sam9x60: how to select TD_SLCK instead of MD_SLCK for PCK output

[Zixun LI]

Hi,

I’m using linux-mchp 6.6.

In order to provide 32.768kHz clock to a SDIO device from PCK0  I’ve added
a mmc-pwrseq-simple node to the DT:

wifi_pwrseq: wifi_pwrseq {
compatible = "mmc-pwrseq-simple";
reset-gpios = <&pioA 14 GPIO_ACTIVE_LOW>;
pinctrl-0 = <&pinctrl_wifi_pwrseq>;
pinctrl-names = "default";
clocks = <&pmc PMC_TYPE_SYSTEM 8>;
clock-names = "ext_clock";
assigned-clocks = <&pmc PMC_TYPE_SYSTEM 8>;
assigned-clock-rates = <32768>;
};

However the output is inaccurate as internal MD_SLCK is selected from
TD_SLCK, which is confirmed by a PMC_PCK0 register reading. If I set
CSS field to 0x01 manually, PCK0 output becomes accurate TD_SLCK.

I’d like to know how to use TD_SLCK by default ?

Thanks,
Zixun LI