On Mon, 18 Mar 2002 05:57, Greg KH wrote:
<snip>
> [EMAIL PROTECTED], 2002-03-17 10:14:24-08:00, [EMAIL PROTECTED]
> USB Urefs for hid-core/hiddev
>
> I've written a patch Vojtech and I discussed for enhancing the
> hiddev code to optionally provide more detailed output on read().
> The old functionality is still supported by default, and in
> situations where HID usage codes are unique across reports, the
> old method is still preferable due to its terseness.
>
> The new method provides the ability to determine exactly which
> value has changed, in cases where the HID usage codes are not
> unique. It also provides a means to optionally receive notification
> when input reports are received from the device, whether or not
> any of the values in the report have changed.
>
> The details of the changes are as follows:
>
> - All current code behaves identically
>
> - A new ioctl pair HIDIOCGFLAG/HIDIOCSFLAG gets and clears
> flags on the hiddev device.
>
> - If you set the flag HIDDEV_FLAG_UREF, the read() call switches
> from reading hiddev_event structures to hiddev_usage_ref
> structures. The change takes effect immediately, even to
> already queued events that haven't been read() yet. Here's
> an example of enabling FLAG_UREF:
>
> {
> int flag = HIDDEV_FLAG_UREF;
> if (ioctl(fd, HIDIOCSFLAG, &flag) != 0) {
> perror("ioctl");
> exit(1);
> }
> }
>
> - With the HIDDEV_FLAG_REPORT set (which is only allowed if
> HIDDEV_FLAG_UREF is also set), there is a special uref that
> will be read() in addition to the ones corresponding to
> changes in the device state: when uref.field_index is set to
> HID_FIELD_INDEX_NONE, this uref is a notification that the
> report referred to by report_type and report_id has been
> received from the device. This can be useful in situations
> when the notification of the arrival of a report is useful
> even if there is no change in state.
>
> drivers/usb/hid-core.c | 34 +++++++++++++-
> drivers/usb/hid.h | 1
> drivers/usb/hiddev.c | 114
> ++++++++++++++++++++++++++++++++++--------------- include/linux/hiddev.h |
> 12 ++++-
> 4 files changed, 123 insertions(+), 38 deletions(-)
<snip>
Looks like updates to Documentation/usb/hiddev.txt got missed. Is anyone
working on this?
Brad
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