From: Peter Osterlund <petero2@telia.com>
Some Synaptics touchpads have a middle mouse button that also works as a
scroll wheel. Scroll data is reported as packets with w == 2 and the scroll
amount in byte 1, treated as a signed character. For some reason, the
smallest possible wheel movement is reported as a scroll amount of 4 units.
This amount is typically spread out over more than one packet, so the driver
has to accumulate scroll delta values to correctly deal with this.
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/input/mouse/synaptics.c | 28 ++++++++++++++++++++++++++--
25-akpm/drivers/input/mouse/synaptics.h | 2 ++
2 files changed, 28 insertions(+), 2 deletions(-)
diff -puN drivers/input/mouse/synaptics.c~input-add-support-for-synaptics-touchpad-scroll-wheels drivers/input/mouse/synaptics.c
--- 25/drivers/input/mouse/synaptics.c~input-add-support-for-synaptics-touchpad-scroll-wheels 2005-02-02 15:08:16.618087840 -0800
+++ 25-akpm/drivers/input/mouse/synaptics.c 2005-02-02 15:08:16.624086928 -0800
@@ -322,8 +322,11 @@ static void synaptics_parse_hw_state(uns
hw->left = (buf[0] & 0x01) ? 1 : 0;
hw->right = (buf[0] & 0x02) ? 1 : 0;
- if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
+ if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities)) {
hw->middle = ((buf[0] ^ buf[3]) & 0x01) ? 1 : 0;
+ if (hw->w == 2)
+ hw->scroll = (signed char)(buf[1]);
+ }
if (SYN_CAP_FOUR_BUTTON(priv->capabilities)) {
hw->up = ((buf[0] ^ buf[3]) & 0x01) ? 1 : 0;
@@ -379,6 +382,26 @@ static void synaptics_process_packet(str
synaptics_parse_hw_state(psmouse->packet, priv, &hw);
+ if (hw.scroll) {
+ priv->scroll += hw.scroll;
+
+ while (priv->scroll >= 4) {
+ input_report_key(dev, BTN_BACK, !hw.down);
+ input_sync(dev);
+ input_report_key(dev, BTN_BACK, hw.down);
+ input_sync(dev);
+ priv->scroll -= 4;
+ }
+ while (priv->scroll <= -4) {
+ input_report_key(dev, BTN_FORWARD, !hw.up);
+ input_sync(dev);
+ input_report_key(dev, BTN_FORWARD, hw.up);
+ input_sync(dev);
+ priv->scroll += 4;
+ }
+ return;
+ }
+
if (hw.z > 0) {
num_fingers = 1;
finger_width = 5;
@@ -528,7 +551,8 @@ static void set_input_params(struct inpu
if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
set_bit(BTN_MIDDLE, dev->keybit);
- if (SYN_CAP_FOUR_BUTTON(priv->capabilities)) {
+ if (SYN_CAP_FOUR_BUTTON(priv->capabilities) ||
+ SYN_CAP_MIDDLE_BUTTON(priv->capabilities)) {
set_bit(BTN_FORWARD, dev->keybit);
set_bit(BTN_BACK, dev->keybit);
}
diff -puN drivers/input/mouse/synaptics.h~input-add-support-for-synaptics-touchpad-scroll-wheels drivers/input/mouse/synaptics.h
--- 25/drivers/input/mouse/synaptics.h~input-add-support-for-synaptics-touchpad-scroll-wheels 2005-02-02 15:08:16.620087536 -0800
+++ 25-akpm/drivers/input/mouse/synaptics.h 2005-02-02 15:08:16.624086928 -0800
@@ -92,6 +92,7 @@ struct synaptics_hw_state {
unsigned int up:1;
unsigned int down:1;
unsigned char ext_buttons;
+ signed char scroll;
};
struct synaptics_data {
@@ -103,6 +104,7 @@ struct synaptics_data {
unsigned char pkt_type; /* packet type - old, new, etc */
unsigned char mode; /* current mode byte */
+ int scroll;
};
#endif /* _SYNAPTICS_H */
_