fwupd/plugins/dfu/fu-dfu-target.c

/*
 * Copyright (C) 2015 Richard Hughes <richard@hughsie.com>
 *
 * SPDX-License-Identifier: LGPL-2.1+
 */

/**
 * SECTION:fu-dfu-target
 * @short_description: Object representing a DFU-capable target
 *
 * This object allows uploading and downloading an image onto a
 * specific DFU-capable target.
 *
 * You only need to use this in preference to #FuDfuDevice if you only
 * want to update one target on the device. Most users will want to
 * update all the targets on the device at the same time.
 *
 * See also: #FuDfuDevice, #FuFirmwareImage
 */

#include "config.h"

#include <string.h>
#include <math.h>

#include "fu-dfu-common.h"
#include "fu-dfu-device.h"
#include "fu-dfu-sector.h"
#include "fu-dfu-target-private.h"

#include "fu-dfu-firmware-private.h"

#include "fwupd-error.h"

#define DFU_TARGET_MANIFEST_MAX_POLLING_TRIES	200

static void fu_dfu_target_finalize			 (GObject *object);

typedef struct {
	FuDfuDevice		*device;		/* not refcounted */
	gboolean		 done_setup;
	guint8			 alt_setting;
	guint8			 alt_idx;
	gchar			*alt_name;
	gchar			*alt_name_for_display;
	GPtrArray		*sectors;		/* of FuDfuSector */
	guint			 old_percentage;
	FwupdStatus		 old_action;
} FuDfuTargetPrivate;

enum {
	SIGNAL_PERCENTAGE_CHANGED,
	SIGNAL_ACTION_CHANGED,
	SIGNAL_LAST
};

static guint signals [SIGNAL_LAST] = { 0 };

G_DEFINE_TYPE_WITH_PRIVATE (FuDfuTarget, fu_dfu_target, G_TYPE_OBJECT)
#define GET_PRIVATE(o) (fu_dfu_target_get_instance_private (o))

static void
fu_dfu_target_class_init (FuDfuTargetClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);

	/**
	 * FuDfuTarget::percentage-changed:
	 * @device: the #FuDfuTarget instance that emitted the signal
	 * @percentage: the new percentage
	 *
	 * The ::percentage-changed signal is emitted when the percentage changes.
	 **/
	signals [SIGNAL_PERCENTAGE_CHANGED] =
		g_signal_new ("percentage-changed",
			      G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (FuDfuTargetClass, percentage_changed),
			      NULL, NULL, g_cclosure_marshal_VOID__UINT,
			      G_TYPE_NONE, 1, G_TYPE_UINT);

	/**
	 * FuDfuTarget::action-changed:
	 * @device: the #FuDfuTarget instance that emitted the signal
	 * @action: the new FwupdStatus
	 *
	 * The ::action-changed signal is emitted when the high level action changes.
	 **/
	signals [SIGNAL_ACTION_CHANGED] =
		g_signal_new ("action-changed",
			      G_TYPE_FROM_CLASS (object_class), G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET (FuDfuTargetClass, action_changed),
			      NULL, NULL, g_cclosure_marshal_VOID__UINT,
			      G_TYPE_NONE, 1, G_TYPE_UINT);

	object_class->finalize = fu_dfu_target_finalize;
}

static void
fu_dfu_target_init (FuDfuTarget *self)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	priv->sectors = g_ptr_array_new_with_free_func ((GDestroyNotify) g_object_unref);
	priv->old_percentage = G_MAXUINT;
	priv->old_action = FWUPD_STATUS_IDLE;
}

static void
fu_dfu_target_finalize (GObject *object)
{
	FuDfuTarget *self = FU_DFU_TARGET (object);
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);

	g_free (priv->alt_name);
	g_free (priv->alt_name_for_display);
	g_ptr_array_unref (priv->sectors);

	/* we no longer care */
	if (priv->device != NULL) {
		g_object_remove_weak_pointer (G_OBJECT (priv->device),
					      (gpointer *) &priv->device);
	}

	G_OBJECT_CLASS (fu_dfu_target_parent_class)->finalize (object);
}

void
fu_dfu_target_to_string (FuDfuTarget *self, guint idt, GString *str)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	fu_common_string_append_kx (str, idt, "AltSetting", priv->alt_setting);
	fu_common_string_append_kx (str, idt, "AltIdx", priv->alt_idx);
	fu_common_string_append_kv (str, idt, "AltName", priv->alt_name);
	if (priv->alt_name_for_display != NULL) {
		fu_common_string_append_kv (str, idt, "AltNameForDisplay",
					    priv->alt_name_for_display);
	}
	for (guint i = 0; i < priv->sectors->len; i++) {
		FuDfuSector *sector = g_ptr_array_index (priv->sectors, i);
		g_autofree gchar *tmp1 = g_strdup_printf ("Idx%02x", i);
		g_autofree gchar *tmp2 = fu_dfu_sector_to_string (sector);
		fu_common_string_append_kv (str, idt + 1, tmp1, tmp2);
	}
}

FuDfuSector *
fu_dfu_target_get_sector_for_addr (FuDfuTarget *self, guint32 addr)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);

	for (guint i = 0; i < priv->sectors->len; i++) {
		FuDfuSector *sector = g_ptr_array_index (priv->sectors, i);
		if (addr < fu_dfu_sector_get_address (sector))
			continue;
		if (addr > fu_dfu_sector_get_address (sector) +
				fu_dfu_sector_get_size (sector))
			continue;
		return sector;
	}
	return NULL;
}

static gboolean
fu_dfu_target_parse_sector (FuDfuTarget *self,
			    const gchar *dfuse_sector_id,
			    guint32 *addr,
			    guint16 zone,
			    guint16 number,
			    GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	FuDfuSectorCap cap = DFU_SECTOR_CAP_NONE;
	gchar *tmp;
	guint32 addr_offset = 0;
	guint64 nr_sectors;
	guint64 sector_size;

