summaryrefslogtreecommitdiff
path: root/include/fdtdec.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/fdtdec.h')
-rw-r--r--include/fdtdec.h1217
1 files changed, 1217 insertions, 0 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h
new file mode 100644
index 0000000..f1e58f9
--- /dev/null
+++ b/include/fdtdec.h
@@ -0,0 +1,1217 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ */
+
+#ifndef __fdtdec_h
+#define __fdtdec_h
+
+/*
+ * This file contains convenience functions for decoding useful and
+ * enlightening information from FDTs. It is intended to be used by device
+ * drivers and board-specific code within U-Boot. It aims to reduce the
+ * amount of FDT munging required within U-Boot itself, so that driver code
+ * changes to support FDT are minimized.
+ */
+
+#include <linux/libfdt.h>
+#include <pci.h>
+
+/*
+ * A typedef for a physical address. Note that fdt data is always big
+ * endian even on a litle endian machine.
+ */
+typedef phys_addr_t fdt_addr_t;
+typedef phys_size_t fdt_size_t;
+
+#ifdef CONFIG_PHYS_64BIT
+#define FDT_ADDR_T_NONE (-1U)
+#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
+#define fdt_size_to_cpu(reg) be64_to_cpu(reg)
+#define cpu_to_fdt_addr(reg) cpu_to_be64(reg)
+#define cpu_to_fdt_size(reg) cpu_to_be64(reg)
+typedef fdt64_t fdt_val_t;
+#else
+#define FDT_ADDR_T_NONE (-1U)
+#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
+#define fdt_size_to_cpu(reg) be32_to_cpu(reg)
+#define cpu_to_fdt_addr(reg) cpu_to_be32(reg)
+#define cpu_to_fdt_size(reg) cpu_to_be32(reg)
+typedef fdt32_t fdt_val_t;
+#endif
+
+/* Information obtained about memory from the FDT */
+struct fdt_memory {
+ fdt_addr_t start;
+ fdt_addr_t end;
+};
+
+struct bd_info;
+
+#ifdef CONFIG_SPL_BUILD
+#define SPL_BUILD 1
+#else
+#define SPL_BUILD 0
+#endif
+
+#ifdef CONFIG_OF_PRIOR_STAGE
+extern phys_addr_t prior_stage_fdt_address;
+#endif
+
+/*
+ * Information about a resource. start is the first address of the resource
+ * and end is the last address (inclusive). The length of the resource will
+ * be equal to: end - start + 1.
+ */
+struct fdt_resource {
+ fdt_addr_t start;
+ fdt_addr_t end;
+};
+
+enum fdt_pci_space {
+ FDT_PCI_SPACE_CONFIG = 0,
+ FDT_PCI_SPACE_IO = 0x01000000,
+ FDT_PCI_SPACE_MEM32 = 0x02000000,
+ FDT_PCI_SPACE_MEM64 = 0x03000000,
+ FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
+ FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
+};
+
+#define FDT_PCI_ADDR_CELLS 3
+#define FDT_PCI_SIZE_CELLS 2
+#define FDT_PCI_REG_SIZE \
+ ((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
+
+/*
+ * The Open Firmware spec defines PCI physical address as follows:
+ *
+ * bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
+ *
+ * phys.hi cell: npt000ss bbbbbbbb dddddfff rrrrrrrr
+ * phys.mid cell: hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
+ * phys.lo cell: llllllll llllllll llllllll llllllll
+ *
+ * where:
+ *
+ * n: is 0 if the address is relocatable, 1 otherwise
+ * p: is 1 if addressable region is prefetchable, 0 otherwise
+ * t: is 1 if the address is aliased (for non-relocatable I/O) below 1MB
+ * (for Memory), or below 64KB (for relocatable I/O)
+ * ss: is the space code, denoting the address space
+ * bbbbbbbb: is the 8-bit Bus Number
+ * ddddd: is the 5-bit Device Number
+ * fff: is the 3-bit Function Number
+ * rrrrrrrr: is the 8-bit Register Number
+ * hhhhhhhh: is a 32-bit unsigned number
+ * llllllll: is a 32-bit unsigned number
+ */
+struct fdt_pci_addr {
+ u32 phys_hi;
+ u32 phys_mid;
+ u32 phys_lo;
+};
+
+/**
+ * Compute the size of a resource.
