[PATCH v2] HID: multitouch: add quirks for Lenovo Yoga Book 9i

[Brian Howard <blhoward2@gmail.com>]

The Lenovo Yoga Book 9i is a dual-screen laptop, with a single composite
USB device providing both touch and tablet interfaces for both screens.
All inputs report through a single device, differentiated solely by report
numbers. As there is no way for udev to differentiate the inputs based on
USB vendor/product ID or interface numbers, custom naming is required to
match against for downstream configuration. A firmware bug also results
in an erroneous InRange message report being received after the stylus
leaves proximity, blocking later touch events. Add required quirks for
Gen 8 to Gen 10 models, including a new quirk providing for custom input
device naming and dropping erroneous InRange reports.

Signed-off-by: Brian Howard <blhoward2@gmail.com>
Tested-by: Brian Howard <blhoward2@gmail.com>
Tested-by: Kris Fredrick <linux.baguette800@slmail.me>
Reported-by: Andrei Shumailov <gentoo1993@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220386
---

V1->V2 Changes:
- Changed definition of f and i varliables to the loop scope.

 drivers/hid/hid-ids.h        |  1 +
 drivers/hid/hid-multitouch.c | 72 ++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 0723b4b1c9ec..e896a6310bb2 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -833,6 +833,7 @@
 #define USB_DEVICE_ID_LENOVO_X1_TAB3	0x60b5
 #define USB_DEVICE_ID_LENOVO_X12_TAB	0x60fe
 #define USB_DEVICE_ID_LENOVO_X12_TAB2	0x61ae
+#define USB_DEVICE_ID_LENOVO_YOGABOOK9I	0x6161
 #define USB_DEVICE_ID_LENOVO_OPTICAL_USB_MOUSE_600E	0x600e
 #define USB_DEVICE_ID_LENOVO_PIXART_USB_MOUSE_608D	0x608d
 #define USB_DEVICE_ID_LENOVO_PIXART_USB_MOUSE_6019	0x6019
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 179dc316b4b5..4b3e7c212a48 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -76,6 +76,7 @@ MODULE_LICENSE("GPL");
 #define MT_QUIRK_DISABLE_WAKEUP		BIT(21)
 #define MT_QUIRK_ORIENTATION_INVERT	BIT(22)
 #define MT_QUIRK_APPLE_TOUCHBAR		BIT(23)
+#define MT_QUIRK_YOGABOOK9I		BIT(24)
 
 #define MT_INPUTMODE_TOUCHSCREEN	0x02
 #define MT_INPUTMODE_TOUCHPAD		0x03
@@ -229,6 +230,7 @@ static void mt_post_parse(struct mt_device *td, struct mt_application *app);
 #define MT_CLS_RAZER_BLADE_STEALTH		0x0112
 #define MT_CLS_SMART_TECH			0x0113
 #define MT_CLS_APPLE_TOUCHBAR			0x0114
+#define MT_CLS_YOGABOOK9I			0x0115
 #define MT_CLS_SIS				0x0457
 
 #define MT_DEFAULT_MAXCONTACT	10
@@ -424,6 +426,14 @@ static const struct mt_class mt_classes[] = {
 		.quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
 			MT_QUIRK_ALWAYS_VALID |
 			MT_QUIRK_CONTACT_CNT_ACCURATE,
+	},
+		{ .name = MT_CLS_YOGABOOK9I,
+		.quirks = MT_QUIRK_ALWAYS_VALID |
+			MT_QUIRK_FORCE_MULTI_INPUT |
+			MT_QUIRK_SEPARATE_APP_REPORT |
+			MT_QUIRK_HOVERING |
+			MT_QUIRK_YOGABOOK9I,
+		.export_all_inputs = true
 	},
 	{ }
 };
@@ -1565,6 +1575,38 @@ static void mt_report(struct hid_device *hid, struct hid_report *report)
 	if (rdata && rdata->is_mt_collection)
 		return mt_touch_report(hid, rdata);
 
+	/* Lenovo Yoga Book 9i requires consuming and dropping certain bogus reports */
+	if (rdata && rdata->application &&
+		(rdata->application->quirks & MT_QUIRK_YOGABOOK9I)) {
+
+		bool all_zero_report = true;
+
+		for (int f = 0; f < report->maxfield && all_zero_report; f++) {
+			struct hid_field *fld = report->field[f];
+
+			for (int i = 0; i < fld->report_count; i++) {
+				unsigned int usage = fld->usage[i].hid;
+
+				if (usage == HID_DG_INRANGE ||
+					usage == HID_DG_TIPSWITCH ||
+					usage == HID_DG_BARRELSWITCH ||
+					usage == HID_DG_BARRELSWITCH2 ||
+					usage == HID_DG_CONTACTID ||
+					usage == HID_DG_TILT_X ||
+					usage == HID_DG_TILT_Y) {
+
+					if (fld->value[i] != 0) {
+						all_zero_report = false;
+						break;
+					}
+				}
+			}
+		}
+
+		if (all_zero_report)
+			return;
+	}
+
 	if (field && field->hidinput && field->hidinput->input)
 		input_sync(field->hidinput->input);
 }
@@ -1761,6 +1803,30 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
 		break;
 	}
 
+	/* Lenovo Yoga Book 9i requires custom naming to allow differentiation in udev */
+	if (hi->report && td->mtclass.quirks & MT_QUIRK_YOGABOOK9I) {
+		switch (hi->report->id) {
+		case 48:
+			suffix = "Touchscreen Top";
+			break;
+		case 56:
+			suffix = "Touchscreen Bottom";
+			break;
+		case 20:
+			suffix = "Stylus Top";
+			break;
+		case 40:
+			suffix = "Stylus Bottom";
+			break;
+		case 80:
+			suffix = "Emulated Touchpad";
+			break;
+		default:
+			suffix = "";
+			break;
+		}
+	}
+
 	if (suffix) {
 		hi->input->name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
 						 "%s %s", hdev->name, suffix);
@@ -2266,6 +2332,12 @@ static const struct hid_device_id mt_devices[] = {
 			   USB_VENDOR_ID_LENOVO,
 			   USB_DEVICE_ID_LENOVO_X12_TAB2) },
 
+	/* Lenovo Yoga Book 9i */
+	{ .driver_data = MT_CLS_YOGABOOK9I,
+		HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH_WIN_8,
+			   USB_VENDOR_ID_LENOVO,
+			   USB_DEVICE_ID_LENOVO_YOGABOOK9I) },
+
 	/* Logitech devices */
 	{ .driver_data = MT_CLS_NSMU,
 		HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_MULTITOUCH_WIN_8,
-- 
2.49.0