[PATCH v3 09/12] HID: microsoft: support the Surface Dial

From: Benjamin Tissoires
Date: Thu Jun 21 2018 - 08:10:35 EST


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@xxxxxxxxxx>

---

no changes in v2
no changes in v3
---
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