[PATCH V5] HID: asus: add support for ASUS N-Key keyboard

[Luke Jones <luke@ljones.dev>]

From: Luke D Jones <luke@ljones.dev>

Enable missing functionality of the keyboard found in many ASUS
Zephyrus laptops: Fn key combos and hotkeys, keyboard backlight
brightness control, and notify asus-wmi to toggle "fan-mode".
Two input event codes are added for keyboard LED mode switching
prev/next.

The keyboard has many of the same key outputs as the existing G752
keyboard including a few extras, and varies a little between laptop
models.

Additionally the keyboard requires the LED interface to be
intitialised before such things as keyboard backlight control work.

Misc changes in scope: update some hardcoded comparisons to use an
available define, change "Mic Toggle" to use a keycode that works.

Signed-off-by: Luke D Jones <luke@ljones.dev>
---
 drivers/hid/hid-asus.c                     | 165 ++++++++++++++++++---
 drivers/hid/hid-ids.h                      |   1 +
 include/linux/platform_data/x86/asus-wmi.h |   2 +
 include/uapi/linux/input-event-codes.h     |   7 +
 4 files changed, 152 insertions(+), 23 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index c183caf89d49..4745ed6526cd 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -26,6 +26,7 @@
 #include <linux/dmi.h>
 #include <linux/hid.h>
 #include <linux/module.h>
+#include <linux/acpi.h>
 #include <linux/platform_data/x86/asus-wmi.h>
 #include <linux/input/mt.h>
 #include <linux/usb.h> /* For to_usb_interface for T100 touchpad intf check */
@@ -48,6 +49,8 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define INPUT_REPORT_ID 0x5d
 #define FEATURE_KBD_REPORT_ID 0x5a
 #define FEATURE_KBD_REPORT_SIZE 16
+#define FEATURE_KBD_LED_REPORT_ID1 0x5d
+#define FEATURE_KBD_LED_REPORT_ID2 0x5e

 #define SUPPORT_KBD_BACKLIGHT BIT(0)

@@ -80,6 +83,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
 #define QUIRK_T101HA_DOCK		BIT(9)
 #define QUIRK_T90CHI			BIT(10)
 #define QUIRK_MEDION_E1239T		BIT(11)
+#define QUIRK_ROG_NKEY_KEYBOARD		BIT(12)

 #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
 						 QUIRK_NO_INIT_REPORTS | \
@@ -305,10 +309,33 @@ static int asus_e1239t_event(struct asus_drvdata *drvdat, u8 *data, int size)
 	return 0;
 }

+/*
+ * This enables triggering events in asus-wmi
+ */
+static int asus_wmi_send_event(struct asus_drvdata *drvdat, u8 code)
+{
+	int err;
+	u32 retval;
+
+	err = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DEVS,
+		ASUS_WMI_METHODID_NOTIF, code, &retval);
+	if (err) {
+		pr_warn("Failed to notify asus-wmi: %d\n", err);
+		return err;
+	}
+
+	if (retval != 0) {
+		pr_warn("Failed to notify asus-wmi (retval): 0x%x\n", retval);
+		return -EIO;
+	}
+
+	return 0;
+}
+
 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_UP_ASUSVENDOR &&
 	    (usage->hid & HID_USAGE) != 0x00 &&
 	    (usage->hid & HID_USAGE) != 0xff && !usage->type) {
 		hid_warn(hdev, "Unmapped Asus vendor usagepage code 0x%02x\n",
@@ -332,6 +359,20 @@ static int asus_raw_event(struct hid_device *hdev,
 	if (drvdata->quirks & QUIRK_MEDION_E1239T)
 		return asus_e1239t_event(drvdata, data, size);

+	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
+		/*
+		 * Skip these report ID, the device emits a continuous stream associated
+		 * with the AURA mode it is in
+		 */
+		if (report->id == FEATURE_KBD_LED_REPORT_ID1 ||
+				report->id == FEATURE_KBD_LED_REPORT_ID2) {
+			return -1;
+		/* Fn+F5 "fan" symbol, trigger WMI event to toggle next mode */
+		} else if (report->id == FEATURE_KBD_REPORT_ID && data[1] == 0xae) {
+			return asus_wmi_send_event(drvdata, 0xae);
+		}
+	}
+
 	return 0;
 }

@@ -344,7 +385,9 @@ static int asus_kbd_set_report(struct hid_device *hdev, u8 *buf, size_t buf_size
 	if (!dmabuf)
 		return -ENOMEM;

-	ret = hid_hw_raw_request(hdev, FEATURE_KBD_REPORT_ID, dmabuf,
+	// The report ID should be set from the incoming buffer due to LED and key
+	// interfaces having different pages
+	ret = hid_hw_raw_request(hdev, buf[0], dmabuf,
 				 buf_size, HID_FEATURE_REPORT,
 				 HID_REQ_SET_REPORT);
 	kfree(dmabuf);
@@ -397,6 +440,44 @@ static int asus_kbd_get_functions(struct hid_device *hdev,
 	return ret;
 }

