Input: introduce device properties

Today, userspace sets up an input device based on the data it emits.
This is not always enough; a tablet and a touchscreen may emit exactly
the same data, for instance, but the former should be set up with a
pointer whereas the latter does not need to. Recently, a new type of
touchpad has emerged where the buttons are under the pad, which
changes logic without changing the emitted data. This patch introduces
a new ioctl, EVIOCGPROP, which enables user access to a set of device
properties useful during setup. The properties are given as a bitmap
in the same fashion as the event types, and are also made available
via sysfs, uevent and /proc/bus/input/devices.

Acked-by: Ping Cheng <pingc@wacom.com>
Acked-by: Chase Douglas <chase.douglas@canonical.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/input.h b/include/linux/input.h
index b3a1e02080c0..8d9c76cd3c43 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -91,6 +91,7 @@ struct input_keymap_entry {
 #define EVIOCGNAME(len)		_IOC(_IOC_READ, 'E', 0x06, len)		/* get device name */
 #define EVIOCGPHYS(len)		_IOC(_IOC_READ, 'E', 0x07, len)		/* get physical location */
 #define EVIOCGUNIQ(len)		_IOC(_IOC_READ, 'E', 0x08, len)		/* get unique identifier */
+#define EVIOCGPROP(len)		_IOC(_IOC_READ, 'E', 0x09, len)		/* get device properties */
 
 #define EVIOCGKEY(len)		_IOC(_IOC_READ, 'E', 0x18, len)		/* get global key state */
 #define EVIOCGLED(len)		_IOC(_IOC_READ, 'E', 0x19, len)		/* get all LEDs */
@@ -108,6 +109,18 @@ struct input_keymap_entry {
 #define EVIOCGRAB		_IOW('E', 0x90, int)			/* Grab/Release device */
 
 /*
+ * Device properties and quirks
+ */
+
+#define INPUT_PROP_POINTER		0x00	/* needs a pointer */
+#define INPUT_PROP_DIRECT		0x01	/* direct input devices */
+#define INPUT_PROP_BUTTONPAD		0x02	/* has button(s) under pad */
+#define INPUT_PROP_SEMI_MT		0x03	/* touch rectangle only */
+
+#define INPUT_PROP_MAX			0x1f
+#define INPUT_PROP_CNT			(INPUT_PROP_MAX + 1)
+
+/*
  * Event types
  */
 
@@ -1090,6 +1103,7 @@ struct ff_effect {
  * @phys: physical path to the device in the system hierarchy
  * @uniq: unique identification code for the device (if device has it)
  * @id: id of the device (struct input_id)
+ * @propbit: bitmap of device properties and quirks
  * @evbit: bitmap of types of events supported by the device (EV_KEY,
  *	EV_REL, etc.)
  * @keybit: bitmap of keys/buttons this device has
@@ -1173,6 +1187,8 @@ struct input_dev {
 	const char *uniq;
 	struct input_id id;
 
+	unsigned long propbit[BITS_TO_LONGS(INPUT_PROP_CNT)];
+
 	unsigned long evbit[BITS_TO_LONGS(EV_CNT)];
 	unsigned long keybit[BITS_TO_LONGS(KEY_CNT)];
 	unsigned long relbit[BITS_TO_LONGS(REL_CNT)];