diff options
| author | Frank Rowand <frowand.list@gmail.com> | 2024-02-16 17:05:51 -0800 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2024-03-08 12:50:39 -0600 |
| commit | 7b937cc243e5b1df8780a0aa743ce800df6c68d1 (patch) | |
| tree | 24e9c7b552d99ba89f96c3af21017913e996ec1c /include/linux/of.h | |
| parent | dc1460fe1b2dc883195d21759676d55b183fd495 (diff) | |
of: Create of_root if no dtb provided by firmware
When enabling CONFIG_OF on a platform where 'of_root' is not populated
by firmware, we end up without a root node. In order to apply overlays
and create subnodes of the root node, we need one. Create this root node
by unflattening an empty builtin dtb.
If firmware provides a flattened device tree (FDT) then the FDT is
unflattened via setup_arch(). Otherwise, the call to
unflatten(_and_copy)?_device_tree() will create an empty root node.
We make of_have_populated_dt() return true only if the DTB was loaded by
firmware so that existing callers don't change behavior after this
patch. The call in the of platform code is removed because it prevents
overlays from creating platform devices when the empty root node is
used.
[sboyd@kernel.org: Update of_have_populated_dt() to treat this empty dtb
as not populated. Drop setup_of() initcall]
Signed-off-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20230317053415.2254616-2-frowand.list@gmail.com
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240217010557.2381548-3-sboyd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'include/linux/of.h')
| -rw-r--r-- | include/linux/of.h | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/include/linux/of.h b/include/linux/of.h index a3e8e429ad7f..d5e7acdc8c8e 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -180,11 +180,6 @@ static inline bool is_of_node(const struct fwnode_handle *fwnode) &__of_fwnode_handle_node->fwnode : NULL; \ }) -static inline bool of_have_populated_dt(void) -{ - return of_root != NULL; -} - static inline bool of_node_is_root(const struct device_node *node) { return node && (node->parent == NULL); @@ -546,11 +541,6 @@ static inline struct device_node *of_find_node_with_property( #define of_fwnode_handle(node) NULL -static inline bool of_have_populated_dt(void) -{ - return false; -} - static inline struct device_node *of_get_compatible_child(const struct device_node *parent, const char *compatible) { @@ -1634,6 +1624,21 @@ static inline bool of_device_is_system_power_controller(const struct device_node return of_property_read_bool(np, "system-power-controller"); } +/** + * of_have_populated_dt() - Has DT been populated by bootloader + * + * Return: True if a DTB has been populated by the bootloader and it isn't the + * empty builtin one. False otherwise. + */ +static inline bool of_have_populated_dt(void) +{ +#ifdef CONFIG_OF + return of_property_present(of_root, "compatible"); +#else + return false; +#endif +} + /* * Overlay support */ |