Bluetooth: btintel: Check firmware version before download

This checks the firmware build number, week and year against the
repective loaded version. If details are a match, skip the download
process.

Signed-off-by: Luiz Augusto von Dentz <[e-mail]>
Tested-by: Tedd Ho-Jeong An <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

drivers/bluetooth/btintel.c

···
 #define ECDSA_OFFSET		644
 #define ECDSA_HEADER_LEN	320
 
+#define CMD_WRITE_BOOT_PARAMS	0xfc0e
+struct cmd_write_boot_params {
+	u32 boot_addr;
+	u8  fw_build_num;
+	u8  fw_build_ww;
+	u8  fw_build_yy;
+} __packed;
+
 int btintel_check_bdaddr(struct hci_dev *hdev)
 {
 	struct hci_rp_read_bd_addr *bda;
···
 
 static int btintel_download_firmware_payload(struct hci_dev *hdev,
 					     const struct firmware *fw,
-					     u32 *boot_param, size_t offset)
+					     size_t offset)
 {
 	int err;
 	const u8 *fw_ptr;
···
 
 	while (fw_ptr - fw->data < fw->size) {
 		struct hci_command_hdr *cmd = (void *)(fw_ptr + frag_len);
-
-		/* Each SKU has a different reset parameter to use in the
-		 * HCI_Intel_Reset command and it is embedded in the firmware
-		 * data. So, instead of using static value per SKU, check
-		 * the firmware data and save it for later use.
-		 */
-		if (le16_to_cpu(cmd->opcode) == 0xfc0e) {
-			/* The boot parameter is the first 32-bit value
-			 * and rest of 3 octets are reserved.
-			 */
-			*boot_param = get_unaligned_le32(fw_ptr + frag_len +
-							 sizeof(*cmd));
-
-			bt_dev_dbg(hdev, "boot_param=0x%x", *boot_param);
-		}
 
 		frag_len += sizeof(*cmd) + cmd->plen;
 
···
 	return err;
 }
 
+static bool btintel_firmware_version(struct hci_dev *hdev,
+				     u8 num, u8 ww, u8 yy,
+				     const struct firmware *fw,
+				     u32 *boot_addr)
+{
+	const u8 *fw_ptr;
+
+	fw_ptr = fw->data;
+
+	while (fw_ptr - fw->data < fw->size) {
+		struct hci_command_hdr *cmd = (void *)(fw_ptr);
+
+		/* Each SKU has a different reset parameter to use in the
+		 * HCI_Intel_Reset command and it is embedded in the firmware
+		 * data. So, instead of using static value per SKU, check
+		 * the firmware data and save it for later use.
+		 */
+		if (le16_to_cpu(cmd->opcode) == CMD_WRITE_BOOT_PARAMS) {
+			struct cmd_write_boot_params *params;
+
+			params = (void *)(fw_ptr + sizeof(*cmd));
+
+			bt_dev_info(hdev, "Boot Address: 0x%x",
+				    le32_to_cpu(params->boot_addr));
+
+			bt_dev_info(hdev, "Firmware Version: %u-%u.%u",
+				    params->fw_build_num, params->fw_build_ww,
+				    params->fw_build_yy);
+
+			return (num == params->fw_build_num &&
+				ww == params->fw_build_ww &&
+				yy == params->fw_build_yy);
+		}
+
+		fw_ptr += sizeof(*cmd) + cmd->plen;
+	}
+
+	return false;
+}
+
 int btintel_download_firmware(struct hci_dev *hdev,
+			      struct intel_version *ver,
 			      const struct firmware *fw,
 			      u32 *boot_param)
 {
 	int err;
 
+	/* SfP and WsP don't seem to update the firmware version on file
+	 * so version checking is currently not possible.
+	 */
+	switch (ver->hw_variant) {
+	case 0x0b:	/* SfP */
+	case 0x0c:	/* WsP */
+		/* Skip version checking */
+		break;
+	default:
+		/* Skip download if firmware has the same version */
+		if (btintel_firmware_version(hdev, ver->fw_build_num,
+					     ver->fw_build_ww, ver->fw_build_yy,
+					     fw, boot_param)) {
+			bt_dev_info(hdev, "Firmware already loaded");
+			/* Return -EALREADY to indicate that the firmware has
+			 * already been loaded.
+			 */
+			return -EALREADY;
+		}
+	}
+
 	err = btintel_sfi_rsa_header_secure_send(hdev, fw);
 	if (err)
 		return err;
 
