From 5e060d8bcca86dd4b88af607396a96cf6c557ca7 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Thu, 18 May 2017 20:08:53 -0600 Subject: [PATCH] dm: core: Add livetree definitions Add a Kconfig option to enable a live device tree, built at run time from the flat tree. Also add structure definitions and a root node. Signed-off-by: Simon Glass --- dts/Kconfig | 11 ++++ include/asm-generic/global_data.h | 3 + include/dm/of.h | 106 ++++++++++++++++++++++++++++++ 3 files changed, 120 insertions(+) create mode 100644 include/dm/of.h diff --git a/dts/Kconfig b/dts/Kconfig index 9a0622154a..b3009af03f 100644 --- a/dts/Kconfig +++ b/dts/Kconfig @@ -32,6 +32,17 @@ config SPL_OF_CONTROL which is not enough to support device tree. Enable this option to allow such boards to be supported by U-Boot SPL. +config OF_LIVE + bool "Enable use of a live tree" + depends on OF_CONTROL + help + Normally U-Boot uses a flat device tree which saves space and + avoids the need to unpack the tree before use. However a flat + tree does not support modifcation from within U-Boot since it + can invalidate driver-model device tree offsets. This option + enables a live tree which is available after relocation, + and can be adjusted as needed. + choice prompt "Provider of DTB for DT control" depends on OF_CONTROL diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h index 51838b5ead..e6f905110e 100644 --- a/include/asm-generic/global_data.h +++ b/include/asm-generic/global_data.h @@ -72,6 +72,9 @@ typedef struct global_data { const void *fdt_blob; /* Our device tree, NULL if none */ void *new_fdt; /* Relocated FDT */ unsigned long fdt_size; /* Space reserved for relocated FDT */ +#ifdef CONFIG_OF_LIVE + struct device_node *of_root; +#endif struct jt_funcs *jt; /* jump table */ char env_buf[32]; /* buffer for getenv() before reloc. */ #ifdef CONFIG_TRACE diff --git a/include/dm/of.h b/include/dm/of.h new file mode 100644 index 0000000000..6b5afab1c1 --- /dev/null +++ b/include/dm/of.h @@ -0,0 +1,106 @@ +/* + * Copyright (c) 2017 Google, Inc + * Written by Simon Glass + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _DM_OF_H +#define _DM_OF_H + +#include +#include + +/* integer value within a device tree property which references another node */ +typedef u32 phandle; + +/** + * struct property: Device tree property + * + * @name: Property name + * @length: Length of property in bytes + * @value: Pointer to property value + * @next: Pointer to next property, or NULL if none + */ +struct property { + char *name; + int length; + void *value; + struct property *next; +}; + +/** + * struct device_node: Device tree node + * + * @name: Node name + * @type: Node type (value of device_type property) or "" if none + * @phandle: Phandle value of this none, or 0 if none + * @full_name: Full path to node, e.g. "/bus@1/spi@1100" + * @properties: Pointer to head of list of properties, or NULL if none + * @parent: Pointer to parent node, or NULL if this is the root node + * @child: Pointer to head of child node list, or NULL if no children + * @sibling: Pointer to the next sibling node, or NULL if this is the last + */ +struct device_node { + const char *name; + const char *type; + phandle phandle; + const char *full_name; + + struct property *properties; + struct device_node *parent; + struct device_node *child; + struct device_node *sibling; +}; + +#define OF_MAX_PHANDLE_ARGS 16 + +/** + * struct of_phandle_args - structure to hold phandle and arguments + * + * This is used when decoding a phandle in a device tree property. Typically + * these look like this: + * + * wibble { + * phandle = <5>; + * }; + * + * ... + * some-prop = <&wibble 1 2 3> + * + * Here &node is the phandle of the node 'wibble', i.e. 5. There are three + * arguments: 1, 2, 3. + * + * So when decoding the phandle in some-prop, np will point to wibble, + * args_count will be 3 and the three arguments will be in args. + * + * @np: Node that the phandle refers to + * @args_count: Number of arguments + * @args: Argument values + */ +struct of_phandle_args { + struct device_node *np; + int args_count; + uint32_t args[OF_MAX_PHANDLE_ARGS]; +}; + +DECLARE_GLOBAL_DATA_PTR; + +/** + * of_live_active() - check if livetree is active + * + * @returns true if livetree is active, false it not + */ +#ifdef CONFIG_OF_LIVE +static inline bool of_live_active(void) +{ + return gd->of_root != NULL; +} +#else +static inline bool of_live_active(void) +{ + return false; +} +#endif + +#endif -- 2.39.2