	/* parse # of sectors */
	nr_sectors = g_ascii_strtoull (dfuse_sector_id, &tmp, 10);
	if (nr_sectors > 999) {
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "Invalid number of sectors: %s",
			     dfuse_sector_id);
		return FALSE;
	}

	/* check this is the delimiter */
	if (tmp[0] != '*') {
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "Invalid sector ID: %s",
			     dfuse_sector_id);
		return FALSE;
	}

	/* parse sector size */
	sector_size = g_ascii_strtoull (tmp + 1, &tmp, 10);
	if (sector_size > 999) {
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "Invalid sector size: %s",
			     dfuse_sector_id);
		return FALSE;
	}

	/* handle weirdness */
	if (fu_device_has_custom_flag (FU_DEVICE (fu_dfu_target_get_device (self)),
				       "absent-sector-size")) {
		if (tmp[1] == '\0') {
			tmp[1] = tmp[0];
			tmp[0] = 'B';
		}
	}

	/* get multiplier */
	switch (tmp[0]) {
	case 'B':		/* byte */
	case ' ':		/* byte, ST reference bootloader :/ */
		break;
	case 'K':		/* Kilo */
		sector_size *= 0x400;
		break;
	case 'M':		/* Mega */
		sector_size *= 0x100000	;
		break;
	default:
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "Invalid sector multiplier: %s",
			     tmp);
		return FALSE;
	}

	/* get sector type */
	switch (tmp[1]) {
	case 'a':
		cap = DFU_SECTOR_CAP_READABLE;
		break;
	case 'b':
		cap = DFU_SECTOR_CAP_ERASEABLE;
		break;
	case 'c':
		cap = DFU_SECTOR_CAP_READABLE |
		      DFU_SECTOR_CAP_ERASEABLE;
		break;
	case 'd':
		cap = DFU_SECTOR_CAP_WRITEABLE;
		break;
	case 'e':
		cap = DFU_SECTOR_CAP_READABLE |
		      DFU_SECTOR_CAP_WRITEABLE;
		break;
	case 'f':
		cap = DFU_SECTOR_CAP_ERASEABLE |
		      DFU_SECTOR_CAP_WRITEABLE;
		break;
	case 'g':
		cap = DFU_SECTOR_CAP_READABLE |
		      DFU_SECTOR_CAP_ERASEABLE |
		      DFU_SECTOR_CAP_WRITEABLE;
		break;
	default:
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "Invalid sector type: %s",
			     tmp);
		return FALSE;
	}

	/* add all the sectors */
	for (guint i = 0; i < nr_sectors; i++) {
		FuDfuSector *sector;
		sector = fu_dfu_sector_new (*addr + addr_offset,
					 (guint32) sector_size,
					 (guint32) ((nr_sectors * sector_size) - addr_offset),
					 zone,
					 number,
					 cap);
		g_ptr_array_add (priv->sectors, sector);
		addr_offset += fu_dfu_sector_get_size (sector);
	}

	/* update for next sector */
	*addr += addr_offset;
	return TRUE;
}

gboolean
fu_dfu_target_parse_sectors (FuDfuTarget *self, const gchar *alt_name, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_auto(GStrv) zones = NULL;

	/* not set */
	if (alt_name == NULL)
		return TRUE;

	/* From the Neo Freerunner */
	if (g_str_has_prefix (alt_name, "RAM 0x")) {
		FuDfuSector *sector;
		guint64 addr_tmp;
		addr_tmp = g_ascii_strtoull (alt_name + 6, NULL, 16);
		if (addr_tmp == 0 || addr_tmp > G_MAXUINT32)
			return FALSE;
		g_debug ("RAM description, so parsing");
		sector = fu_dfu_sector_new ((guint32) addr_tmp,
					 0x0, /* size */
					 0x0, /* size_left */
					 0x0, /* zone */
					 0x0, /* number */
					 DFU_SECTOR_CAP_ERASEABLE |
					 DFU_SECTOR_CAP_READABLE |
					 DFU_SECTOR_CAP_WRITEABLE);
		g_ptr_array_add (priv->sectors, sector);
	}

	/* not a DfuSe alternative name */
	if (alt_name[0] != '@')
		return TRUE;

	/* clear any existing zones */
	g_ptr_array_set_size (priv->sectors, 0);

	/* parse zones */
	zones = g_strsplit (alt_name, "/", -1);
	g_free (priv->alt_name_for_display);
	priv->alt_name_for_display = g_strdup (g_strchomp (zones[0] + 1));
	for (guint i = 1; zones[i] != NULL; i += 2) {
		guint32 addr;
		guint64 addr_tmp;
		g_auto(GStrv) sectors = NULL;

		/* parse address */
		if (!g_str_has_prefix (zones[i], "0x")) {
			g_set_error_literal (error,
					     FWUPD_ERROR,
					     FWUPD_ERROR_NOT_SUPPORTED,
					     "No sector address");
			return FALSE;
		}
		addr_tmp = g_ascii_strtoull (zones[i] + 2, NULL, 16);
		if (addr_tmp > G_MAXUINT32) {
			g_set_error_literal (error,
					     FWUPD_ERROR,
					     FWUPD_ERROR_NOT_SUPPORTED,
					     "Sector address too large");
			return FALSE;
		}
		addr = (guint32) addr_tmp;

		/* no sectors?! */
		if (zones[i+1] == NULL) {
			g_set_error_literal (error,
					     FWUPD_ERROR,
					     FWUPD_ERROR_NOT_SUPPORTED,
					     "No sector section");
			return FALSE;
		}

