[PATCH] phy: usbphyc: use regulator_set_enable_if_allowed for disabling vbus supply

[Patrice CHOTARD]

Hi Patrick

On 9/20/22 13:39, Patrick Delaunay wrote:
> Use regulator_set_enable_if_allowed() api instead of regulator_set_enable()
> while disabling vbus supply. This way the driver doesn't see an error
> when it disable an always-on regulator for VBUS.
> 
> This patch is needed for STM32MP157C-DK2 board when the regulator
> v3v3: buck4 used as the phy vbus supply in kernel device tree
> is always on with the next hack for low power use-case:
> 
> &usbphyc_port0 {
>         ...
> 	/*
> 	 * Hack to keep hub active until all connected devices are suspended
> 	 * otherwise the hub will be powered off as soon as the v3v3 is disabled
> 	 * and it can disturb connected devices.
> 	 */
> 	connector {
> 		compatible = "usb-a-connector";
> 		vbus-supply = <&v3v3>;
> 	};
> };
> 
> Without this patch and the previous update in DT the command
> "usb stop" failed and the next command "usb start" cause a crash.
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> ---
> 
>  drivers/phy/phy-stm32-usbphyc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/phy-stm32-usbphyc.c b/drivers/phy/phy-stm32-usbphyc.c
> index 9f0b7d71187..dcf2194e9a7 100644
> --- a/drivers/phy/phy-stm32-usbphyc.c
> +++ b/drivers/phy/phy-stm32-usbphyc.c
> @@ -375,7 +375,7 @@ static int stm32_usbphyc_phy_power_off(struct phy *phy)
>  		return 0;
>  
>  	if (usbphyc_phy->vbus) {
> -		ret = regulator_set_enable(usbphyc_phy->vbus, false);
> +		ret = regulator_set_enable_if_allowed(usbphyc_phy->vbus, false);
>  		if (ret)
>  			return ret;
>  	}
Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>

Thanks
Patrice