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 <sjg@chromium.org>

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 <sjg@chromium.org>
Simon Glass
1 parent fd7029029f
Showing 3 changed files with 120 additions and 0 deletions Side-by-side Diff
dts/Kconfig
include/asm-generic/global_data.h
include/dm/of.h
@@ -32,6 +32,17 @@
 	  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
@@ -72,6 +72,9 @@
 	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
+/*
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _DM_OF_H
+#define _DM_OF_H
+
+#include <asm/u-boot.h>
+#include <asm/global_data.h>
+
+/* 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 "<NULL>" 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
...	...	@@ -32,6 +32,17 @@
32	32	which is not enough to support device tree. Enable this option to
33	33	allow such boards to be supported by U-Boot SPL.
34	34
	35	+config OF_LIVE
	36	+ bool "Enable use of a live tree"
	37	+ depends on OF_CONTROL
	38	+ help
	39	+ Normally U-Boot uses a flat device tree which saves space and
	40	+ avoids the need to unpack the tree before use. However a flat
	41	+ tree does not support modifcation from within U-Boot since it
	42	+ can invalidate driver-model device tree offsets. This option
	43	+ enables a live tree which is available after relocation,
	44	+ and can be adjusted as needed.
	45	+
35	46	choice
36	47	prompt "Provider of DTB for DT control"
37	48	depends on OF_CONTROL
...	...	@@ -72,6 +72,9 @@
72	72	const void fdt_blob; / Our device tree, NULL if none */
73	73	void new_fdt; / Relocated FDT */
74	74	unsigned long fdt_size; /* Space reserved for relocated FDT */
	75	+#ifdef CONFIG_OF_LIVE
	76	+ struct device_node *of_root;
	77	+#endif
75	78	struct jt_funcs jt; / jump table */
76	79	char env_buf[32]; /* buffer for getenv() before reloc. */
77	80	#ifdef CONFIG_TRACE
	1	+/*
	2	+ * Copyright (c) 2017 Google, Inc
	3	+ * Written by Simon Glass <sjg@chromium.org>
	4	+ *
	5	+ * SPDX-License-Identifier: GPL-2.0+
	6	+ */
	7	+
	8	+#ifndef _DM_OF_H
	9	+#define _DM_OF_H
	10	+
	11	+#include <asm/u-boot.h>
	12	+#include <asm/global_data.h>
	13	+
	14	+/* integer value within a device tree property which references another node */
	15	+typedef u32 phandle;
	16	+
	17	+/**
	18	+ * struct property: Device tree property
	19	+ *
	20	+ * @name: Property name
	21	+ * @length: Length of property in bytes
	22	+ * @value: Pointer to property value
	23	+ * @next: Pointer to next property, or NULL if none
	24	+ */
	25	+struct property {
	26	+ char *name;
	27	+ int length;
	28	+ void *value;
	29	+ struct property *next;
	30	+};
	31	+
	32	+/**
	33	+ * struct device_node: Device tree node
	34	+ *
	35	+ * @name: Node name
	36	+ * @type: Node type (value of device_type property) or "<NULL>" if none
	37	+ * @phandle: Phandle value of this none, or 0 if none
	38	+ * @full_name: Full path to node, e.g. "/bus@1/spi@1100"
	39	+ * @properties: Pointer to head of list of properties, or NULL if none
	40	+ * @parent: Pointer to parent node, or NULL if this is the root node
	41	+ * @child: Pointer to head of child node list, or NULL if no children
	42	+ * @sibling: Pointer to the next sibling node, or NULL if this is the last
	43	+ */
	44	+struct device_node {
	45	+ const char *name;
	46	+ const char *type;
	47	+ phandle phandle;
	48	+ const char *full_name;
	49	+
	50	+ struct property *properties;
	51	+ struct device_node *parent;
	52	+ struct device_node *child;
	53	+ struct device_node *sibling;
	54	+};
	55	+
	56	+#define OF_MAX_PHANDLE_ARGS 16
	57	+
	58	+/**
	59	+ * struct of_phandle_args - structure to hold phandle and arguments
	60	+ *
	61	+ * This is used when decoding a phandle in a device tree property. Typically
	62	+ * these look like this:
	63	+ *
	64	+ * wibble {
	65	+ * phandle = <5>;
	66	+ * };
	67	+ *
	68	+ * ...
	69	+ * some-prop = <&wibble 1 2 3>
	70	+ *
	71	+ * Here &node is the phandle of the node 'wibble', i.e. 5. There are three
	72	+ * arguments: 1, 2, 3.
	73	+ *
	74	+ * So when decoding the phandle in some-prop, np will point to wibble,
	75	+ * args_count will be 3 and the three arguments will be in args.
	76	+ *
	77	+ * @np: Node that the phandle refers to
	78	+ * @args_count: Number of arguments
	79	+ * @args: Argument values
	80	+ */
	81	+struct of_phandle_args {
	82	+ struct device_node *np;
	83	+ int args_count;
	84	+ uint32_t args[OF_MAX_PHANDLE_ARGS];
	85	+};
	86	+
	87	+DECLARE_GLOBAL_DATA_PTR;
	88	+
	89	+/**
	90	+ * of_live_active() - check if livetree is active
	91	+ *
	92	+ * @returns true if livetree is active, false it not
	93	+ */
	94	+#ifdef CONFIG_OF_LIVE
	95	+static inline bool of_live_active(void)
	96	+{
	97	+ return gd->of_root != NULL;
	98	+}
	99	+#else
	100	+static inline bool of_live_active(void)
	101	+{
	102	+ return false;
	103	+}
	104	+#endif
	105	+
	106	+#endif