I want to change value of GPIO1_25 (phy_reset)
but following error comes
root@var-som-mx6:~# echo 25 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
What should i do to change the value of phy reset pin
Following is current status
root@var-som-mx6:~# cat /sys/kernel/debug/gpio
GPIOs 0-31, platform/209c000.gpio, 209c000.gpio:
gpio-6 (cd ) in lo
gpio-25 (phy-reset ) out lo
gpio-28 (usb_h1_vbus ) out loGPIOs 32-63, platform/20a0000.gpio, 20a0000.gpio:
GPIOs 64-95, platform/20a4000.gpio, 20a4000.gpio:
GPIOs 96-127, platform/20a8000.gpio, 20a8000.gpio:
gpio-101 (tlv320aic3x reset ) out lo
gpio-111 (usb_otg_vbus ) out lo
gpio-121 (Menu ) in hi
gpio-122 (Back ) in hiGPIOs 128-159, platform/20ac000.gpio, 20ac000.gpio:
gpio-139 (Home ) in hiGPIOs 160-191, platform/20b0000.gpio, 20b0000.gpio:
gpio-178 (sysfs ) out loGPIOs 192-223, platform/20b4000.gpio, 20b4000.gpio:
gpio-200 (wlan-en-regulator ) out lo
Thanks and Regards
Hi sameerarvikar,
most likely the gpio is being used by another driver, in this case no other driver can access to the gpio. You can look into the devi tree file (.dts) and look which module is using this pin. Then you can comment or delete the line where the pin is being initialized within such module and after rebuilding the dtb file you may be able to use it as a gpio.
Best regards,
TIC
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