Staging: iio: fix ring buffer build

max1363 uses both the iio hardware ring buffer and software
ring buffer interfaces, but its Makefile and Kconfig do not
reflect that usage, so its build breaks.  Add a new Kconfig
symbol to reflect that usage and change max1363.h & Makefile
to use the new Kconfig symbol.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>

drivers/staging/iio/adc/Kconfig

@@ -12,3 +12,12 @@ config MAX1363
 	  convertors (ADC). (max1361, max1362, max1363, max1364, max1136,
 	  max1136, max1137, max1138, max1139, max1236, max1237, max11238,
 	  max1239) Provides direct access via sysfs.
+
+config MAX1363_RING_BUFFER
+	bool "MAXIM max1363: use ring buffer"
+	depends on MAX1363
+	select IIO_RING_BUFFER
+	select IIO_SW_RING
+	help
+	  Say yes here to include ring buffer support in the MAX1363
+	  ADC driver.

drivers/staging/iio/adc/Makefile

@@ -3,6 +3,6 @@
 #
 
 max1363-y := max1363_core.o
-max1363-$(CONFIG_IIO_RING_BUFFER) += max1363_ring.o
+max1363-$(CONFIG_MAX1363_RING_BUFFER) += max1363_ring.o
 
 obj-$(CONFIG_MAX1363) += max1363.o

drivers/staging/iio/adc/max1363.h

@@ -228,7 +228,7 @@ struct max1363_state {
 	struct iio_trigger		*trig;
 	struct regulator		*reg;
 };
-#ifdef CONFIG_IIO_RING_BUFFER
+#ifdef CONFIG_MAX1363_RING_BUFFER
 
 ssize_t max1363_scan_from_ring(struct device *dev,
 			       struct device_attribute *attr,
@@ -239,7 +239,7 @@ void max1363_ring_cleanup(struct iio_dev *indio_dev);
 int max1363_initialize_ring(struct iio_ring_buffer *ring);
 void max1363_uninitialize_ring(struct iio_ring_buffer *ring);
 
-#else /* CONFIG_IIO_RING_BUFFER */
+#else /* CONFIG_MAX1363_RING_BUFFER */
 
 static inline void max1363_uninitialize_ring(struct iio_ring_buffer *ring)
 {
@@ -265,5 +265,5 @@ max1363_register_ring_funcs_and_init(struct iio_dev *indio_dev)
 };
 
 static inline void max1363_ring_cleanup(struct iio_dev *indio_dev) {};
-#endif /* CONFIG_IIO_RING_BUFFER */
+#endif /* CONFIG_MAX1363_RING_BUFFER */
 #endif /* _MAX1363_H_ */