Re: [PATCH 3/6] HID: asus: add support for T3304 detachable keyboard

Denis Benato
2026-05-03T22:23:21Z

On 5/3/26 09:26, James Ye wrote:
> ASUSTek Computer, Inc. T3304 Soft Keyboard [0b05:1aad] is the detachable
> keyboard of the ASUS Vivobook 13 Slate OLED (T3304). It presents as a
> USB device with two interfaces: a keyboard and a pointing device
> (touchpad).
>
> Basic keyboard and full touchpad functionality work out-of-the-box with
> hid-generic and hid-multitouch, but function key combos e.g. volume,
> brightness control, home/end/pgup/pgdown require initialization.
>
> Bind the keyboard interface to hid-asus for initialization. The
> OEM-specific report descriptors required for this are present only on
> the touchpad interface, not the keyboard, so a quirk is used to add the
> required feature descriptor.
Reviewed-By: Denis Benato <denis.benato@linux.dev>
> Signed-off-by: James Ye <jye836@gmail.com>
> ---
> drivers/hid/hid-asus.c | 58 +++++++++++++++++++++++++++++++++++++++---
> drivers/hid/hid-ids.h | 1 +
> 2 files changed, 56 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index ef9d5eba4dc9..e4c97fddfaf1 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -99,6 +99,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
> #define QUIRK_ROG_CLAYMORE_II_KEYBOARD BIT(12)
> #define QUIRK_ROG_ALLY_XPAD BIT(13)
> #define QUIRK_HID_FN_LOCK BIT(14)
> +#define QUIRK_T3304_KEYBOARD BIT(15)
>
> #define I2C_KEYBOARD_QUIRKS (QUIRK_FIX_NOTEBOOK_REPORT | \
> QUIRK_NO_INIT_REPORTS | \
> @@ -494,6 +495,14 @@ static int asus_kbd_init(struct hid_device *hdev, u8 report_id)
> return ret;
> }
>
> + struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
> +
> + /* T3304 keyboard always replies with 16 0xff bytes. Don't check for
> + * acknowledgment.
> + */
> + if (drvdata->quirks & QUIRK_T3304_KEYBOARD)
> + return 0;
> +
> u8 *readbuf __free(kfree) = kzalloc(FEATURE_KBD_REPORT_SIZE, GFP_KERNEL);
> if (!readbuf)
> return -ENOMEM;
> @@ -1312,10 +1321,12 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
> hid_warn(hdev, "Failed to initialize backlight.\n");
>
> /*
> - * For ROG keyboards, skip rename for consistency and ->input check as
> - * some devices do not have inputs.
> + * For ROG and T3304 keyboards, skip rename for consistency.
> + * For ROG keyboards, skip ->input check as some devices do not have
> + * inputs.
> */
> - if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD)
> + if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD ||
> + drvdata->quirks & QUIRK_T3304_KEYBOARD)
> return 0;
>
> /*
> @@ -1369,6 +1380,22 @@ static const __u8 asus_g752_fixed_rdesc[] = {
> 0x2A, 0xFF, 0x00, /* Usage Maximum (0xFF) */
> };
>
> +static const __u8 asus_t3304_fixed_rdesc[] = {
> + 0x06, 0x31, 0xff, // Usage Page (Vendor Usage Page 0xff31)
> + 0x09, 0x76, // Usage (Vendor Usage 0x76)
> + 0xa1, 0x01, // Collection (Application)
> + 0x05, 0xff, // Usage Page (Vendor Usage Page 0xff)
> + 0x85, 0x5a, // Report ID (90)
> + 0x19, 0x00, // Usage Minimum (0)
> + 0x2a, 0xff, 0x00, // Usage Maximum (255)
> + 0x15, 0x00, // Logical Minimum (0)
> + 0x26, 0xff, 0x00, // Logical Maximum (255)
> + 0x75, 0x08, // Report Size (8)
> + 0x95, 0x0f, // Report Count (15)
> + 0xb1, 0x02, // Feature (Data,Var,Abs)
> + 0xc0, // End Collection
> +};
> +
> static const __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
> unsigned int *rsize)
> {
> @@ -1473,6 +1500,28 @@ static const __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
> }
> }
>
> + /* T3304 keyboard's vendor descriptors are on the touchpad interface,
> + * not the keyboard. But we need hid-multitouch to handle the touchpad,
> + * Add a descriptor with only the config report so that this driver can
> + * perform initialization.
> + */
> + if (drvdata->quirks & QUIRK_T3304_KEYBOARD) {
> + __u8 *new_rdesc;
> + size_t new_size = *rsize + sizeof(asus_t3304_fixed_rdesc);
> +
> + new_rdesc = devm_kzalloc(&hdev->dev, new_size, GFP_KERNEL);
> + if (new_rdesc == NULL)
> + return rdesc;
> +
> + hid_info(hdev, "Fixing up Asus T3304 keyboard report descriptor\n");
> + memcpy(new_rdesc, rdesc, *rsize);
> + memcpy(new_rdesc + *rsize, asus_t3304_fixed_rdesc,
> + sizeof(asus_t3304_fixed_rdesc));
> +
> + *rsize = new_size;
> + rdesc = new_rdesc;
> + }
> +
> return rdesc;
> }
>
> @@ -1536,6 +1585,9 @@ static const struct hid_device_id asus_devices[] = {
> QUIRK_USE_KBD_BACKLIGHT | QUIRK_ROG_NKEY_KEYBOARD },
> { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
> USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_T101HA_KEYBOARD) },
> + { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
> + USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_T3304_KEYBOARD),
> + QUIRK_T3304_KEYBOARD },
> { }
> };
> MODULE_DEVICE_TABLE(hid, asus_devices);
> diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> index 0cf63742315b..ecf30e36a99d 100644
> --- a/drivers/hid/hid-ids.h
> +++ b/drivers/hid/hid-ids.h
> @@ -219,6 +219,7 @@
> #define USB_DEVICE_ID_ASUSTEK_T100CHI_KEYBOARD 0x8502
> #define USB_DEVICE_ID_ASUSTEK_T101HA_KEYBOARD 0x183d
> #define USB_DEVICE_ID_ASUSTEK_T304_KEYBOARD 0x184a
> +#define USB_DEVICE_ID_ASUSTEK_T3304_KEYBOARD 0x1aad
> #define USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD 0x8585
> #define USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD 0x0101
> #define USB_DEVICE_ID_ASUSTEK_ROG_KEYBOARD1 0x1854
> --
> 2.54.0