Add division support

1 files changed, 59 insertions, 1 deletions

diff --git a/src/hid-input.c b/src/hid-input.c
index fd72363..e00b173 100644
--- a/src/hid-input.c
+++ b/src/hid-input.c
@@ -14,12 +14,12 @@
  */
 
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
 
 #include <linux/hid.h>
 #include <linux/hid-debug.h>
-#include <linux/moduleparam.h>
 
 // FASTMOUSE SRC
 
@@ -1508,6 +1508,63 @@ static void hid_report_set_tool(struct hid_report *report, struct input_dev *inp
 	report->tool = new_tool;
 }
 
+
+struct fastmouse_state {
+	int division;
+	int x, y;
+};
+static struct fastmouse_state fastmouse = {
+	.division = 1,
+	.x = 0,
+	.y = 0,
+};
+
+static int set_division(const char *val, const struct kernel_param *kp) {
+	const int ret = kstrtoint(val, 0, &fastmouse.division);
+	if (ret != 0 || fastmouse.division <= 0) {
+		return -EINVAL;
+	}
+	// Modifying divison should reset accumlated events.
+	fastmouse.x = fastmouse.y = 0;
+
+	return ret;
+}
+
+static const struct kernel_param_ops division_ops = {
+	.set = set_division,
+	.get = param_get_int,
+};
+module_param_cb(division, &division_ops, &fastmouse.division, 0664);
+MODULE_PARM_DESC(division, "Mouse movement division amount (default: 1)");
+
+static int apply_fastmouse(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value) {
+	if (hid->type != HID_TYPE_USBMOUSE) {
+		return value;
+	}
+
+	if (usage->type != EV_REL) {
+		return value;
+	}
+
+	int* target;
+	switch (usage->code) {
+		case REL_X:
+			target = &fastmouse.x;
+			break;
+		case REL_Y:
+			target = &fastmouse.y;
+			break;
+		default:
+			return value;
+	};
+
+	*target += value;
+	const int result = *target / fastmouse.division;
+	*target %= fastmouse.division;
+
+	return result;
+}
+
 void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value)
 {
 	struct input_dev *input;
@@ -1716,6 +1773,7 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
 	    (!test_bit(usage->code, input->key)) == value)
 		input_event(input, EV_MSC, MSC_SCAN, usage->hid);
 
+	value = apply_fastmouse(hid, field, usage, value);
 	input_event(input, usage->type, usage->code, value);
 
 	if ((field->flags & HID_MAIN_ITEM_RELATIVE) &&