[PATCH 0/3] phy: sun4i-usb: Support VBUS detection via power supply

[PATCH 0/3] phy: sun4i-usb: Support VBUS detection via power supply

[Samuel Holland]

This converts a hack (a virtual GPIO pin) to less of a hack (not-really
a regulator), but at least it now supports the device tree. This series
adds the consumer side. The new code won't do anything useful until the
regulator driver is merged (which depends on the DM_PMIC driver), but it
shouldn't hurt anything either.


Samuel Holland (3):
  phy: sun4i-usb: Remove a couple of debug messages
  phy: sun4i-usb: Refactor VBUS detection to match Linux
  phy: sun4i-usb: Support VBUS detection via power supply

 drivers/phy/allwinner/Kconfig         |  1 +
 drivers/phy/allwinner/phy-sun4i-usb.c | 34 ++++++++++++++-------------
 2 files changed, 19 insertions(+), 16 deletions(-)

-- 
2.31.1

[PATCH 1/3] phy: sun4i-usb: Remove a couple of debug messages

[Samuel Holland]

Both of these messages log the GPIO number of the ID detection GPIO,
which is not terribly useful, especially in the VBUS detection function.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 drivers/phy/allwinner/phy-sun4i-usb.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
index 82713b83815..5302b809ee6 100644
--- a/drivers/phy/allwinner/phy-sun4i-usb.c
+++ b/drivers/phy/allwinner/phy-sun4i-usb.c
@@ -393,8 +393,6 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy)
 	struct sun4i_usb_phy_plat *usb_phy = &data->usb_phy[phy->id];
 	int err, retries = 3;
 
-	debug("%s: id_det = %d\n", __func__, usb_phy->gpio_id_det);
-
 	if (usb_phy->gpio_vbus_det < 0)
 		return usb_phy->gpio_vbus_det;
 
@@ -417,8 +415,6 @@ int sun4i_usb_phy_id_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];
 
-	debug("%s: id_det = %d\n", __func__, usb_phy->gpio_id_det);
-
 	if (usb_phy->gpio_id_det < 0)
 		return usb_phy->gpio_id_det;
 
-- 
2.31.1

Re: [PATCH 1/3] phy: sun4i-usb: Remove a couple of debug messages

[Andre Przywara]

On Sun, 12 Sep 2021 09:22:40 -0500
Samuel Holland <samuel@sholland.org> wrote:

> Both of these messages log the GPIO number of the ID detection GPIO,
> which is not terribly useful, especially in the VBUS detection function.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
> 
>  drivers/phy/allwinner/phy-sun4i-usb.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
> index 82713b83815..5302b809ee6 100644
> --- a/drivers/phy/allwinner/phy-sun4i-usb.c
> +++ b/drivers/phy/allwinner/phy-sun4i-usb.c
> @@ -393,8 +393,6 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy)
>  	struct sun4i_usb_phy_plat *usb_phy = &data->usb_phy[phy->id];
>  	int err, retries = 3;
>  
> -	debug("%s: id_det = %d\n", __func__, usb_phy->gpio_id_det);
> -
>  	if (usb_phy->gpio_vbus_det < 0)
>  		return usb_phy->gpio_vbus_det;
>  
> @@ -417,8 +415,6 @@ int sun4i_usb_phy_id_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];
>  
> -	debug("%s: id_det = %d\n", __func__, usb_phy->gpio_id_det);
> -
>  	if (usb_phy->gpio_id_det < 0)
>  		return usb_phy->gpio_id_det;
>  

[PATCH 2/3] phy: sun4i-usb: Refactor VBUS detection to match Linux

[Samuel Holland]

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(-)

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;
-- 
2.31.1

Re: [PATCH 2/3] phy: sun4i-usb: Refactor VBUS detection to match Linux

[Andre Przywara]

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;

[PATCH 3/3] phy: sun4i-usb: Support VBUS detection via power supply

[Samuel Holland]

The device tree binding provides for getting VBUS state from a device
referenced by phandle, as an optional alternative to using a GPIO. In
U-Boot, where there is no power supply class, this VBUS detection will
be implemented using a regulator device and its get_enable method.
Let's hook this up to the PHY driver.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 drivers/phy/allwinner/Kconfig         | 1 +
 drivers/phy/allwinner/phy-sun4i-usb.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/phy/allwinner/Kconfig b/drivers/phy/allwinner/Kconfig
index dba3bae61c4..aa9d0e7e6a5 100644
--- a/drivers/phy/allwinner/Kconfig
+++ b/drivers/phy/allwinner/Kconfig
@@ -4,6 +4,7 @@
 config PHY_SUN4I_USB
 	bool "Allwinner Sun4I USB PHY driver"
 	depends on ARCH_SUNXI
+	select DM_REGULATOR
 	select PHY
 	help
 	  Enable this to support the transceiver that is part of Allwinner
diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
index 827ecd70f27..ab2a5d17fcf 100644
--- a/drivers/phy/allwinner/phy-sun4i-usb.c
+++ b/drivers/phy/allwinner/phy-sun4i-usb.c
@@ -26,6 +26,7 @@
 #include <linux/bitops.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <power/regulator.h>
 
