HID: force feedback driver for Logitech Rumblepad 2

Add force feedback support for Logitech Rumblepad 2.

Tested-By: Edgar Simo <bobbens@gmail.com>
Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/usbhid/hid-lg2ff.c b/drivers/hid/usbhid/hid-lg2ff.c
new file mode 100644
index 0000000..d469bd0
--- /dev/null
+++ b/drivers/hid/usbhid/hid-lg2ff.c
@@ -0,0 +1,114 @@
+/*
+ *  Force feedback support for Logitech Rumblepad 2
+ *
+ *  Copyright (c) 2008 Anssi Hannula <anssi.hannula@gmail.com>
+ */
+
+/*
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/hid.h>
+#include "usbhid.h"
+
+struct lg2ff_device {
+	struct hid_report *report;
+};
+
+static int play_effect(struct input_dev *dev, void *data,
+			 struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct lg2ff_device *lg2ff = data;
+	int weak, strong;
+
+	strong = effect->u.rumble.strong_magnitude;
+	weak = effect->u.rumble.weak_magnitude;
+
+	if (weak || strong) {
+		weak = weak * 0xff / 0xffff;
+		strong = strong * 0xff / 0xffff;
+
+		lg2ff->report->field[0]->value[0] = 0x51;
+		lg2ff->report->field[0]->value[2] = weak;
+		lg2ff->report->field[0]->value[4] = strong;
+	} else {
+		lg2ff->report->field[0]->value[0] = 0xf3;
+		lg2ff->report->field[0]->value[2] = 0x00;
+		lg2ff->report->field[0]->value[4] = 0x00;
+	}
+
+	usbhid_submit_report(hid, lg2ff->report, USB_DIR_OUT);
+	return 0;
+}
+
+int hid_lg2ff_init(struct hid_device *hid)
+{
+	struct lg2ff_device *lg2ff;
+	struct hid_report *report;
+	struct hid_input *hidinput = list_entry(hid->inputs.next,
+						struct hid_input, list);
+	struct list_head *report_list =
+			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
+	struct input_dev *dev = hidinput->input;
+	int error;
+
+	if (list_empty(report_list)) {
+		printk(KERN_ERR "hid-lg2ff: no output report found\n");
+		return -ENODEV;
+	}
+
+	report = list_entry(report_list->next, struct hid_report, list);
+
+	if (report->maxfield < 1) {
+		printk(KERN_ERR "hid-lg2ff: output report is empty\n");
+		return -ENODEV;
+	}
+	if (report->field[0]->report_count < 7) {
+		printk(KERN_ERR "hid-lg2ff: not enough values in the field\n");
+		return -ENODEV;
+	}
+
+	lg2ff = kmalloc(sizeof(struct lg2ff_device), GFP_KERNEL);
+	if (!lg2ff)
+		return -ENOMEM;
+
+	set_bit(FF_RUMBLE, dev->ffbit);
+
+	error = input_ff_create_memless(dev, lg2ff, play_effect);
+	if (error) {
+		kfree(lg2ff);
+		return error;
+	}
+
+	lg2ff->report = report;
+	report->field[0]->value[0] = 0xf3;
+	report->field[0]->value[1] = 0x00;
+	report->field[0]->value[2] = 0x00;
+	report->field[0]->value[3] = 0x00;
+	report->field[0]->value[4] = 0x00;
+	report->field[0]->value[5] = 0x00;
+	report->field[0]->value[6] = 0x00;
+
+	usbhid_submit_report(hid, report, USB_DIR_OUT);
+
+	printk(KERN_INFO "Force feedback for Logitech Rumblepad 2 by "
+	       "Anssi Hannula <anssi.hannula@gmail.com>\n");
+
+	return 0;
+}