		/* parse sectors */
		sectors = g_strsplit (zones[i+1], ",", -1);
		for (guint16 j = 0; sectors[j] != NULL; j++) {
			if (!fu_dfu_target_parse_sector (self,
							 sectors[j],
							 &addr,
							 (i - 1) / 2, j,
							 error)) {
				g_prefix_error (error,
						"Failed to parse: '%s': ",
						sectors[j]);
				return FALSE;
			}
		}
	}

	/* success */
	return TRUE;
}

/**
 * fu_dfu_target_new: (skip)
 *
 * Creates a new DFU target, which represents an alt-setting on a
 * DFU-capable device.
 *
 * Return value: a #FuDfuTarget
 **/
FuDfuTarget *
fu_dfu_target_new (void)
{
	FuDfuTarget *self;
	self = g_object_new (FU_TYPE_DFU_TARGET, NULL);
	return self;
}

/**
 * fu_dfu_target_get_sectors:
 * @self: a #FuDfuTarget
 *
 * Gets the sectors exported by the target.
 *
 * Return value: (transfer none) (element-type FuDfuSector): sectors
 **/
GPtrArray *
fu_dfu_target_get_sectors (FuDfuTarget *self)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_return_val_if_fail (FU_IS_DFU_TARGET (self), NULL);
	return priv->sectors;
}

/**
 * fu_dfu_target_get_sector_default:
 * @self: a #FuDfuTarget
 *
 * Gets the default (first) sector exported by the target.
 *
 * Return value: (transfer none): a #FuDfuSector, or %NULL
 **/
FuDfuSector *
fu_dfu_target_get_sector_default (FuDfuTarget *self)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_return_val_if_fail (FU_IS_DFU_TARGET (self), NULL);
	if (priv->sectors->len == 0)
		return NULL;
	return FU_DFU_SECTOR (g_ptr_array_index (priv->sectors, 0));
}

/**
 * fu_dfu_target_status_to_error_msg:
 * @status: a #FuDfuStatus, e.g. %FU_DFU_STATUS_ERR_ERASE
 *
 * Converts an enumerated value to an error description.
 *
 * Return value: a string
 **/
static const gchar *
fu_dfu_target_status_to_error_msg (FuDfuStatus status)
{
	if (status == FU_DFU_STATUS_OK)
		return "No error condition is present";
	if (status == FU_DFU_STATUS_ERR_TARGET)
		return "Firmware is not for designed this device";
	if (status == FU_DFU_STATUS_ERR_FILE)
		return "Firmware is for this device but fails verification";
	if (status == FU_DFU_STATUS_ERR_WRITE)
		return "Device is unable to write memory";
	if (status == FU_DFU_STATUS_ERR_ERASE)
		return "Memory erase function failed";
	if (status == FU_DFU_STATUS_ERR_CHECK_ERASED)
		return "Memory erase check failed";
	if (status == FU_DFU_STATUS_ERR_PROG)
		return "Program memory function failed";
	if (status == FU_DFU_STATUS_ERR_VERIFY)
		return "Programmed memory failed verification";
	if (status == FU_DFU_STATUS_ERR_ADDRESS)
		return "Cannot program memory due to address out of range";
	if (status == FU_DFU_STATUS_ERR_NOTDONE)
		return "Received zero-length download but data is incomplete";
	if (status == FU_DFU_STATUS_ERR_FIRMWARE)
		return "Device firmware is corrupt";
	if (status == FU_DFU_STATUS_ERR_VENDOR)
		return "Vendor-specific error";
	if (status == FU_DFU_STATUS_ERR_USBR)
		return "Device detected unexpected USB reset signaling";
	if (status == FU_DFU_STATUS_ERR_POR)
		return "Device detected unexpected power on reset";
	if (status == FU_DFU_STATUS_ERR_UNKNOWN)
		return "Something unexpected went wrong";
	if (status == FU_DFU_STATUS_ERR_STALLDPKT)
		return "Device stalled an unexpected request";
	return NULL;
}

static gboolean
fu_dfu_target_manifest_wait (FuDfuTarget *self, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	guint polling_count = 0;

	/* get the status */
	if (!fu_dfu_device_refresh (priv->device, error))
		return FALSE;

	/* wait for FU_DFU_STATE_DFU_MANIFEST to not be set */
	while (fu_dfu_device_get_state (priv->device) == FU_DFU_STATE_DFU_MANIFEST_SYNC ||
	       fu_dfu_device_get_state (priv->device) == FU_DFU_STATE_DFU_MANIFEST) {
		g_debug ("waiting for FU_DFU_STATE_DFU_MANIFEST to clear");

		if (polling_count++ > DFU_TARGET_MANIFEST_MAX_POLLING_TRIES) {
			g_set_error_literal (error,
					     FWUPD_ERROR,
					     FWUPD_ERROR_INTERNAL,
					     "reach to max polling tries");
			return FALSE;
		}

		g_usleep ((fu_dfu_device_get_download_timeout (priv->device) + 1000) * 1000);
		if (!fu_dfu_device_refresh (priv->device, error))
			return FALSE;
	}

	/* in an error state */
	if (fu_dfu_device_get_state (priv->device) == FU_DFU_STATE_DFU_ERROR) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_INTERNAL,
				     fu_dfu_target_status_to_error_msg (fu_dfu_device_get_status (priv->device)));
		return FALSE;
	}

	return TRUE;
}

gboolean
fu_dfu_target_check_status (FuDfuTarget *self, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	FuDfuStatus status;
	g_autoptr(GTimer) timer = g_timer_new ();

	/* get the status */
	if (!fu_dfu_device_refresh (priv->device, error))
		return FALSE;

