Apalis iMX8QM PCIe 100M Reference Clock issue

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

Has found the reason that due to there is inside 40K pull up on the OE pin of external OSC, just test change the gpio4_io11 pin pinctrl config to 0x02000060 (open drain, pull disable) in device tree , then this pin can be controlled high/low accordingly.