Re: [PATCH] usb: dwc3: Addition of "dr_mode" dt property.

[Michael Grzeschik <mgr@pengutronix.de>]

Hi,

On Thu, May 30, 2013 at 03:14:54PM -0500, Ruchika Kharwar wrote:
> This patch adds an optional parameter "dr_mode" to the dwc3 core device node.
> In the case the compile flag for the DWC3 controller is set to
> "USB_DWC3_DUAL_ROLE" a device tree could restrain to either functionality of
> host or gadget. In the case the device tree does not use this optional flag or
> specifies it superfluously to "drd" the functionality will be that
> of a dual role device.
> 
> Signed-off-by: Ruchika Kharwar <ruchika@ti.com>
> ---
>  Documentation/devicetree/bindings/usb/dwc3.txt |    3 ++-
>  drivers/usb/dwc3/core.c                        |   21 +++++++++++++++++----
>  2 files changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> index 7a95c65..2f5d584 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -10,7 +10,8 @@ Required properties:
>  
>  Optional properties:
>   - tx-fifo-resize: determines if the FIFO *has* to be reallocated.
> -
> + - dr_mode: determines the mode of core. Supported modes are "gadget", "host"
> +   and "drd".
>  This is usually a subnode to DWC3 glue to which it is connected.
>  
>  dwc3@4a030000 {
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index c35d49d..e11660a 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -378,7 +378,7 @@ static int dwc3_probe(struct platform_device *pdev)
>  	void			*mem;
>  
>  	u8			mode;
> -
> +	char			*dr_mode;
>  	mem = devm_kzalloc(dev, sizeof(*dwc) + DWC3_ALIGN_MASK, GFP_KERNEL);
>  	if (!mem) {
>  		dev_err(dev, "not enough memory\n");
> @@ -520,9 +520,22 @@ static int dwc3_probe(struct platform_device *pdev)
>  		mode = DWC3_MODE_HOST;
>  	else if (IS_ENABLED(CONFIG_USB_DWC3_GADGET))
>  		mode = DWC3_MODE_DEVICE;
> -	else
> -		mode = DWC3_MODE_DRD;
> -
> +	else {
> +		if (of_property_read_string(node, "dr_mode", &dr_mode))
> +			mode = DWC3_MODE_DRD;
> +		else {
> +			if (strcmp(dr_mode, "host") == 0)
> +				mode = DWC3_MODE_HOST;
> +			else if (strcmp(dr_mode, "gadget") == 0)
> +				mode = DWC3_MODE_DEVICE;
> +			else if (strcmp(dr_mode, "drd") == 0)
> +				mode = DWC3_MODE_DRD;
> +			else {
> +				dev_err(dev, "invalid dr_mode property value\n");
> +				goto err2;
> +			}
> +		}
> +	}
>  	switch (mode) {
>  	case DWC3_MODE_DEVICE:
>  		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
> -- 

Why not help to make use of that code?

https://patchwork.kernel.org/patch/2193321/

We currently stuck in the discussion about all possible dr_mode
properties. There came up a device that is host and device capable,
but not otg.

What does the property drd stand for?

Thanks,
Michael

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