greybus: firmware: Update Documentation and sample application

Update documentation and sample application to capture the 'status' byte
in backend version operation and new error types in backend firmware
update operation.

Signed-off-by: Viresh Kumar <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/greybus/Documentation/firmware/firmware-management

···
 #define GB_FW_BACKEND_FW_STATUS_FAIL_FETCH	0x03
 #define GB_FW_BACKEND_FW_STATUS_FAIL_WRITE	0x04
 #define GB_FW_BACKEND_FW_STATUS_INT		0x05
+#define GB_FW_BACKEND_FW_STATUS_RETRY		0x06
+#define GB_FW_BACKEND_FW_STATUS_NOT_SUPPORTED	0x07
 
-struct fw_mgmt_ioc_get_fw {
-	__u8			firmware_tag[GB_FIRMWARE_TAG_MAX_LEN];
-	__u16			major;
-	__u16			minor;
-} __packed;
+#define GB_FW_BACKEND_VERSION_STATUS_SUCCESS		0x01
+#define GB_FW_BACKEND_VERSION_STATUS_NOT_AVAILABLE	0x02
+#define GB_FW_BACKEND_VERSION_STATUS_NOT_SUPPORTED	0x03
+#define GB_FW_BACKEND_VERSION_STATUS_RETRY		0x04
+#define GB_FW_BACKEND_VERSION_STATUS_FAIL_INT		0x05
+
+
+struct fw_mgmt_ioc_get_intf_version {
+	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_LEN];
+	__u16 major;
+	__u16 minor;
+} __attribute__ ((__packed__));
+
+struct fw_mgmt_ioc_get_backend_version {
+	__u8 firmware_tag[GB_FIRMWARE_U_TAG_MAX_LEN];
+	__u16 major;
+	__u16 minor;
+	__u8 status;
+} __attribute__ ((__packed__));
 
 struct fw_mgmt_ioc_intf_load_and_validate {
 	__u8			firmware_tag[GB_FIRMWARE_TAG_MAX_LEN];
···
 } __packed;
 
 #define FW_MGMT_IOCTL_BASE			'S'
-#define FW_MGMT_IOC_GET_INTF_FW			_IOR(FW_MGMT_IOCTL_BASE, 0, struct fw_mgmt_ioc_get_fw)
-#define FW_MGMT_IOC_GET_BACKEND_FW		_IOWR(FW_MGMT_IOCTL_BASE, 1, struct fw_mgmt_ioc_get_fw)
+#define FW_MGMT_IOC_GET_INTF_FW			_IOR(FW_MGMT_IOCTL_BASE, 0, struct fw_mgmt_ioc_get_intf_version)
+#define FW_MGMT_IOC_GET_BACKEND_FW		_IOWR(FW_MGMT_IOCTL_BASE, 1, struct fw_mgmt_ioc_get_backend_version)
 #define FW_MGMT_IOC_INTF_LOAD_AND_VALIDATE	_IOWR(FW_MGMT_IOCTL_BASE, 2, struct fw_mgmt_ioc_intf_load_and_validate)
 #define FW_MGMT_IOC_INTF_BACKEND_FW_UPDATE	_IOWR(FW_MGMT_IOCTL_BASE, 3, struct fw_mgmt_ioc_backend_fw_update)
 #define FW_MGMT_IOC_SET_TIMEOUT_MS		_IOW(FW_MGMT_IOCTL_BASE, 4, unsigned int)

drivers/staging/greybus/Documentation/firmware/firmware.c

···
 static int fw_update_type = FW_UPDATE_TYPE_DEFAULT;
 static int fw_timeout = FW_TIMEOUT_DEFAULT;
 
-static struct fw_mgmt_ioc_get_fw fw_info;
+static struct fw_mgmt_ioc_get_intf_version intf_fw_info;
+static struct fw_mgmt_ioc_get_backend_version backend_fw_info;
 static struct fw_mgmt_ioc_intf_load_and_validate intf_load;
 static struct fw_mgmt_ioc_backend_fw_update backend_update;
 
···
 	/* Get Interface Firmware Version */
 	printf("Get Interface Firmware Version\n");
 
-	ret = ioctl(fd, FW_MGMT_IOC_GET_INTF_FW, &fw_info);
+	ret = ioctl(fd, FW_MGMT_IOC_GET_INTF_FW, &intf_fw_info);
 	if (ret < 0) {
 		printf("Failed to get interface firmware version: %s (%d)\n",
 			fwdev, ret);
···
 	}
 
 	printf("Interface Firmware tag (%s), major (%d), minor (%d)\n",
-		fw_info.firmware_tag, fw_info.major, fw_info.minor);
+		intf_fw_info.firmware_tag, intf_fw_info.major,
+		intf_fw_info.minor);
 
 	/* Try Interface Firmware load over Unipro */
 	printf("Loading Interface Firmware\n");
···
 	/* Get Backend Firmware Version */
 	printf("Getting Backend Firmware Version\n");
 
-	fw_info.major = 0;
-	fw_info.minor = 0;
-	strncpy((char *)&fw_info.firmware_tag, firmware_tag,
+	strncpy((char *)&backend_fw_info.firmware_tag, firmware_tag,
 		GB_FIRMWARE_U_TAG_MAX_LEN);
 
-	ret = ioctl(fd, FW_MGMT_IOC_GET_BACKEND_FW, &fw_info);
+retry_fw_version:
+	ret = ioctl(fd, FW_MGMT_IOC_GET_BACKEND_FW, &backend_fw_info);
 	if (ret < 0) {
 		printf("Failed to get backend firmware version: %s (%d)\n",
 			fwdev, ret);
 		return -1;
 	}
 
-	printf("Backend Firmware tag (%s), major (%d), minor (%d)\n",
-		fw_info.firmware_tag, fw_info.major, fw_info.minor);
+	printf("Backend Firmware tag (%s), major (%d), minor (%d), status (%d)\n",
+		backend_fw_info.firmware_tag, backend_fw_info.major,
+		backend_fw_info.minor, backend_fw_info.status);
+
+	if (backend_fw_info.status == GB_FW_U_BACKEND_VERSION_STATUS_RETRY)
+		goto retry_fw_version;
+
+	if ((backend_fw_info.status != GB_FW_U_BACKEND_VERSION_STATUS_SUCCESS)
+	    && (backend_fw_info.status != GB_FW_U_BACKEND_VERSION_STATUS_NOT_AVAILABLE)) {
+		printf("Failed to get backend firmware version: %s (%d)\n",
+			fwdev, backend_fw_info.status);
+		return -1;
+	}
 
 	/* Try Backend Firmware Update over Unipro */
 	printf("Updating Backend Firmware\n");
 
-	backend_update.status = 0;
 	strncpy((char *)&backend_update.firmware_tag, firmware_tag,
 		GB_FIRMWARE_U_TAG_MAX_LEN);
+
+retry_fw_update:
+	backend_update.status = 0;
 
 	ret = ioctl(fd, FW_MGMT_IOC_INTF_BACKEND_FW_UPDATE, &backend_update);
 	if (ret < 0) {
 		printf("Failed to load backend firmware: %s (%d)\n", fwdev, ret);
 		return -1;
+	}
+
+	if (backend_update.status == GB_FW_U_BACKEND_FW_STATUS_RETRY) {
+		printf("Retrying firmware update: %d\n", backend_update.status);
+		goto retry_fw_update;
 	}
 
 	if (backend_update.status != GB_FW_U_BACKEND_FW_STATUS_SUCCESS) {