Wireless device detection, and CadMouse avoidance logic

New 3dconnexion devices seem to all use the same dongle with USB id
256f:c526. That includes at least the SpaceMouse Wireless and the
CadMouse Wireless. This is a set of hacks to guess what's connected
and act accordingly:

  - Drop the CadMouse (num_axes == 0)
  - Enable the button hack if it's a SpaceMouse Pro Wireless
  - Detect SpaceMouse Wirless and update name/type.

Also added a test for the assumption that devices marked for button
remapping always report 255-256 buttons. If that's not the case undo the
button-hack and ask the user to report it as a bug.

src/dev.c

@@ -35,8 +35,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #endif
 
 
-#define VENDOR_3DCONNEXION	0x256f
-
 /* The device flags are introduced to normalize input across all known
  * supported 6dof devices. Newer USB devices seem to use axis 1 as fwd/back and
  * axis 2 as up/down, while older serial devices (and possibly also the early
@@ -57,9 +55,6 @@ enum {
  * actual buttons when a negative number is passed as argument, and the button
  * mapping otherwise.
  */
-int bnhack_smpro(int bn);
-int bnhack_sment(int bn);
-
 static struct usbdb_entry {
 	int usbid[2];
 	int type;
@@ -76,7 +71,7 @@ static struct usbdb_entry {
 	{{0x046d, 0xc627}, DEV_SEXP,		DF_SWAPYZ | DF_INVYZ,	0},				/* space explorer */
 	{{0x046d, 0xc628}, DEV_SNAVNB,		DF_SWAPYZ | DF_INVYZ,	0},				/* space navigator for notebooks*/
 	{{0x046d, 0xc629}, DEV_SPILOTPRO,	DF_SWAPYZ | DF_INVYZ,	0},				/* space pilot pro*/
-	{{0x046d, 0xc62b}, DEV_SMPRO,		DF_SWAPYZ | DF_INVYZ,	0},				/* space mouse pro*/
+	{{0x046d, 0xc62b}, DEV_SMPRO,		DF_SWAPYZ | DF_INVYZ,	bnhack_smpro},	/* space mouse pro*/
 	{{0x046d, 0xc640}, DEV_NULOOQ,		0,						0},				/* nulooq */
 	{{0x256f, 0xc62e}, DEV_SMW,			DF_SWAPYZ | DF_INVYZ,	0},				/* spacemouse wireless (USB cable) */
 	{{0x256f, 0xc62f}, DEV_SMW,			DF_SWAPYZ | DF_INVYZ,	0},				/* spacemouse wireless  receiver */
@@ -191,7 +186,7 @@ int init_devices_usb(void)
 				remove_device(dev);
 			} else {
 				/* add the 6dof remapping flags to every future 3dconnexion device */
-				if(dev->usbid[0] == VENDOR_3DCONNEXION) {
+				if(dev->usbid[0] == VID_3DCONN) {
 					dev->flags |= DF_SWAPYZ | DF_INVYZ;
 				}
 				/* sanity-check the device flags */
@@ -395,7 +390,7 @@ static int match_usbdev(const struct usb_dev_info *devinfo)
 		}
 
 		/* match any device with the new 3Dconnexion device id */
-		if(vid == VENDOR_3DCONNEXION) {
+		if(vid == VID_3DCONN) {
 			/* avoid matching and trying to grab the CAD mouse, when connected
 			 * on the same universal receiver as the spacemouse.
 			 */

src/dev_usb.h

@@ -18,6 +18,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef SPNAV_DEV_USB_H_
 #define SPNAV_DEV_USB_H_
 
+#define VID_3DCONN		0x256f
+#define PID_WIRELESS	0xc652
+
 struct device;
 
 int open_dev_usb(struct device *dev);
@@ -37,4 +40,8 @@ struct usb_dev_info *find_usb_devices(int (*match)(const struct usb_dev_info*));
 void free_usb_devices_list(struct usb_dev_info *list);
 void print_usb_device_info(struct usb_dev_info *devinfo);
 
