staging: iio: light sensor: Add a calibscale file to the isl29018 light sensor driver.

Defaulting to 1, this gives a way to amplify the lux value before being
reduced by the programmed adc_bit shift.
Only support whole numbers right now.  When this driver is converted to the new
IIO_CHAN framework, it will be easy to support the framework's pseudo float.

Add illuminance0_calibscale documentation to sysfs-bus-iio-light.

Signed-off-by: Bryan Freed <bfreed@chromium.org>
Acked-by: Rhyland Klein <rklein@nvidia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-light b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
index 21d27740581..edbf470e4e3 100644
--- a/drivers/staging/iio/Documentation/sysfs-bus-iio-light
+++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
@@ -75,3 +75,11 @@ KernelVersion:	2.6.37
 Contact:        linux-iio@vger.kernel.org
 Description:
                 This property gets/sets the sensors ADC analog integration time.
+
+What:           /sys/bus/iio/devices/device[n]/illuminance0_calibscale
+KernelVersion:  2.6.37
+Contact:        linux-iio@vger.kernel.org
+Description:
+                Hardware or software applied calibration scale factor assumed
+                to account for attenuation due to industrial design (glass
+                filters or aperture holes).