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-rw-r--r--drivers/input/mouse/alps.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 8996323ce8d9..62ffea00902a 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -21,6 +21,7 @@
#include "psmouse.h"
#include "alps.h"
+#include "trackpoint.h"
/*
* Definitions for ALPS version 3 and 4 command mode protocol
@@ -2861,6 +2862,23 @@ static const struct alps_protocol_info *alps_match_table(unsigned char *e7,
return NULL;
}
+static bool alps_is_cs19_trackpoint(struct psmouse *psmouse)
+{
+ u8 param[2] = { 0 };
+
+ if (ps2_command(&psmouse->ps2dev,
+ param, MAKE_PS2_CMD(0, 2, TP_READ_ID)))
+ return false;
+
+ /*
+ * param[0] contains the trackpoint device variant_id while
+ * param[1] contains the firmware_id. So far all alps
+ * trackpoint-only devices have their variant_ids equal
+ * TP_VARIANT_ALPS and their firmware_ids are in 0x20~0x2f range.
+ */
+ return param[0] == TP_VARIANT_ALPS && (param[1] & 0x20);
+}
+
static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
{
const struct alps_protocol_info *protocol;
@@ -3162,6 +3180,20 @@ int alps_detect(struct psmouse *psmouse, bool set_properties)
return error;
/*
+ * ALPS cs19 is a trackpoint-only device, and uses different
+ * protocol than DualPoint ones, so we return -EINVAL here and let
+ * trackpoint.c drive this device. If the trackpoint driver is not
+ * enabled, the device will fall back to a bare PS/2 mouse.
+ * If ps2_command() fails here, we depend on the immediately
+ * followed psmouse_reset() to reset the device to normal state.
+ */
+ if (alps_is_cs19_trackpoint(psmouse)) {
+ psmouse_dbg(psmouse,
+ "ALPS CS19 trackpoint-only device detected, ignoring\n");
+ return -EINVAL;
+ }
+
+ /*
* Reset the device to make sure it is fully operational:
* on some laptops, like certain Dell Latitudes, we may
* fail to properly detect presence of trackstick if device