Aliases are used to provide U-Boot's numbering of devices, such as:
aliases { spi0 = "/spi@12330000"; }
spi@12330000 { ... }
This tells us that the SPI controller at 12330000 is considered to be the first SPI controller (SPI 0). So we have a numbering for the SPI node.
Add a function that returns the numbering for a node assume that it exists in the list of aliases.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v2: None
include/fdtdec.h | 18 ++++++++++++++++++ lib/fdtdec.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+)
diff --git a/include/fdtdec.h b/include/fdtdec.h index a7e6ee7..f454f7e 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -345,6 +345,24 @@ int fdtdec_find_aliases_for_id(const void *blob, const char *name, int fdtdec_add_aliases_for_id(const void *blob, const char *name, enum fdt_compat_id id, int *node_list, int maxcount);
+/** + * Get the alias sequence number of a node + * + * This works out whether a node is pointed to by an alias, and if so, the + * sequence number of that alias. Aliases are of the form <base><num> where + * <num> is the sequence number. For example spi2 would be sequence number + * 2. + * + * @param blob Device tree blob (if NULL, then error is returned) + * @param base Base name for alias (before the underscore) + * @param node Node to look up + * @param seqp This is set to the sequence number if one is found, + * but otherwise the value is left alone + * @return 0 if a sequence was found, -ve if not + */ +int fdtdec_get_alias_seq(const void *blob, const char *base, int node, + int *seqp); + /* * Get the name for a compatible ID * diff --git a/lib/fdtdec.c b/lib/fdtdec.c index aaa6620..1b4ae9f 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -5,9 +5,11 @@
#ifndef USE_HOSTCC #include <common.h> +#include <errno.h> #include <serial.h> #include <libfdt.h> #include <fdtdec.h> +#include <linux/ctype.h>
#include <asm/gpio.h>
@@ -319,6 +321,50 @@ int fdtdec_add_aliases_for_id(const void *blob, const char *name, return num_found; }
+int fdtdec_get_alias_seq(const void *blob, const char *base, int offset, + int *seqp) +{ + int base_len = strlen(base); + const char *find_name; + int find_namelen; + int prop_offset; + int aliases; + + find_name = fdt_get_name(blob, offset, &find_namelen); + debug("Looking for '%s' at %d, name %s\n", base, offset, find_name); + + 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; + const char *slash; + const char *p; + int len; + + prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len); + debug(" - %s, %s\n", name, prop); + if (len < find_namelen || *prop != '/' || prop[len - 1] || + strncmp(name, base, base_len)) + continue; + + slash = strrchr(prop, '/'); + if (strcmp(slash + 1, find_name)) + continue; + for (p = name; *p; p++) { + if (isdigit(*p)) { + *seqp = simple_strtoul(p, NULL, 10); + debug("Found seq %d\n", *seqp); + return 0; + } + } + } + + debug("Not found\n"); + return -ENOENT; +} + int fdtdec_check_fdt(void) { /*