Find out the highest alias ID used for certain subsystem. This call will be used for alocating IDs for i2c buses which are not described in DT.
Signed-off-by: Michal Simek michal.simek@xilinx.com ---
Changes in v2: None
include/fdtdec.h | 13 +++++++++++++ lib/fdtdec.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+)
diff --git a/include/fdtdec.h b/include/fdtdec.h index f1bcbf837ffb..c2dd87ede226 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -626,6 +626,19 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int node, int *seqp);
/** + * Get the highest alias number for susbystem. + * + * It parses all aliases and find out highest recorded alias for subsystem. + * Aliases are of the form <base><num> where <num> is the sequence number. + * + * @param blob Device tree blob (if NULL, then error is returned) + * @param base Base name for alias susbystem (before the number) + * + * @return 0 highest alias ID, -1 if not found + */ +int fdtdec_get_alias_highest_id(const void *blob, const char *base); + +/** * Get a property from the /chosen node * * @param blob Device tree blob (if NULL, then NULL is returned) diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 18663ce6bdac..55811975ef54 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -549,6 +549,39 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int offset, return -ENOENT; }
+int fdtdec_get_alias_highest_id(const void *blob, const char *base) +{ + int base_len = strlen(base); + int prop_offset; + int aliases; + int max = -1; + + debug("Looking for highest alias id for '%s'\n", base); + + aliases = fdt_path_offset(blob, "/aliases"); + for (prop_offset = fdt_first_property_offset(blob, aliases); + prop_offset > 0; + prop_offset = fdt_next_property_offset(blob, prop_offset)) { + const char *prop; + const char *name; + int len, val; + + prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len); + debug(" - %s, %s\n", name, prop); + if (*prop != '/' || prop[len - 1] || + strncmp(name, base, base_len)) + continue; + + val = trailing_strtol(name); + if (val > max) { + debug("Found seq %d\n", val); + max = val; + } + } + + return max; +} + const char *fdtdec_get_chosen_prop(const void *blob, const char *name) { int chosen_node;