Re: [PATCH 0/4] Add GET/SET_REPORT support to HoG

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

Hi David,

On Nov 21 2014 or thereabouts, David Herrmann wrote:
> Hi
> 
> With linux-3.18 uhid will gain GET/SET_REPORT support. 3.18 isn't released, yet,
> but the uhid features are part of 3.18-rc5 so I think it's fine to rely on it.
> We can always revert it if it will not be released (for whatever reason..).
> 
> Benjamin wrote these 4 patches about 2 months ago and I promised to fix a few
> bugs and send them upstream. I already feel bad for letting them rot for 2
> months.. sorry!

No problems from my side. As long as it gets applied in the end, that's
fine (or at least that the features are implemented).

> 
> Anyway, I fixed the ID tracking, some typos, and fixed handling of devices that
> dont send report IDs in GET_REPORT. Patches should be straightforward. The
> GET/SET_REPORT feature is important for nearly all non-standard HID device
> drivers. It's used to query and modify device behavior. With this in place, we
> should be able to use all the kernel hid drivers via uhid/hog.

Yay, thanks for that!

> 
> Benjamin has an example program to modify MS Arc Surface Touch mouse behavior,
> which needs these patches to query/modify the device. See:
>     https://github.com/bentiss/mstouchmouse/tree/WIP-USB
> (If you check it out, make sure to use the WIP-USB branch! You should also apply
>  the diff below, to make sure it works even if the report-ID is not prepended.)
> 
> Works fine with my devices here!
> David
> 
> 
> diff --git a/set_touchmode.c b/set_touchmode.c
> index 7e5d59a..0e6f412 100644
> --- a/set_touchmode.c
> +++ b/set_touchmode.c
> @@ -48,6 +48,11 @@ static int get_report(int fd, unsigned char id, ...
>      } else {
>          printf("Report data (%d):\n\t", id);
>          pr_buffer(buf, res);
> +        /* prepend report-ID if not sent by device */
> +        if (res > 0 && buf[0] != id) {
> +            memmove(buf + 1, buf, (res >= len) ? (res - 1) : res);
> +            buf[0] = id;
> +        }
>      }
>      return res;
>  }

Committed and pushed to the repo, so there will be no need to apply it
now :)

Cheers,
Benjamin

> 
> Benjamin Tissoires (4):
>   hog: import latest uhid.h definition
>   hog: break out the report retrieval in its own function
>   hog: implement get_report functionality
>   hog: implement set_report functionality
> 
>  profiles/input/hog.c       | 204 +++++++++++++++++++++++++++++++++++++++++----
>  profiles/input/uhid_copy.h | 117 +++++++++++++++++++++++---
>  2 files changed, 292 insertions(+), 29 deletions(-)
> 
> -- 
> 2.1.3
>