fdt: Introduce fdtdec_get_alias_highest_id()

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>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Michal Simek 2019-01-31 16:30:58 +01:00 committed by Heiko Schocher
parent 5ebc7c7e27
commit 003c9dc891
2 changed files with 46 additions and 0 deletions

View File

@ -625,6 +625,19 @@ int fdtdec_add_aliases_for_id(const void *blob, const char *name,
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
*

View File

@ -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;