From: John Youn <[email protected]> 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 <[email protected]> Signed-off-by: Sevak Arakelyan <[email protected]> --- drivers/usb/gadget/composite.c | 8 ++++++-- include/linux/usb/gadget.h | 3 +++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index abec93ab81ee..d62f53d7f418 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -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); } diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index e4516e9ded0f..927df464100d 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -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)) -- 2.11.0
