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Commit a9548c55 authored by John Youn's avatar John Youn Committed by Felipe Balbi
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usb: gadget: Allow a non-SuperSpeed gadget to support LPM 



This commit allows a gadget that does not support SuperSpeed to indicate
that it supports LPM. It does this by setting the 'lpm_capable' flag in
the gadget structure.

If a gadget sets this, the composite gadget framework will set the
bcdUSB to 0x0201 to indicate that this supports BOS descriptors, and
also return a USB 2.0 Extension descriptor as part of the BOS descriptor
set.

See USB 2.0 LPM ECN Section 3.

Signed-off-by: default avatarJohn Youn <johnyoun@synopsys.com>
Signed-off-by: default avatarSevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 0b67a6be

drivers/usb/gadget/composite.c

+6 −2
Original line number Diff line number Diff line
@@ -1608,6 +1608,9 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 
					cdev->desc.bcdUSB = cpu_to_le16(0x0210);

				}

			} else {

				if (gadget->lpm_capable)

					cdev->desc.bcdUSB = cpu_to_le16(0x0201);

				else

					cdev->desc.bcdUSB = cpu_to_le16(0x0200);

			}
@@ -1639,7 +1642,8 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) 
				value = min(w_length, (u16) value);

			break;

		case USB_DT_BOS:

			if (gadget_is_superspeed(gadget)) {

			if (gadget_is_superspeed(gadget) ||

			    gadget->lpm_capable) {

				value = bos_desc(cdev);

				value = min(w_length, (u16) value);

			}

include/linux/usb/gadget.h

+3 −0
Original line number Diff line number Diff line
@@ -352,6 +352,8 @@ struct usb_gadget_ops { 
 * @deactivated: True if gadget is deactivated - in deactivated state it cannot

 *	be connected.

 * @connected: True if gadget is connected.

 * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag

 *	indicates that it supports LPM as per the LPM ECN & errata.

 *

 * Gadgets have a mostly-portable "gadget driver" implementing device

 * functions, handling all usb configurations and interfaces.  Gadget
@@ -404,6 +406,7 @@ struct usb_gadget { 
	unsigned			is_selfpowered:1;

	unsigned			deactivated:1;

	unsigned			connected:1;

	unsigned			lpm_capable:1;

};

#define work_to_gadget(w)	(container_of((w), struct usb_gadget, work))