[PATCH] mfd/syscon: Add device_node_to_regmap()

[Paul Cercueil <paul@crapouillou.net>]

device_node_to_regmap() is exactly like syscon_node_to_regmap(), but it
does not check that the node is compatible with "syscon".

The rationale behind this, is that one device node with a standard
compatible string "foo,bar" can be covered by multiple drivers sharing a
regmap, or by a single driver doing all the job without a regmap, but
these are implementation details which shouldn't reflect on the
devicetree.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 drivers/mfd/syscon.c       | 14 ++++++++++----
 include/linux/mfd/syscon.h |  6 ++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b65e585fc8c6..3dcb56d4688d 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -51,9 +51,6 @@ static struct syscon *of_syscon_register(struct device_node *np)
 	struct regmap_config syscon_config = syscon_regmap_config;
 	struct resource res;
 
-	if (!of_device_is_compatible(np, "syscon"))
-		return ERR_PTR(-EINVAL);
-
 	syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
 	if (!syscon)
 		return ERR_PTR(-ENOMEM);
@@ -150,7 +147,7 @@ static struct syscon *of_syscon_register(struct device_node *np)
 	return ERR_PTR(ret);
 }
 
-struct regmap *syscon_node_to_regmap(struct device_node *np)
+struct regmap *device_node_to_regmap(struct device_node *np)
 {
 	struct syscon *entry, *syscon = NULL;
 
@@ -172,6 +169,15 @@ struct regmap *syscon_node_to_regmap(struct device_node *np)
 
 	return syscon->regmap;
 }
+EXPORT_SYMBOL_GPL(device_node_to_regmap);
+
+struct regmap *syscon_node_to_regmap(struct device_node *np)
+{
+	if (!of_device_is_compatible(np, "syscon"))
+		return ERR_PTR(-EINVAL);
+
+	return device_node_to_regmap(np);
+}
 EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
 
 struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index 8cfda0554381..112dc66262cc 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -17,12 +17,18 @@
 struct device_node;
 
 #ifdef CONFIG_MFD_SYSCON
+extern struct regmap *device_node_to_regmap(struct device_node *np);
 extern struct regmap *syscon_node_to_regmap(struct device_node *np);
 extern struct regmap *syscon_regmap_lookup_by_compatible(const char *s);
 extern struct regmap *syscon_regmap_lookup_by_phandle(
 					struct device_node *np,
 					const char *property);
 #else
+static inline struct regmap *device_node_to_regmap(struct device_node *np)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+
 static inline struct regmap *syscon_node_to_regmap(struct device_node *np)
 {
 	return ERR_PTR(-ENOTSUPP);
-- 
2.21.0.593.g511ec345e18