+ *
+ * @param res the resource to operate on
+ * @return the size of the resource
+ */
+static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
+{
+ return res->end - res->start + 1;
+}
+
+/**
+ * Compat types that we know about and for which we might have drivers.
+ * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
+ * within drivers.
+ */
+enum fdt_compat_id {
+ COMPAT_UNKNOWN,
+ COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
+ COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
+ COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
+ COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
+ /* Tegra124 XUSB pad controller */
+ COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
+ /* Tegra210 XUSB pad controller */
+ COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
+ COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
+ COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
+ COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
+ COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
+ COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */
+ COMPAT_SAMSUNG_EXYNOS_DWMMC, /* Exynos DWMMC controller */
+ COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
+ COMPAT_SAMSUNG_EXYNOS_SYSMMU, /* Exynos sysmmu */
+ COMPAT_INTEL_MICROCODE, /* Intel microcode update */
+ COMPAT_INTEL_QRK_MRC, /* Intel Quark MRC */
+ COMPAT_ALTERA_SOCFPGA_DWMAC, /* SoCFPGA Ethernet controller */
+ COMPAT_ALTERA_SOCFPGA_DWMMC, /* SoCFPGA DWMMC controller */
+ COMPAT_ALTERA_SOCFPGA_DWC2USB, /* SoCFPGA DWC2 USB controller */
+ COMPAT_INTEL_BAYTRAIL_FSP, /* Intel Bay Trail FSP */
+ COMPAT_INTEL_BAYTRAIL_FSP_MDP, /* Intel FSP memory-down params */
+ COMPAT_INTEL_IVYBRIDGE_FSP, /* Intel Ivy Bridge FSP */
+ COMPAT_SUNXI_NAND, /* SUNXI NAND controller */
+ COMPAT_ALTERA_SOCFPGA_CLK, /* SoCFPGA Clock initialization */
+ COMPAT_ALTERA_SOCFPGA_PINCTRL_SINGLE, /* SoCFPGA pinctrl-single */
+ COMPAT_ALTERA_SOCFPGA_H2F_BRG, /* SoCFPGA hps2fpga bridge */
+ COMPAT_ALTERA_SOCFPGA_LWH2F_BRG, /* SoCFPGA lwhps2fpga bridge */
+ COMPAT_ALTERA_SOCFPGA_F2H_BRG, /* SoCFPGA fpga2hps bridge */
+ COMPAT_ALTERA_SOCFPGA_F2SDR0, /* SoCFPGA fpga2SDRAM0 bridge */
+ COMPAT_ALTERA_SOCFPGA_F2SDR1, /* SoCFPGA fpga2SDRAM1 bridge */
+ COMPAT_ALTERA_SOCFPGA_F2SDR2, /* SoCFPGA fpga2SDRAM2 bridge */
+ COMPAT_ALTERA_SOCFPGA_FPGA0, /* SOCFPGA FPGA manager */
+ COMPAT_ALTERA_SOCFPGA_NOC, /* SOCFPGA Arria 10 NOC */
+ COMPAT_ALTERA_SOCFPGA_CLK_INIT, /* SOCFPGA Arria 10 clk init */
+
+ COMPAT_COUNT,
+};
+
+#define MAX_PHANDLE_ARGS 16
+struct fdtdec_phandle_args {
+ int node;
+ int args_count;
+ uint32_t args[MAX_PHANDLE_ARGS];
+};
+
+/**
+ * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * #list-cells = <2>;
+ * }
+ *
+ * phandle2: node2 {
+ * #list-cells = <1>;
+ * }
+ *
+ * node3 {
+ * list = <&phandle1 1 2 &phandle2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
+ * &args);
+ *
+ * (This function is a modified version of __of_parse_phandle_with_args() from
+ * Linux 3.18)
+ *
+ * @blob: Pointer to device tree
+ * @src_node: Offset of device tree node containing a list
+ * @list_name: property name that contains a list
+ * @cells_name: property name that specifies the phandles' arguments count,
+ * or NULL to use @cells_count
+ * @cells_count: Cell count to use if @cells_name is NULL
+ * @index: index of a phandle to parse out
+ * @out_args: optional pointer to output arguments structure (will be filled)
+ * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
+ * @list_name does not exist, a phandle was not found, @cells_name
+ * could not be found, the arguments were truncated or there were too
+ * many arguments.