+static int asus_kbd_led_init(struct hid_device *hdev)
+{
+	u8 buf_init_start[] = { FEATURE_KBD_LED_REPORT_ID1, 0xB9 };
+	u8 buf_init2[] = { FEATURE_KBD_LED_REPORT_ID1, 0x41, 0x53, 0x55, 0x53, 0x20,
+				0x54, 0x65, 0x63, 0x68, 0x2e, 0x49, 0x6e, 0x63, 0x2e, 0x00 };
+	u8 buf_init3[] = { FEATURE_KBD_LED_REPORT_ID1,
+						0x05, 0x20, 0x31, 0x00, 0x08 };
+	int ret;
+
+	hid_warn(hdev, "Asus initialise N-KEY Device");
+	/* The first message is an init start */
+	ret = asus_kbd_set_report(hdev, buf_init_start, sizeof(buf_init_start));
+	if (ret < 0)
+		hid_err(hdev, "Asus failed to send init start command: %d\n", ret);
+	/* Followed by a string */
+	ret = asus_kbd_set_report(hdev, buf_init2, sizeof(buf_init2));
+	if (ret < 0)
+		hid_err(hdev, "Asus failed to send init command 1.0: %d\n", ret);
+	/* Followed by a string */
+	ret = asus_kbd_set_report(hdev, buf_init3, sizeof(buf_init3));
+	if (ret < 0)
+		hid_err(hdev, "Asus failed to send init command 1.1: %d\n", ret);
+
+	/* begin second report ID with same data */
+	buf_init2[0] = FEATURE_KBD_LED_REPORT_ID2;
+	buf_init3[0] = FEATURE_KBD_LED_REPORT_ID2;
+
+	ret = asus_kbd_set_report(hdev, buf_init2, sizeof(buf_init2));
+	if (ret < 0)
+		hid_err(hdev, "Asus failed to send init command 2.0: %d\n", ret);
+
+	ret = asus_kbd_set_report(hdev, buf_init3, sizeof(buf_init3));
+	if (ret < 0)
+		hid_err(hdev, "Asus failed to send init command 2.1: %d\n", ret);
+
+	return ret;
+}
+
 static void asus_kbd_backlight_set(struct led_classdev *led_cdev,
 				   enum led_brightness brightness)
 {
@@ -460,19 +541,28 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
 	unsigned char kbd_func;
 	int ret;

-	/* Initialize keyboard */
-	ret = asus_kbd_init(hdev);
-	if (ret < 0)
-		return ret;
+	if (drvdata->quirks & QUIRK_G752_KEYBOARD) {
+		/* Initialize keyboard */
+		ret = asus_kbd_init(hdev);
+		if (ret < 0)
+			return ret;

-	/* Get keyboard functions */
-	ret = asus_kbd_get_functions(hdev, &kbd_func);
-	if (ret < 0)
-		return ret;
+		/* Get keyboard functions */
+		ret = asus_kbd_get_functions(hdev, &kbd_func);
+		if (ret < 0)
+			return ret;

-	/* Check for backlight support */
-	if (!(kbd_func & SUPPORT_KBD_BACKLIGHT))
-		return -ENODEV;
+		/* Check for backlight support */
+		if (!(kbd_func & SUPPORT_KBD_BACKLIGHT))
+			return -ENODEV;
+	}
+
+	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
+		/* Initialize keyboard LED interface and Vendor keys on 0x1866 */
+		ret = asus_kbd_led_init(hdev);
+		if (ret < 0)
+			return ret;
+	}

 	drvdata->kbd_backlight = devm_kzalloc(&hdev->dev,
 					      sizeof(struct asus_kbd_leds),
@@ -751,14 +841,14 @@ static int asus_input_mapping(struct hid_device *hdev,
 	     usage->hid == (HID_UP_GENDEVCTRLS | 0x0026)))
 		return -1;

-	/* ASUS-specific keyboard hotkeys */
-	if ((usage->hid & HID_USAGE_PAGE) == 0xff310000) {
+	/* ASUS-specific keyboard hotkeys and led backlight */
+	if ((usage->hid & HID_USAGE_PAGE) == HID_UP_ASUSVENDOR) {
 		switch (usage->hid & HID_USAGE) {
 		case 0x10: asus_map_key_clear(KEY_BRIGHTNESSDOWN);	break;
 		case 0x20: asus_map_key_clear(KEY_BRIGHTNESSUP);		break;
 		case 0x35: asus_map_key_clear(KEY_DISPLAY_OFF);		break;
 		case 0x6c: asus_map_key_clear(KEY_SLEEP);		break;
-		case 0x7c: asus_map_key_clear(KEY_MICMUTE);		break;
+		case 0x7c: asus_map_key_clear(KEY_F20);		break;
 		case 0x82: asus_map_key_clear(KEY_CAMERA);		break;
 		case 0x88: asus_map_key_clear(KEY_RFKILL);			break;
 		case 0xb5: asus_map_key_clear(KEY_CALC);			break;
@@ -771,16 +861,42 @@ static int asus_input_mapping(struct hid_device *hdev,
 		/* ROG key */
 		case 0x38: asus_map_key_clear(KEY_PROG1);		break;

