Staging: IIO: lis3l02dq ring buffer and data ready trigger support

Example of relatively common case of device sampling
based on internal clock and providing a data ready
signal to indicate that new data is available to be
read out.

Generic trigger approach used to allow other devices
to be sampled 'at the same time' as this the accelerometer.
This is very useful in various motion estimation algorithms.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/accel/Makefile

@@ -4,6 +4,7 @@
 obj-$(CONFIG_KXSD9)	+= kxsd9.o
 
 lis3l02dq-y		:= lis3l02dq_core.o
+lis3l02dq-$(CONFIG_IIO_RING_BUFFER) += lis3l02dq_ring.o
 obj-$(CONFIG_LIS3L02DQ)	+= lis3l02dq.o
 
 sca3000-y		:= sca3000_core.o sca3000_ring.o

drivers/staging/iio/accel/lis3l02dq.h

@@ -183,6 +183,26 @@ int lis3l02dq_spi_write_reg_8(struct device *dev,
 #define LIS3L02DQ_SCAN_ACC_Y 1
 #define LIS3L02DQ_SCAN_ACC_Z 2
 
+
+#ifdef CONFIG_IIO_RING_BUFFER
+/* At the moment triggers are only used for ring buffer
+ * filling. This may change!
+ */
+void lis3l02dq_remove_trigger(struct iio_dev *indio_dev);
+int lis3l02dq_probe_trigger(struct iio_dev *indio_dev);
+
+ssize_t lis3l02dq_read_accel_from_ring(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf);
+
+
+int lis3l02dq_configure_ring(struct iio_dev *indio_dev);
+void lis3l02dq_unconfigure_ring(struct iio_dev *indio_dev);
+
+int lis3l02dq_initialize_ring(struct iio_ring_buffer *ring);
+void lis3l02dq_uninitialize_ring(struct iio_ring_buffer *ring);
+#else /* CONFIG_IIO_RING_BUFFER */
+
 static inline void lis3l02dq_remove_trigger(struct iio_dev *indio_dev) {};
 static inline int lis3l02dq_probe_trigger(struct iio_dev *indio_dev)
 {
@@ -208,5 +228,5 @@ static inline int lis3l02dq_initialize_ring(struct iio_ring_buffer *ring)
 	return 0;
 };
 static inline void lis3l02dq_uninitialize_ring(struct iio_ring_buffer *ring) {};
-
+#endif /* CONFIG_IIO_RING_BUFFER */
 #endif /* SPI_LIS3L02DQ_H_ */