iio:imu: Add support for the ADIS16480 and similar IMUs

This patch adds support for the ADIS16375, ADIS16480, ADIS16485, ADIS16488 6
degree to 10 degree of freedom IMUs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index e82cd08..ff781dc 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -20,6 +20,8 @@
 #define ADIS_PAGE_SIZE 0x80
 #define ADIS_REG_PAGE_ID 0x00
 
+struct adis;
+
 /**
  * struct adis_data - ADIS chip variant specific data
  * @read_delay: SPI delay for read operations in us
@@ -44,6 +46,8 @@
 	const char * const *status_error_msgs;
 	unsigned int status_error_mask;
 
+	int (*enable_irq)(struct adis *adis, bool enable);
+
 	bool has_paging;
 };