+ *
+ */
+int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
+ const char *list_name,
+ const char *cells_name,
+ int cell_count, int index,
+ struct fdtdec_phandle_args *out_args);
+
+/**
+ * Find the next numbered alias for a peripheral. This is used to enumerate
+ * all the peripherals of a certain type.
+ *
+ * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
+ * this function will return a pointer to the node the alias points to, and
+ * then update *upto to 1. Next time you call this function, the next node
+ * will be returned.
+ *
+ * All nodes returned will match the compatible ID, as it is assumed that
+ * all peripherals use the same driver.
+ *
+ * @param blob FDT blob to use
+ * @param name Root name of alias to search for
+ * @param id Compatible ID to look for
+ * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
+ */
+int fdtdec_next_alias(const void *blob, const char *name,
+ enum fdt_compat_id id, int *upto);
+
+/**
+ * Find the compatible ID for a given node.
+ *
+ * Generally each node has at least one compatible string attached to it.
+ * This function looks through our list of known compatible strings and
+ * returns the corresponding ID which matches the compatible string.
+ *
+ * @param blob FDT blob to use
+ * @param node Node containing compatible string to find
+ * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
+ */
+enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
+
+/**
+ * Find the next compatible node for a peripheral.
+ *
+ * Do the first call with node = 0. This function will return a pointer to
+ * the next compatible node. Next time you call this function, pass the
+ * value returned, and the next node will be provided.
+ *
+ * @param blob FDT blob to use
+ * @param node Start node for search
+ * @param id Compatible ID to look for (enum fdt_compat_id)
+ * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
+ */
+int fdtdec_next_compatible(const void *blob, int node,
+ enum fdt_compat_id id);
+
+/**
+ * Find the next compatible subnode for a peripheral.
+ *
+ * Do the first call with node set to the parent and depth = 0. This
+ * function will return the offset of the next compatible node. Next time
+ * you call this function, pass the node value returned last time, with
+ * depth unchanged, and the next node will be provided.
+ *
+ * @param blob FDT blob to use
+ * @param node Start node for search
+ * @param id Compatible ID to look for (enum fdt_compat_id)
+ * @param depthp Current depth (set to 0 before first call)
+ * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
+ */
+int fdtdec_next_compatible_subnode(const void *blob, int node,
+ enum fdt_compat_id id, int *depthp);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant assumes a known and fixed number of cells are used to
+ * represent the address and size.
+ *
+ * You probably don't want to use this function directly except to parse
+ * non-standard properties, and never to parse the "reg" property. Instead,
+ * use one of the "auto" variants below, which automatically honor the
+ * #address-cells and #size-cells properties in the parent node.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param na the number of cells used to represent an address
+ * @param ns the number of cells used to represent a size
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @param translate Indicates whether to translate the returned value
+ * using the parent node's ranges property.
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
+ const char *prop_name, int index, int na, int ns,
+ fdt_size_t *sizep, bool translate);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant automatically determines the number of cells used to represent
+ * the address and size by parsing the provided parent node's #address-cells
+ * and #size-cells properties.
+ *
+ * @param blob FDT blob
+ * @param parent parent node of @node
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @param translate Indicates whether to translate the returned value
+ * using the parent node's ranges property.
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
+ int node, const char *prop_name, int index, fdt_size_t *sizep,
+ bool translate);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant automatically determines the number of cells used to represent
+ * the address and size by parsing the parent node's #address-cells
+ * and #size-cells properties. The parent node is automatically found.
+ *
+ * The automatic parent lookup implemented by this function is slow.
+ * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
+ * possible.
+ *
+ * @param blob FDT blob
+ * @param parent parent node of @node
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @param translate Indicates whether to translate the returned value
+ * using the parent node's ranges property.
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
+ const char *prop_name, int index, fdt_size_t *sizep,
+ bool translate);
+
+/*
+ * Look up an address property in a node and return the parsed address.
+ *
+ * This variant hard-codes the number of cells used to represent the address
+ * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
+ * always returns the first address value in the property (index 0).