 #define REG_ISCR			0x00
 #define REG_PHYCTL_A10			0x04
@@ -137,6 +138,7 @@ struct sun4i_usb_phy_data {
 	void __iomem *base;
 	const struct sun4i_usb_phy_cfg *cfg;
 	struct sun4i_usb_phy_plat *usb_phy;
+	struct udevice *vbus_power_supply;
 };
 
 static int initial_usb_scan_delay = CONFIG_INITIAL_USB_SCAN_DELAY;
@@ -404,6 +406,8 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy)
 			mdelay(100);
 			err = gpio_get_value(usb_phy->gpio_vbus_det);
 		}
+	} else if (data->vbus_power_supply) {
+		err = regulator_get_enable(data->vbus_power_supply);
 	}
 
 	return err;
@@ -447,6 +451,9 @@ static int sun4i_usb_phy_probe(struct udevice *dev)
 	if (IS_ERR(data->base))
 		return PTR_ERR(data->base);
 
+	device_get_supply_regulator(dev, "usb0_vbus_power-supply",
+				    &data->vbus_power_supply);
+
 	data->usb_phy = plat;
 	for (i = 0; i < data->cfg->num_phys; i++) {
 		struct sun4i_usb_phy_plat *phy = &plat[i];
-- 
2.31.1

Re: [PATCH 3/3] phy: sun4i-usb: Support VBUS detection via power supply

[Andre Przywara]

On Sun, 12 Sep 2021 09:22:42 -0500
Samuel Holland <samuel@sholland.org> wrote:

> The device tree binding provides for getting VBUS state from a device
> referenced by phandle, as an optional alternative to using a GPIO. In
> U-Boot, where there is no power supply class, this VBUS detection will
> be implemented using a regulator device and its get_enable method.
> Let's hook this up to the PHY driver.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>

Looks good, but curious if that works on all those boards ...

Acked-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
> 
>  drivers/phy/allwinner/Kconfig         | 1 +
>  drivers/phy/allwinner/phy-sun4i-usb.c | 7 +++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/phy/allwinner/Kconfig b/drivers/phy/allwinner/Kconfig
> index dba3bae61c4..aa9d0e7e6a5 100644
> --- a/drivers/phy/allwinner/Kconfig
> +++ b/drivers/phy/allwinner/Kconfig
> @@ -4,6 +4,7 @@
>  config PHY_SUN4I_USB
>  	bool "Allwinner Sun4I USB PHY driver"
>  	depends on ARCH_SUNXI
> +	select DM_REGULATOR
>  	select PHY
>  	help
>  	  Enable this to support the transceiver that is part of Allwinner
> diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
> index 827ecd70f27..ab2a5d17fcf 100644
> --- a/drivers/phy/allwinner/phy-sun4i-usb.c
> +++ b/drivers/phy/allwinner/phy-sun4i-usb.c
> @@ -26,6 +26,7 @@
>  #include <linux/bitops.h>
>  #include <linux/delay.h>
>  #include <linux/err.h>
> +#include <power/regulator.h>
>  
>  #define REG_ISCR			0x00
>  #define REG_PHYCTL_A10			0x04
> @@ -137,6 +138,7 @@ struct sun4i_usb_phy_data {
>  	void __iomem *base;
>  	const struct sun4i_usb_phy_cfg *cfg;
>  	struct sun4i_usb_phy_plat *usb_phy;
> +	struct udevice *vbus_power_supply;
>  };
>  
>  static int initial_usb_scan_delay = CONFIG_INITIAL_USB_SCAN_DELAY;
> @@ -404,6 +406,8 @@ int sun4i_usb_phy_vbus_detect(struct phy *phy)
>  			mdelay(100);
>  			err = gpio_get_value(usb_phy->gpio_vbus_det);
>  		}
> +	} else if (data->vbus_power_supply) {
> +		err = regulator_get_enable(data->vbus_power_supply);
>  	}
>  
>  	return err;
> @@ -447,6 +451,9 @@ static int sun4i_usb_phy_probe(struct udevice *dev)
>  	if (IS_ERR(data->base))
>  		return PTR_ERR(data->base);
>  
> +	device_get_supply_regulator(dev, "usb0_vbus_power-supply",
> +				    &data->vbus_power_supply);
> +
>  	data->usb_phy = plat;
>  	for (i = 0; i < data->cfg->num_phys; i++) {
>  		struct sun4i_usb_phy_plat *phy = &plat[i];