Hello Support Team,
Is it possible to control the pcie 100MHz reference clock output(MXM3 pin 53/55) on/off via the OE pin gpio(GPIO4_IO11) of the external OSC? have tried under uboot command line, but it keeps 100M clock output whatever i set the gpio4_IO11 pin to low or high.
Apalis iMX8 # gpio clear 139
gpio: pin 139 (gpio 139) value is 0
Apalis iMX8 # gpio status GPIO4_11
Bank GPIO4_:
GPIO4_11: output: 0 [ ]
then also tried modify below entry of pcie_sata_refclk_gate node of imx8-apalis-v1.1.dtsi as below to another fake gpio pin, and export the gpio4_io11 as general gpio pin instead to test, but the 100MHz clock is still always there whatever set the gpio to high or low under liniux with sysfs command.
enable-gpios = <&lsio_gpio4 11 GPIO_ACTIVE_HIGH>;
then finally find a way to disable this clock is to set the enable-gpios entry to active_low like below, so may i know more details of the principle to chontrol this clock?
enable-gpios = <&lsio_gpio4 11 GPIO_ACTIVE_LOW>;
Thanks and best regards