diff options
| -rw-r--r-- | drivers/core/Kconfig | 24 | ||||
| -rw-r--r-- | include/dm/ofnode_decl.h | 33 |
2 files changed, 55 insertions, 2 deletions
diff --git a/drivers/core/Kconfig b/drivers/core/Kconfig index 007dc6a1de3..c9bf5de4332 100644 --- a/drivers/core/Kconfig +++ b/drivers/core/Kconfig @@ -400,6 +400,30 @@ config DM_DEV_READ_INLINE bool default y if !OF_LIVE +config OFNODE_MULTI_TREE + bool "Allow the ofnode interface to access any tree" + default y if EVENT && !DM_DEV_READ_INLINE && !DM_INLINE_OFNODE + help + Normally U-Boot makes use of its control FDT, the one used to bind + devices and provide options. In some cases, U-Boot must also process + a separate FDT, e.g. one provided by the operating system, which + needs additions to the /chosen node. + + This works fine with live tree (OF_LIVE), but with flat tree the + offset provided in ofnode is only useful with the control FDT. This + option adds a 'tree ID' to the offset, so that multiple trees can + be used. Call oftree_from_fdt() to register a new tree. + +config OFNODE_MULTI_TREE_MAX + int "Maximum number of FDTs" + range 2 8 + depends on OFNODE_MULTI_TREE + default 4 + help + Sets the maximum number of device trees which can be used with the + ofnode interface when using flat trees (OF_LIVE). This is only + available in U-Boot proper and only after relocation. + config ACPIGEN bool "Support ACPI table generation in driver model" default y if SANDBOX || (GENERATE_ACPI_TABLE && !QEMU) diff --git a/include/dm/ofnode_decl.h b/include/dm/ofnode_decl.h index f666a0287ba..5c2115aab0b 100644 --- a/include/dm/ofnode_decl.h +++ b/include/dm/ofnode_decl.h @@ -31,8 +31,18 @@ * this increases code size slightly due to the subtraction. Since it offers no * real benefit, the approach described here seems best. * - * For now these points use constant types, since we don't allow writing - * the DT. + * Where multiple trees are in use, this works without any trouble with live + * tree, except for aliases, such as ofnode_path("mmc0"), which only work on the + * control FDT. When the flat tree is in use, the trees are registered and a + * 'tree ID' is encoded into the top bits of @of_offset - see immediately below + * for the associated macro definitions. Note that 64-bit machines use the same + * encoding, even though there is more space available. This is partly because + * the FDT format contains 32-bit values for things like the string-table + * offset, therefore 64-bit offsets cannot be supported anyway. + * + * For the multiple-tree case, an invalid offset (i.e. with of_offset < 0) is + * still invalid. It does not contain a tree ID. So there is no way of knowing + * which tree produced the invalid offset. * * @np: Pointer to device node, used for live tree * @of_offset: Pointer into flat device tree, used for flat tree. Note that this @@ -43,6 +53,25 @@ typedef union ofnode_union { long of_offset; } ofnode; +/* shift for the tree ID within of_offset */ +#define OF_TREE_SHIFT 28 + +/* mask to obtain the device tree offset from of_offset */ +#define OF_TREE_MASK ((1 << OF_TREE_SHIFT) - 1) + +/* encode a tree ID and node offset into an of_offset value */ +#define OFTREE_NODE(tree_id, offs) ((tree_id) << OF_TREE_SHIFT | (offs)) + +/* decode the node offset from an of_offset value */ +#define OFTREE_OFFSET(of_offs) ((of_offs) & OF_TREE_MASK) + +/* decode the tree ID from an of_offset value */ +#define OFTREE_TREE_ID(of_offs) ((of_offs) >> OF_TREE_SHIFT) + +/* encode a node offset in the tree given by another node's of_offset value */ +#define OFTREE_MAKE_NODE(other_of_offset, offs) \ + (((offs) & OF_TREE_MASK) | ((other_of_offset) & ~OF_TREE_MASK)) + /** * struct ofprop - reference to a property of a device tree node * |