dm: core: Add of_alias_get_highest_id()

The same functionality was added to Linux for i2c bus registration with this
commit message:

"
of: base: add function to get highest id of an alias stem

I2C supports adding adapters using either a dynamic or fixed id. The
latter is provided by aliases in the DT case. To prevent id collisions
of those two types, install this function which gives us the highest
fixed id, so we can then let the dynamically created ones come after
this highest number.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
"

Add it also to U-Boot for DM I2C support.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/core/of_access.c b/drivers/core/of_access.c
index 14c020a687b75c97d6fc85e8d8f33b8e95f652c6..945b81448ccef04fc9aa308695ea3f82e38d5003 100644 (file)
--- a/drivers/core/of_access.c
+++ b/drivers/core/of_access.c
@@ -812,6 +812,24 @@ int of_alias_get_id(const struct device_node *np, const char *stem)
        return id;
 }
 
+int of_alias_get_highest_id(const char *stem)
+{
+       struct alias_prop *app;
+       int id = -1;
+
+       mutex_lock(&of_mutex);
+       list_for_each_entry(app, &aliases_lookup, link) {
+               if (strcmp(app->stem, stem) != 0)
+                       continue;
+
+               if (app->id > id)
+                       id = app->id;
+       }
+       mutex_unlock(&of_mutex);
+
+       return id;
+}
+
 struct device_node *of_get_stdout(void)
 {
        return of_stdout;

diff --git a/include/dm/of_access.h b/include/dm/of_access.h
index 5ed1a0cdb42799750f65cd3f3de4a1e41e0b93b3..13fedb7cf5e60e6ff11e49ac6a39d3dc5baeecb4 100644 (file)
--- a/include/dm/of_access.h
+++ b/include/dm/of_access.h
@@ -424,6 +424,16 @@ int of_alias_scan(void);
  */
 int of_alias_get_id(const struct device_node *np, const char *stem);
 
+/**
+ * of_alias_get_highest_id - Get highest alias id for the given stem
+ * @stem:      Alias stem to be examined
+ *
+ * The function travels the lookup table to get the highest alias id for the
+ * given alias stem.
+ * @return alias ID, if found, else -1
+ */
+int of_alias_get_highest_id(const char *stem);
+
 /**
  * of_get_stdout() - Get node to use for stdout
  *