[PATCH] usb: dwc3-generic: use DR_MODE_OTG when dr_mode isn't specified

[Caleb Connolly]

On 16/10/2024 10:26, Neil Armstrong via groups.io wrote:
> The USB DRD bindingsa at [1] are clear, if not specified the dr_mode
> property defaults to otg, and this is how Linux behaves.

I guess this is (kind of?) a subset of

https://lore.kernel.org/u-boot/20240621021135.1600847-2-caleb.connolly@linaro.org/

I need to respin that one...
> 
> A cleanup is ongoing on the Linux Device Trees to remove dr_mode when
> set to "otg", so take this in account and do not fail anymore when
> dr_mode isn't specified in the glue or dwc3 node.

Definitely an improvement over the status quo heh

Reviewed-by: Caleb Connolly <caleb.connolly at linaro.org>
> 
> [1] https://www.kernel.org/doc/Documentation/devicetree/bindings/usb/usb-drd.yaml
> 
> Signed-off-by: Neil Armstrong <neil.armstrong at linaro.org>
> ---
>   drivers/usb/dwc3/dwc3-generic.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
> index 2ab41cbae45..d62d687ece3 100644
> --- a/drivers/usb/dwc3/dwc3-generic.c
> +++ b/drivers/usb/dwc3/dwc3-generic.c
> @@ -183,10 +183,10 @@ static int dwc3_generic_of_to_plat(struct udevice *dev)
>   		/* might be a leaf so check the parent for mode */
>   		node = dev_ofnode(dev->parent);
>   		plat->dr_mode = usb_get_dr_mode(node);
> -		if (plat->dr_mode == USB_DR_MODE_UNKNOWN) {
> -			pr_err("Invalid usb mode setup\n");
> -			return -ENODEV;
> -		}
> +
> +		/* If none of the nodes have dr_mode, bindings says default is OTG */
> +		if (!plat->dr_mode)
> +			plat->dr_mode = USB_DR_MODE_OTG;
>   	}
>   
>   	return 0;
> @@ -527,6 +527,10 @@ static int dwc3_glue_bind_common(struct udevice *parent, ofnode node)
>   	if (!dr_mode)
>   		dr_mode = usb_get_dr_mode(node);
>   
> +	/* If none of the nodes have dr_mode, bindings says default is OTG */
> +	if (!dr_mode)
> +		dr_mode = USB_DR_MODE_OTG;
> +
>   	if (CONFIG_IS_ENABLED(DM_USB_GADGET) &&
>   	    (dr_mode == USB_DR_MODE_PERIPHERAL || dr_mode == USB_DR_MODE_OTG)) {
>   		debug("%s: dr_mode: OTG or Peripheral\n", __func__);
> 
> ---
> base-commit: d5cab0d6adc26ec1bbd45c2fed101184d04454ae
> change-id: 20241016-topic-usb-dwc3-dr-mode-otg-88ec307e0970
> 
> Best regards,

-- 
// Caleb (they/them)