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SubjectRe: [PATCH v2] usb: host: ehci-platform: add support for optional external vbus supply
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Hi,

On 20/02/18 14:58, Amelie Delaunay wrote:
> On some boards, especially when vbus supply requires large current,
> and the charge pump on the PHY isn't enough, an external vbus power switch
> may be used.
> Add support for this optional external vbus supply in ehci-platform.
>
> Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
>
> ---
> Changes in v2:
> * Address Roger Quadros comments: move regulator_enable/disable from
> ehci_platform_power_on/off to ehci_platform_port_power.
> ---
> Documentation/devicetree/bindings/usb/usb-ehci.txt | 1 +
> drivers/usb/host/ehci-platform.c | 31 ++++++++++++++++++++++
> 2 files changed, 32 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> index 3efde12..fc480cd 100644
> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> @@ -19,6 +19,7 @@ Optional properties:
> - phys : phandle + phy specifier pair
> - phy-names : "usb"
> - resets : phandle + reset specifier pair
> + - vbus-supply : phandle of regulator supplying vbus
>

Can platforms have more than one regulator e.g. one regulator per port?

> Example (Sequoia 440EPx):
> ehci@e0000300 {
> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> index b065a96..05be100 100644
> --- a/drivers/usb/host/ehci-platform.c
> +++ b/drivers/usb/host/ehci-platform.c
> @@ -29,6 +29,7 @@
> #include <linux/of.h>
> #include <linux/phy/phy.h>
> #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/reset.h>
> #include <linux/usb.h>
> #include <linux/usb/hcd.h>
> @@ -46,6 +47,7 @@ struct ehci_platform_priv {
> struct reset_control *rsts;
> struct phy **phys;
> int num_phys;
> + struct regulator *vbus_supply;
> bool reset_on_resume;
> };
>
> @@ -76,6 +78,25 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
> return 0;
> }
>
> +static int ehci_platform_port_power(struct usb_hcd *hcd, int portnum,
> + bool enable)
> +{
> + struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
> + int ret = 0;
> +
> + if (priv->vbus_supply) {
> + if (enable)
> + ret = regulator_enable(priv->vbus_supply);
> + else
> + ret = regulator_disable(priv->vbus_supply);
> + if (ret)
> + dev_err(hcd->self.controller,
> + "failed to %s vbus supply: %d\n",
> + enable ? "enable" : "disable", ret);
> + }
> + return ret;
> +}
> +
> static int ehci_platform_power_on(struct platform_device *dev)
> {
> struct usb_hcd *hcd = platform_get_drvdata(dev);
> @@ -134,6 +155,7 @@ static struct hc_driver __read_mostly ehci_platform_hc_driver;
> static const struct ehci_driver_overrides platform_overrides __initconst = {
> .reset = ehci_platform_reset,
> .extra_priv_size = sizeof(struct ehci_platform_priv),
> + .port_power = ehci_platform_port_power,
> };
>
> static struct usb_ehci_pdata ehci_platform_defaults = {
> @@ -247,6 +269,15 @@ static int ehci_platform_probe(struct platform_device *dev)
> if (err)
> goto err_put_clks;
>
> + priv->vbus_supply = devm_regulator_get_optional(&dev->dev, "vbus");
> + if (IS_ERR(priv->vbus_supply)) {
> + err = PTR_ERR(priv->vbus_supply);
> + if (err == -ENODEV)
> + priv->vbus_supply = NULL;
> + else
> + goto err_reset;
> + }
> +
> if (pdata->big_endian_desc)
> ehci->big_endian_desc = 1;
> if (pdata->big_endian_mmio)
>

--
cheers,
-roger

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