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usb: gadget: Allow a non-SuperSpeed gadget to support LPM

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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: John Youn <johnyoun@synopsys.com>
Signed-off-by: Sevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
John Youn 2017-04-28 12:55:20 +04:00 committed by Felipe Balbi
parent 0b67a6be14
commit a9548c5529
2 changed files with 9 additions and 2 deletions
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8
drivers/usb/gadget/composite.c
View File

@ -1608,7 +1608,10 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
cdev->desc.bcdUSB = cpu_to_le16(0x0210);
}
} else {
cdev->desc.bcdUSB = cpu_to_le16(0x0200);
if (gadget->lpm_capable)
cdev->desc.bcdUSB = cpu_to_le16(0x0201);
else
cdev->desc.bcdUSB = cpu_to_le16(0x0200);
}
value = min(w_length, (u16) sizeof cdev->desc);
@ -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);
}

3
include/linux/usb/gadget.h
View File

@ -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))