soc: rockchip: io-domain: handle missing supply correctly

The original Linux code calls regulator_get_optional and handles its
-ENODEV return code, which morphed into regulator_get when ported to
barebox. The error handling stayed as-is leading to causing supplies to
trigger errors instead of being silently ignored.

As we use NULL to describe the dummy regulator in barebox, we can add a
trivial regulator_get_optional implementation and use it to fix the
I/O domain driver.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20240415053130.368278-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/regulator.h b/include/regulator.h
index 135fe6d91f..305da0d774 100644
--- a/include/regulator.h
+++ b/include/regulator.h
@@ -3,6 +3,7 @@
 #define __REGULATOR_H
 
 #include <linux/bitops.h>
+#include <linux/err.h>
 
 struct device;
 
@@ -284,4 +285,11 @@ static inline int regulator_get_voltage(struct regulator *regulator)
 
 #endif
 
+static inline struct regulator *regulator_get_optional(struct device *dev,
+						       const char *id)
+{
+	return regulator_get(dev, id) ?: ERR_PTR(-ENODEV);
+}
+
+
 #endif /* __REGULATOR_H */