[PATCH 2/9 v2] Input: synaptics - refactor agm packet parsing

djkurtz
2011-07-20T13:39:22Z

From: Daniel Kurtz <djkurtz@chromium.org>

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>
---
drivers/input/mouse/synaptics.c | 19 ++++++++++++++-----
drivers/input/mouse/synaptics.h | 6 +++++-
2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 297e88f..e966894 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/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
diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
index a4394e1..da8e969 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/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);
--
1.7.3.1