+
+/**
+ * Find the nodes for a peripheral and return a list of them in the correct
+ * order. This is used to enumerate all the peripherals of a certain type.
+ *
+ * To use this, optionally set up a /aliases node with alias properties for
+ * a peripheral. For example, for usb you could have:
+ *
+ * aliases {
+ * usb0 = "/ehci@c5008000";
+ * usb1 = "/ehci@c5000000";
+ * };
+ *
+ * Pass "usb" as the name to this function and will return a list of two
+ * nodes offsets: /ehci@c5008000 and ehci@c5000000.
+ *
+ * All nodes returned will match the compatible ID, as it is assumed that
+ * all peripherals use the same driver.
+ *
+ * If no alias node is found, then the node list will be returned in the
+ * order found in the fdt. If the aliases mention a node which doesn't
+ * exist, then this will be ignored. If nodes are found with no aliases,
+ * they will be added in any order.
+ *
+ * If there is a gap in the aliases, then this function return a 0 node at
+ * that position. The return value will also count these gaps.
+ *
+ * This function checks node properties and will not return nodes which are
+ * marked disabled (status = "disabled").
+ *
+ * @param blob FDT blob to use
+ * @param name Root name of alias to search for
+ * @param id Compatible ID to look for
+ * @param node_list Place to put list of found nodes
+ * @param maxcount Maximum number of nodes to find
+ * @return number of nodes found on success, FTD_ERR_... on error
+ */
+int fdtdec_find_aliases_for_id(const void *blob, const char *name,
+ enum fdt_compat_id id, int *node_list, int maxcount);
+
+/*
+ * This function is similar to fdtdec_find_aliases_for_id() except that it
+ * adds to the node_list that is passed in. Any 0 elements are considered
+ * available for allocation - others are considered already used and are
+ * skipped.
+ *
+ * You can use this by calling fdtdec_find_aliases_for_id() with an
+ * uninitialised array, then setting the elements that are returned to -1,
+ * say, then calling this function, perhaps with a different compat id.
+ * Any elements you get back that are >0 are new nodes added by the call
+ * to this function.
+ *
+ * Note that if you have some nodes with aliases and some without, you are
+ * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
+ * one compat_id may fill in positions for which you have aliases defined
+ * for another compat_id. When you later call *this* function with the second
+ * compat_id, the alias positions may already be used. A debug warning may
+ * be generated in this case, but it is safest to define aliases for all
+ * nodes when you care about the ordering.
+ */
+int fdtdec_add_aliases_for_id(const void *blob, const char *name,
+ enum fdt_compat_id id, int *node_list, int maxcount);
+
+/*
+ * Get the name for a compatible ID
+ *
+ * @param id Compatible ID to look for
+ * @return compatible string for that id
+ */
+const char *fdtdec_get_compatible(enum fdt_compat_id id);
+
+/* Look up a phandle and follow it to its node. Then return the offset
+ * of that node.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return node offset if found, -ve error code on error
+ */
+int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
+
+/**
+ * Look up a property in a node and return its contents in an integer
+ * array of given length. The property must have at least enough data for
+ * the array (4*count bytes). It may have more, but this will be ignored.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param array array to fill with data
+ * @param count number of array elements
+ * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
+ * or -FDT_ERR_BADLAYOUT if not enough data
+ */
+int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
+ u32 *array, int count);
+
+/**
+ * Look up a property in a node and return a pointer to its contents as a
+ * unsigned int array of given length. The property must have at least enough
+ * data for the array ('count' cells). It may have more, but this will be
+ * ignored. The data is not copied.
+ *
+ * Note that you must access elements of the array with fdt32_to_cpu(),
+ * since the elements will be big endian even on a little endian machine.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param count number of array elements
+ * @return pointer to array if found, or NULL if the property is not
+ * found or there is not enough data
+ */
+const u32 *fdtdec_locate_array(const void *blob, int node,
+ const char *prop_name, int count);
+
+/**
+ * Look up a boolean property in a node and return it.
+ *
+ * A boolean properly is true if present in the device tree and false if not
+ * present, regardless of its value.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return 1 if the properly is present; 0 if it isn't present
+ */
+int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
+
+/**
+ * Decode a single GPIOs from an FDT.
+ *
+ * If the property is not found, then the GPIO structure will still be
+ * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
+ * provide optional GPIOs.
+ *
+ * @param blob FDT blob to use
+ * @param node Node to look at
+ * @param prop_name Node property name
+ * @param gpio gpio elements to fill from FDT
+ * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
+ */
+int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
+ struct fdt_gpio_state *gpio);
+
+/**
+ * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
+ * terminating item.
+ *
+ * @param blob FDT blob to use
+ * @param node Node to look at
+ * @param prop_name Node property name
+ * @param gpio Array of gpio elements to fill from FDT. This will be
+ * untouched if either 0 or an error is returned
+ * @param max_count Maximum number of elements allowed
+ * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
+ * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
+ */
+int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
+ struct fdt_gpio_state *gpio, int max_count);
+
+/**
+ * Set up a GPIO pin according to the provided gpio information. At present this
+ * just requests the GPIO.
+ *
+ * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
+ * deal with optional GPIOs.
+ *
+ * @param gpio GPIO info to use for set up
+ * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
+ */
+int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
+
+/**
+ * Look in the FDT for a config item with the given name and return its value
+ * as a 32-bit integer. The property must have at least 4 bytes of data. The
+ * value of the first cell is returned.
+ *
+ * @param blob FDT blob to use
+ * @param prop_name Node property name
+ * @param default_val default value to return if the property is not found
+ * @return integer value, if found, or default_val if not
+ */
+int fdtdec_get_config_int(const void *blob, const char *prop_name,
+ int default_val);
+
+/**
+ * Look in the FDT for a config item with the given name
+ * and return whether it exists.
+ *
+ * @param blob FDT blob
+ * @param prop_name property name to look up
+ * @return 1, if it exists, or 0 if not
+ */
+int fdtdec_get_config_bool(const void *blob, const char *prop_name);
+
+/**
+ * Look in the FDT for a config item with the given name and return its value
+ * as a string.
+ *
+ * @param blob FDT blob
+ * @param prop_name property name to look up
+ * @returns property string, NULL on error.
+ */
+char *fdtdec_get_config_string(const void *blob, const char *prop_name);
+
+/*
+ * Look up a property in a node and return its contents in a byte
+ * array of given length. The property must have at least enough data for
+ * the array (count bytes). It may have more, but this will be ignored.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param array array to fill with data
+ * @param count number of array elements
+ * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
+ * or -FDT_ERR_BADLAYOUT if not enough data
+ */
+int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
+ u8 *array, int count);
+
+/**
+ * Look up a property in a node and return a pointer to its contents as a
+ * byte array of given length. The property must have at least enough data
+ * for the array (count bytes). It may have more, but this will be ignored.
+ * The data is not copied.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param count number of array elements
+ * @return pointer to byte array if found, or NULL if the property is not
+ * found or there is not enough data
+ */
+const u8 *fdtdec_locate_byte_array(const void *blob, int node,
+ const char *prop_name, int count);
+
+/**
+ * Look up a property in a node which contains a memory region address and
+ * size. Then return a pointer to this address.
+ *
+ * The property must hold one address with a length. This is only tested on
+ * 32-bit machines.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param ptrp returns pointer to region, or NULL if no address
+ * @param size returns size of region
+ * @return 0 if ok, -1 on error (propery not found)
+ */
+int fdtdec_decode_region(const void *blob, int node,
+ const char *prop_name, void **ptrp, size_t *size);
+#endif