+ *
+ * Use of this function is not recommended due to the hard-coding of cell
+ * counts. There is no programmatic validation that these hard-coded values
+ * actually match the device tree content in any way at all. This assumption
+ * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
+ * set in the U-Boot build and exercising strict control over DT content to
+ * ensure use of matching #address-cells/#size-cells properties. However, this
+ * approach is error-prone; those familiar with DT will not expect the
+ * assumption to exist, and could easily invalidate it. If the assumption is
+ * invalidated, this function will not report the issue, and debugging will
+ * be required. Instead, use fdtdec_get_addr_size_auto_parent().
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr(const void *blob, int node,
+ const char *prop_name);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant hard-codes the number of cells used to represent the address
+ * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
+ * always returns the first address value in the property (index 0).
+ *
+ * Use of this function is not recommended due to the hard-coding of cell
+ * counts. There is no programmatic validation that these hard-coded values
+ * actually match the device tree content in any way at all. This assumption
+ * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
+ * set in the U-Boot build and exercising strict control over DT content to
+ * ensure use of matching #address-cells/#size-cells properties. However, this
+ * approach is error-prone; those familiar with DT will not expect the
+ * assumption to exist, and could easily invalidate it. If the assumption is
+ * invalidated, this function will not report the issue, and debugging will
+ * be required. Instead, use fdtdec_get_addr_size_auto_parent().
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
+ const char *prop_name, fdt_size_t *sizep);
+
+/**
+ * Look at the compatible property of a device node that represents a PCI
+ * device and extract pci vendor id and device id from it.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param vendor vendor id of the pci device
+ * @param device device id of the pci device
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_get_pci_vendev(const void *blob, int node,
+ u16 *vendor, u16 *device);
+
+/**
+ * Look at the pci address of a device node that represents a PCI device
+ * and return base address of the pci device's registers.
+ *
+ * @param dev device to examine
+ * @param addr pci address in the form of fdt_pci_addr
+ * @param bar returns base address of the pci device's registers
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_get_pci_bar32(struct udevice *dev, struct fdt_pci_addr *addr,
+ u32 *bar);
+
+/**
+ * Look up a 32-bit integer property in a node and return it. The property
+ * must have at least 4 bytes of data. The value of the first cell is
+ * returned.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param default_val default value to return if the property is not found
+ * @return integer value, if found, or default_val if not
+ */
+s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
+ s32 default_val);
+
+/**
+ * Unsigned version of fdtdec_get_int. The property must have at least
+ * 4 bytes of data. The value of the first cell is returned.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param default_val default value to return if the property is not found
+ * @return unsigned integer value, if found, or default_val if not
+ */
+unsigned int fdtdec_get_uint(const void *blob, int node, const char *prop_name,
+ unsigned int default_val);
+
+/**
+ * Get a variable-sized number from a property
+ *
+ * This reads a number from one or more cells.
+ *
+ * @param ptr Pointer to property
+ * @param cells Number of cells containing the number
+ * @return the value in the cells
+ */
+u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
+
+/**
+ * Look up a 64-bit integer property in a node and return it. The property
+ * must have at least 8 bytes of data (2 cells). The first two cells are
+ * concatenated to form a 8 bytes value, where the first cell is top half and
+ * the second cell is bottom half.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param default_val default value to return if the property is not found
+ * @return integer value, if found, or default_val if not
+ */
+uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
+ uint64_t default_val);
+
+/**
+ * Checks whether a node is enabled.
+ * This looks for a 'status' property. If this exists, then returns 1 if
+ * the status is 'ok' and 0 otherwise. If there is no status property,
+ * it returns 1 on the assumption that anything mentioned should be enabled
+ * by default.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @return integer value 0 (not enabled) or 1 (enabled)
+ */
+int fdtdec_get_is_enabled(const void *blob, int node);
+
+/**
+ * Make sure we have a valid fdt available to control U-Boot.
+ *
+ * If not, a message is printed to the console if the console is ready.
+ *
+ * @return 0 if all ok, -1 if not
+ */
+int fdtdec_prepare_fdt(void);
+
+/**
+ * Checks that we have a valid fdt available to control U-Boot.
+
+ * However, if not then for the moment nothing is done, since this function
+ * is called too early to panic().
+ *
+ * @returns 0
+ */
+int fdtdec_check_fdt(void);
+
+/**
+ * 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, FDT_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 alias sequence number of a node
+ *
+ * This works out whether a node is pointed to by an alias, and if so, the
+ * sequence number of that alias. Aliases are of the form <base><num> where
+ * <num> is the sequence number. For example spi2 would be sequence number
+ * 2.
+ *
+ * @param blob Device tree blob (if NULL, then error is returned)
+ * @param base Base name for alias (before the underscore)
+ * @param node Node to look up
+ * @param seqp This is set to the sequence number if one is found,
+ * but otherwise the value is left alone
+ * @return 0 if a sequence was found, -ve if not
+ */
+int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
+ int *seqp);
+
+/**
+ * Get the highest alias number for susbystem.
+ *
+ * It parses all aliases and find out highest recorded alias for subsystem.
+ * Aliases are of the form <base><num> where <num> is the sequence number.
+ *
+ * @param blob Device tree blob (if NULL, then error is returned)
+ * @param base Base name for alias susbystem (before the number)
+ *
+ * @return 0 highest alias ID, -1 if not found
+ */
+int fdtdec_get_alias_highest_id(const void *blob, const char *base);
+
+/**
+ * Get a property from the /chosen node
+ *
+ * @param blob Device tree blob (if NULL, then NULL is returned)
+ * @param name Property name to look up
+ * @return Value of property, or NULL if it does not exist
+ */
+const char *fdtdec_get_chosen_prop(const void *blob, const char *name);
+
+/**
+ * Get the offset of the given /chosen node
+ *
+ * This looks up a property in /chosen containing the path to another node,
+ * then finds the offset of that node.
+ *
+ * @param blob Device tree blob (if NULL, then error is returned)
+ * @param name Property name, e.g. "stdout-path"
+ * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
+ */
+int fdtdec_get_chosen_node(const void *blob, const char *name);
+
+/*
+ * 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 its contents in an integer
+ * array of given length. The property must exist but may have less data that
+ * expected (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 number of array elements if ok, or -FDT_ERR_NOTFOUND if the
+ * property is not found
+ */
+int fdtdec_get_int_array_count(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);
+
+/*
+ * Count child nodes of one parent node.
+ *
+ * @param blob FDT blob
+ * @param node parent node
+ * @return number of child node; 0 if there is not child node
+ */
+int fdtdec_get_child_count(const void *blob, int node);
+
+/**
+ * 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);
+
+/**
+ * Obtain an indexed resource from a device property.
+ *
+ * @param fdt FDT blob
+ * @param node node to examine
+ * @param property name of the property to parse
+ * @param index index of the resource to retrieve
+ * @param res returns the resource
+ * @return 0 if ok, negative on error
+ */
+int fdt_get_resource(const void *fdt, int node, const char *property,
+ unsigned int index, struct fdt_resource *res);
+
+/**
+ * Obtain a named resource from a device property.
+ *
+ * Look up the index of the name in a list of strings and return the resource
+ * at that index.
+ *
+ * @param fdt FDT blob
+ * @param node node to examine
+ * @param property name of the property to parse
+ * @param prop_names name of the property containing the list of names
+ * @param name the name of the entry to look up
+ * @param res returns the resource
+ */
+int fdt_get_named_resource(const void *fdt, int node, const char *property,
+ const char *prop_names, const char *name,
+ struct fdt_resource *res);
+
+/* Display timings from linux include/video/display_timing.h */
+enum display_flags {
+ DISPLAY_FLAGS_HSYNC_LOW = 1 << 0,
+ DISPLAY_FLAGS_HSYNC_HIGH = 1 << 1,
+ DISPLAY_FLAGS_VSYNC_LOW = 1 << 2,
+ DISPLAY_FLAGS_VSYNC_HIGH = 1 << 3,
+
+ /* data enable flag */
+ DISPLAY_FLAGS_DE_LOW = 1 << 4,
+ DISPLAY_FLAGS_DE_HIGH = 1 << 5,
+ /* drive data on pos. edge */
+ DISPLAY_FLAGS_PIXDATA_POSEDGE = 1 << 6,
+ /* drive data on neg. edge */
+ DISPLAY_FLAGS_PIXDATA_NEGEDGE = 1 << 7,
+ DISPLAY_FLAGS_INTERLACED = 1 << 8,
+ DISPLAY_FLAGS_DOUBLESCAN = 1 << 9,
+ DISPLAY_FLAGS_DOUBLECLK = 1 << 10,
+};
+
+/*
+ * A single signal can be specified via a range of minimal and maximal values
+ * with a typical value, that lies somewhere inbetween.
