HID: add new driver for non-compliant Saitek devices

The driver currently only supports the PS1000 controller.
It fixes the report descriptor by removing a non-existing axis and
clearing the constant bit on the d-pad and button input reports.

Signed-off-by: Andreas Hübner <andreas@k4n.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/Kconfig

@@ -532,6 +532,15 @@ config HID_ROCCAT_PYRA
 	---help---
 	Support for Roccat Pyra mouse.
 
+config HID_SAITEK
+	tristate "Saitek non-fully HID-compliant devices"
+	depends on USB_HID
+	---help---
+	Support for Saitek devices that are not fully compliant with the
+	HID standard.
+
+	Currently only supports the PS1000 controller.
+
 config HID_SAMSUNG
 	tristate "Samsung InfraRed remote control or keyboards"
 	depends on USB_HID

drivers/hid/Makefile

@@ -72,6 +72,7 @@ obj-$(CONFIG_HID_ROCCAT_KONE)	+= hid-roccat-kone.o
 obj-$(CONFIG_HID_ROCCAT_KONEPLUS)	+= hid-roccat-koneplus.o
 obj-$(CONFIG_HID_ROCCAT_KOVAPLUS)	+= hid-roccat-kovaplus.o
 obj-$(CONFIG_HID_ROCCAT_PYRA)	+= hid-roccat-pyra.o
+obj-$(CONFIG_HID_SAITEK)	+= hid-saitek.o
 obj-$(CONFIG_HID_SAMSUNG)	+= hid-samsung.o
 obj-$(CONFIG_HID_SMARTJOYPLUS)	+= hid-sjoy.o
 obj-$(CONFIG_HID_SONY)		+= hid-sony.o

drivers/hid/hid-core.c

@@ -1519,6 +1519,7 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_KOVAPLUS) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_PYRA_WIRED) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ROCCAT, USB_DEVICE_ID_ROCCAT_PYRA_WIRELESS) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SAITEK, USB_DEVICE_ID_SAITEK_PS1000) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SAMSUNG, USB_DEVICE_ID_SAMSUNG_IR_REMOTE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SAMSUNG, USB_DEVICE_ID_SAMSUNG_WIRELESS_KBD_MOUSE) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_SKYCABLE, USB_DEVICE_ID_SKYCABLE_WIRELESS_PRESENTER) },

drivers/hid/hid-ids.h

@@ -615,6 +615,7 @@
 
 #define USB_VENDOR_ID_SAITEK		0x06a3
 #define USB_DEVICE_ID_SAITEK_RUMBLEPAD	0xff17
+#define USB_DEVICE_ID_SAITEK_PS1000	0xff17
 
 #define USB_VENDOR_ID_SAMSUNG		0x0419
 #define USB_DEVICE_ID_SAMSUNG_IR_REMOTE	0x0001

drivers/hid/hid-saitek.c

@@ -0,0 +1,70 @@
+/*
+ *  HID driver for Saitek devices, currently only the PS1000 (USB gamepad).
+ *  Fixes the HID report descriptor by removing a non-existent axis and
+ *  clearing the constant bit on the input reports for buttons and d-pad.
+ *  (This module is based on "hid-ortek".)
+ *
+ *  Copyright (c) 2012 Andreas Hübner
+ */
+
+/*
+ * 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/hid.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include "hid-ids.h"
+
+static __u8 *saitek_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
+{
+	if (*rsize == 137 && rdesc[20] == 0x09 && rdesc[21] == 0x33
+			&& rdesc[94] == 0x81 && rdesc[95] == 0x03
+			&& rdesc[110] == 0x81 && rdesc[111] == 0x03) {
+
+		hid_info(hdev, "Fixing up Saitek PS1000 report descriptor\n");
+
+		/* convert spurious axis to a "noop" Logical Minimum (0) */
+		rdesc[20] = 0x15;
+		rdesc[21] = 0x00;
+
+		/* clear constant bit on buttons and d-pad */
+		rdesc[95] = 0x02;
+		rdesc[111] = 0x02;
+
+	}
+	return rdesc;
+}
+
+static const struct hid_device_id saitek_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SAITEK, USB_DEVICE_ID_SAITEK_PS1000)},
+	{ }
+};
+
+MODULE_DEVICE_TABLE(hid, saitek_devices);
+
+static struct hid_driver saitek_driver = {
+	.name = "saitek",
+	.id_table = saitek_devices,
+	.report_fixup = saitek_report_fixup
+};
+
+static int __init saitek_init(void)
+{
+	return hid_register_driver(&saitek_driver);
+}
+
+static void __exit saitek_exit(void)
+{
+	hid_unregister_driver(&saitek_driver);
+}
+
+module_init(saitek_init);
+module_exit(saitek_exit);
+MODULE_LICENSE("GPL");