linux-kernel - Re: [PATCH] usb/phy-generic: Add support for OTG VBUS supply control

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Message-ID: <20200528112051.GB2604@b29397-desktop>
Date:   Thu, 28 May 2020 11:20:26 +0000
From:   Peter Chen <peter.chen@....com>
To:     Mike Looijmans <mike.looijmans@...ic.nl>
CC:     "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "balbi@...nel.org" <balbi@...nel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] usb/phy-generic: Add support for OTG VBUS supply control

On 20-05-26 16:50:51, Mike Looijmans wrote:
> This enables support for VBUS on boards where the power is supplied
> by a regulator. The regulator is enabled when the USB port enters
> HOST mode.
> 

Why you don't do this at your host controller driver?

Peter
> Signed-off-by: Mike Looijmans <mike.looijmans@...ic.nl>
> ---
>  .../devicetree/bindings/usb/usb-nop-xceiv.txt |  3 ++
>  drivers/usb/phy/phy-generic.c                 | 44 ++++++++++++++++++-
>  drivers/usb/phy/phy-generic.h                 |  2 +
>  3 files changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt b/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt
> index 4dc6a8ee3071..775a19fdb613 100644
> --- a/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt
> @@ -16,6 +16,9 @@ Optional properties:
>  
>  - vcc-supply: phandle to the regulator that provides power to the PHY.
>  
> +- vbus-supply: phandle to the regulator that provides the VBUS power for when
> +  the device is in HOST mode.
> +
>  - reset-gpios: Should specify the GPIO for reset.
>  
>  - vbus-detect-gpio: should specify the GPIO detecting a VBus insertion
> diff --git a/drivers/usb/phy/phy-generic.c b/drivers/usb/phy/phy-generic.c
> index 661a229c105d..ebfb90764511 100644
> --- a/drivers/usb/phy/phy-generic.c
> +++ b/drivers/usb/phy/phy-generic.c
> @@ -203,13 +203,43 @@ static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
>  	return 0;
>  }
>  
> +static int nop_set_vbus(struct usb_otg *otg, bool enabled)
> +{
> +	struct usb_phy_generic *nop;
> +	int ret;
> +
> +	if (!otg)
> +		return -ENODEV;
> +
> +	nop = container_of(otg->usb_phy, struct usb_phy_generic, phy);
> +
> +	if (!nop->vbus_reg)
> +		return 0;
> +
> +	if (enabled) {
> +		if (nop->vbus_reg_enabled)
> +			return 0;
> +		ret = regulator_enable(nop->vbus_reg);
> +		if (ret < 0)
> +			return ret;
> +		nop->vbus_reg_enabled = true;
> +	} else {
> +		if (!nop->vbus_reg_enabled)
> +			return 0;
> +		ret = regulator_disable(nop->vbus_reg);
> +		if (ret < 0)
> +			return ret;
> +		nop->vbus_reg_enabled = false;
> +	}
> +}
> +
>  int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
>  {
>  	enum usb_phy_type type = USB_PHY_TYPE_USB2;
>  	int err = 0;
>  
>  	u32 clk_rate = 0;
> -	bool needs_vcc = false, needs_clk = false;
> +	bool needs_vcc = false, needs_clk = false, needs_vbus = false;
>  
>  	if (dev->of_node) {
>  		struct device_node *node = dev->of_node;
> @@ -219,6 +249,7 @@ int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
>  
>  		needs_vcc = of_property_read_bool(node, "vcc-supply");
>  		needs_clk = of_property_read_bool(node, "clocks");
> +		needs_vbus = of_property_read_bool(node, "vbus-supply");
>  	}
>  	nop->gpiod_reset = devm_gpiod_get_optional(dev, "reset",
>  						   GPIOD_ASIS);
> @@ -268,6 +299,16 @@ int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
>  			return -EPROBE_DEFER;
>  	}
>  
> +	nop->vbus_reg = devm_regulator_get(dev, "vbus");
> +	if (IS_ERR(nop->vbus_reg)) {
> +		dev_dbg(dev, "Error getting vbus regulator: %ld\n",
> +					PTR_ERR(nop->vbus_reg));
> +		if (needs_vbus)
> +			return -EPROBE_DEFER;
> +
> +		nop->vbus_reg = NULL;
> +	}
> +
>  	nop->dev		= dev;
>  	nop->phy.dev		= nop->dev;
>  	nop->phy.label		= "nop-xceiv";
> @@ -278,6 +319,7 @@ int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop)
>  	nop->phy.otg->usb_phy		= &nop->phy;
>  	nop->phy.otg->set_host		= nop_set_host;
>  	nop->phy.otg->set_peripheral	= nop_set_peripheral;
> +	nop->phy.otg->set_vbus		= nop_set_vbus;
>  
>  	return 0;
>  }
> diff --git a/drivers/usb/phy/phy-generic.h b/drivers/usb/phy/phy-generic.h
> index 7ee80211a688..a3663639ea1e 100644
> --- a/drivers/usb/phy/phy-generic.h
> +++ b/drivers/usb/phy/phy-generic.h
> @@ -14,7 +14,9 @@ struct usb_phy_generic {
>  	struct gpio_desc *gpiod_reset;
>  	struct gpio_desc *gpiod_vbus;
>  	struct regulator *vbus_draw;
> +	struct regulator *vbus_reg;
>  	bool vbus_draw_enabled;
> +	bool vbus_reg_enabled;
>  	unsigned long mA;
>  	unsigned int vbus;
>  };
> -- 
> 2.17.1
> 

-- 

Thanks,
Peter Chen