[PATCH v2 1/1] mfd: syscon: return -ENOSYS if CONFIG_MFD_SYSCON is not enabled

[Peter Chen]

Some platforms may not define CONFIG_MFD_SYSCON (or haven't syscon),
it can fix build error for these platforms.

Signed-off-by: Peter Chen <peter.chen at freescale.com>

---

Changes for v2:
- Using #ifdef instead of IS_ENABLED
- Using ENOSYS instead of ENXIO as return val

 include/linux/mfd/syscon.h |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index b473577..8789fa3 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -17,10 +17,35 @@
 
 struct device_node;
 
+#ifdef CONFIG_MFD_SYSCON
 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_pdevname(const char *s);
 extern struct regmap *syscon_regmap_lookup_by_phandle(
 					struct device_node *np,
 					const char *property);
+#else
+static inline struct regmap *syscon_node_to_regmap(struct device_node *np)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct regmap *syscon_regmap_lookup_by_phandle(
+					struct device_node *np,
+					const char *property)
+{
+	return ERR_PTR(-ENOSYS);
+}
+#endif
+
 #endif /* __LINUX_MFD_SYSCON_H__ */
-- 
1.7.1