HID: multitouch: add support of clickpads

Touchpads that have only one button are called clickpads and should
be advertised as such by the kernel.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index f65e78b46999..ef06dc30b9b1 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -116,6 +116,7 @@ struct mt_device {
         __u8 touches_by_report; /* how many touches are present in one report:
                                 * 1 means we should use a serial protocol
                                 * > 1 means hybrid (multitouch) protocol */
+        __u8 buttons_count;     /* number of physical buttons per touchpad */
         bool serial_maybe;      /* need to check for serial protocol */
         bool curvalid;          /* is the current contact valid? */
         unsigned mt_flags;      /* flags to pass to input-mt */
@@ -379,6 +380,10 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                 td->inputmode_value = MT_INPUTMODE_TOUCHPAD;
         }
 
+        /* count the buttons on touchpads */
+        if ((usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON)
+                td->buttons_count++;
+
         if (usage->usage_index)
                 prev_usage = &field->usage[usage->usage_index - 1];
 
@@ -728,6 +733,10 @@ static void mt_touch_input_configured(struct hid_device *hdev,
         if (cls->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
                 td->mt_flags |= INPUT_MT_DROP_UNUSED;
 
+        /* check for clickpads */
+        if ((td->mt_flags & INPUT_MT_POINTER) && (td->buttons_count == 1))
+                __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+
         input_mt_init_slots(input, td->maxcontacts, td->mt_flags);
 
         td->mt_flags = 0;