Recommendations for programming HID in FreeBSD 9

[Hans Petter Selasky]

On Friday 01 June 2012 18:12:20 Engineering wrote:
> From: Hans Petter Selasky [mailto:hselasky at c2i.net]
> 
> >> uhid is not going to get obsoleted, though using libraries from
> 
> user-space is sometimes more convenient.
> 
> Thanks HPS (and Xiaofan)
> 
> I definitely agree with that, but I've got legacy code...
> 
> Last question - I've updated my code to convert the old 'usb_ctl_report'
> and such to the new generic descriptors at runtime, and I've got two HIDs
> up and running.
> 
> As I read uhid.c, it seems to assume only one feature report ID and size. I
> have devices that have multiple feature report sizes. And one device which
> I'm pretty sure has bad device descriptors, so the size is wrong.
> 
> In the BSD7, I added the following fakery to uhid.c:
> 
> 	case USB_SET_REPORTZ: // report id and size are in first two bytes
> 		re = (struct usb_ctl_report *)addr;
> 		id = re->ucr_data[0];
> 		size = re->ucr_data[1];
> 		err = usbd_set_report(sc->sc_iface, re->ucr_report, id,
> &re->ucr_data[2],size);
> 		if (err)
> 		{
> 			return (EIO);
> 		}
> 		break;
> 
> Do you think it would make sense to do this again with the BSD9 uhid.c?

I think mav @ did some work in that area?

Are you sure you cannot use:

        case USB_SET_REPORT:
                if (!(fflags & FWRITE)) {
                        error = EPERM;
                        break;
                }
                ugd = addr;
                switch (ugd->ugd_report_type) {
                case UHID_INPUT_REPORT:
                        size = sc->sc_isize;
                        id = sc->sc_iid;
                        break;
                case UHID_OUTPUT_REPORT:
                        size = sc->sc_osize;
                        id = sc->sc_oid;
                        break;
                case UHID_FEATURE_REPORT:
                        size = sc->sc_fsize;
                        id = sc->sc_fid;
                        break;
                default:
                        return (EINVAL);
                }
                if (id != 0)
                        copyin(ugd->ugd_data, &id, 1);
                error = uhid_set_report(sc, ugd->ugd_report_type, id,
                    NULL, ugd->ugd_data, imin(ugd->ugd_maxlen, size));
                break;

--HPS