interconnect: Add of_icc_get_by_index() helper function

This is the same as the traditional of_icc_get() function, but the
difference is that it takes index as an argument, instead of name.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200512125327.1868-4-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 2c6515e..aba5d38 100644 (file)
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -351,9 +351,9 @@ static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
 }
 
 /**
- * of_icc_get() - get a path handle from a DT node based on name
+ * of_icc_get_by_index() - get a path handle from a DT node based on index
  * @dev: device pointer for the consumer device
- * @name: interconnect path name
+ * @idx: interconnect path index
  *
  * This function will search for a path between two endpoints and return an
  * icc_path handle on success. Use icc_put() to release constraints when they
@@ -365,13 +365,12 @@ static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
  * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
  * when the API is disabled or the "interconnects" DT property is missing.
  */
-struct icc_path *of_icc_get(struct device *dev, const char *name)
+struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
 {
-       struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
+       struct icc_path *path;
        struct icc_node *src_node, *dst_node;
-       struct device_node *np = NULL;
+       struct device_node *np;
        struct of_phandle_args src_args, dst_args;
-       int idx = 0;
        int ret;
 
        if (!dev || !dev->of_node)
@@ -391,12 +390,6 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
         * lets support only global ids and extend this in the future if needed
         * without breaking DT compatibility.
         */
-       if (name) {
-               idx = of_property_match_string(np, "interconnect-names", name);
-               if (idx < 0)
-                       return ERR_PTR(idx);
-       }
-
        ret = of_parse_phandle_with_args(np, "interconnects",
                                         "#interconnect-cells", idx * 2,
                                         &src_args);
@@ -439,12 +432,8 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
                return path;
        }
 
-       if (name)
-               path->name = kstrdup_const(name, GFP_KERNEL);
-       else
-               path->name = kasprintf(GFP_KERNEL, "%s-%s",
-                                      src_node->name, dst_node->name);
-
+       path->name = kasprintf(GFP_KERNEL, "%s-%s",
+                              src_node->name, dst_node->name);
        if (!path->name) {
                kfree(path);
                return ERR_PTR(-ENOMEM);
@@ -452,6 +441,53 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
 
        return path;
 }
+EXPORT_SYMBOL_GPL(of_icc_get_by_index);
+
+/**
+ * of_icc_get() - get a path handle from a DT node based on name
+ * @dev: device pointer for the consumer device
+ * @name: interconnect path name
+ *
+ * This function will search for a path between two endpoints and return an
+ * icc_path handle on success. Use icc_put() to release constraints when they
+ * are not needed anymore.
+ * If the interconnect API is disabled, NULL is returned and the consumer
+ * drivers will still build. Drivers are free to handle this specifically,
+ * but they don't have to.
+ *
+ * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
+ * when the API is disabled or the "interconnects" DT property is missing.
+ */
+struct icc_path *of_icc_get(struct device *dev, const char *name)
+{
+       struct device_node *np;
+       int idx = 0;
+
+       if (!dev || !dev->of_node)
+               return ERR_PTR(-ENODEV);
+
+       np = dev->of_node;
+
+       /*
+        * When the consumer DT node do not have "interconnects" property
+        * return a NULL path to skip setting constraints.
+        */
+       if (!of_find_property(np, "interconnects", NULL))
+               return NULL;
+
+       /*
+        * We use a combination of phandle and specifier for endpoint. For now
+        * lets support only global ids and extend this in the future if needed
+        * without breaking DT compatibility.
+        */
+       if (name) {
+               idx = of_property_match_string(np, "interconnect-names", name);
+               if (idx < 0)
+                       return ERR_PTR(idx);
+       }
+
+       return of_icc_get_by_index(dev, idx);
+}
 EXPORT_SYMBOL_GPL(of_icc_get);
 
 /**

diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
index d70a914..34e9723 100644 (file)
--- a/include/linux/interconnect.h
+++ b/include/linux/interconnect.h
@@ -28,6 +28,7 @@ struct device;
 struct icc_path *icc_get(struct device *dev, const int src_id,
                         const int dst_id);
 struct icc_path *of_icc_get(struct device *dev, const char *name);
+struct icc_path *of_icc_get_by_index(struct device *dev, int idx);
 void icc_put(struct icc_path *path);
 int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw);
 void icc_set_tag(struct icc_path *path, u32 tag);
@@ -46,6 +47,11 @@ static inline struct icc_path *of_icc_get(struct device *dev,
        return NULL;
 }
 
+static inline struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
+{
+       return NULL;
+}
+
 static inline void icc_put(struct icc_path *path)
 {
 }