[PATCH v2 1/2] remoteproc: core: Add rproc OF look-up functions

[Lee Jones]

- of_rproc_by_index(): look-up and obtain a reference to a rproc
                       using the DT phandle "rprocs" and a index.

- of_rproc_by_name():  lookup and obtain a reference to a rproc
                       using the DT phandle "rprocs" and "rproc-names".

Signed-off-by: Ludovic Barre <ludovic.barre at st.com>
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---

v1 => v2:
 - s/ti,rprocs/ti,rproc

drivers/remoteproc/remoteproc_core.c | 78 +++++++++++++++++++++++++++++++++++-
 include/linux/remoteproc.h           | 25 +++++++++++-
 2 files changed, 101 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index fe0539e..fe362fb 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -41,6 +41,8 @@
 #include <linux/virtio_ids.h>
 #include <linux/virtio_ring.h>
 #include <asm/byteorder.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
 
 #include "remoteproc_internal.h"
 
@@ -1191,6 +1193,81 @@ out:
 }
 EXPORT_SYMBOL(rproc_shutdown);
 
+#ifdef CONFIG_OF
+/**
+ * of_get_rproc_by_index() - lookup and obtain a reference to an rproc
+ * @np: node to search for rproc phandle
+ * @index: index into the phandle list
+ *
+ * This function increments the remote processor's refcount, so always
+ * use rproc_put() to decrement it back once rproc isn't needed anymore.
+ *
+ * Returns a pointer to the rproc struct on success or an appropriate error
+ * code otherwise.
+ */
+struct rproc *of_get_rproc_by_index(struct device_node *np, int index)
+{
+	struct rproc *rproc = NULL, *r;
+	struct device_node *rproc_np;
+
+	if (index < 0) {
+		pr_err("Invalid index: %d\n", index);
+		return ERR_PTR(-EINVAL);
+	}
+
+	rproc_np = of_parse_phandle(np, "rprocs", index);
+	if (!rproc_np) {
+		/* Unfortunately we have to support this, at least for now */
+		rproc_np = of_parse_phandle(np, "ti,rproc", index);
+		if (!rproc_np) {
+			pr_err("Failed to obtain phandle\n");
+			return ERR_PTR(-ENODEV);
+		}
+	}
+
+	mutex_lock(&rproc_list_mutex);
+	list_for_each_entry(r, &rproc_list, node) {
+		if (r->dev.parent && r->dev.parent->of_node == rproc_np) {
+			get_device(&r->dev);
+			rproc = r;
+			break;
+		}
+	}
+	mutex_unlock(&rproc_list_mutex);
+
+	of_node_put(rproc_np);
+
+	if (!rproc)
+		pr_err("Could not find rproc, deferring\n");
+
+	return rproc ?: ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL(of_get_rproc_by_index);
+
+/**
+ * of_get_rproc_by_name() - lookup and obtain a reference to an rproc
+ * @np: node to search for rproc
+ * @name: name of the remoteproc from device's point of view
+ *
+ * This function increments the remote processor's refcount, so always
+ * use rproc_put() to decrement it back once rproc isn't needed anymore.
+ *
+ * Returns a pointer to the rproc struct on success or an appropriate error
+ * code otherwise.
+ */
+struct rproc *of_get_rproc_by_name(struct device_node *np, const char *name)
+{
+	int index;
+
+	if (unlikely(!name))
+		return ERR_PTR(-EINVAL);
+
+	index = of_property_match_string(np, "rproc-names", name);
+
+	return of_get_rproc_by_index(np, index);
+}
+EXPORT_SYMBOL(of_get_rproc_by_name);
+
 /**
  * rproc_get_by_phandle() - find a remote processor by phandle
  * @phandle: phandle to the rproc
@@ -1203,7 +1280,6 @@ EXPORT_SYMBOL(rproc_shutdown);
  *
  * Returns the rproc handle on success, and NULL on failure.
  */
-#ifdef CONFIG_OF
 struct rproc *rproc_get_by_phandle(phandle phandle)
 {
 	struct rproc *rproc = NULL, *r;
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 1c457a8..f130938 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -487,7 +487,6 @@ struct rproc_vdev {
 	u32 rsc_offset;
 };
 
-struct rproc *rproc_get_by_phandle(phandle phandle);
 struct rproc *rproc_alloc(struct device *dev, const char *name,
 				const struct rproc_ops *ops,
 				const char *firmware, int len);
@@ -511,4 +510,28 @@ static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
 	return rvdev->rproc;
 }
 
+#ifdef CONFIG_OF
+extern struct rproc *of_get_rproc_by_index(struct device_node *np,
+					   int index);
+extern struct rproc *of_get_rproc_by_name(struct device_node *np,
+					  const char *name);
+extern struct rproc *rproc_get_by_phandle(phandle phandle);
+#else
+static inline
+struct rproc *of_get_rproc_by_index(struct device_node *np, int index)
+{
+	return NULL;
+}
+static inline
+struct rproc *of_get_rproc_by_name(struct device_node *np, const char *name)
+{
+	return NULL;
+}
+static inline
+struct rproc *rproc_get_by_phandle(phandle phandle)
+{
+	return NULL;
+}
+#endif /* CONFIG_OF */
+
 #endif /* REMOTEPROC_H */
-- 
2.9.0