Ranran <ransha...@gmail.com> writes: > Hello, > > From my reading about HID gadget driver (hidg), it seems that it > support input reports, but not get/set features. > This is my understanding from the documentation: > https://www.kernel.org/doc/Documentation/usb/gadget_hid.txt > > Is that correct ?
you might wanna read the actual implementation, instead. If you're keen,
please update the documentation where it's lacking.
static int hidg_setup(struct usb_function *f,
const struct usb_ctrlrequest *ctrl)
{
struct f_hidg *hidg = func_to_hidg(f);
struct usb_composite_dev *cdev = f->config->cdev;
struct usb_request *req = cdev->req;
int status = 0;
__u16 value, length;
value = __le16_to_cpu(ctrl->wValue);
length = __le16_to_cpu(ctrl->wLength);
VDBG(cdev,
"%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
__func__, ctrl->bRequestType, ctrl->bRequest, value);
switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_GET_REPORT):
VDBG(cdev, "get_report\n");
/* send an empty report */
length = min_t(unsigned, length, hidg->report_length);
memset(req->buf, 0x0, length);
goto respond;
break;
case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_GET_PROTOCOL):
VDBG(cdev, "get_protocol\n");
length = min_t(unsigned int, length, 1);
((u8 *) req->buf)[0] = hidg->protocol;
goto respond;
break;
case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_SET_REPORT):
VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
goto stall;
break;
case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
| HID_REQ_SET_PROTOCOL):
VDBG(cdev, "set_protocol\n");
if (value > HID_REPORT_PROTOCOL)
goto stall;
length = 0;
/*
* We assume that programs implementing the Boot protocol
* are also compatible with the Report Protocol
*/
if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
hidg->protocol = value;
goto respond;
}
goto stall;
break;
case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
| USB_REQ_GET_DESCRIPTOR):
switch (value >> 8) {
case HID_DT_HID:
{
struct hid_descriptor hidg_desc_copy = hidg_desc;
VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
hidg_desc_copy.desc[0].wDescriptorLength =
cpu_to_le16(hidg->report_desc_length);
length = min_t(unsigned short, length,
hidg_desc_copy.bLength);
memcpy(req->buf, &hidg_desc_copy, length);
goto respond;
break;
}
case HID_DT_REPORT:
VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
length = min_t(unsigned short, length,
hidg->report_desc_length);
memcpy(req->buf, hidg->report_desc, length);
goto respond;
break;
default:
VDBG(cdev, "Unknown descriptor request 0x%x\n",
value >> 8);
goto stall;
break;
}
break;
default:
VDBG(cdev, "Unknown request 0x%x\n",
ctrl->bRequest);
goto stall;
break;
}
stall:
return -EOPNOTSUPP;
respond:
req->zero = 0;
req->length = length;
status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
if (status < 0)
ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
return status;
}
--
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