Merge branch 'for-4.20/logitech-highres' into for-linus

High-resolution support for hid-logitech

include/linux/hid.h

@@ -1139,6 +1139,34 @@ static inline u32 hid_report_len(struct hid_report *report)
 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
 		int interrupt);
 
+
+/**
+ * struct hid_scroll_counter - Utility class for processing high-resolution
+ *                             scroll events.
+ * @dev: the input device for which events should be reported.
+ * @microns_per_hi_res_unit: the amount moved by the user's finger for each
+ *                           high-resolution unit reported by the mouse, in
+ *                           microns.
+ * @resolution_multiplier: the wheel's resolution in high-resolution mode as a
+ *                         multiple of its lower resolution. For example, if
+ *                         moving the wheel by one "notch" would result in a
+ *                         value of 1 in low-resolution mode but 8 in
+ *                         high-resolution, the multiplier is 8.
+ * @remainder: counts the number of high-resolution units moved since the last
+ *             low-resolution event (REL_WHEEL or REL_HWHEEL) was sent. Should
+ *             only be used by class methods.
+ */
+struct hid_scroll_counter {
+	struct input_dev *dev;
+	int microns_per_hi_res_unit;
+	int resolution_multiplier;
+
+	int remainder;
+};
+
+void hid_scroll_counter_handle_scroll(struct hid_scroll_counter *counter,
+				      int hi_res_value);
+
 /* HID quirks API */
 unsigned long hid_lookup_quirk(const struct hid_device *hdev);
 int hid_quirks_init(char **quirks_param, __u16 bus, int count);

include/uapi/linux/input-event-codes.h

@@ -708,6 +708,15 @@
 #define REL_DIAL		0x07
 #define REL_WHEEL		0x08
 #define REL_MISC		0x09
+/*
+ * 0x0a is reserved and should not be used in input drivers.
+ * It was used by HID as REL_MISC+1 and userspace needs to detect if
+ * the next REL_* event is correct or is just REL_MISC + n.
+ * We define here REL_RESERVED so userspace can rely on it and detect
+ * the situation described above.
+ */
+#define REL_RESERVED		0x0a
+#define REL_WHEEL_HI_RES	0x0b
 #define REL_MAX			0x0f
 #define REL_CNT			(REL_MAX+1)
 
@@ -744,6 +753,15 @@
 
 #define ABS_MISC		0x28
 
+/*
+ * 0x2e is reserved and should not be used in input drivers.
+ * It was used by HID as ABS_MISC+6 and userspace needs to detect if
+ * the next ABS_* event is correct or is just ABS_MISC + n.
+ * We define here ABS_RESERVED so userspace can rely on it and detect
+ * the situation described above.
+ */
+#define ABS_RESERVED		0x2e
+
 #define ABS_MT_SLOT		0x2f	/* MT slot being modified */
 #define ABS_MT_TOUCH_MAJOR	0x30	/* Major axis of touching ellipse */
 #define ABS_MT_TOUCH_MINOR	0x31	/* Minor axis (omit if circular) */