Input: synaptics - add support for ForcePads

ForcePads are found on HP EliteBook 1040 laptops. They lack any kind of
physical buttons, instead they generate primary button click when user
presses somewhat hard on the surface of the touchpad. Unfortunately they
also report primary button click whenever there are 2 or more contacts
on the pad, messing up all multi-finger gestures (2-finger scrolling,
multi-finger tapping, etc). To cope with this behavior we introduce a
delay (currently 50 msecs) in reporting primary press in case more
contacts appear.

Cc: stable@vger.kernel.org
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
index e594af0b264b..fb2e076738ae 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/drivers/input/mouse/synaptics.h
@@ -78,6 +78,11 @@
  * 2    0x08    image sensor            image sensor tracks 5 fingers, but only
  *                                      reports 2.
  * 2    0x20    report min              query 0x0f gives min coord reported
+ * 2    0x80    forcepad                forcepad is a variant of clickpad that
+ *                                      does not have physical buttons but rather
+ *                                      uses pressure above certain threshold to
+ *                                      report primary clicks. Forcepads also have
+ *                                      clickpad bit set.
  */
 #define SYN_CAP_CLICKPAD(ex0c)          ((ex0c) & 0x100000) /* 1-button ClickPad */
 #define SYN_CAP_CLICKPAD2BTN(ex0c)      ((ex0c) & 0x000100) /* 2-button ClickPad */
@@ -86,6 +91,7 @@
 #define SYN_CAP_ADV_GESTURE(ex0c)       ((ex0c) & 0x080000)
 #define SYN_CAP_REDUCED_FILTERING(ex0c) ((ex0c) & 0x000400)
 #define SYN_CAP_IMAGE_SENSOR(ex0c)      ((ex0c) & 0x000800)
+#define SYN_CAP_FORCEPAD(ex0c)          ((ex0c) & 0x008000)
 
 /* synaptics modes query bits */
 #define SYN_MODE_ABSOLUTE(m)            ((m) & (1 << 7))
@@ -177,6 +183,11 @@ struct synaptics_data {
          */
         struct synaptics_hw_state agm;
         bool agm_pending;                       /* new AGM packet received */
+
+        /* ForcePad handling */
+        unsigned long                           press_start;
+        bool                                    press;
+        bool                                    report_press;
 };
 
 void synaptics_module_init(void);