-		/* Fn+C ASUS Splendid */
-		case 0xba: asus_map_key_clear(KEY_PROG2);		break;
+		default:
+			if (drvdata->quirks & QUIRK_G752_KEYBOARD) {
+				switch (usage->hid & HID_USAGE) {
+				/* Fn+C ASUS Splendid */
+				case 0xba: asus_map_key_clear(KEY_PROG2);		break;

-		/* Fn+Space Power4Gear Hybrid */
-		case 0x5c: asus_map_key_clear(KEY_PROG3);		break;
+				/* Fn+Space Power4Gear Hybrid */
+				case 0x5c: asus_map_key_clear(KEY_PROG3);		break;

-		/* Fn+F5 "fan" symbol on FX503VD */
-		case 0x99: asus_map_key_clear(KEY_PROG4);		break;
+				/* Fn+F5 "fan" symbol on FX503VD */
+				case 0x99: asus_map_key_clear(KEY_PROG4);		break;
+
+				default:
+					return -1;
+				}
+				break;
+			}
+
+			/* device 0x1866, N-KEY Device specific */
+			if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
+				switch (usage->hid & HID_USAGE) {
+				/* Fn+Ret "Calc" symbol on device 0x1866, N-KEY Device */
+				case 0x92: asus_map_key_clear(KEY_CALC);		break;
+
+				/* Fn+Left Aura mode previous */
+				case 0xb2: asus_map_key_clear(KEY_KBDILLUM_MODE_PREV);	break;
+
+				/* Fn+Right Aura mode next */
+				case 0xb3: asus_map_key_clear(KEY_KBDILLUM_MODE_NEXT);	break;
+
+				default:
+					return -1;
+				}
+				break;
+			}

-		default:
 			/* ASUS lazily declares 256 usages, ignore the rest,
 			 * as some make the keyboard appear as a pointer device. */
 			return -1;
@@ -1126,6 +1242,9 @@ static const struct hid_device_id asus_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 		USB_DEVICE_ID_ASUSTEK_FX503VD_KEYBOARD),
 	  QUIRK_USE_KBD_BACKLIGHT },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
+	    USB_DEVICE_ID_ASUSTEK_ROG_NKEY_KEYBOARD),
+	  QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ASUSTEK,
 		USB_DEVICE_ID_ASUSTEK_T100TA_KEYBOARD),
 	  QUIRK_T100_KEYBOARD | QUIRK_NO_CONSUMER_USAGES },
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 6f370e020feb..c9f930ddcfd7 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -190,6 +190,7 @@
 #define USB_DEVICE_ID_ASUSTEK_ROG_KEYBOARD1 0x1854
 #define USB_DEVICE_ID_ASUSTEK_ROG_KEYBOARD2 0x1837
 #define USB_DEVICE_ID_ASUSTEK_ROG_KEYBOARD3 0x1822
+#define USB_DEVICE_ID_ASUSTEK_ROG_NKEY_KEYBOARD	0x1866
 #define USB_DEVICE_ID_ASUSTEK_FX503VD_KEYBOARD	0x1869

 #define USB_VENDOR_ID_ATEN		0x0557
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index 897b8332a39f..05253cfe786c 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -27,6 +27,8 @@
 #define ASUS_WMI_METHODID_INIT		0x54494E49 /* INITialize */
 #define ASUS_WMI_METHODID_HKEY		0x59454B48 /* Hot KEY ?? */

+#define ASUS_WMI_METHODID_NOTIF		0x00100021 /* Notify method ?? */
+
 #define ASUS_WMI_UNSUPPORTED_METHOD	0xFFFFFFFE

 /* Wireless */
diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h
index 0c2e27d28e0a..ca59f7d7a25e 100644
--- a/include/uapi/linux/input-event-codes.h
+++ b/include/uapi/linux/input-event-codes.h
@@ -772,6 +772,13 @@
 #define BTN_TRIGGER_HAPPY39		0x2e6
 #define BTN_TRIGGER_HAPPY40		0x2e7

+/*
+ * Some keyboards have function keys associated with
+ * changing the keyboard backlight modes, e.g, RGB patterns
+ */
+#define KEY_KBDILLUM_MODE_PREV	0x2ea
+#define KEY_KBDILLUM_MODE_NEXT	0x2eb
+
 /* We avoid low common keys in module aliases so they don't get huge. */
 #define KEY_MIN_INTERESTING	KEY_MUTE
 #define KEY_MAX			0x2ff
--
2.26.2