62xx-evm:~# echo 1 > /sys/class/gpio/gpio498/value      /* On Scope: Signal is Not HIGH */

root@am62xx-evm:~# cat /sys/kernel/debug/gpio
gpiochip2: GPIOs 344-395, parent: platform/601000.gpio, 601000.gpio:

gpiochip1: GPIOs 396-487, parent: platform/600000.gpio, 600000.gpio:
gpio-427 ( |tlv71033 ) out lo

gpiochip0: GPIOs 488-511, parent: platform/4201000.gpio, 4201000.gpio:
gpio-498 ( |sysfs ) out lo

Hi Paul,

Just as a check, are you able to toggle the GPIO normally without the device connected?

Thanks,

Anshu

Hello Anshu, 

We removed the device and we are also not able to see signal HIGH or LOW. (we also try with below gpioset).

root@am62xx-evm:~# ls -l /sys/class/gpio
total 0
--w------- 1 root root 4096 Apr 28 2022 export
lrwxrwxrwx 1 root root 0 Apr 28 2022 gpiochip344 -> ../../devices/platform/bus@f0000/601000.gpio/gpio/gpiochip344
lrwxrwxrwx 1 root root 0 Apr 28 2022 gpiochip396 -> ../../devices/platform/bus@f0000/600000.gpio/gpio/gpiochip396
lrwxrwxrwx 1 root root 0 Apr 28 2022 gpiochip488 -> ../../devices/platform/bus@f0000/bus@f0000:bus@4000000/4201000.gpio/gpio/gpiochip488 = gpiochip0
--w------- 1 root root 4096 Apr 28 2022 unexport

root@am62xx-evm:~# gpiodetect
gpiochip0 [4201000.gpio] (24 lines)
gpiochip1 [600000.gpio] (92 lines)
gpiochip2 [601000.gpio] (52 lines)

root@am62xx-evm:~# gpioset 0 10=0
root@am62xx-evm:~# gpioset 0 10=1
root@am62xx-evm:~# gpioinfo
gpiochip0 - 24 lines:
line 0: unnamed unused input active-high
line 1: unnamed unused input active-high
line 2: unnamed unused input active-high
line 3: unnamed unused input active-high
line 4: unnamed unused input active-high
line 5: unnamed unused input active-high
line 6: unnamed unused input active-high
line 7: unnamed unused input active-high
line 8: unnamed unused input active-high
line 9: unnamed unused input active-high
line 10: unnamed unused output active-high
line 11: unnamed unused input active-high
line 12: unnamed unused input active-high

FYI, Our current dts setting ( with the muxing or not, the result is the same).

&mcu_pmx0 {
touchscreen_pins_default: touchscreen-default-pins {
pinctrl-single,pins = <
AM62X_MCU_IOPAD(0x0024, PIN_INPUT, 0) /* (B4) WKUP_UART0_RXD */ /* for interrupt pin*/
AM62X_MCU_IOPAD(0x0028, PIN_OUTPUT, 0) /* (C5) WKUP_UART0_TXD */  /* for reset pin*/
>;
};
};

Hello Anshu

May you help?

We face difficulty to control MCU_GPIO0_10 and MCU_GPIO0_9 to low or high.