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CHROMIUM: Input: synaptics - refactor agm packet parsing

When a Synaptics touchpad is in "AGM" mode, and multiple fingers are
detected, the touchpad sends alternating "Advanced Gesture Mode" (AGM) and
"Simple Gesture Mode" (SGM) packets.
  The AGM packets have w=2, and contain reduced resolution finger data.
  The SGM packets have w={0,1} and contain full resolution finger data.

Refactor the parsing of agm packets to its own function, and rename the
synaptics_data.mt field to .agm to indicate that it contains the contents of
the last agm packet.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Chase Douglas <chase.douglas@canonical.com>

Change-Id: I5b3104855f55d561a35f13bea0b61b2460dcd48e
BUG=chromium-os:19094
TEST=builds clean; check sgm and agm packets with evtest
Reviewed-on: http://gerrit.chromium.org/gerrit/4255
Reviewed-by: Andrew de los Reyes <adlr@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Daniel Kurtz <djkurtz@chromium.org>
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1 parent 7f6fd4f commit 8de8f45c58921749707e2af162b0a4094077782d @djkurtz djkurtz committed Jul 18, 2011
Showing with 19 additions and 6 deletions.
  1. +14 −5 drivers/input/mouse/synaptics.c
  2. +5 −1 drivers/input/mouse/synaptics.h
View
19 drivers/input/mouse/synaptics.c
@@ -419,6 +419,17 @@ static void synaptics_pt_create(struct psmouse *psmouse)
* Functions to interpret the absolute mode packets
****************************************************************************/
+static void synaptics_parse_agm(const unsigned char buf[],
+ struct synaptics_data *priv)
+{
+ struct synaptics_hw_state *agm = &priv->agm;
+
+ /* Gesture packet: (x, y, z) at half resolution */
+ agm->x = (((buf[4] & 0x0f) << 8) | buf[1]) << 1;
+ agm->y = (((buf[4] & 0xf0) << 4) | buf[2]) << 1;
+ agm->z = ((buf[3] & 0x30) | (buf[5] & 0x0f)) << 1;
+}
+
static int synaptics_parse_hw_state(const unsigned char buf[],
struct synaptics_data *priv,
struct synaptics_hw_state *hw)
@@ -453,10 +464,7 @@ static int synaptics_parse_hw_state(const unsigned char buf[],
}
if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c) && hw->w == 2) {
- /* Gesture packet: (x, y, z) at half resolution */
- priv->mt.x = (((buf[4] & 0x0f) << 8) | buf[1]) << 1;
- priv->mt.y = (((buf[4] & 0xf0) << 4) | buf[2]) << 1;
- priv->mt.z = ((buf[3] & 0x30) | (buf[5] & 0x0f)) << 1;
+ synaptics_parse_agm(buf, priv);
return 1;
}
@@ -595,7 +603,8 @@ static void synaptics_process_packet(struct psmouse *psmouse)
}
if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c))
- synaptics_report_semi_mt_data(dev, &hw, &priv->mt, num_fingers);
+ synaptics_report_semi_mt_data(dev, &hw, &priv->agm,
+ num_fingers);
/* Post events
* BTN_TOUCH has to be first as mousedev relies on it when doing
View
6 drivers/input/mouse/synaptics.h
@@ -146,7 +146,11 @@ struct synaptics_data {
struct serio *pt_port; /* Pass-through serio port */
- struct synaptics_hw_state mt; /* current gesture packet */
+ /*
+ * Last received Advanced Gesture Mode (AGM) packet. An AGM packet
+ * contains position data for a second contact, at half resolution.
+ */
+ struct synaptics_hw_state agm;
};
void synaptics_module_init(void);

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