Bluetooth: btusb: mediatek: add MT7922 subsystem reset

Add the support of MT7922 bluetooth subsystem reset that was called the
auto revert to self-recover from the fatal error in the controller like
the host encounters HCI cmd timeout or the controller crashes.
Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Hao Qin <hao.qin@mediatek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/btusb.c

@@ -3039,7 +3039,16 @@ static int btusb_mtk_subsys_reset(struct hci_dev *hdev, u32 dev_id)
 	u32 val;
 	int err;
 
-	if (dev_id == 0x7925) {
+	if (dev_id == 0x7922) {
+		btusb_mtk_uhw_reg_read(data, MTK_BT_SUBSYS_RST, &val);
+		val |= 0x00002020;
+		btusb_mtk_uhw_reg_write(data, MTK_BT_SUBSYS_RST, val);
+		btusb_mtk_uhw_reg_write(data, MTK_EP_RST_OPT, 0x00010001);
+		btusb_mtk_uhw_reg_read(data, MTK_BT_SUBSYS_RST, &val);
+		val |= BIT(0);
+		btusb_mtk_uhw_reg_write(data, MTK_BT_SUBSYS_RST, val);
+		msleep(100);
+	} else if (dev_id == 0x7925) {
 		btusb_mtk_uhw_reg_read(data, MTK_BT_RESET_REG_CONNV3, &val);
 		val |= (1 << 5);
 		btusb_mtk_uhw_reg_write(data, MTK_BT_RESET_REG_CONNV3, val);
@@ -3079,6 +3088,9 @@ static int btusb_mtk_subsys_reset(struct hci_dev *hdev, u32 dev_id)
 	if (err < 0)
 		bt_dev_err(hdev, "Reset timeout");
 
+	if (dev_id == 0x7922)
+		btusb_mtk_uhw_reg_write(data, MTK_UDMA_INT_STA_BT, 0x000000FF);
+
 	btusb_mtk_id_get(data, 0x70010200, &val);
 	if (!val)
 		bt_dev_err(hdev, "Can't get device id, subsys reset fail.");