-	return btintel_download_firmware_payload(hdev, fw, boot_param,
-						 RSA_HEADER_LEN);
+	return btintel_download_firmware_payload(hdev, fw, RSA_HEADER_LEN);
 }
 EXPORT_SYMBOL_GPL(btintel_download_firmware);
 
 int btintel_download_firmware_newgen(struct hci_dev *hdev,
+				     struct intel_version_tlv *ver,
 				     const struct firmware *fw, u32 *boot_param,
 				     u8 hw_variant, u8 sbe_type)
 {
 	int err;
 	u32 css_header_ver;
+
+	/* Skip download if firmware has the same version */
+	if (btintel_firmware_version(hdev, ver->min_fw_build_nn,
+				     ver->min_fw_build_cw, ver->min_fw_build_yy,
+				     fw, boot_param)) {
+		bt_dev_info(hdev, "Firmware already loaded");
+		/* Return -EALREADY to indicate that firmware has already been
+		 * loaded.
+		 */
+		return -EALREADY;
+	}
 
 	/* iBT hardware variants 0x0b, 0x0c, 0x11, 0x12, 0x13, 0x14 support
 	 * only RSA secure boot engine. Hence, the corresponding sfi file will
···
 		if (err)
 			return err;
 
-		err = btintel_download_firmware_payload(hdev, fw, boot_param, RSA_HEADER_LEN);
+		err = btintel_download_firmware_payload(hdev, fw, RSA_HEADER_LEN);
 		if (err)
 			return err;
 	} else if (hw_variant >= 0x17) {
···
 				return err;
 
 			err = btintel_download_firmware_payload(hdev, fw,
-								boot_param,
 								RSA_HEADER_LEN + ECDSA_HEADER_LEN);
 			if (err)
 				return err;
···
 				return err;
 
 			err = btintel_download_firmware_payload(hdev, fw,
-								boot_param,
 								RSA_HEADER_LEN + ECDSA_HEADER_LEN);
 			if (err)
 				return err;

drivers/bluetooth/btintel.h

···
 int btintel_send_intel_reset(struct hci_dev *hdev, u32 boot_param);
 int btintel_read_boot_params(struct hci_dev *hdev,
 			     struct intel_boot_params *params);
-int btintel_download_firmware(struct hci_dev *dev, const struct firmware *fw,
-			      u32 *boot_param);
+int btintel_download_firmware(struct hci_dev *dev, struct intel_version *ver,
+			      const struct firmware *fw, u32 *boot_param);
 int btintel_download_firmware_newgen(struct hci_dev *hdev,
+				     struct intel_version_tlv *ver,
 				     const struct firmware *fw,
 				     u32 *boot_param, u8 hw_variant,
 				     u8 sbe_type);

drivers/bluetooth/btusb.c

···
 	set_bit(BTUSB_DOWNLOADING, &data->flags);
 
 	/* Start firmware downloading and get boot parameter */
-	err = btintel_download_firmware_newgen(hdev, fw, boot_param,
+	err = btintel_download_firmware_newgen(hdev, ver, fw, boot_param,
 					       INTEL_HW_VARIANT(ver->cnvi_bt),
 					       ver->sbe_type);
 	if (err < 0) {
+		if (err == -EALREADY) {
+			/* Firmware has already been loaded */
+			set_bit(BTUSB_FIRMWARE_LOADED, &data->flags);
+			err = 0;
+			goto done;
+		}
+
 		/* When FW download fails, send Intel Reset to retry
 		 * FW download.
 		 */
···
 	set_bit(BTUSB_DOWNLOADING, &data->flags);
 
 	/* Start firmware downloading and get boot parameter */
-	err = btintel_download_firmware(hdev, fw, boot_param);
+	err = btintel_download_firmware(hdev, ver, fw, boot_param);
 	if (err < 0) {
+		if (err == -EALREADY) {
+			/* Firmware has already been loaded */
+			set_bit(BTUSB_FIRMWARE_LOADED, &data->flags);
+			err = 0;
+			goto done;
+		}
+
 		/* When FW download fails, send Intel Reset to retry
 		 * FW download.
 		 */

drivers/bluetooth/hci_intel.c

···
 	set_bit(STATE_DOWNLOADING, &intel->flags);
 
 	/* Start firmware downloading and get boot parameter */
-	err = btintel_download_firmware(hdev, fw, &boot_param);
+	err = btintel_download_firmware(hdev, &ver, fw, &boot_param);
 	if (err < 0)
 		goto done;
 
···
 done:
 	release_firmware(fw);
 
-	if (err < 0)
+	/* Check if there was an error and if is not -EALREADY which means the
+	 * firmware has already been loaded.
+	 */
+	if (err < 0 && err != -EALREADY)
 		return err;
 
 	/* We need to restore the default speed before Intel reset */