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GPIO

The old sysfs GPIO interface is deprecated and will be phased out of the kernel. As part of this the base offset of GPIO ports has been omitted in the kernel. Setting the base GPIO number to zero will result in a boot up error on kernels from 6.6. At the same time, the sysfs interface to the GPIOs has been deprecated - some distributions have already disabled it and are expecting users to go through libgpiod. In 6.6, high-numbered GPIOs - probably still available by sysfs, but eventually that will be switched off.

Query GPIO ports

cat /sys/kernel/debug/gpio
--------------------------
gpiochip0: GPIOs 512-565, parent: platform/3f200000.gpio, pinctrl-bcm2835:
 gpio-512 (ID_SDA              )
 gpio-513 (ID_SCL              )
 gpio-514 (GPIO2               )
 gpio-515 (GPIO3               )
 gpio-516 (GPIO4               )
 gpio-517 (GPIO5               |sysfs               ) in  hi 
 gpio-518 (GPIO6               )
 gpio-519 (GPIO7               )
 gpio-520 (GPIO8               )
 gpio-521 (GPIO9               )
 gpio-522 (GPIO10              )
 gpio-523 (GPIO11              )
 gpio-524 (GPIO12              )
 gpio-525 (GPIO13              )
 gpio-526 (GPIO14              )
 gpio-527 (GPIO15              )
 gpio-528 (GPIO16              )
 gpio-529 (GPIO17              )
 gpio-530 (GPIO18              )
 gpio-531 (GPIO19              )
 gpio-532 (GPIO20              )
 gpio-533 (GPIO21              )
 gpio-534 (GPIO22              )
 gpio-535 (GPIO23              )
 gpio-536 (GPIO24              )
 gpio-537 (GPIO25              )
 gpio-538 (GPIO26              )
 gpio-539 (GPIO27              )
 gpio-540 (SDA0                )
 gpio-541 (SCL0                )
 gpio-542 (NC                  )
 gpio-543 (LAN_RUN             )
 gpio-544 (CAM_GPIO1           )
 gpio-545 (NC                  )
 gpio-546 (NC                  )
 gpio-547 (PWR_LOW_N           |PWR                 ) in  lo 
 gpio-548 (NC                  )
 gpio-549 (NC                  )
 gpio-550 (USB_LIMIT           )
 gpio-551 (NC                  )
 gpio-552 (PWM0_OUT            )
 gpio-553 (CAM_GPIO0           |cam1_regulator      ) out lo 
 gpio-554 (SMPS_SCL            )
 gpio-555 (SMPS_SDA            )
 gpio-556 (ETH_CLK             )
 gpio-557 (PWM1_OUT            )
 gpio-558 (HDMI_HPD_N          |hpd                 ) in  hi ACTIVE LOW
 gpio-559 (STATUS_LED          |ACT                 ) out lo 
 gpio-560 (SD_CLK_R            )
 gpio-561 (SD_CMD_R            )
 gpio-562 (SD_DATA0_R          )
 gpio-563 (SD_DATA1_R          )
 gpio-564 (SD_DATA2_R          )
 gpio-565 (SD_DATA3_R          )

gpiochip1: GPIOs 566-569, parent: usb/1-1.4:1.0, ftdi-cbus, can sleep: