iio: core: introduce IIO_CHAN_INFO_HARDWAREGAIN

Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Acked-by: NJonathan Cameron <jic23@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-bus-iio

@@ -280,6 +280,13 @@ Description:
 		If a discrete set of scale values are available, they
 		are listed in this attribute.
 
+What		/sys/bus/iio/devices/iio:deviceX/out_voltageY_hardwaregain
+KernelVersion:	2.6.35
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Hardware applied gain factor. If shared across all channels,
+		<type>_hardwaregain is used.
+
 What:		/sys/.../in_accel_filter_low_pass_3db_frequency
 What:		/sys/.../in_magn_filter_low_pass_3db_frequency
 What:		/sys/.../in_anglvel_filter_low_pass_3db_frequency

drivers/iio/industrialio-core.c

@@ -91,6 +91,7 @@ static const char * const iio_chan_info_postfix[] = {
 	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 	[IIO_CHAN_INFO_FREQUENCY] = "frequency",
 	[IIO_CHAN_INFO_PHASE] = "phase",
+	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 };
 
 const struct iio_chan_spec

include/linux/iio/iio.h

@@ -34,6 +34,7 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_SAMP_FREQ,
 	IIO_CHAN_INFO_FREQUENCY,
 	IIO_CHAN_INFO_PHASE,
+	IIO_CHAN_INFO_HARDWAREGAIN,
 };
 
 #define IIO_CHAN_INFO_SHARED_BIT(type) BIT(type*2)
@@ -95,6 +96,10 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_PHASE)
 #define IIO_CHAN_INFO_PHASE_SHARED_BIT			\
 	IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_PHASE)
+#define IIO_CHAN_INFO_HARDWAREGAIN_SEPARATE_BIT			\
+	IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_HARDWAREGAIN)
+#define IIO_CHAN_INFO_HARDWAREGAIN_SHARED_BIT			\
+	IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_HARDWAREGAIN)
 
 enum iio_endian {
 	IIO_CPU,