+/* see usbdb_entry table bnmap field in dev.c */
+int bnhack_smpro(int bn);
+int bnhack_sment(int bn);
+
 #endif	/* SPNAV_DEV_USB_H_ */

src/dev_usb_linux.c

@@ -109,6 +109,15 @@ int open_dev_usb(struct device *dev)
 	}
 	dev->num_axes = axes_rel + axes_abs;
 	if(!dev->num_axes) {
+		if(dev->usbid[0] == VID_3DCONN && dev->usbid[1] == PID_WIRELESS) {
+			/* a wireless 3Dconnexion device without axes is probably one of the
+			 * CadMouse products, drop it.
+			 */
+			logmsg(LOG_DEBUG, "No axes detected, probably a CadMouse, dropping\n");
+			close(dev->fd);
+			dev->fd = -1;
+			return -1;
+		}
 		logmsg(LOG_WARNING, "failed to retrieve number of axes. assuming 6\n");
 		dev->num_axes = 6;
 	} else {
@@ -118,25 +127,49 @@ int open_dev_usb(struct device *dev)
 	}
 
 	/* get number of buttons */
+	dev->num_buttons = 0;
+	if(ioctl(dev->fd, EVIOCGBIT(EV_KEY, sizeof evtype_mask), evtype_mask) != -1) {
+		for(i=0; i<KEY_CNT; i++) {
+			int idx = i / 8;
+			int bit = i % 8;
+
+			if(evtype_mask[idx] & (1 << bit)) {
+				dev->num_buttons++;
+			}
+		}
+	} else {
+		logmsg(LOG_DEBUG, "EVIOCGBIT(EV_KEY) ioctl failed: %s\n", strerror(errno));
+	}
+
+	/* sanity check, problematic devices appear to report 256 buttons, if that's
+	 * not the case, this is probably a mistake.
+	 */
+	if(dev->bnhack && dev->num_buttons < 255) {
+		logmsg(LOG_DEBUG, "BUG! Please report this at https://github.com/FreeSpacenav/spacenavd/issues, "
+				"or by sending an email to nuclear@member.fsf.org.\n");
+		logmsg(LOG_DEBUG, "This device (%04x:%04x) was marked for disjointed "
+				"button remapping, but unexpectedly reports %d buttons\n",
+				dev->usbid[0], dev->usbid[1], dev->num_buttons);
+
+		dev->bnhack = 0;
+	}
+
 	if(dev->bnhack) {
-		/* for those problematic devices, rely on the hardcoded button value in
-		 * their button remapping hack
-		 */
 		dev->num_buttons = dev->bnhack(-1);
 	} else {
-		dev->num_buttons = 0;
+		if(dev->usbid[0] == VID_3DCONN && dev->usbid[1] == PID_WIRELESS) {
-		if(ioctl(dev->fd, EVIOCGBIT(EV_KEY, sizeof evtype_mask), evtype_mask) != -1) {
+			/* Wireless devices use the same dongle, try to guess which actual
-			for(i=0; i<KEY_CNT; i++) {
+			 * device this is, and apply the button hack if it's a SpcMouse Pro
-				int idx = i / 8;
+			 */
-				int bit = i % 8;
+			if(dev->num_buttons >= 255) {
-
+				dev->type = DEV_SMPROW;
-				if(evtype_mask[idx] & (1 << bit)) {
+				dev->bnhack = bnhack_smpro;
-					logmsg(LOG_DEBUG, "bit %d (part %d bit %d)\n", idx * 8 + i, idx, bit);
+				dev->num_buttons = bnhack_smpro(-1);
-					dev->num_buttons++;
+				strcpy(dev->name, "3Dconnexion SpaceMouse Pro Wireless (guess)");
-				}
+			} else {
+				dev->type = DEV_SMW;
+				strcpy(dev->name, "3Dconnexion SpaceMouse Wireless (guess)");
 			}
-		} else {
-			logmsg(LOG_DEBUG, "EVIOCGBIT(EV_KEY) ioctl failed: %s\n", strerror(errno));
 		}
 	}
 	if(!dev->num_buttons) {