| Message ID | 20210912142243.9912-3-samuel@sholland.org |
|---|---|
| State | Accepted |
| Commit | 1da7b88cade196434b84e701c1dadcd3b37c97bc |
| Delegated to: | Andre Przywara |
| Headers | show |
| Series | phy: sun4i-usb: Support VBUS detection via power supply | expand |
On Sun, 12 Sep 2021 09:22:41 -0500 Samuel Holland <samuel@sholland.org> wrote: Hi, > The Linux driver checks the VBUS detection GPIO first; then VBUS power > supply; then finally assumes VBUS is present. When adding VBUS power > supply support, we want to match that order, so we get the same behavior > in case both a GPIO and a power supply are provided in the device tree. > > So refactor the function a bit to remove the early return, and use the > same "assume VBUS is present" final fallback. > > Signed-off-by: Samuel Holland <samuel@sholland.org> Let's see if testing reveals any subtle issues ;-) Acked-by: Andre Przywara <andre.przywara@arm.com> Cheers, Andre > --- > > drivers/phy/allwinner/phy-sun4i-usb.c | 25 ++++++++++++------------- > 1 file changed, 12 insertions(+), 13 deletions(-) > > diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c > index 5302b809ee6..827ecd70f27 100644 > --- a/drivers/phy/allwinner/phy-sun4i-usb.c > +++ b/drivers/phy/allwinner/phy-sun4i-usb.c > @@ -391,20 +391,19 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy) > { > struct sun4i_usb_phy_data *data = dev_get_priv(phy->dev); > struct sun4i_usb_phy_plat *usb_phy = &data->usb_phy[phy->id]; > - int err, retries = 3; > - > - if (usb_phy->gpio_vbus_det < 0) > - return usb_phy->gpio_vbus_det; > - > - err = gpio_get_value(usb_phy->gpio_vbus_det); > - /* > - * Vbus may have been provided by the board and just been turned of > - * some milliseconds ago on reset, what we're measuring then is a > - * residual charge on Vbus, sleep a bit and try again. > - */ > - while (err > 0 && retries--) { > - mdelay(100); > + int err = 1, retries = 3; > + > + if (usb_phy->gpio_vbus_det >= 0) { > err = gpio_get_value(usb_phy->gpio_vbus_det); > + /* > + * Vbus may have been provided by the board and just turned off > + * some milliseconds ago on reset. What we're measuring then is > + * a residual charge on Vbus. Sleep a bit and try again. > + */ > + while (err > 0 && retries--) { > + mdelay(100); > + err = gpio_get_value(usb_phy->gpio_vbus_det); > + } > } > > return err;
diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c index 5302b809ee6..827ecd70f27 100644 --- a/drivers/phy/allwinner/phy-sun4i-usb.c +++ b/drivers/phy/allwinner/phy-sun4i-usb.c @@ -391,20 +391,19 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy) { struct sun4i_usb_phy_data *data = dev_get_priv(phy->dev); struct sun4i_usb_phy_plat *usb_phy = &data->usb_phy[phy->id]; - int err, retries = 3; - - if (usb_phy->gpio_vbus_det < 0) - return usb_phy->gpio_vbus_det; - - err = gpio_get_value(usb_phy->gpio_vbus_det); - /* - * Vbus may have been provided by the board and just been turned of - * some milliseconds ago on reset, what we're measuring then is a - * residual charge on Vbus, sleep a bit and try again. - */ - while (err > 0 && retries--) { - mdelay(100); + int err = 1, retries = 3; + + if (usb_phy->gpio_vbus_det >= 0) { err = gpio_get_value(usb_phy->gpio_vbus_det); + /* + * Vbus may have been provided by the board and just turned off + * some milliseconds ago on reset. What we're measuring then is + * a residual charge on Vbus. Sleep a bit and try again. + */ + while (err > 0 && retries--) { + mdelay(100); + err = gpio_get_value(usb_phy->gpio_vbus_det); + } } return err;
The Linux driver checks the VBUS detection GPIO first; then VBUS power supply; then finally assumes VBUS is present. When adding VBUS power supply support, we want to match that order, so we get the same behavior in case both a GPIO and a power supply are provided in the device tree. So refactor the function a bit to remove the early return, and use the same "assume VBUS is present" final fallback. Signed-off-by: Samuel Holland <samuel@sholland.org> --- drivers/phy/allwinner/phy-sun4i-usb.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)