This is a commonly-used requirement, so add a function to support it easily.
Signed-off-by: Simon Glass sjg@chromium.org --- include/fdtdec.h | 13 +++++++++++++ lib/fdtdec.c | 11 +++++++++++ 2 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/include/fdtdec.h b/include/fdtdec.h index e705124..81ce3f6 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -239,6 +239,19 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id); int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
/** + * Look up a phandle and follow it to its node. Then return the register + * address of that node as a pointer. This can be used to access the + * peripheral directly. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @return pointer to node's register address + */ +void *fdtdec_lookup_phandle_reg(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. diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 48abf02..bcb2343 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -311,6 +311,17 @@ int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name) return lookup; }
+void *fdtdec_lookup_phandle_reg(const void *blob, int node, + const char *prop_name) +{ + int lookup; + + lookup = fdtdec_lookup_phandle(blob, node, prop_name); + if (lookup < 0) + return NULL; + return (void *)fdtdec_get_addr(blob, lookup, "reg"); +} + /** * Look up a property in a node and check that it has a minimum length. *