Hi Levin,
Am Dienstag, 31. Juli 2018, 07:59:22 CEST schrieb djw@xxxxxxxxxxxxx:
> From: Levin Du <djw@xxxxxxxxxxxxx>
>
> In roc-rk3328-cc board, the signal voltage of sdmmc is supplied by the
> vcc_sdio regulator, which is a mux between 1.8V and 3.3V, controlled by
> a special output only gpio pin labeled "gpiomut_pmuio_iout",
> corresponding bit 1 of the syscon GRF_SOC_CON10.
>
> This special pin can now be reference as <&grf_gpio 0>, thanks to the
> gpio-syscon driver, which makes writing regulator-gpio possible.
>
> If the signal voltage changes, the io domain needs to change
> correspondingly.
>
> To use this feature, the following options are required in kernel config:
> - CONFIG_GPIO_SYSCON=y
> - CONFIG_POWER_AVS=y
> - CONFIG_ROCKCHIP_IODOMAIN=y
>
> Signed-off-by: Levin Du <djw@xxxxxxxxxxxxx>
[...]
> @@ -277,3 +295,7 @@
> &usb_host0_ohci {
> status = "okay";
> };
> +
> +&grf_gpio {
> + status = "okay";
> +};
>
applied to my dts64 branch after dropping the grf_gpio enablement,
see comment in patch2 regarding the always present pin.
Thanks
Heiko
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