[PATCH v7 4/9] HID: asus: prevent binding to all HID devices on ROG

[Antheas Kapenekakis <lkml@antheas.dev>]

Currently, when hid-asus is not loaded, NKEY keyboards load as ~6
event devices with a pretty ASUSTEK name. When it loads, it concatenates
all applications per HID endpoint, renames them, and prints errors
when some of them do not have an input device.

Therefore, change probe so that this is no longer the case. Stop
renaming the devices, omit the check for .input which causes errors on
e.g., the Z13 for some hiddev only devices, and add
HID_QUIRK_INPUT_PER_APP so that each application gets its own event.

When this is done, the probes are called multiple times. Due to this,
the rgb check needs to be moved into probe, and the report fixup should
be skipped for non-vendor endpoints (prevents multiple prints).

Reviewed-by: Luke D. Jones <luke@ljones.dev>
Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
---
 drivers/hid/hid-asus.c | 59 +++++++++++++++++++++++++++---------------
 1 file changed, 38 insertions(+), 21 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 03f0d86936fc..bbbac98f76c6 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -47,6 +47,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define T100CHI_MOUSE_REPORT_ID 0x06
 #define FEATURE_REPORT_ID 0x0d
 #define INPUT_REPORT_ID 0x5d
+#define HID_USAGE_PAGE_VENDOR 0xff310000
 #define FEATURE_KBD_REPORT_ID 0x5a
 #define FEATURE_KBD_REPORT_SIZE 64
 #define FEATURE_KBD_LED_REPORT_ID1 0x5d
@@ -89,6 +90,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define QUIRK_ROG_NKEY_KEYBOARD		BIT(11)
 #define QUIRK_ROG_CLAYMORE_II_KEYBOARD BIT(12)
 #define QUIRK_ROG_ALLY_XPAD		BIT(13)
+#define QUIRK_SKIP_REPORT_FIXUP		BIT(14)
 
 #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
 						 QUIRK_NO_INIT_REPORTS | \
@@ -125,7 +127,6 @@ struct asus_drvdata {
 	struct input_dev *tp_kbd_input;
 	struct asus_kbd_leds *kbd_backlight;
 	const struct asus_touchpad_info *tp;
-	bool enable_backlight;
 	struct power_supply *battery;
 	struct power_supply_desc battery_desc;
 	int battery_capacity;
@@ -316,7 +317,7 @@ static int asus_e1239t_event(struct asus_drvdata *drvdat, u8 *data, int size)
 static int asus_event(struct hid_device *hdev, struct hid_field *field,
 		      struct hid_usage *usage, __s32 value)
 {
-	if ((usage->hid & HID_USAGE_PAGE) == 0xff310000 &&
+	if ((usage->hid & HID_USAGE_PAGE) == HID_USAGE_PAGE_VENDOR &&
 	    (usage->hid & HID_USAGE) != 0x00 &&
 	    (usage->hid & HID_USAGE) != 0xff && !usage->type) {
 		hid_warn(hdev, "Unmapped Asus vendor usagepage code 0x%02x\n",
@@ -931,11 +932,6 @@ static int asus_input_configured(struct hid_device *hdev, struct hid_input *hi)
 
 	drvdata->input = input;
 
-	if (drvdata->enable_backlight &&
-	    !asus_kbd_wmi_led_control_present(hdev) &&
-	    asus_kbd_register_leds(hdev))
-		hid_warn(hdev, "Failed to initialize backlight.\n");
-
 	return 0;
 }
 
@@ -1008,15 +1004,6 @@ static int asus_input_mapping(struct hid_device *hdev,
 			return -1;
 		}
 
-		/*
-		 * Check and enable backlight only on devices with UsagePage ==
-		 * 0xff31 to avoid initializing the keyboard firmware multiple
-		 * times on devices with multiple HID descriptors but same
-		 * PID/VID.
-		 */
-		if (drvdata->quirks & QUIRK_USE_KBD_BACKLIGHT)
-			drvdata->enable_backlight = true;
-
 		set_bit(EV_REP, hi->input->evbit);
 		return 1;
 	}
@@ -1133,8 +1120,10 @@ static int __maybe_unused asus_reset_resume(struct hid_device *hdev)
 
 static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
-	int ret;
+	struct hid_report_enum *rep_enum;
 	struct asus_drvdata *drvdata;
+	struct hid_report *rep;
+	int ret, is_vendor = 0;
 
 	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
 	if (drvdata == NULL) {
@@ -1218,18 +1207,42 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		return ret;
 	}
 
+	/* Check for vendor for RGB init and handle generic devices properly. */
+	rep_enum = &hdev->report_enum[HID_INPUT_REPORT];
+	list_for_each_entry(rep, &rep_enum->report_list, list) {
+		if ((rep->application & HID_USAGE_PAGE) == HID_USAGE_PAGE_VENDOR)
+			is_vendor = true;
+	}
+
+	/*
+	 * For ROG keyboards, make them HID/hiddev compliant by creating one
+	 * input per application. For interfaces other than the vendor one,
+	 * disable report fixups.
+	 */
+	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
+		if (!is_vendor)
+			drvdata->quirks |= QUIRK_SKIP_REPORT_FIXUP;
+		hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
+	}
+
 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 	if (ret) {
 		hid_err(hdev, "Asus hw start failed: %d\n", ret);
 		return ret;
 	}
 
+	if (is_vendor && (drvdata->quirks & QUIRK_USE_KBD_BACKLIGHT) &&
+	    !asus_kbd_wmi_led_control_present(hdev) &&
+	    asus_kbd_register_leds(hdev))
+		hid_warn(hdev, "Failed to initialize backlight.\n");
+
 	/*
-	 * Check that input registration succeeded. Checking that
-	 * HID_CLAIMED_INPUT is set prevents a UAF when all input devices
-	 * were freed during registration due to no usages being mapped,
-	 * leaving drvdata->input pointing to freed memory.
+	 * For ROG keyboards, skip rename for consistency and ->input check as
+	 * some devices do not have inputs.
 	 */
+	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD)
+		return 0;
+
 	if (!drvdata->input || !(hdev->claimed & HID_CLAIMED_INPUT)) {
 		hid_err(hdev, "Asus input not registered\n");
 		ret = -ENOMEM;
@@ -1352,6 +1365,10 @@ static const __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		rdesc = new_rdesc;
 	}
 
+	/* Vendor fixups should only apply to NKEY vendor devices. */
+	if (drvdata->quirks & QUIRK_SKIP_REPORT_FIXUP)
+		return rdesc;
+
 	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD &&
 			*rsize == 331 && rdesc[190] == 0x85 && rdesc[191] == 0x5a &&
 			rdesc[204] == 0x95 && rdesc[205] == 0x05) {
-- 
2.51.0