How to use the extended GPIO resources of AM335X development board?

How can I use the extended GPIO of the J11 terminal of the Mir MYD-AM335X-J development board, and what is the corresponding GPIO definition or pin?

Mir technical support replied: this only needs to configure a device tree. Refer to the following way to use TI's pinmux tool for configuration. Once configured, you can use sysfs to control gpio. The specific pin definition can be determined by combining the schematic of the backplane and 01-Documents\ UserManual\ Chinese\ MYC_J335X PIN List.pdf.

& am33xx_pinmux {

Pinctrl-names = "default"

Pinctrl-0 =

Misc_gpios: pinmux_misc_gpios {

Pinctrl-single,pins = <

0x20 (PIN_OUTPUT_PULLUP | MUX_MODE7) / (U10) gpmc_ad8.gpio0 [22] /

0x24 (PIN_OUTPUT_PULLUP | MUX_MODE7) / (T10) gpmc_ad9.gpio0 [23] /

0x28 (PIN_OUTPUT_PULLUP | MUX_MODE7) / (T11) gpmc_ad10.gpio0 [26] /

0x2c (PIN_OUTPUT_PULLUP | MUX_MODE7) / (U12) gpmc_ad11.gpio0 [27] /

0x30 (PIN_INPUT_PULLUP | MUX_MODE7) / (T12) gpmc_ad12.gpio1 [12] /

0x34 (PIN_INPUT_PULLUP | MUX_MODE7) / (R12) gpmc_ad13.gpio1 [13] /

0x38 (PIN_OUTPUT_PULLUP | MUX_MODE7) / (V13) gpmc_ad14.gpio1 [14] /

0x3c (PIN_OUTPUT_PULLUP | MUX_MODE7) / (U13) gpmc_ad15.gpio1 [15] /

0x88 (PIN_OUTPUT_PULLUP | MUX_MODE7) / (T13) gpmc_csn3.gpio2 [0] /

0x8c (PIN_OUTPUT_PULLUP | MUX_MODE7) / (V12) gpmc_clk.gpio2 [1] /

}

& gpio0 {

Status = "okay"

Ti,no-reset-on-init

}

& gpio1 {

Status = "okay"

Ti,no-reset-on-init

}

& gpio2 {

Status = "okay"

Ti,no-reset-on-init

}

After the modification, use the following command to recompile the device tree

Make dtbs