[PATCH v2 1/4] usb: dwc2: Add support for optional usb phy

[Sascha Hauer]

On Thu, Dec 10, 2020 at 11:31:01AM +0100, Jules Maselbas wrote:
> Signed-off-by: Jules Maselbas <jmaselbas at kalray.eu>
> ---
>  drivers/usb/dwc2/core.h |  2 ++
>  drivers/usb/dwc2/dwc2.c | 24 ++++++++++++++++++++++++
>  drivers/usb/dwc2/dwc2.h |  1 +
>  3 files changed, 27 insertions(+)
> 
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> index 090ca15fe..b9845b552 100644
> --- a/drivers/usb/dwc2/core.h
> +++ b/drivers/usb/dwc2/core.h
> @@ -466,6 +466,8 @@ struct dwc2 {
>  	struct dwc2_hw_params hw_params;
>  	struct dwc2_core_params params;
>  
> +	struct phy *phy; /* optional */
> +
>  #ifdef CONFIG_USB_DWC2_HOST
>  	struct usb_host host;
>  	u8 in_data_toggle[MAX_DEVICE][MAX_ENDPOINT];
> diff --git a/drivers/usb/dwc2/dwc2.c b/drivers/usb/dwc2/dwc2.c
> index 282e6754b..9ab3b5b53 100644
> --- a/drivers/usb/dwc2/dwc2.c
> +++ b/drivers/usb/dwc2/dwc2.c
> @@ -50,6 +50,20 @@ static int dwc2_probe(struct device_d *dev)
>  	dwc2->regs = IOMEM(iores->start);
>  	dwc2->dev = dev;
>  
> +	dwc2->phy = phy_optional_get(dev, "usb2-phy");
> +	if (IS_ERR(dwc2->phy)) {
> +		ret = PTR_ERR(dwc2->phy);
> +		return ret;
> +	}
> +
> +	if (dwc2->phy) {
> +		ret = phy_power_on(dwc2->phy);
> +		if (ret == 0)
> +			ret = phy_init(dwc2->phy);
> +		if (ret)
> +			goto error;
> +	}

Just like with clocks a NULL pointer is handled like a dummy phy, you
can drop the if (dwc2->phy) tests here.

Shouldn't phy_init() called before phy_power_on()? At least that's the
order I find in the Kernel in several places.

>  	dwc2_gadget_uninit(dwc2);
> +
> +	if (dwc2->phy) {
> +		ret = phy_exit(dwc2->phy);
> +		if (ret == 0)
> +			phy_power_off(dwc2->phy);
> +	}

Likewise phy_power_off() before phy_exit().

Sascha


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