+ */
+struct timing_entry {
+ u32 min;
+ u32 typ;
+ u32 max;
+};
+
+/*
+ * Single "mode" entry. This describes one set of signal timings a display can
+ * have in one setting. This struct can later be converted to struct videomode
+ * (see include/video/videomode.h). As each timing_entry can be defined as a
+ * range, one struct display_timing may become multiple struct videomodes.
+ *
+ * Example: hsync active high, vsync active low
+ *
+ * Active Video
+ * Video ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
+ * |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
+ * | | porch | | porch |
+ *
+ * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
+ *
+ * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
+ */
+struct display_timing {
+ struct timing_entry pixelclock;
+
+ struct timing_entry hactive; /* hor. active video */
+ struct timing_entry hfront_porch; /* hor. front porch */
+ struct timing_entry hback_porch; /* hor. back porch */
+ struct timing_entry hsync_len; /* hor. sync len */
+
+ struct timing_entry vactive; /* ver. active video */
+ struct timing_entry vfront_porch; /* ver. front porch */
+ struct timing_entry vback_porch; /* ver. back porch */
+ struct timing_entry vsync_len; /* ver. sync len */
+
+ enum display_flags flags; /* display flags */
+ bool hdmi_monitor; /* is hdmi monitor? */
+};
+
+/**
+ * fdtdec_decode_display_timing() - decode display timings
+ *
+ * Decode display timings from the supplied 'display-timings' node.
+ * See doc/device-tree-bindings/video/display-timing.txt for binding
+ * information.
+ *
+ * @param blob FDT blob
+ * @param node 'display-timing' node containing the timing subnodes
+ * @param index Index number to read (0=first timing subnode)
+ * @param config Place to put timings
+ * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
+ */
+int fdtdec_decode_display_timing(const void *blob, int node, int index,
+ struct display_timing *config);
+
+/**
+ * fdtdec_setup_mem_size_base_fdt() - decode and setup gd->ram_size and
+ * gd->ram_start
+ *
+ * Decode the /memory 'reg' property to determine the size and start of the
+ * first memory bank, populate the global data with the size and start of the
+ * first bank of memory.
+ *
+ * This function should be called from a boards dram_init(). This helper
+ * function allows for boards to query the device tree for DRAM size and start
+ * address instead of hard coding the value in the case where the memory size
+ * and start address cannot be detected automatically.
+ *
+ * @param blob FDT blob
+ *
+ * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
+ * invalid
+ */
+int fdtdec_setup_mem_size_base_fdt(const void *blob);
+
+/**
+ * fdtdec_setup_mem_size_base() - decode and setup gd->ram_size and
+ * gd->ram_start
+ *
+ * Decode the /memory 'reg' property to determine the size and start of the
+ * first memory bank, populate the global data with the size and start of the
+ * first bank of memory.
+ *
+ * This function should be called from a boards dram_init(). This helper
+ * function allows for boards to query the device tree for DRAM size and start
+ * address instead of hard coding the value in the case where the memory size
+ * and start address cannot be detected automatically.
+ *
+ * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
+ * invalid
+ */
+int fdtdec_setup_mem_size_base(void);
+
+/**
+ * fdtdec_setup_memory_banksize_fdt() - decode and populate gd->bd->bi_dram
+ *
+ * Decode the /memory 'reg' property to determine the address and size of the
+ * memory banks. Use this data to populate the global data board info with the
+ * phys address and size of memory banks.
+ *
+ * This function should be called from a boards dram_init_banksize(). This
+ * helper function allows for boards to query the device tree for memory bank
+ * information instead of hard coding the information in cases where it cannot
+ * be detected automatically.
+ *
+ * @param blob FDT blob
+ *
+ * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
+ * invalid
+ */
+int fdtdec_setup_memory_banksize_fdt(const void *blob);
+
+/**
+ * fdtdec_setup_memory_banksize() - decode and populate gd->bd->bi_dram
+ *
+ * Decode the /memory 'reg' property to determine the address and size of the
+ * memory banks. Use this data to populate the global data board info with the
+ * phys address and size of memory banks.
+ *
+ * This function should be called from a boards dram_init_banksize(). This
+ * helper function allows for boards to query the device tree for memory bank
+ * information instead of hard coding the information in cases where it cannot
+ * be detected automatically.
