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

[T Karthik Reddy <tkarthik@xilinx.com>]

Hi Vignesh,

> -----Original Message-----
> From: Vignesh Raghavendra <vigneshr@ti.com>
> Sent: Friday, October 25, 2019 10:13 AM
> To: Michal Simek <michals@xilinx.com>; u-boot at lists.denx.de; git
> <git@xilinx.com>
> Cc: Marek Vasut <marex@denx.de>; T Karthik Reddy <tkarthik@xilinx.com>
> Subject: Re: [U-Boot] [PATCH] usb: composite: add BOS descriptor support to
> composite framework
> 
> Hi Michal,
> 
> On 14/10/19 6:22 PM, Michal Simek wrote:
> > From: T Karthik Reddy <t.karthik.reddy@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?

Commit 771e76515ed5abe7eff73a54ccb0c9ae55f34388 has added support for detecting usb 3.0 device. For the enquiry from host we are sending bos descriptor to host as a part to support 3.0 & we have tested it with DFU function.

Regards
T karthik
> 
> Regards
> Vignesh
> 
> > Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
> > Signed-off-by: Siva Durga Prasad Paladugu
> > <siva.durga.paladugu@xilinx.com>
> > Signed-off-by: Michal Simek <michal.simek@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