Re: [PATCH 2/3] hid-multitouch: Filter collections by application usage.

Stéphane Chatty
2011-07-25T09:24:16Z

Le 25 juil. 2011 à 00:07, jeffbrown@android.com a écrit :

> From: Jeff Brown <jeffbrown@google.com>
>
> This change fixes two problems.
>
> First, it ensures that the hid-multitouch driver does not incorrectly
> map GenericDesktop usages that are intended for other applications,
> such as a Mouse.
>
> Second, it sets the appropriate input properties so that user-space
> can distinguish TouchScreen devices (INPUT_PROP_DIRECT) from
> TouchPad devices (INPUT_PROP_POINTER) and configure them accordingly.
>
> Signed-off-by: jeffbrown@android.com
> ---
> drivers/hid/hid-multitouch.c | 10 ++++++++++
> 1 files changed, 10 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index 58d0e7a..4ee21ac 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -213,6 +213,16 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> struct mt_class *cls = td->mtclass;
> __s32 quirks = cls->quirks;
>
> + /* Only map fields from TouchScreen or TouchPad collections.
> + * We need to ignore fields that belong to other collections
> + * such as Mouse that might have the same GenericDesktop usages. */
> + if (field->application == HID_DG_TOUCHSCREEN)
> + set_bit(INPUT_PROP_DIRECT, hi->input->propbit);
> + else if (field->application == HID_DG_TOUCHPAD)
> + set_bit(INPUT_PROP_POINTER, hi->input->propbit);
> + else
> + return 0;
> +
> switch (usage->hid & HID_USAGE_PAGE) {
>
> case HID_UP_GENDESK:
> --
> 1.7.0.4
>

Looks clever to me. Still, in principle we should check that all (or at least most) known devices fill the application field properly. I'll try to have a look at the report descriptors we have here.

St.