HID: multitouch: implement precision touchpad latency and switches

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@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 8878de9eedba5c6e4ae3c4cb9b1fc9e8412ced04..82c98bf14d608734cafa95b75e2a40018d82c38f 100644 (file)
--- 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 f03d7a410c5df9b7f32312579c8d768721c53778..a1be991e1eae40388ce1cab2924ba997a6c77a60 100644 (file)
--- 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
 /*