Re: [Patch V3 10/18] usb: gadget: tegra-xudc: Add usb-phy support

[Thierry Reding <thierry.reding@gmail.com>]

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On Mon, Dec 30, 2019 at 04:39:47PM +0530, Nagarjuna Kristam wrote:
> usb-phy is used to get notified on the USB role changes. Get usb-phy from
> the utmi phy.

s/utmi phy/UTMI PHY/

> 
> Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
> ---
> V2-V3:
>  - No changes in this version
> ---
>  drivers/usb/gadget/udc/tegra-xudc.c | 39 +++++++++++++++++++++++++++++++++----
>  1 file changed, 35 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
> index 6ddb974..0f27d57 100644
> --- a/drivers/usb/gadget/udc/tegra-xudc.c
> +++ b/drivers/usb/gadget/udc/tegra-xudc.c
> @@ -26,7 +26,9 @@
>  #include <linux/reset.h>
>  #include <linux/usb/ch9.h>
>  #include <linux/usb/gadget.h>
> +#include <linux/usb/otg.h>
>  #include <linux/usb/role.h>
> +#include <linux/usb/phy.h>
>  #include <linux/workqueue.h>
>  
>  /* XUSB_DEV registers */
> @@ -488,6 +490,9 @@ struct tegra_xudc {
>  	bool suspended;
>  	bool powergated;
>  
> +	struct usb_phy *usbphy;
> +	struct notifier_block vbus_nb;
> +
>  	struct completion disconnect_complete;
>  
>  	bool selfpowered;
> @@ -678,7 +683,22 @@ static void tegra_xudc_usb_role_sw_work(struct work_struct *work)
>  		tegra_xudc_device_mode_on(xudc);
>  	else
>  		tegra_xudc_device_mode_off(xudc);
> +}
> +
> +static int tegra_xudc_vbus_notifier(struct notifier_block *nb,
> +					 unsigned long action, void *data)
> +{
> +	struct tegra_xudc *xudc = container_of(nb, struct tegra_xudc,
> +					       vbus_nb);
> +
> +	dev_dbg(xudc->dev, "%s action is %ld\n", __func__, action);

I'd add the parentheses here, too. Maybe also a colon:

	"%s(): action is %ld\n"

> +
> +	xudc->role = (enum usb_role)action;
>  
> +	if (!xudc->suspended)
> +		schedule_work(&xudc->usb_role_sw_work);
> +
> +	return NOTIFY_OK;
>  }
>  
>  static void tegra_xudc_plc_reset_work(struct work_struct *work)
> @@ -1949,6 +1969,9 @@ static int tegra_xudc_gadget_start(struct usb_gadget *gadget,
>  		xudc_writel(xudc, val, CTRL);
>  	}
>  
> +	if (xudc->usbphy)
> +		otg_set_peripheral(xudc->usbphy->otg, gadget);
> +
>  	xudc->driver = driver;
>  unlock:
>  	dev_dbg(xudc->dev, "%s: ret value is %d", __func__, ret);
> @@ -1969,6 +1992,9 @@ static int tegra_xudc_gadget_stop(struct usb_gadget *gadget)
>  
>  	spin_lock_irqsave(&xudc->lock, flags);
>  
> +	if (xudc->usbphy)
> +		otg_set_peripheral(xudc->usbphy->otg, NULL);
> +
>  	val = xudc_readl(xudc, CTRL);
>  	val &= ~(CTRL_IE | CTRL_ENABLE);
>  	xudc_writel(xudc, val, CTRL);
> @@ -3573,10 +3599,15 @@ static int tegra_xudc_probe(struct platform_device *pdev)
>  	INIT_DELAYED_WORK(&xudc->port_reset_war_work,
>  				tegra_xudc_port_reset_war_work);
>  
> -	/* Set the mode as device mode and this keeps phy always ON */
> -	dev_info(xudc->dev, "Set usb role to device mode always");

This obsoletes my comment in the previous patch, but maybe consider not
adding it in the first place.

> -	xudc->role = USB_ROLE_DEVICE;
> -	schedule_work(&xudc->usb_role_sw_work);
> +	xudc->vbus_nb.notifier_call = tegra_xudc_vbus_notifier;
> +	xudc->usbphy = devm_usb_get_phy_by_node(xudc->dev,
> +						xudc->utmi_phy->dev.of_node,
> +						&xudc->vbus_nb);
> +	if (IS_ERR(xudc->usbphy)) {
> +		err = PTR_ERR(xudc->usbphy);
> +		dev_err(xudc->dev, "failed to get usbphy phy: %d\n", err);

I'd make this: "failed to get USB PHY: %d\n", which is easier to read
than the above.

Thierry

> +		goto free_eps;
> +	}
>  
>  	pm_runtime_enable(&pdev->dev);
>  
> -- 
> 2.7.4
> 

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