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authorSimon Glass <sjg@chromium.org>2014-07-23 06:55:09 -0600
committerSimon Glass <sjg@chromium.org>2014-07-23 14:07:25 +0100
commit5c33c9fdbb3f074676466b18c95dd64e8e6cf6d7 (patch)
tree2a7a3244b7c55df556460330d2da9cf7e7a6e669
parent9ca296a1b0ef37e53ca62ec8a345d9970f987599 (diff)
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fdt: Add a function to get the alias sequence of a node
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>
-rw-r--r--include/fdtdec.h18
-rw-r--r--lib/fdtdec.c46
2 files changed, 64 insertions, 0 deletions
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)
{
/*