	/* wait for dfuDNBUSY to not be set */
	while (fu_dfu_device_get_state (priv->device) == FU_DFU_STATE_DFU_DNBUSY) {
		g_debug ("waiting for FU_DFU_STATE_DFU_DNBUSY to clear");
		g_usleep (fu_dfu_device_get_download_timeout (priv->device) * 1000);
		if (!fu_dfu_device_refresh (priv->device, error))
			return FALSE;
		/* this is a really long time to save fwupd in case
		 * the device has got wedged */
		if (g_timer_elapsed (timer, NULL) > 120.f) {
			g_set_error_literal (error,
					     FWUPD_ERROR,
					     FWUPD_ERROR_INTERNAL,
					     "Stuck in DFU_DNBUSY");
			return FALSE;
		}
	}

	/* not in an error state */
	if (fu_dfu_device_get_state (priv->device) != FU_DFU_STATE_DFU_ERROR)
		return TRUE;

	/* STM32-specific long errors */
	status = fu_dfu_device_get_status (priv->device);
	if (fu_dfu_device_get_version (priv->device) == DFU_VERSION_DFUSE) {
		if (status == FU_DFU_STATUS_ERR_VENDOR) {
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "Read protection is active");
			return FALSE;
		}
		if (status == FU_DFU_STATUS_ERR_TARGET) {
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "Address is wrong or unsupported");
			return FALSE;
		}
	}

	/* use a proper error description */
	g_set_error_literal (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     fu_dfu_target_status_to_error_msg (status));
	return FALSE;
}

/**
 * fu_dfu_target_use_alt_setting:
 * @self: a #FuDfuTarget
 * @error: a #GError, or %NULL
 *
 * Opens a DFU-capable target.
 *
 * Return value: %TRUE for success
 **/
static gboolean
fu_dfu_target_use_alt_setting (FuDfuTarget *self, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	GUsbDevice *usb_device = fu_usb_device_get_dev (FU_USB_DEVICE (priv->device));
	g_autoptr(GError) error_local = NULL;

	g_return_val_if_fail (FU_IS_DFU_TARGET (self), FALSE);
	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

	/* ensure interface is claimed */
	if (!fu_dfu_device_ensure_interface (priv->device, error))
		return FALSE;

	/* use the correct setting */
	if (fu_device_has_flag (FU_DEVICE (priv->device), FWUPD_DEVICE_FLAG_IS_BOOTLOADER)) {
		if (!g_usb_device_set_interface_alt (usb_device,
						     (gint) fu_dfu_device_get_interface (priv->device),
						     (gint) priv->alt_setting,
						     &error_local)) {
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "cannot set alternate setting 0x%02x on interface %i: %s",
				     priv->alt_setting,
				     fu_dfu_device_get_interface (priv->device),
				     error_local->message);
			return FALSE;
		}
	}

	return TRUE;
}

void
fu_dfu_target_set_alt_name (FuDfuTarget *self, const gchar *alt_name)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);

	/* not changed */
	if (g_strcmp0 (priv->alt_name, alt_name) == 0)
		return;

	g_free (priv->alt_name);
	priv->alt_name = g_strdup (alt_name);
}

void
fu_dfu_target_set_device (FuDfuTarget *self, FuDfuDevice *device)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_set_object (&priv->device, device);

	/* if we try to ref the target and destroy the device */
	g_object_add_weak_pointer (G_OBJECT (priv->device),
				   (gpointer *) &priv->device);
}

/**
 * fu_dfu_target_setup:
 * @self: a #FuDfuTarget
 * @error: a #GError, or %NULL
 *
 * Opens a DFU-capable target.
 *
 * Return value: %TRUE for success
 **/
gboolean
fu_dfu_target_setup (FuDfuTarget *self, GError **error)
{
	FuDfuTargetClass *klass = FU_DFU_TARGET_GET_CLASS (self);
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	FuDevice *device = FU_DEVICE (fu_dfu_target_get_device (self));

	g_return_val_if_fail (FU_IS_DFU_TARGET (self), FALSE);
	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

	/* already done */
	if (priv->done_setup)
		return TRUE;

	/* superclassed */
	if (klass->setup != NULL) {
		if (!klass->setup (self,error))
			return FALSE;
	}

	/* GD32VF103 devices features and peripheral list */
	if (priv->alt_setting == 0x0 &&
	    fu_device_has_custom_flag (device, "gd32")) {
		/*             RB R8 R6 R4  VB V8
		 * Flash (KB) 128 64 32 16 128 64
		 *             TB T8 T6 T4  CB C8 C6 C4
		 * Flash (KB) 128 64 32 16 128 64 32 16
		 */
		const gchar *serial = fu_device_get_serial (device);
		if (serial == NULL || strlen (serial) < 4 || serial[3] != 'J') {
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "GD32 serial number %s invalid",
				     serial);
			return FALSE;
		}
		if (serial[2] == '2') {
			fu_dfu_target_set_alt_name (self, "@Internal Flash  /0x8000000/8*1Kg");
		} else if (serial[2] == '4') {
			fu_dfu_target_set_alt_name (self, "@Internal Flash  /0x8000000/16*1Kg");
		} else if (serial[2] == '6') {
			fu_dfu_target_set_alt_name (self, "@Internal Flash  /0x8000000/32*1Kg");
		} else if (serial[2] == '8') {
			fu_dfu_target_set_alt_name (self, "@Internal Flash  /0x8000000/64*1Kg");
		} else if (serial[2] == 'B') {
			fu_dfu_target_set_alt_name (self, "@Internal Flash  /0x8000000/128*1Kg");
		} else if (serial[2] == 'D') {
			fu_dfu_target_set_alt_name (self, "@Internal Flash  /0x8000000/256*1Kg");
		} else {
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "Unknown GD32 sector size: %c",
				     serial[2]);
			return FALSE;
		}
	}

	/* get string */
	if (priv->alt_idx != 0x00 && priv->alt_name == NULL) {
		GUsbDevice *usb_device = fu_usb_device_get_dev (FU_USB_DEVICE (priv->device));
		priv->alt_name =
			g_usb_device_get_string_descriptor (usb_device,
							    priv->alt_idx,
							    NULL);
	}

