[PATCH v2 6/6] HID: multitouch: implement precision touchpad latency and switches

From: Benjamin Tissoires
Date: Tue Apr 24 2018 - 04:06:00 EST


The Win 8.1 precision touchpad spec introduce new modes for touchpads
that can come in handy[1].

Implement the settings of these modes, so we are not taken off-guard if
a firmware decides to enforce them.

[1] https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/windows-precision-touchpad-required-hid-top-level-collections

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/hid/hid-multitouch.c | 34 +++++++++++++++++++++++++++++-----
include/linux/hid.h | 3 +++
2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 8878de9eedba..82c98bf14d60 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -81,6 +81,11 @@ MODULE_LICENSE("GPL");

#define MT_BUTTONTYPE_CLICKPAD 0

+enum latency_mode {
+ HID_LATENCY_NORMAL = 0,
+ HID_LATENCY_HIGH = 1,
+};
+
#define MT_IO_FLAGS_RUNNING 0
#define MT_IO_FLAGS_ACTIVE_SLOTS 1
#define MT_IO_FLAGS_PENDING_SLOTS 2
@@ -1156,7 +1161,10 @@ static void mt_report(struct hid_device *hid, struct hid_report *report)

static bool mt_need_to_apply_feature(struct hid_device *hdev,
struct hid_field *field,
- struct hid_usage *usage)
+ struct hid_usage *usage,
+ enum latency_mode latency,
+ bool surface_switch,
+ bool button_switch)
{
struct mt_device *td = hid_get_drvdata(hdev);
struct mt_class *cls = &td->mtclass;
@@ -1195,12 +1203,25 @@ static bool mt_need_to_apply_feature(struct hid_device *hdev,
}
}
break;
+
+ case HID_DG_LATENCYMODE:
+ field->value[index] = latency;
+ return 1;
+
+ case HID_DG_SURFACESWITCH:
+ field->value[index] = surface_switch;
+ return 1;
+
+ case HID_DG_BUTTONSWITCH:
+ field->value[index] = button_switch;
+ return 1;
}

return false; /* no need to update the report */
}

-static void mt_set_modes(struct hid_device *hdev)
+static void mt_set_modes(struct hid_device *hdev, enum latency_mode latency,
+ bool surface_switch, bool button_switch)
{
struct hid_report_enum *rep_enum;
struct hid_report *rep;
@@ -1222,7 +1243,10 @@ static void mt_set_modes(struct hid_device *hdev)

if (mt_need_to_apply_feature(hdev,
rep->field[i],
- usage))
+ usage,
+ latency,
+ surface_switch,
+ button_switch))
update_report = true;
}
}
@@ -1467,7 +1491,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
dev_warn(&hdev->dev, "Cannot allocate sysfs group for %s\n",
hdev->name);

- mt_set_modes(hdev);
+ mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);

/* release .fields memory as it is not used anymore */
devm_kfree(&hdev->dev, td->fields);
@@ -1480,7 +1504,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
static int mt_reset_resume(struct hid_device *hdev)
{
mt_release_contacts(hdev);
- mt_set_modes(hdev);
+ mt_set_modes(hdev, HID_LATENCY_NORMAL, true, true);
return 0;
}

diff --git a/include/linux/hid.h b/include/linux/hid.h
index d3bd83d9127f..d65ce4ab82d6 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -292,9 +292,12 @@ struct hid_item {
#define HID_DG_CONTACTCOUNT 0x000d0054
#define HID_DG_CONTACTMAX 0x000d0055
#define HID_DG_SCANTIME 0x000d0056
+#define HID_DG_SURFACESWITCH 0x000d0057
+#define HID_DG_BUTTONSWITCH 0x000d0058
#define HID_DG_BUTTONTYPE 0x000d0059
#define HID_DG_BARRELSWITCH2 0x000d005a
#define HID_DG_TOOLSERIALNUMBER 0x000d005b
+#define HID_DG_LATENCYMODE 0x000d0060

#define HID_VD_ASUS_CUSTOM_MEDIA_KEYS 0xff310076
/*
--
2.14.3