[PATCH 5/8] nvmem: core: Properly handle connection ID in of_nvmem_device_get()

[Alban Bedel]

of_nvmem_device_get() would crash if NULL was passed as a connection
ID. Rework this to use the usual sementic of assuming the first
connection when no connection ID is given.

Furthermore of_nvmem_device_get() would return -EINVAL when it failed
to resolve the connection, making it impossible to properly implement
an optional connection. Return -ENOENT instead to let the caller know
that the connection doesn't exists.

Signed-off-by: Alban Bedel <albeu@xxxxxxx>
---
 drivers/nvmem/core.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index a7556b20cff4..28e01a9876c6 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -839,13 +839,14 @@ struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
 {
 
 	struct device_node *nvmem_np;
-	int index;
+	int index = 0;
 
-	index = of_property_match_string(np, "nvmem-names", id);
+	if (id)
+		index = of_property_match_string(np, "nvmem-names", id);
 
 	nvmem_np = of_parse_phandle(np, "nvmem", index);
 	if (!nvmem_np)
-		return ERR_PTR(-EINVAL);
+		return ERR_PTR(-ENOENT);
 
 	return __nvmem_device_get(nvmem_np, NULL);
 }
-- 
2.19.1