[PATCH 9/9] HID: microsoft: support the Surface Dial

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

The tool works nicely with hid-generic, but it ends up creating 9
different input nodes with most of them only having ABS_MISC set.

Filter the axis out, which reduces the amount of devices to 2. One is
the proper System Multi-axis collection, the other exported device
seems to provide SLEEP and POWER Key, not sure how one can trigger
those events though.

Filtering the ABS_X and ABS_Y axes also prevents udev to detect this as
a touchscreen.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
 drivers/hid/hid-microsoft.c | 49 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 43 insertions(+), 6 deletions(-)

diff --git a/drivers/hid/hid-microsoft.c b/drivers/hid/hid-microsoft.c
index 96e7d3231d2f..72d983626afd 100644
--- a/drivers/hid/hid-microsoft.c
+++ b/drivers/hid/hid-microsoft.c
@@ -22,12 +22,13 @@
 
 #include "hid-ids.h"
 
-#define MS_HIDINPUT		0x01
-#define MS_ERGONOMY		0x02
-#define MS_PRESENTER		0x04
-#define MS_RDESC		0x08
-#define MS_NOGET		0x10
-#define MS_DUPLICATE_USAGES	0x20
+#define MS_HIDINPUT		BIT(0)
+#define MS_ERGONOMY		BIT(1)
+#define MS_PRESENTER		BIT(2)
+#define MS_RDESC		BIT(3)
+#define MS_NOGET		BIT(4)
+#define MS_DUPLICATE_USAGES	BIT(5)
+#define MS_SURFACE_DIAL		BIT(6)
 
 static __u8 *ms_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		unsigned int *rsize)
@@ -130,6 +131,30 @@ static int ms_presenter_8k_quirk(struct hid_input *hi, struct hid_usage *usage,
 	return 1;
 }
 
+static int ms_surface_dial_quirk(struct hid_input *hi, struct hid_field *field,
+		struct hid_usage *usage, unsigned long **bit, int *max)
+{
+	switch (usage->hid & HID_USAGE_PAGE) {
+	case 0xff070000:
+		/* fall-through */
+	case HID_UP_DIGITIZER:
+		/* ignore those axis */
+		return -1;
+	case HID_UP_GENDESK:
+		switch (usage->hid) {
+		case HID_GD_X:
+			/* fall-through */
+		case HID_GD_Y:
+			/* fall-through */
+		case HID_GD_RFKILL_BTN:
+			/* ignore those axis */
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
 static int ms_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
@@ -146,6 +171,13 @@ static int ms_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			ms_presenter_8k_quirk(hi, usage, bit, max))
 		return 1;
 
+	if (quirks & MS_SURFACE_DIAL) {
+		int ret = ms_surface_dial_quirk(hi, field, usage, bit, max);
+
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -229,6 +261,9 @@ static int ms_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	if (quirks & MS_NOGET)
 		hdev->quirks |= HID_QUIRK_NOGET;
 
+	if (quirks & MS_SURFACE_DIAL)
+		hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
+
 	ret = hid_parse(hdev);
 	if (ret) {
 		hid_err(hdev, "parse failed\n");
@@ -281,6 +316,8 @@ static const struct hid_device_id ms_devices[] = {
 
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_PRESENTER_8K_BT),
 		.driver_data = MS_PRESENTER },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_MICROSOFT, 0x091B),
+		.driver_data = MS_SURFACE_DIAL },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, ms_devices);
-- 
2.14.3