	/* parse the DfuSe format according to UM0424 */
	if (priv->sectors->len == 0) {
		if (!fu_dfu_target_parse_sectors (self, priv->alt_name, error))
			return FALSE;
	}

	/* add a dummy entry */
	if (priv->sectors->len == 0) {
		FuDfuSector *sector;
		sector = fu_dfu_sector_new (0x0, /* addr */
					 0x0, /* size */
					 0x0, /* size_left */
					 0x0, /* zone */
					 0x0, /* number */
					 DFU_SECTOR_CAP_READABLE |
					 DFU_SECTOR_CAP_WRITEABLE);
		g_debug ("no UM0424 sector description in %s", priv->alt_name);
		g_ptr_array_add (priv->sectors, sector);
	}

	priv->done_setup = TRUE;
	return TRUE;
}

/**
 * fu_dfu_target_mass_erase:
 * @self: a #FuDfuTarget
 * @error: a #GError, or %NULL
 *
 * Mass erases the device clearing all SRAM and EEPROM memory.
 *
 * IMPORTANT: This only works on STM32 devices from ST and AVR32 devices from Atmel.
 *
 * Return value: %TRUE for success
 **/
gboolean
fu_dfu_target_mass_erase (FuDfuTarget *self, GError **error)
{
	FuDfuTargetClass *klass = FU_DFU_TARGET_GET_CLASS (self);
	if (!fu_dfu_target_setup (self,error))
		return FALSE;
	if (klass->mass_erase == NULL) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "mass erase not supported");
		return FALSE;
	}
	return klass->mass_erase (self,error);
}

gboolean
fu_dfu_target_download_chunk (FuDfuTarget *self, guint16 index, GBytes *bytes, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	GUsbDevice *usb_device = fu_usb_device_get_dev (FU_USB_DEVICE (priv->device));
	g_autoptr(GError) error_local = NULL;
	gsize actual_length;

	/* low level packet debugging */
	if (g_getenv ("FWUPD_DFU_VERBOSE") != NULL)
		fu_common_dump_bytes (G_LOG_DOMAIN, "Message", bytes);

	if (!g_usb_device_control_transfer (usb_device,
					    G_USB_DEVICE_DIRECTION_HOST_TO_DEVICE,
					    G_USB_DEVICE_REQUEST_TYPE_CLASS,
					    G_USB_DEVICE_RECIPIENT_INTERFACE,
					    FU_DFU_REQUEST_DNLOAD,
					    index,
					    fu_dfu_device_get_interface (priv->device),
					    (guint8 *) g_bytes_get_data (bytes, NULL),
					    g_bytes_get_size (bytes),
					    &actual_length,
					    fu_dfu_device_get_timeout (priv->device),
					    NULL,
					    &error_local)) {
		/* refresh the error code */
		fu_dfu_device_error_fixup (priv->device, &error_local);
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "cannot download data: %s",
			     error_local->message);
		return FALSE;
	}

	/* for STM32 devices, the action only occurs when we do GetStatus */
	if (fu_dfu_device_get_version (priv->device) == DFU_VERSION_DFUSE) {
		if (!fu_dfu_device_refresh (priv->device, error))
			return FALSE;
	}

	/* wait for the device to write contents to the EEPROM */
	if (g_bytes_get_size (bytes) == 0 &&
	    fu_dfu_device_get_download_timeout (priv->device) > 0) {
		fu_dfu_target_set_action (self,FWUPD_STATUS_IDLE);
		fu_dfu_target_set_action (self,FWUPD_STATUS_DEVICE_BUSY);
	}
	if (fu_dfu_device_get_download_timeout (priv->device) > 0) {
		g_debug ("sleeping for %ums…",
			 fu_dfu_device_get_download_timeout (priv->device));
		g_usleep (fu_dfu_device_get_download_timeout (priv->device) * 1000);
	}

	/* find out if the write was successful, waiting for BUSY to clear */
	if (!fu_dfu_target_check_status (self,error))
		return FALSE;

	g_assert (actual_length == g_bytes_get_size (bytes));
	return TRUE;
}

GBytes *
fu_dfu_target_upload_chunk (FuDfuTarget *self, guint16 index, gsize buf_sz, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	GUsbDevice *usb_device = fu_usb_device_get_dev (FU_USB_DEVICE (priv->device));
	g_autoptr(GError) error_local = NULL;
	guint8 *buf;
	gsize actual_length;

	/* unset */
	if (buf_sz == 0)
		buf_sz = (gsize) fu_dfu_device_get_transfer_size (priv->device);

	buf = g_new0 (guint8, buf_sz);
	if (!g_usb_device_control_transfer (usb_device,
					    G_USB_DEVICE_DIRECTION_DEVICE_TO_HOST,
					    G_USB_DEVICE_REQUEST_TYPE_CLASS,
					    G_USB_DEVICE_RECIPIENT_INTERFACE,
					    FU_DFU_REQUEST_UPLOAD,
					    index,
					    fu_dfu_device_get_interface (priv->device),
					    buf, buf_sz,
					    &actual_length,
					    fu_dfu_device_get_timeout (priv->device),
					    NULL,
					    &error_local)) {
		/* refresh the error code */
		fu_dfu_device_error_fixup (priv->device, &error_local);
		g_set_error (error,
			     FWUPD_ERROR,
			     FWUPD_ERROR_NOT_SUPPORTED,
			     "cannot upload data: %s",
			     error_local->message);
		return NULL;
	}

	/* low level packet debugging */
	if (g_getenv ("FWUPD_DFU_VERBOSE") != NULL)
		fu_common_dump_raw (G_LOG_DOMAIN, "Message", buf, actual_length);

	return g_bytes_new_take (buf, actual_length);
}

void
fu_dfu_target_set_alt_idx (FuDfuTarget *self, guint8 alt_idx)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	priv->alt_idx = alt_idx;
}

void
fu_dfu_target_set_alt_setting (FuDfuTarget *self, guint8 alt_setting)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	priv->alt_setting = alt_setting;
}

void
fu_dfu_target_set_action (FuDfuTarget *self, FwupdStatus action)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);

