On Fri, Jun 19, 2020 at 04:25:12PM +0200, Mike Looijmans wrote:
> +void dwc3_set_vbus(struct dwc3 *dwc, bool enable)
> +{
> + int ret;
> +
> + if (enable != dwc->vbus_reg_enabled) {
> + if (enable)
> + ret = regulator_enable(dwc->vbus_reg);
> + else
> + ret = regulator_disable(dwc->vbus_reg);
dwc->vbus_reg is set to NULL when the regulator is not present. These
regulator_* functions expect a non-NULL pointer so a NULL check is
required before calling them.
> + if (!ret)
> + dwc->vbus_reg_enabled = enable;
> + }
> +
> + if (dwc->usb2_phy)
> + otg_set_vbus(dwc->usb2_phy->otg, enable);
> +}
> +
> static void __dwc3_set_mode(struct work_struct *work)
> {
> struct dwc3 *dwc = work_to_dwc(work);
> @@ -164,8 +182,7 @@ static void __dwc3_set_mode(struct work_struct *work)
> if (ret) {
> dev_err(dwc->dev, "failed to initialize host\n");
> } else {
> - if (dwc->usb2_phy)
> - otg_set_vbus(dwc->usb2_phy->otg, true);
> + dwc3_set_vbus(dwc, true);
> phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
> }
> @@ -173,8 +190,7 @@ static void __dwc3_set_mode(struct work_struct *work)
> case DWC3_GCTL_PRTCAP_DEVICE:
> dwc3_event_buffers_setup(dwc);
>
> - if (dwc->usb2_phy)
> - otg_set_vbus(dwc->usb2_phy->otg, false);
> + dwc3_set_vbus(dwc, false);
> phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_DEVICE);
> phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_DEVICE);
>
> @@ -1183,8 +1199,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
> case USB_DR_MODE_PERIPHERAL:
> dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
>
> - if (dwc->usb2_phy)
> - otg_set_vbus(dwc->usb2_phy->otg, false);
> + dwc3_set_vbus(dwc, false);
> phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_DEVICE);
> phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_DEVICE);
>
> @@ -1198,8 +1213,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
> case USB_DR_MODE_HOST:
> dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
>
> - if (dwc->usb2_phy)
> - otg_set_vbus(dwc->usb2_phy->otg, true);
> + dwc3_set_vbus(dwc, true);
> phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>
> @@ -1470,6 +1484,14 @@ static int dwc3_probe(struct platform_device *pdev)
>
> dwc3_get_properties(dwc);
>
> + dwc->vbus_reg = devm_regulator_get_optional(dev, "vbus");
> + if (IS_ERR(dwc->vbus_reg)) {
> + if (PTR_ERR(dwc->vbus_reg) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
Some drivers seem to do it this way, but I think it would be more
correct to return all errors that aren't ENODEV, like
drivers/gpu/drm/exynos/exynos_hdmi.c does. That way you would allow the
regulator to not be present, but you also wouldn't silently ignore other
errors such as ENOMEM.
> +
> + dwc->vbus_reg = NULL;
> + }
> +
