BACKPORT: bluetooth: btqca: Add WCN6855 firmware priority selection feature

Historically, WCN685x and QCA2066 shared the same firmware files.
Now, changes are planned for the firmware that will make it incompatible
with QCA2066, so a new firmware name is required for WCN685x.

Test Steps:
 - Boot device
 - Check the BTFW loading status via dmesg

Sanity pass and Test Log:
QCA Downloading qca/wcnhpbftfw21.tlv
Direct firmware load for qca/wcnhpbftfw21.tlv failed with error -2
QCA Downloading qca/hpbftfw21.tlv

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.com>
Link: https://lore.kernel.org/all/20260106043503.534557-3-shuai.zhang@oss.qualcomm.com/

Author: shuaz-shuai

drivers/bluetooth/btqca.c

@@ -830,8 +830,12 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
 				 "qca/msbtfw%02x.mbn", rom_ver);
 			break;
 		case QCA_WCN6855:
+			/* Due to historical reasons, WCN685x chip has been using firmware
+			 * without the "wcn" prefix. The mapping between the chip and its
+			 * corresponding firmware has now been corrected.
+			 */
 			snprintf(config.fwname, sizeof(config.fwname),
-				 "qca/hpbtfw%02x.tlv", rom_ver);
+				 "qca/wcnhpbtfw%02x.tlv", rom_ver);
 			break;
 		case QCA_WCN7850:
 			snprintf(config.fwname, sizeof(config.fwname),
@@ -855,6 +859,10 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
 			 "qca/msbtfw%02x.tlv", rom_ver);
 		bt_dev_info(hdev, "QCA Downloading %s", config.fwname);
 		err = qca_download_firmware(hdev, &config, soc_type, rom_ver);
+	} else if (err < 0 && !rampatch_name && soc_type == QCA_WCN6855) {
+		snprintf(config.fwname, sizeof(config.fwname),
+			 "qca/hpbtfw%02x.tlv", rom_ver);
+		err = qca_download_firmware(hdev, &config, soc_type, rom_ver);
 	}
 
 	if (err < 0) {
@@ -920,7 +928,7 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
 		case QCA_WCN6855:
 			qca_read_fw_board_id(hdev, &boardid);
 			qca_get_nvm_name_by_board(config.fwname, sizeof(config.fwname),
-						  "hpnv", soc_type, ver, rom_ver, boardid);
+						  "wcnhpnv", soc_type, ver, rom_ver, boardid);
 			break;
 		case QCA_WCN7850:
 			qca_get_nvm_name_by_board(config.fwname, sizeof(config.fwname),
@@ -933,8 +941,15 @@ int qca_uart_setup(struct hci_dev *hdev, uint8_t baudrate,
 	}
 
 	err = qca_download_firmware(hdev, &config, soc_type, rom_ver);
+	if (err < 0 && !firmware_name && soc_type == QCA_WCN6855) {
+		qca_get_nvm_name_by_board(config.fwname, sizeof(config.fwname),
+					  "hpnv", soc_type, ver, rom_ver, boardid);
+		err = qca_download_firmware(hdev, &config, soc_type, rom_ver);
+	}
+
 	if (err < 0) {
-		bt_dev_err(hdev, "QCA Failed to download NVM (%d)", err);
+		bt_dev_err(hdev, "QCA Failed to request file: %s (%d)",
+			   config.fwname, err);
 		return err;
 	}