[PATCH] [100/223] HID: Fix for problems with eGalax/DWAV multi-touch-screen

From: Andi Kleen
Date: Sun Dec 12 2010 - 19:12:32 EST


2.6.35-longterm review patch. If anyone has any objections, please let me know.

------------------
From: Philipp Merkel <mail@xxxxxxxxxxx>

commit f51661105c3c8a0afcd69f995a4f4a10e53da153 upstream.

This patch fixes three problems with the eGalax/DWAV multi-touch
screen found in the Eee PC T101MT:

1) While there is a dedicated multitouch driver for the screen
(hid-egalax.c), the MULTI_INPUT quirk is also applied, preventing
the hid-egalax driver from working. This patch removes the quirk
so the hid-egalax driver can handle the device correctly.
2) The x and y coordinates sent by the screen in multi-touch mode are
shifted by three bits from the events sent in single-touch mode, thus
the coordinates are out of range, leading to the pointer being stuck
in the bottom-right corner if no additional calibration is applied
(e.g. in the X evdev driver). This patch shifts the coordinates back.
This does not decrease accuracy as the last three bits of the "wrong"
coordinates are always 0.
3) Only multi-touch pressure events are sent, single touch emulation is
missing pressure information. This patch adds single-touch
ABS_PRESSURE events.

Signed-off-by: Philipp Merkel <mail@xxxxxxxxxxx>
Acked-by: Stéphane Chatty <chatty@xxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
drivers/hid/hid-egalax.c | 16 +++++++++++-----
drivers/hid/usbhid/hid-quirks.c | 1 -
2 files changed, 11 insertions(+), 6 deletions(-)

Index: linux/drivers/hid/hid-egalax.c
===================================================================
--- linux.orig/drivers/hid/hid-egalax.c
+++ linux/drivers/hid/hid-egalax.c
@@ -31,7 +31,7 @@ struct egalax_data {
bool first; /* is this the first finger in the frame? */
bool valid; /* valid finger data, or just placeholder? */
bool activity; /* at least one active finger previously? */
- __u16 lastx, lasty; /* latest valid (x, y) in the frame */
+ __u16 lastx, lasty, lastz; /* latest valid (x, y, z) in the frame */
};

static int egalax_input_mapping(struct hid_device *hdev, struct hid_input *hi,
@@ -79,6 +79,10 @@ static int egalax_input_mapping(struct h
case HID_DG_TIPPRESSURE:
hid_map_usage(hi, usage, bit, max,
EV_ABS, ABS_MT_PRESSURE);
+ /* touchscreen emulation */
+ input_set_abs_params(hi->input, ABS_PRESSURE,
+ field->logical_minimum,
+ field->logical_maximum, 0, 0);
return 1;
}
return 0;
@@ -109,8 +113,8 @@ static void egalax_filter_event(struct e
if (td->valid) {
/* emit multitouch events */
input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
- input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
- input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);
+ input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x >> 3);
+ input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y >> 3);
input_event(input, EV_ABS, ABS_MT_PRESSURE, td->z);

input_mt_sync(input);
@@ -121,6 +125,7 @@ static void egalax_filter_event(struct e
*/
td->lastx = td->x;
td->lasty = td->y;
+ td->lastz = td->z;
}

/*
@@ -129,8 +134,9 @@ static void egalax_filter_event(struct e
* the oldest on the panel, the one we want for single touch
*/
if (!td->first && td->activity) {
- input_event(input, EV_ABS, ABS_X, td->lastx);
- input_event(input, EV_ABS, ABS_Y, td->lasty);
+ input_event(input, EV_ABS, ABS_X, td->lastx >> 3);
+ input_event(input, EV_ABS, ABS_Y, td->lasty >> 3);
+ input_event(input, EV_ABS, ABS_PRESSURE, td->lastz);
}

if (!td->valid) {
Index: linux/drivers/hid/usbhid/hid-quirks.c
===================================================================
--- linux.orig/drivers/hid/usbhid/hid-quirks.c
+++ linux/drivers/hid/usbhid/hid-quirks.c
@@ -33,7 +33,6 @@ static const struct hid_blacklist {
{ USB_VENDOR_ID_AASHIMA, USB_DEVICE_ID_AASHIMA_PREDATOR, HID_QUIRK_BADPAD },
{ USB_VENDOR_ID_ALPS, USB_DEVICE_ID_IBM_GAMEPAD, HID_QUIRK_BADPAD },
{ USB_VENDOR_ID_CHIC, USB_DEVICE_ID_CHIC_GAMEPAD, HID_QUIRK_BADPAD },
- { USB_VENDOR_ID_DWAV, USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH, HID_QUIRK_MULTI_INPUT },
{ USB_VENDOR_ID_MOJO, USB_DEVICE_ID_RETRO_ADAPTER, HID_QUIRK_MULTI_INPUT },
{ USB_VENDOR_ID_HAPP, USB_DEVICE_ID_UGCI_DRIVING, HID_QUIRK_BADPAD | HID_QUIRK_MULTI_INPUT },
{ USB_VENDOR_ID_HAPP, USB_DEVICE_ID_UGCI_FLYING, HID_QUIRK_BADPAD | HID_QUIRK_MULTI_INPUT },
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/