[PATCH] Input: ALPS - Detect trackstick presence for v7 protocol

["Pali Rohár" <pali.rohar@gmail.com>]

This patch adds detection of trackstick for v7 protocol devices. Code in this
patch is used in official Dell touchpad linux drivers for Dell models:
Dell Latitude E5250/5250, E5450/5450, E5550/5550

Detection code and base reg for alps v3 rushmore and v7 devices is exacly same.

Also user in bug https://bugzilla.kernel.org/show_bug.cgi?id=94801 reported
that Toshiba Sattellite Z30-A-1DG has only alps v7 touchpad device without
trackstick and kernel reports to userspace also redundant trackstick device.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
---
 drivers/input/mouse/alps.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 33198b9..c9cd27a 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -30,6 +30,7 @@
 #define ALPS_CMD_NIBBLE_10	0x01f2
 
 #define ALPS_REG_BASE_RUSHMORE	0xc2c0
+#define ALPS_REG_BASE_V7	0xc2c0
 #define ALPS_REG_BASE_PINNACLE	0x0000
 
 static const struct alps_nibble_commands alps_v3_nibble_commands[] = {
@@ -1795,7 +1796,7 @@ static int alps_absolute_mode_v3(struct psmouse *psmouse)
 	return 0;
 }
 
-static int alps_probe_trackstick_v3(struct psmouse *psmouse, int reg_base)
+static int alps_probe_trackstick_v3_v7(struct psmouse *psmouse, int reg_base)
 {
 	int ret = -EIO, reg_val;
 
@@ -1880,7 +1881,7 @@ static int alps_hw_init_v3(struct psmouse *psmouse)
 	int reg_val;
 	unsigned char param[4];
 
-	reg_val = alps_probe_trackstick_v3(psmouse, ALPS_REG_BASE_PINNACLE);
+	reg_val = alps_probe_trackstick_v3_v7(psmouse, ALPS_REG_BASE_PINNACLE);
 	if (reg_val == -EIO)
 		goto error;
 
@@ -2260,8 +2261,8 @@ static int alps_set_protocol(struct psmouse *psmouse,
 		priv->x_bits = 16;
 		priv->y_bits = 12;
 
-		if (alps_probe_trackstick_v3(psmouse,
-					     ALPS_REG_BASE_RUSHMORE) < 0)
+		if (alps_probe_trackstick_v3_v7(psmouse,
+						ALPS_REG_BASE_RUSHMORE) < 0)
 			priv->flags &= ~ALPS_DUALPOINT;
 
 		break;
@@ -2311,6 +2312,9 @@ static int alps_set_protocol(struct psmouse *psmouse,
 		if (priv->fw_ver[1] != 0xba)
 			priv->flags |= ALPS_BUTTONPAD;
 
+		if (alps_probe_trackstick_v3_v7(psmouse, ALPS_REG_BASE_V7) < 0)
+			priv->flags &= ~ALPS_DUALPOINT;
+
 		break;
 	}
 
-- 
1.7.9.5