HID: support for Kensington slimblade device

0x47d/0x2041 device sends two extra buttons in 0xff00 usage
page and therefore requires special handling.

Reported-by: Jason Noble <nobleja@polezero.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 9cc662c..c16fc4f 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -150,6 +150,13 @@
 	---help---
 	Support for Gyration remote control.
 
+config HID_KENSINGTON
+	tristate "Kensington" if EMBEDDED
+	depends on USB_HID
+	default !EMBEDDED
+	---help---
+	Support for Kensington Slimblade Trackball.
+
 config HID_LOGITECH
 	tristate "Logitech" if EMBEDDED
 	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 0fdbda6..53e1331 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -29,6 +29,7 @@
 obj-$(CONFIG_DRAGONRISE_FF)	+= hid-drff.o
 obj-$(CONFIG_HID_EZKEY)		+= hid-ezkey.o
 obj-$(CONFIG_HID_GYRATION)	+= hid-gyration.o
+obj-$(CONFIG_HID_KENSINGTON)	+= hid-kensington.o
 obj-$(CONFIG_HID_LOGITECH)	+= hid-logitech.o
 obj-$(CONFIG_HID_MICROSOFT)	+= hid-microsoft.o
 obj-$(CONFIG_HID_MONTEREY)	+= hid-monterey.o
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 7bc2f37..646ba22 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1270,6 +1270,7 @@
 	{ HID_USB_DEVICE(USB_VENDOR_ID_GREENASIA, 0x0012) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_GYRATION, USB_DEVICE_ID_GYRATION_REMOTE_2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_KENSINGTON, USB_DEVICE_ID_KS_SLIMBLADE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LABTEC, USB_DEVICE_ID_LABTEC_WIRELESS_KEYBOARD) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_MX3000_RECEIVER) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_S510_RECEIVER) },
diff --git a/drivers/hid/hid-dummy.c b/drivers/hid/hid-dummy.c
index 536aa15..28815fd 100644
--- a/drivers/hid/hid-dummy.c
+++ b/drivers/hid/hid-dummy.c
@@ -37,6 +37,9 @@
 #ifdef CONFIG_HID_GYRATION_MODULE
 	HID_COMPAT_CALL_DRIVER(gyration);
 #endif
+#ifdef CONFIG_HID_KENSINGTON_MODULE
+	HID_COMPAT_CALL_DRIVER(kensington);
+#endif
 #ifdef CONFIG_HID_LOGITECH_MODULE
 	HID_COMPAT_CALL_DRIVER(logitech);
 #endif
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 9e83ca4..7270ccc 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -274,6 +274,9 @@
 #define USB_DEVICE_ID_LD_POWERCONTROL	0x2030
 #define USB_DEVICE_ID_LD_MACHINETEST	0x2040
 
+#define USB_VENDOR_ID_KENSINGTON	0x047d
+#define USB_DEVICE_ID_KS_SLIMBLADE	0x2041
+
 #define USB_VENDOR_ID_LOGITECH		0x046d
 #define USB_DEVICE_ID_LOGITECH_RECEIVER	0xc101
 #define USB_DEVICE_ID_LOGITECH_HARMONY_FIRST  0xc110
diff --git a/drivers/hid/hid-kensington.c b/drivers/hid/hid-kensington.c
new file mode 100644
index 0000000..747fee5
--- /dev/null
+++ b/drivers/hid/hid-kensington.c
@@ -0,0 +1,65 @@
+/*
+ *  HID driver for Kensigton Slimblade Trackball
+ *
+ *  Copyright (c) 2009 Jiri Kosina
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define ks_map_key(c)	hid_map_usage(hi, usage, bit, max, EV_KEY, (c))
+
+static int ks_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_MSVENDOR)
+		return 0;
+
+	switch (usage->hid & HID_USAGE) {
+	case 0x01: ks_map_key(BTN_MIDDLE);	break;
+	case 0x02: ks_map_key(BTN_SIDE);	break;
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+static const struct hid_device_id ks_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_KENSINGTON, USB_DEVICE_ID_KS_SLIMBLADE) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, ks_devices);
+
+static struct hid_driver ks_driver = {
+	.name = "kensington",
+	.id_table = ks_devices,
+	.input_mapping = ks_input_mapping,
+};
+
+static int ks_init(void)
+{
+	return hid_register_driver(&ks_driver);
+}
+
+static void ks_exit(void)
+{
+	hid_unregister_driver(&ks_driver);
+}
+
+module_init(ks_init);
+module_exit(ks_exit);
+MODULE_LICENSE("GPL");
+
+HID_COMPAT_LOAD_DRIVER(kensington);