Pre-probe the device (eventcomm only).

For auto-dev, we'd probe the device node and get the axis ranges. If we
specify the device however we didn't retrieve the axis ranges and thus got
stuck with the defaults - losing out on automatic edge and accel calculation.

This is an issue if the device is hotplugged, as HAL will specify the device
node.

This patch adds another hook to synproto_operations to pre-probe the device.
This hook is only used by eventcomm and opens the FD, queries the axis range
and closes the FD again.

6 files changed, 37 insertions, 6 deletions

diff --git a/src/alpscomm.c b/src/alpscomm.c
index 4f19d04..0b93fef 100644
--- a/src/alpscomm.c
+++ b/src/alpscomm.c
@@ -262,5 +262,6 @@ struct SynapticsProtocolOperations alps_proto_operations = {
     ALPSDeviceOffHook,
     ALPSQueryHardware,
     ALPSReadHwState,
-    ALPSAutoDevProbe
+    ALPSAutoDevProbe,
+    NULL /* ProbeDevice */
 };
diff --git a/src/eventcomm.c b/src/eventcomm.c
index e3ac20e..6c37dbd 100644
--- a/src/eventcomm.c
+++ b/src/eventcomm.c
@@ -305,6 +305,31 @@ static int EventDevOnly(const struct dirent *dir) {
 	return strncmp(EVENT_DEV_NAME, dir->d_name, 5) == 0;
 }
 
+/**
+ * Probe the given device name for axis ranges, if appropriate.
+ */
+static Bool
+EventProbeDevice(LocalDevicePtr local, char* device)
+{
+    int fd;
+
+    SYSCALL(fd = open(device, O_RDONLY));
+    if (fd < 0)
+        goto out;
+
+    if (!event_query_is_touchpad(fd))
+        goto out;
+
+    event_query_axis_ranges(fd, local);
+
+out:
+    if (fd >= 0)
+        SYSCALL(close(fd));
+
+    /* Always return TRUE, PreInit will complain for us if necessary */
+    return TRUE;
+}
+
 static Bool
 EventAutoDevProbe(LocalDevicePtr local)
 {
@@ -361,5 +386,6 @@ struct SynapticsProtocolOperations event_proto_operations = {
     EventDeviceOffHook,
     EventQueryHardware,
     EventReadHwState,
-    EventAutoDevProbe
+    EventAutoDevProbe,
+    EventProbeDevice
 };
diff --git a/src/ps2comm.c b/src/ps2comm.c
index 32e3dc9..cc2a202 100644
--- a/src/ps2comm.c
+++ b/src/ps2comm.c
@@ -758,5 +758,6 @@ struct SynapticsProtocolOperations psaux_proto_operations = {
     PS2DeviceOffHook,
     PS2QueryHardware,
     PS2ReadHwState,
-    PS2AutoDevProbe
+    PS2AutoDevProbe,
+    NULL /* ProbeDevice */
 };
diff --git a/src/psmcomm.c b/src/psmcomm.c
index 95364ab..c36bed3 100644
--- a/src/psmcomm.c
+++ b/src/psmcomm.c
@@ -177,5 +177,6 @@ struct SynapticsProtocolOperations psm_proto_operations = {
     PSMDeviceOffHook,
     PSMQueryHardware,
     PSMReadHwState,
-    PSMAutoDevProbe
+    PSMAutoDevProbe,
+    NULL /* ProbeDevice */
 };
diff --git a/src/synaptics.c b/src/synaptics.c
index 7aa5c79..e7f929f 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -181,8 +181,9 @@ SetDeviceAndProtocol(LocalDevicePtr local)
     }
     if (device && strstr(device, "/dev/input/event")) {
 #ifdef BUILD_EVENTCOMM
-	/* trust the device name if we've been given one */
-	proto = SYN_PROTO_EVENT;
+        if (event_proto_operations.ProbeDevice &&
+            event_proto_operations.ProbeDevice(local, device))
+            proto = SYN_PROTO_EVENT;
 #endif
     } else {
 	str_par = xf86FindOptionValue(local->options, "Protocol");
diff --git a/src/synproto.h b/src/synproto.h
index d5ae8f9..246adbd 100644
--- a/src/synproto.h
+++ b/src/synproto.h
@@ -96,6 +96,7 @@ struct SynapticsProtocolOperations {
 			struct SynapticsProtocolOperations *proto_ops,
 			struct CommData *comm, struct SynapticsHwState *hwRet);
     Bool (*AutoDevProbe)(LocalDevicePtr local);
+    Bool (*ProbeDevice)(LocalDevicePtr local, char* name);
 };
 
 extern struct SynapticsProtocolOperations psaux_proto_operations;