[PATCH v3 0/8] Bluetooth: Add MediaTek MT7927 (MT6639) support

[Javier Tia]

This series adds Bluetooth support for the MediaTek MT7927 (Filogic 380)
combo WiFi 7 + BT 5.4 module. The BT subsystem uses hardware variant
0x6639 and connects via USB.

The MT7927 is shipping in motherboards and PCIe add-in cards from ASUS,
Gigabyte, Lenovo, MSI, and TP-Link since mid-2024. Without these patches,
users see "Unsupported hardware variant (00006639)" or the BT subsystem
hangs during firmware download.

The series consists of eight patches:

  [1/8] Bluetooth: btmtk: Add MT6639 (MT7927) Bluetooth support
  [2/8] Bluetooth: btmtk: fix ISO interface setup for single alt setting
  [3/8] Bluetooth: btusb: Add MT7927 ID for ASUS ROG Crosshair X870E Hero
  [4/8] Bluetooth: btusb: Add MT7927 ID for Lenovo Legion Pro 7 16ARX9
  [5/8] Bluetooth: btusb: Add MT7927 ID for Gigabyte Z790 AORUS MASTER X
  [6/8] Bluetooth: btusb: Add MT7927 ID for MSI X870E Ace Max
  [7/8] Bluetooth: btusb: Add MT7927 ID for TP-Link Archer TBE550E
  [8/8] Bluetooth: btusb: Add MT7927 ID for ASUS X870E / ProArt X870E-Creator

Three driver changes are needed for MT6639 (patch 1):

1. CHIPID workaround: On some boards the BT USB MMIO register reads
   0x0000 for dev_id. Force dev_id to 0x6639 only when the USB VID/PID
   matches a known MT6639 device, avoiding misdetection if a future
   chip also reads zero. This follows the WiFi-side pattern.

2. Firmware naming: MT6639 uses firmware version prefix "2_1" instead of
   "1_1" used by MT7925 and other variants. The firmware path is
   mediatek/mt7927/BT_RAM_CODE_MT6639_2_1_hdr.bin, using the mt7927
   directory to match the WiFi firmware convention. The filename will
   likely change to use MT7927 once MediaTek submits a dedicated
   Linux firmware binary.

3. Section filtering: The firmware binary contains 9 sections, but only
   sections with (dlmodecrctype & 0xff) == 0x01 are Bluetooth-related.
   Sending WiFi/other sections causes an irreversible BT subsystem hang.

Patch 2 fixes the ISO interface setup for devices that expose only a
single alternate setting (alt 0) on the ISO endpoint. Without this fix,
btmtk_usb_claim_iso_intf() fails with EINVAL, causing ~20 second
initialization delays on 13d3:3588 devices.

Tested on:
- ASUS ROG Crosshair X870E Hero (USB 0489:e13a)
- ASUS ROG STRIX X870E-E (USB 13d3:3588)
- ASUS ROG STRIX B850-E GAMING WIFI (USB 0489:e13a)
- Gigabyte Z790 AORUS MASTER X (USB 0489:e10f)
- Lenovo Legion Pro 7 16ARX9 (USB 0489:e0fa)
- MSI MEG X870E ACE MAX (USB 0489:e110)
- TP-Link Archer TBE550E PCIe (USB 0489:e116)

The firmware blob is being submitted separately to linux-firmware via
GitLab MR !946. The firmware path has been updated to mediatek/mt7927/
per maintainer feedback.

Changes in v3 (suggested by Sean Wang):
- Scoped CHIPID workaround to a static VID/PID table of known MT6639
  USB devices instead of mapping all zero-CHIPID cases to 0x6639
- Changed firmware path from mediatek/mt6639/ to mediatek/mt7927/ to
  match the WiFi firmware convention and avoid confusion
- Added MODULE_FIRMWARE(FIRMWARE_MT7927) for initramfs firmware discovery
- Added Tested-by for 0489:e110 (Nitin Gurram)

Changes in v2:
- Split USB device IDs into per-device commits as requested (Luiz)
- Added 0489:e110 (MSI X870E Ace Max, new hardware report)
- Added ISO interface fix for single alt setting (13d3:3588 devices)
- Added Tested-by trailers for all USB IDs
- Added USB descriptor output to all per-device commits
- Removed BTMTK_FIRMWARE_LOADED skip logic (Sean Wang)

Link to v2: https://lore.kernel.org/linux-bluetooth/20260325-mt7927-bt-support-v2-0-b892a3252880@jetm.me/T/#t
Link to v1: https://lore.kernel.org/linux-bluetooth/177272816248.352280.12453518046823439297@jetm.me/

Signed-off-by: Javier Tia <floss at jetm.me>
---
Javier Tia (8):
      Bluetooth: btmtk: Add MT6639 (MT7927) Bluetooth support
      Bluetooth: btmtk: fix ISO interface setup for single alt setting
      Bluetooth: btusb: Add MT7927 ID for ASUS ROG Crosshair X870E Hero
      Bluetooth: btusb: Add MT7927 ID for Lenovo Legion Pro 7 16ARX9
      Bluetooth: btusb: Add MT7927 ID for Gigabyte Z790 AORUS MASTER X
      Bluetooth: btusb: Add MT7927 ID for MSI X870E Ace Max
      Bluetooth: btusb: Add MT7927 ID for TP-Link Archer TBE550E
      Bluetooth: btusb: Add MT7927 ID for ASUS X870E / ProArt X870E-Creator

 drivers/bluetooth/btmtk.c | 56 ++++++++++++++++++++++++++++++++++++++++++++---
 drivers/bluetooth/btmtk.h |  1 +
 drivers/bluetooth/btusb.c | 12 ++++++++++
 3 files changed, 66 insertions(+), 3 deletions(-)
---
base-commit: 50003ce2085a7f7dacf2426065d1a69c84b5b963
change-id: 20260305-mt7927-bt-support-6589a50c961f

Best regards,
--  
Javier Tia <floss at jetm.me>