+ *
+ * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
+ * invalid
+ */
+int fdtdec_setup_memory_banksize(void);
+
+/**
+ * fdtdec_set_ethernet_mac_address() - set MAC address for default interface
+ *
+ * Looks up the default interface via the "ethernet" alias (in the /aliases
+ * node) and stores the given MAC in its "local-mac-address" property. This
+ * is useful on platforms that store the MAC address in a custom location.
+ * Board code can call this in the late init stage to make sure that the
+ * interface device tree node has the right MAC address configured for the
+ * Ethernet uclass to pick it up.
+ *
+ * Typically the FDT passed into this function will be U-Boot's control DTB.
+ * Given that a lot of code may be holding offsets to various nodes in that
+ * tree, this code will only set the "local-mac-address" property in-place,
+ * which means that it needs to exist and have space for the 6-byte address.
+ * This ensures that the operation is non-destructive and does not invalidate
+ * offsets that other drivers may be using.
+ *
+ * @param fdt FDT blob
+ * @param mac buffer containing the MAC address to set
+ * @param size size of MAC address
+ * @return 0 on success or a negative error code on failure
+ */
+int fdtdec_set_ethernet_mac_address(void *fdt, const u8 *mac, size_t size);
+
+/**
+ * fdtdec_set_phandle() - sets the phandle of a given node
+ *
+ * @param blob FDT blob
+ * @param node offset in the FDT blob of the node whose phandle is to
+ * be set
+ * @param phandle phandle to set for the given node
+ * @return 0 on success or a negative error code on failure
+ */
+static inline int fdtdec_set_phandle(void *blob, int node, uint32_t phandle)
+{
+ return fdt_setprop_u32(blob, node, "phandle", phandle);
+}
+
+/**
+ * fdtdec_add_reserved_memory() - add or find a reserved-memory node
+ *
+ * If a reserved-memory node already exists for the given carveout, a phandle
+ * for that node will be returned. Otherwise a new node will be created and a
+ * phandle corresponding to it will be returned.
+ *
+ * See Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
+ * for details on how to use reserved memory regions.
+ *
+ * As an example, consider the following code snippet:
+ *
+ * struct fdt_memory fb = {
+ * .start = 0x92cb3000,
+ * .end = 0x934b2fff,
+ * };
+ * uint32_t phandle;
+ *
+ * fdtdec_add_reserved_memory(fdt, "framebuffer", &fb, &phandle);
+ *
+ * This results in the following subnode being added to the top-level
+ * /reserved-memory node:
+ *
+ * reserved-memory {
+ * #address-cells = <0x00000002>;
+ * #size-cells = <0x00000002>;
+ * ranges;
+ *
+ * framebuffer@92cb3000 {
+ * reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
+ * phandle = <0x0000004d>;
+ * };
+ * };
+ *
+ * If the top-level /reserved-memory node does not exist, it will be created.
+ * The phandle returned from the function call can be used to reference this
+ * reserved memory region from other nodes.
+ *
+ * See fdtdec_set_carveout() for a more elaborate example.
+ *
+ * @param blob FDT blob
+ * @param basename base name of the node to create
+ * @param carveout information about the carveout region
+ * @param phandlep return location for the phandle of the carveout region
+ * @return 0 on success or a negative error code on failure
+ */
+int fdtdec_add_reserved_memory(void *blob, const char *basename,
+ const struct fdt_memory *carveout,
+ uint32_t *phandlep);
+
+/**
+ * fdtdec_get_carveout() - reads a carveout from an FDT
+ *
+ * Reads information about a carveout region from an FDT. The carveout is a
+ * referenced by its phandle that is read from a given property in a given
+ * node.
+ *
+ * @param blob FDT blob
+ * @param node name of a node
+ * @param name name of the property in the given node that contains
+ * the phandle for the carveout
+ * @param index index of the phandle for which to read the carveout
+ * @param carveout return location for the carveout information
+ * @return 0 on success or a negative error code on failure
+ */
+int fdtdec_get_carveout(const void *blob, const char *node, const char *name,
+ unsigned int index, struct fdt_memory *carveout);
+
+/**
+ * fdtdec_set_carveout() - sets a carveout region for a given node
+ *
+ * Sets a carveout region for a given node. If a reserved-memory node already
+ * exists for the carveout, the phandle for that node will be reused. If no
+ * such node exists, a new one will be created and a phandle to it stored in
+ * a specified property of the given node.
