tablet: add libinput_tool_get_tool_id()

The tool ID on wacom tablets is what really defines the tool, so one can
differ between say an Intuos Grip Pen, Art Pen or Classic Pen. They're all
BTN_TOOL_PEN in the kernel driver.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Stephen Chandler Paul <thatslyude@gmail.com>

src/evdev-tablet.c

@@ -62,6 +62,11 @@ tablet_process_absolute(struct tablet_dispatch *tablet,
 		set_bit(tablet->changed_axes, axis);
 		tablet_set_status(tablet, TABLET_AXES_UPDATED);
 		break;
+	/* tool_id is the identifier for the tool we can use in libwacom
+	 * to identify it (if we have one anyway) */
+	case ABS_MISC:
+		tablet->current_tool_id = e->value;
+		break;
 	default:
 		log_info(device->base.seat->libinput,
 			 "Unhandled ABS event code %#x\n", e->code);
@@ -324,6 +329,7 @@ tablet_process_misc(struct tablet_dispatch *tablet,
 static struct libinput_tool *
 tablet_get_tool(struct tablet_dispatch *tablet,
 		enum libinput_tool_type type,
+		uint32_t tool_id,
 		uint32_t serial)
 {
 	struct libinput_tool *tool = NULL, *t;
@@ -362,6 +368,7 @@ tablet_get_tool(struct tablet_dispatch *tablet,
 		*tool = (struct libinput_tool) {
 			.type = type,
 			.serial = serial,
+			.tool_id = tool_id,
 			.refcount = 1,
 		};
 
@@ -499,6 +506,7 @@ tablet_flush(struct tablet_dispatch *tablet,
 	struct libinput_tool *tool =
 		tablet_get_tool(tablet,
 				tablet->current_tool_type,
+				tablet->current_tool_id,
 				tablet->current_tool_serial);
 
 	if (tablet_has_status(tablet, TABLET_TOOL_LEAVING_PROXIMITY)) {

src/evdev-tablet.h

@@ -59,6 +59,7 @@ struct tablet_dispatch {
 	struct button_state prev_button_state;
 
 	enum libinput_tool_type current_tool_type;
+	uint32_t current_tool_id;
 	uint32_t current_tool_serial;
 };
 

src/libinput-private.h

@@ -188,6 +188,7 @@ struct libinput_device {
 struct libinput_tool {
 	struct list link;
 	uint32_t serial;
+	uint32_t tool_id;
 	enum libinput_tool_type type;
 	unsigned char axis_caps[NCHARS(LIBINPUT_TABLET_AXIS_MAX + 1)];
 	int refcount;

src/libinput.c

@@ -662,6 +662,12 @@ libinput_tool_get_type(struct libinput_tool *tool)
 	return tool->type;
 }
 
+LIBINPUT_EXPORT uint32_t
+libinput_tool_get_tool_id(struct libinput_tool *tool)
+{
+	return tool->tool_id;
+}
+
 LIBINPUT_EXPORT uint32_t
 libinput_tool_get_serial(struct libinput_tool *tool)
 {

src/libinput.h

@@ -160,6 +160,7 @@ struct libinput_tool;
  * usage of the tool as advertised by the manufacturer. Multiple different
  * physical tools may share the same tool type, e.g. a Wacom Classic Pen,
  * Wacom Pro Pen and a Wacom Grip Pen are all of type LIBINPUT_TOOL_PEN.
+ * Use libinput_tool_get_tool_id() to get a specific model where applicable.
  *
  * Note that on some device, the eraser tool is on the tail end of a pen
  * device. On other devices, e.g. MS Surface 3, the eraser is the pen tip
@@ -1192,10 +1193,30 @@ libinput_event_tablet_get_time(struct libinput_event_tablet *event);
  *
  * @param tool The libinput tool
  * @return The tool type for this tool object
+ *
+ * @see libinput_tool_get_tool_id
  */
 enum libinput_tool_type
 libinput_tool_get_type(struct libinput_tool *tool);
 
+/**
+ * @ingroup event_tablet
+ *
+ * Return the tool ID for a tool object. If nonzero, this number identifies
+ * the specific type of the tool with more precision than the type returned in
+ * libinput_tool_get_type(). Not all tablets support a tool ID.
+ *
+ * Tablets known to support tool IDs include the Wacom Intuos 3, 4, 5, Wacom
+ * Cintiq and Wacom Intuos Pro series.
+ *
+ * @param tool The libinput tool
+ * @return The tool ID for this tool object or 0 if none is provided
+ *
+ * @see libinput_tool_get_type
+ */
+uint32_t
+libinput_tool_get_tool_id(struct libinput_tool *tool);
+
 /**
  * @ingroup event_tablet
  *

src/libinput.sym

@@ -153,6 +153,7 @@ LIBINPUT_0.12.0 {
 	libinput_event_tablet_get_x_transformed;
 	libinput_event_tablet_get_y_transformed;
 	libinput_tool_get_serial;
+	libinput_tool_get_tool_id;
 	libinput_tool_get_type;
 	libinput_tool_get_user_data;
 	libinput_tool_has_axis;