Bluetooth: btusb: Add support Mediatek MT7920

This patch is added support Mediatek MT7920
The firmware location of MT7920 will set to
/lib/firmware/mediatek/

The information in /sys/kernel/debug/usb/devices about MT7920U
Bluetooth device is listed as the below

T:  Bus=01 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 12 Spd=480  MxCh= 0
D:  Ver= 2.10 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=0e8d ProdID=7920 Rev= 1.00
S:  Manufacturer=MediaTek Inc.
S:  Product=Wireless_Device
S:  SerialNumber=000000000
C:* #Ifs= 3 Cfg#= 1 Atr=e0 MxPwr=100mA
A:  FirstIf#= 0 IfCount= 3 Cls=e0(wlcon) Sub=01 Prot=01
I:* If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=81(I) Atr=03(Int.) MxPS=  16 Ivl=125us
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   0 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   0 Ivl=1ms
I:  If#= 1 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=   9 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=   9 Ivl=1ms
I:  If#= 1 Alt= 2 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  17 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  17 Ivl=1ms
I:  If#= 1 Alt= 3 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  25 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  25 Ivl=1ms
I:  If#= 1 Alt= 4 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  33 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  33 Ivl=1ms
I:  If#= 1 Alt= 5 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  49 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  49 Ivl=1ms
I:  If#= 1 Alt= 6 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
E:  Ad=83(I) Atr=01(Isoc) MxPS=  63 Ivl=1ms
E:  Ad=03(O) Atr=01(Isoc) MxPS=  63 Ivl=1ms
I:* If#= 2 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=(none)
E:  Ad=8a(I) Atr=03(Int.) MxPS=  64 Ivl=125us
E:  Ad=0a(O) Atr=03(Int.) MxPS=  64 Ivl=125us
I:  If#= 2 Alt= 1 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=(none)
E:  Ad=8a(I) Atr=03(Int.) MxPS= 512 Ivl=125us
E:  Ad=0a(O) Atr=03(Int.) MxPS= 512 Ivl=125us
Signed-off-by: Peter Tsao <peter.tsao@mediatek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/btusb.c

@@ -3088,7 +3088,7 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 	int err, status;
 	u32 dev_id = 0;
 	char fw_bin_name[64];
-	u32 fw_version = 0;
+	u32 fw_version = 0, fw_flavor = 0;
 	u8 param;
 	struct btmediatek_data *mediatek;
 
@@ -3111,6 +3111,11 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 			bt_dev_err(hdev, "Failed to get fw version (%d)", err);
 			return err;
 		}
+		err = btusb_mtk_id_get(data, 0x70010020, &fw_flavor);
+		if (err < 0) {
+			bt_dev_err(hdev, "Failed to get fw flavor (%d)", err);
+			return err;
+		}
 	}
 
 	mediatek = hci_get_priv(hdev);
@@ -3135,6 +3140,10 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 			snprintf(fw_bin_name, sizeof(fw_bin_name),
 				 "mediatek/mt%04x/BT_RAM_CODE_MT%04x_1_%x_hdr.bin",
 				 dev_id & 0xffff, dev_id & 0xffff, (fw_version & 0xff) + 1);
+		else if (dev_id == 0x7961 && fw_flavor)
+			snprintf(fw_bin_name, sizeof(fw_bin_name),
+				 "mediatek/BT_RAM_CODE_MT%04x_1a_%x_hdr.bin",
+				 dev_id & 0xffff, (fw_version & 0xff) + 1);
 		else
 			snprintf(fw_bin_name, sizeof(fw_bin_name),
 				 "mediatek/BT_RAM_CODE_MT%04x_1_%x_hdr.bin",