	/* unchanged */
	if (priv->old_action == action)
		return;
	if (priv->old_action != FWUPD_STATUS_IDLE &&
	    action != FWUPD_STATUS_IDLE) {
		g_debug ("ignoring action %s as %s already set and not idle",
			 fwupd_status_to_string (action),
			 fwupd_status_to_string (priv->old_action));
		return;
	}
	g_debug ("setting action %s", fwupd_status_to_string (action));
	g_signal_emit (self,signals[SIGNAL_ACTION_CHANGED], 0, action);
	priv->old_action = action;
}

FuDfuDevice *
fu_dfu_target_get_device (FuDfuTarget *self)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	return priv->device;
}

void
fu_dfu_target_set_percentage_raw (FuDfuTarget *self, guint percentage)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	if (percentage == priv->old_percentage)
		return;
	g_debug ("setting percentage %u%% of %s",
		 percentage, fwupd_status_to_string (priv->old_action));
	g_signal_emit (self,
		       signals[SIGNAL_PERCENTAGE_CHANGED],
		       0, percentage);
	priv->old_percentage = percentage;
}

void
fu_dfu_target_set_percentage (FuDfuTarget *self, guint value, guint total)
{
	guint percentage;

	g_return_if_fail (total > 0);

	percentage = (value * 100) / total;
	if (percentage >= 100)
		return;
	fu_dfu_target_set_percentage_raw (self, percentage);
}

gboolean
fu_dfu_target_attach (FuDfuTarget *self, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	FuDfuTargetClass *klass = FU_DFU_TARGET_GET_CLASS (self);

	/* ensure populated */
	if (!fu_dfu_target_setup (self, error))
		return FALSE;

	/* implemented as part of a superclass */
	if (klass->attach != NULL)
		return klass->attach (self, error);

	/* normal DFU mode just needs a bus reset */
	return fu_dfu_device_reset (priv->device, error);
}

static FuChunk *
fu_dfu_target_upload_element_dfu (FuDfuTarget *self,
				  guint32 address,
				  gsize expected_size,
				  gsize maximum_size,
				  GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	GBytes *chunk_tmp;
	guint32 offset = 0;
	guint percentage_size = expected_size > 0 ? expected_size : maximum_size;
	gsize total_size = 0;
	guint16 transfer_size = fu_dfu_device_get_transfer_size (priv->device);
	g_autoptr(GBytes) contents = NULL;
	g_autoptr(GPtrArray) chunks = NULL;

	/* update UI */
	fu_dfu_target_set_action (self, FWUPD_STATUS_DEVICE_READ);

	/* get all the chunks from the hardware */
	chunks = g_ptr_array_new_with_free_func ((GDestroyNotify) g_bytes_unref);
	for (guint16 idx = 0; idx < G_MAXUINT16; idx++) {
		guint32 chunk_size;

		/* read chunk of data */
		chunk_tmp = fu_dfu_target_upload_chunk (self,
							idx,
							0, /* device transfer size */
							error);
		if (chunk_tmp == NULL)
			return NULL;

		/* keep a sum of all the chunks */
		chunk_size = (guint32) g_bytes_get_size (chunk_tmp);
		total_size += chunk_size;
		offset += chunk_size;

		/* add to array */
		g_debug ("got #%04x chunk of size %" G_GUINT32_FORMAT,
			 idx, chunk_size);
		g_ptr_array_add (chunks, chunk_tmp);

		/* update UI */
		if (chunk_size > 0)
			fu_dfu_target_set_percentage (self, total_size, percentage_size);

		/* detect short write as EOF */
		if (chunk_size < transfer_size)
			break;
	}

	/* check final size */
	if (expected_size > 0) {
		if (total_size != expected_size) {
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_INVALID_FILE,
				     "invalid size, got %" G_GSIZE_FORMAT ", "
				     "expected %" G_GSIZE_FORMAT ,
				     total_size, expected_size);
			return NULL;
		}
	}

	/* done */
	fu_dfu_target_set_percentage_raw (self, 100);
	fu_dfu_target_set_action (self, FWUPD_STATUS_IDLE);

	/* create new image */
	contents = fu_dfu_utils_bytes_join_array (chunks);
	return fu_chunk_bytes_new (contents);
}

static FuChunk *
fu_dfu_target_upload_element (FuDfuTarget *self,
			      guint32 address,
			      gsize expected_size,
			      gsize maximum_size,
			      GError **error)
{
	FuDfuTargetClass *klass = FU_DFU_TARGET_GET_CLASS (self);

	/* implemented as part of a superclass */
	if (klass->upload_element != NULL) {
		return klass->upload_element (self, address, expected_size,
					      maximum_size, error);
	}
	return fu_dfu_target_upload_element_dfu (self,
						 address,
						 expected_size,
						 maximum_size,
						 error);
}

static guint32
fu_dfu_target_get_size_of_zone (FuDfuTarget *self, guint16 zone)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	guint32 len = 0;
	for (guint i = 0; i < priv->sectors->len; i++) {
		FuDfuSector *sector = g_ptr_array_index (priv->sectors, i);
		if (fu_dfu_sector_get_zone (sector) != zone)
			continue;
		len += fu_dfu_sector_get_size (sector);
	}
	return len;
}

/* private */
gboolean
fu_dfu_target_upload (FuDfuTarget *self,
		      FuFirmware *firmware,
		      FuDfuTargetTransferFlags flags,
		      GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	FuDfuSector *sector;
	guint16 zone_cur;
	guint32 zone_size = 0;
	guint32 zone_last = G_MAXUINT;
	g_autoptr(FuFirmwareImage) image = NULL;

	g_return_val_if_fail (FU_IS_DFU_TARGET (self), FALSE);
	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

