[PATCH 3.12 040/142] Input: elantech - fix absolute mode setting on some ASUS laptops

Jiri Slaby
2015-05-16T08:03:46Z

From: Ulrik De Bie <ulrik.debie-os@e2big.org>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit bd884149aca61de269fd9bad83fe2a4232ffab21 upstream.

On ASUS TP500LN and X750JN, the touchpad absolute mode is reset each
time set_rate is done.

In order to fix this, we will verify the firmware version, and if it
matches the one in those laptops, the set_rate function is overloaded
with a function elantech_set_rate_restore_reg_07 that performs the
set_rate with the original function, followed by a restore of reg_07
(the register that sets the absolute mode on elantech v4 hardware).

Also the ASUS TP500LN and X750JN firmware version, capabilities, and
button constellation is added to elantech.c

Reported-and-tested-by: George Moutsopoulos <gmoutso@yahoo.co.uk>
Signed-off-by: Ulrik De Bie <ulrik.debie-os@e2big.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/input/mouse/elantech.c | 22 ++++++++++++++++++++++
drivers/input/mouse/elantech.h | 1 +
2 files changed, 23 insertions(+)

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 0ec8604aadcf..04a7d9f00928 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -814,6 +814,21 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
}

/*
+ * This writes the reg_07 value again to the hardware at the end of every
+ * set_rate call because the register loses its value. reg_07 allows setting
+ * absolute mode on v4 hardware
+ */
+static void elantech_set_rate_restore_reg_07(struct psmouse *psmouse,
+ unsigned int rate)
+{
+ struct elantech_data *etd = psmouse->private;
+
+ etd->original_set_rate(psmouse, rate);
+ if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
+ psmouse_err(psmouse, "restoring reg_07 failed\n");
+}
+
+/*
* Put the touchpad into absolute mode
*/
static int elantech_set_absolute_mode(struct psmouse *psmouse)
@@ -1015,6 +1030,8 @@ static int elantech_get_resolution_v4(struct psmouse *psmouse,
* Asus K53SV 0x450f01 78, 15, 0c 2 hw buttons
* Asus G46VW 0x460f02 00, 18, 0c 2 hw buttons
* Asus G750JX 0x360f00 00, 16, 0c 2 hw buttons
+ * Asus TP500LN 0x381f17 10, 14, 0e clickpad
+ * Asus X750JN 0x381f17 10, 14, 0e clickpad
* Asus UX31 0x361f00 20, 15, 0e clickpad
* Asus UX32VD 0x361f02 00, 15, 0e clickpad
* Avatar AVIU-145A2 0x361f00 ? clickpad
@@ -1523,6 +1540,11 @@ int elantech_init(struct psmouse *psmouse)
goto init_fail;
}

+ if (etd->fw_version == 0x381f17) {
+ etd->original_set_rate = psmouse->set_rate;
+ psmouse->set_rate = elantech_set_rate_restore_reg_07;
+ }
+
if (elantech_set_input_params(psmouse)) {
psmouse_err(psmouse, "failed to query touchpad range.\n");
goto init_fail;
diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index 9e0e2a1f340d..59263a3a8667 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h
@@ -139,6 +139,7 @@ struct elantech_data {
struct finger_pos mt[ETP_MAX_FINGERS];
unsigned char parity[256];
int (*send_cmd)(struct psmouse *psmouse, unsigned char c, unsigned char *param);
+ void (*original_set_rate)(struct psmouse *psmouse, unsigned int rate);
};

#ifdef CONFIG_MOUSE_PS2_ELANTECH
--
2.3.7