remoteproc: introduce rproc_get_by_phandle API

Allow users of remoteproc the ability to get a handle to an rproc by
passing a phandle supplied in the user's device tree node. This is
useful in situations that require manual booting of the rproc.

This patch uses the code removed by commit 40e575b1d0b3 ("remoteproc:
remove the get_by_name/put API") for the ref counting but is modified
to use a simple list and locking mechanism and has rproc_get_by_name
replaced with an rproc_get_by_phandle API.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
[fix order of Signed-off-by tags]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt
index e6469fdcf89a..ef0219fa4bb4 100644
--- a/Documentation/remoteproc.txt
+++ b/Documentation/remoteproc.txt
@@ -51,6 +51,12 @@ cost.
         rproc_shutdown() returns, and users can still use it with a subsequent
         rproc_boot(), if needed.
 
+  struct rproc *rproc_get_by_phandle(phandle phandle)
+    - Find an rproc handle using a device tree phandle. Returns the rproc
+      handle on success, and NULL on failure. This function increments
+      the remote processor's refcount, so always use rproc_put() to
+      decrement it back once rproc isn't needed anymore.
+
 3. Typical usage
 
 #include <linux/remoteproc.h>