	/* ensure populated */
	if (!fu_dfu_target_setup (self, error))
		return FALSE;

	/* can the target do this? */
	if (!fu_dfu_device_can_upload (priv->device)) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "target cannot do uploading");
		return FALSE;
	}

	/* use correct alt */
	if (!fu_dfu_target_use_alt_setting (self, error))
		return FALSE;

	/* no open?! */
	if (priv->sectors->len == 0) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "no sectors defined for target");
		return FALSE;
	}

	/* create a new image */
	image = fu_firmware_image_new (NULL);
	fu_firmware_image_set_id (image, priv->alt_name);
	fu_firmware_image_set_idx (image, priv->alt_setting);

	/* get all the sectors for the device */
	for (guint i = 0; i < priv->sectors->len; i++) {
		g_autoptr(FuChunk) chk = NULL;

		/* only upload to the start of any zone:sector */
		sector = g_ptr_array_index (priv->sectors, i);
		zone_cur = fu_dfu_sector_get_zone (sector);
		if (zone_cur == zone_last)
			continue;

		/* get the size of the entire continuous zone */
		zone_size = fu_dfu_target_get_size_of_zone (self, zone_cur);
		zone_last = zone_cur;

		/* get the first element from the hardware */
		g_debug ("starting upload from 0x%08x (0x%04x)",
			 fu_dfu_sector_get_address (sector),
			 zone_size);
		chk = fu_dfu_target_upload_element (self,
						    fu_dfu_sector_get_address (sector),
						    0,		/* expected */
						    zone_size,	/* maximum */
						    error);
		if (chk == NULL)
			return FALSE;

		/* this chunk was uploaded okay */
		fu_firmware_image_add_chunk (image, chk);
	}

	/* success */
	fu_firmware_add_image (firmware, image);
	return TRUE;
}

static gchar *
_g_bytes_compare_verbose (GBytes *bytes1, GBytes *bytes2)
{
	const guint8 *data1;
	const guint8 *data2;
	gsize length1;
	gsize length2;

	data1 = g_bytes_get_data (bytes1, &length1);
	data2 = g_bytes_get_data (bytes2, &length2);

	/* not the same length */
	if (length1 != length2) {
		return g_strdup_printf ("got %" G_GSIZE_FORMAT " bytes, "
					"expected %" G_GSIZE_FORMAT,
					length1, length2);
	}

	/* return 00 01 02 03 */
	for (guint i = 0; i < length1; i++) {
		if (data1[i] != data2[i]) {
			return g_strdup_printf ("got 0x%02x, expected 0x%02x @ 0x%04x",
						data1[i], data2[i], i);
		}
	}
	return NULL;
}

static gboolean
fu_dfu_target_download_element_dfu (FuDfuTarget *self,
				    FuChunk *chk,
				    FuDfuTargetTransferFlags flags,
				    GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	guint32 nr_chunks;
	guint16 transfer_size = fu_dfu_device_get_transfer_size (priv->device);
	g_autoptr(GBytes) bytes = NULL;

	/* round up as we have to transfer incomplete blocks */
	bytes = fu_chunk_get_bytes (chk);
	nr_chunks = (guint) ceil ((gdouble) g_bytes_get_size (bytes) /
				  (gdouble) transfer_size);
	if (nr_chunks == 0) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_INVALID_FILE,
				     "zero-length firmware");
		return FALSE;
	}
	fu_dfu_target_set_action (self, FWUPD_STATUS_DEVICE_WRITE);
	for (guint32 i = 0; i < nr_chunks + 1; i++) {
		gsize length;
		guint32 offset;
		g_autoptr(GBytes) bytes_tmp = NULL;

		/* caclulate the offset into the chunk data */
		offset = i * transfer_size;

		/* we have to write one final zero-sized chunk for EOF */
		if (i < nr_chunks) {
			length = g_bytes_get_size (bytes) - offset;
			if (length > transfer_size)
				length = transfer_size;
			bytes_tmp = fu_common_bytes_new_offset (bytes,
								offset,
								length,
								error);
			if (bytes_tmp == NULL)
				return FALSE;
		} else {
			bytes_tmp = g_bytes_new (NULL, 0);
		}
		g_debug ("writing #%04x chunk of size %" G_GSIZE_FORMAT,
			 i, g_bytes_get_size (bytes_tmp));
		if (!fu_dfu_target_download_chunk (self, i, bytes_tmp, error))
			return FALSE;

		/* update UI */
		fu_dfu_target_set_percentage (self, offset, g_bytes_get_size (bytes));
	}

	/* done */
	fu_dfu_target_set_percentage_raw (self, 100);
	fu_dfu_target_set_action (self, FWUPD_STATUS_IDLE);

	/* success */
	return TRUE;
}

static gboolean
fu_dfu_target_download_element (FuDfuTarget *self,
				FuChunk *chk,
				FuDfuTargetTransferFlags flags,
				GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	FuDfuTargetClass *klass = FU_DFU_TARGET_GET_CLASS (self);

	/* implemented as part of a superclass */
	if (klass->download_element != NULL) {
		if (!klass->download_element (self, chk, flags, error))
			return FALSE;
	} else {
		if (!fu_dfu_target_download_element_dfu (self,
							 chk,
							 flags,
							 error))
			return FALSE;
	}