+ *
+ * As an example, consider the following code snippet:
+ *
+ * const char *node = "/host1x@50000000/dc@54240000";
+ * struct fdt_memory fb = {
+ * .start = 0x92cb3000,
+ * .end = 0x934b2fff,
+ * };
+ *
+ * fdtdec_set_carveout(fdt, node, "memory-region", 0, "framebuffer", &fb);
+ *
+ * dc@54200000 is a display controller and was set up by the bootloader to
+ * scan out the framebuffer specified by "fb". This would cause the following
+ * reserved memory region to be added:
+ *
+ * reserved-memory {
+ * #address-cells = <0x00000002>;
+ * #size-cells = <0x00000002>;
+ * ranges;
+ *
+ * framebuffer@92cb3000 {
+ * reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
+ * phandle = <0x0000004d>;
+ * };
+ * };
+ *
+ * A "memory-region" property will also be added to the node referenced by the
+ * offset parameter.
+ *
+ * host1x@50000000 {
+ * ...
+ *
+ * dc@54240000 {
+ * ...
+ * memory-region = <0x0000004d>;
+ * ...
+ * };
+ *
+ * ...
+ * };
+ *
+ * @param blob FDT blob
+ * @param node name of the node to add the carveout to
+ * @param prop_name name of the property in which to store the phandle of
+ * the carveout
+ * @param index index of the phandle to store
+ * @param name base name of the reserved-memory node to create
+ * @param carveout information about the carveout to add
+ * @return 0 on success or a negative error code on failure
+ */
+int fdtdec_set_carveout(void *blob, const char *node, const char *prop_name,
+ unsigned int index, const char *name,
+ const struct fdt_memory *carveout);
+
+/**
+ * Set up the device tree ready for use
+ */
+int fdtdec_setup(void);
+
+#if CONFIG_IS_ENABLED(MULTI_DTB_FIT)
+/**
+ * fdtdec_resetup() - Set up the device tree again
+ *
+ * The main difference with fdtdec_setup() is that it returns if the fdt has
+ * changed because a better match has been found.
+ * This is typically used for boards that rely on a DM driver to detect the
+ * board type. This function sould be called by the board code after the stuff
+ * needed by board_fit_config_name_match() to operate porperly is available.
+ * If this functions signals that a rescan is necessary, the board code must
+ * unbind all the drivers using dm_uninit() and then rescan the DT with
+ * dm_init_and_scan().
+ *
+ * @param rescan Returns a flag indicating that fdt has changed and rescanning
+ * the fdt is required
+ *
+ * @return 0 if OK, -ve on error
+ */
+int fdtdec_resetup(int *rescan);
+#endif
+
+/**
+ * Board-specific FDT initialization. Returns the address to a device tree blob.
+ * Called when CONFIG_OF_BOARD is defined, or if CONFIG_OF_SEPARATE is defined
+ * and the board implements it.
+ */
+void *board_fdt_blob_setup(void);
+
+/*
+ * Decode the size of memory
+ *
+ * RAM size is normally set in a /memory node and consists of a list of
+ * (base, size) cells in the 'reg' property. This information is used to
+ * determine the total available memory as well as the address and size
+ * of each bank.
+ *
+ * Optionally the memory configuration can vary depending on a board id,
+ * typically read from strapping resistors or an EEPROM on the board.
+ *
+ * Finally, memory size can be detected (within certain limits) by probing
+ * the available memory. It is safe to do so within the limits provides by
+ * the board's device tree information. This makes it possible to produce
+ * boards with different memory sizes, where the device tree specifies the
+ * maximum memory configuration, and the smaller memory configuration is
+ * probed.
+ *
+ * This function decodes that information, returning the memory base address,
+ * size and bank information. See the memory.txt binding for full
+ * documentation.
+ *
+ * @param blob Device tree blob
+ * @param area Name of node to check (NULL means "/memory")
+ * @param board_id Board ID to look up
+ * @param basep Returns base address of first memory bank (NULL to
+ * ignore)
+ * @param sizep Returns total memory size (NULL to ignore)
+ * @param bd Updated with the memory bank information (NULL to skip)
+ * @return 0 if OK, -ve on error
+ */
+int fdtdec_decode_ram_size(const void *blob, const char *area, int board_id,
+ phys_addr_t *basep, phys_size_t *sizep,
+ struct bd_info *bd);
+
+#endif