[U-Boot] [PATCH] usb: composite: add BOS descriptor support to composite framework

[Vignesh Raghavendra]

Hi Michal,

On 14/10/19 6:22 PM, Michal Simek wrote:
> From: T Karthik Reddy <t.karthik.reddy at xilinx.com>
> 
> To add usb-3.0 support to peripheral device add BOS & SS capability
> descriptors to gadget composite framework.
> 

How was this patch tested? With what gadget function driver was this tested?
I don't see *any* function drivers claiming SS support. (For e.g.: UMS
only declares fsg_hs_bulk_in_desc but not fsg_ss_bulk_in_desc like in
kernel), Without any function drivers claiming and implementing SS
support how is this supposed to work? Or did I miss something?

Regards
Vignesh

> Signed-off-by: T Karthik Reddy <t.karthik.reddy at xilinx.com>
> Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu at xilinx.com>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
> 
>  drivers/usb/gadget/composite.c | 61 ++++++++++++++++++++++++++++++----
>  include/linux/usb/ch9.h        |  3 ++
>  include/linux/usb/gadget.h     |  9 +++++
>  3 files changed, 67 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index c7e762374752..618a7d5016ee 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -688,6 +688,57 @@ static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
>  				req->status, req->actual, req->length);
>  }
>  
> +static int bos_desc(struct usb_composite_dev *cdev)
> +{
> +	struct usb_ext_cap_descriptor   *usb_ext;
> +	struct usb_bos_descriptor       *bos = cdev->req->buf;
> +
> +	bos->bLength = USB_DT_BOS_SIZE;
> +	bos->bDescriptorType = USB_DT_BOS;
> +
> +	bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
> +	bos->bNumDeviceCaps = 0;
> +
> +	/*
> +	 * A SuperSpeed device shall include the USB2.0 extension descriptor
> +	 * and shall support LPM when operating in USB2.0 HS mode.
> +	 */
> +	usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
> +	bos->bNumDeviceCaps++;
> +	le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
> +	usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
> +	usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
> +	usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
> +	usb_ext->bmAttributes =
> +		cpu_to_le32(USB_LPM_SUPPORT | USB_BESL_SUPPORT);
> +
> +	/*
> +	 * The Superspeed USB Capability descriptor shall be implemented
> +	 * by all SuperSpeed devices.
> +	 */
> +	if (gadget_is_superspeed(cdev->gadget)) {
> +		struct usb_ss_cap_descriptor *ss_cap;
> +
> +		ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
> +		bos->bNumDeviceCaps++;
> +		le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
> +		ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
> +		ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
> +		ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
> +		ss_cap->bmAttributes = 0; /* LTM is not supported yet */
> +		ss_cap->wSpeedSupported =
> +			cpu_to_le16(USB_LOW_SPEED_OPERATION |
> +				    USB_FULL_SPEED_OPERATION |
> +				    USB_HIGH_SPEED_OPERATION |
> +				    USB_5GBPS_OPERATION);
> +		ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
> +		ss_cap->bU1devExitLat = USB_DEFAULT_U1_DEV_EXIT_LAT;
> +		ss_cap->bU2DevExitLat =
> +			cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
> +	}
> +	return le16_to_cpu(bos->wTotalLength);
> +}
> +
>  /*
>   * The setup() callback implements all the ep0 functionality that's
>   * not handled lower down, in hardware or the hardware driver(like
> @@ -776,12 +827,10 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
>  				value = min(w_length, (u16) value);
>  			break;
>  		case USB_DT_BOS:
> -			/*
> -			 * The USB compliance test (USB 2.0 Command Verifier)
> -			 * issues this request. We should not run into the
> -			 * default path here. But return for now until
> -			 * the superspeed support is added.
> -			 */
> +			if (gadget_is_superspeed(cdev->gadget))
> +				value = bos_desc(cdev);
> +			if (value >= 0)
> +				value = min(w_length, (u16)value);
>  			break;
>  		default:
>  			goto unknown;
> diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
> index 264c9712a33a..989a5fcbd966 100644
> --- a/include/linux/usb/ch9.h
> +++ b/include/linux/usb/ch9.h
> @@ -878,6 +878,9 @@ struct usb_ss_cap_descriptor {		/* Link Power Management */
>  	__le16 bU2DevExitLat;
>  } __attribute__((packed));
>  
> +#define USB_DEFAULT_U1_DEV_EXIT_LAT     0x01	/* Less then 1 microsec */
> +#define USB_DEFAULT_U2_DEV_EXIT_LAT     0x01F4	/* Less then 500 microsec */
> +
>  #define USB_DT_USB_SS_CAP_SIZE	10
>  
>  /*
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 497798a32a87..58bfaddd036a 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -566,6 +566,15 @@ static inline int gadget_is_otg(struct usb_gadget *g)
>  #endif
>  }
>  
> +/**
> + * gadget_is_superspeed() - return true if the hardware handles superspeed
> + * @g: controller that might support superspeed
> + */
> +static inline int gadget_is_superspeed(struct usb_gadget *g)
> +{
> +	return g->max_speed >= USB_SPEED_SUPER;
> +}
> +
>  /**
>   * usb_gadget_frame_number - returns the current frame number
>   * @gadget: controller that reports the frame number
> 

-- 
Regards
Vignesh