	/* verify */
	if (flags & DFU_TARGET_TRANSFER_FLAG_VERIFY &&
	    fu_dfu_device_has_attribute (priv->device, FU_DFU_DEVICE_ATTR_CAN_UPLOAD)) {
		g_autoptr(GBytes) bytes = NULL;
		g_autoptr(GBytes) bytes_tmp = NULL;
		g_autoptr(FuChunk) chunk_tmp = NULL;
		fu_dfu_target_set_action (self, FWUPD_STATUS_DEVICE_VERIFY);
		bytes = fu_chunk_get_bytes (chk);
		chunk_tmp = fu_dfu_target_upload_element (self,
							  fu_chunk_get_address (chk),
							  g_bytes_get_size (bytes),
							  g_bytes_get_size (bytes),
							  error);
		if (chunk_tmp == NULL)
			return FALSE;
		bytes_tmp = fu_chunk_get_bytes (chunk_tmp);
		if (g_bytes_compare (bytes_tmp, bytes) != 0) {
			g_autofree gchar *bytes_cmp_str = NULL;
			bytes_cmp_str = _g_bytes_compare_verbose (bytes_tmp, bytes);
			g_set_error (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_READ,
				     "verify failed: %s",
				     bytes_cmp_str);
			return FALSE;
		}
		fu_dfu_target_set_action (self, FWUPD_STATUS_IDLE);
	}

	return TRUE;
}

/**
 * fu_dfu_target_download:
 * @self: a #FuDfuTarget
 * @image: a #FuFirmwareImage
 * @flags: flags to use, e.g. %DFU_TARGET_TRANSFER_FLAG_VERIFY
 * @error: a #GError, or %NULL
 *
 * Downloads firmware from the host to the target, optionally verifying
 * the transfer.
 *
 * Return value: %TRUE for success
 **/
gboolean
fu_dfu_target_download (FuDfuTarget *self,
			FuFirmwareImage *image,
			FuDfuTargetTransferFlags flags,
			GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_autoptr(GPtrArray) chunks = NULL;

	g_return_val_if_fail (FU_IS_DFU_TARGET (self), FALSE);
	g_return_val_if_fail (FU_IS_FIRMWARE_IMAGE (image), FALSE);
	g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

	/* ensure populated */
	if (!fu_dfu_target_setup (self, error))
		return FALSE;

	/* can the target do this? */
	if (!fu_dfu_device_can_download (priv->device)) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_SUPPORTED,
				     "target cannot do downloading");
		return FALSE;
	}

	/* use correct alt */
	if (!fu_dfu_target_use_alt_setting (self, error))
		return FALSE;

	/* download all chunks in the image to the device */
	chunks = fu_firmware_image_get_chunks (image, error);
	if (chunks == NULL)
		return FALSE;
	if (chunks->len == 0) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_INVALID_FILE,
				     "no image chunks");
		return FALSE;
	}
	for (guint i = 0; i < chunks->len; i++) {
		FuChunk *chk = g_ptr_array_index (chunks, i);
		g_debug ("downloading chunk at 0x%04x",
			 fu_chunk_get_address (chk));

		/* auto-detect missing firmware address -- this assumes
		 * that the first target is the main program memory and that
		 * there is only one element in the firmware file */
		if (flags & DFU_TARGET_TRANSFER_FLAG_ADDR_HEURISTIC &&
		    fu_chunk_get_address (chk) == 0x0 &&
		    chunks->len == 1 &&
		    priv->sectors->len > 0) {
			FuDfuSector *sector = g_ptr_array_index (priv->sectors, 0);
			g_debug ("fixing up firmware address from 0x0 to 0x%x",
				 fu_dfu_sector_get_address (sector));
			fu_chunk_set_address (chk, fu_dfu_sector_get_address (sector));
		}

		/* download to device */
		if (!fu_dfu_target_download_element (self, chk, flags, error))
			return FALSE;
	}

	if (fu_device_has_custom_flag (FU_DEVICE (fu_dfu_target_get_device (self)), "manifest-poll") &&
	    fu_dfu_device_has_attribute (priv->device, FU_DFU_DEVICE_ATTR_MANIFEST_TOL))
		if (!fu_dfu_target_manifest_wait (self, error))
			return FALSE;

	/* success */
	return TRUE;
}

/**
 * fu_dfu_target_get_alt_setting:
 * @self: a #FuDfuTarget
 *
 * Gets the alternate setting to use for this interface.
 *
 * Return value: the alternative setting, typically zero
 **/
guint8
fu_dfu_target_get_alt_setting (FuDfuTarget *self)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_return_val_if_fail (FU_IS_DFU_TARGET (self), 0xff);
	return priv->alt_setting;
}

/**
 * fu_dfu_target_get_alt_name:
 * @self: a #FuDfuTarget
 * @error: a #GError, or %NULL
 *
 * Gets the alternate setting name to use for this interface.
 *
 * Return value: the alternative setting name, typically %NULL
 **/
const gchar *
fu_dfu_target_get_alt_name (FuDfuTarget *self, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_return_val_if_fail (FU_IS_DFU_TARGET (self), NULL);

	/* ensure populated */
	if (!fu_dfu_target_setup (self, error))
		return NULL;

	/* nothing */
	if (priv->alt_name == NULL) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_FOUND,
				     "no alt-name");
		return NULL;
	}

	return priv->alt_name;
}

/**
 * fu_dfu_target_get_alt_name_for_display:
 * @self: a #FuDfuTarget
 * @error: a #GError, or %NULL
 *
 * Gets the alternate setting name to use for this interface that can be
 * shown on the display.
 *
 * Return value: the alternative setting name
 **/
const gchar *
fu_dfu_target_get_alt_name_for_display (FuDfuTarget *self, GError **error)
{
	FuDfuTargetPrivate *priv = GET_PRIVATE (self);
	g_return_val_if_fail (FU_IS_DFU_TARGET (self), NULL);

	/* ensure populated */
	if (!fu_dfu_target_setup (self, error))
		return NULL;

	/* nothing */
	if (priv->alt_name_for_display == NULL) {
		g_set_error_literal (error,
				     FWUPD_ERROR,
				     FWUPD_ERROR_NOT_FOUND,
				     "no alt-name for display");
		return NULL;
	}

	return priv->alt_name_for_display;
}