staging: iio: add channel info for sampling frequency

Adding channel info IIO_CHAN_INFO_SAMP_FREQ to select
different sampling frequency per channel wise.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/iio.h

@@ -36,6 +36,7 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
 	IIO_CHAN_INFO_AVERAGE_RAW,
 	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
+	IIO_CHAN_INFO_SAMP_FREQ,
 };
 
 #define IIO_CHAN_INFO_SHARED_BIT(type) BIT(type*2)
@@ -81,6 +82,10 @@ enum iio_chan_info_enum {
 #define IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY_SEPARATE_BIT \
 	IIO_CHAN_INFO_SEPARATE_BIT(			       \
 		IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)
+#define IIO_CHAN_INFO_SAMP_FREQ_SEPARATE_BIT		\
+	IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_SAMP_FREQ)
+#define IIO_CHAN_INFO_SAMP_FREQ_SHARED_BIT			\
+	IIO_CHAN_INFO_SHARED_BIT(IIO_CHAN_INFO_SAMP_FREQ)
 
 enum iio_endian {
 	IIO_CPU,

drivers/staging/iio/industrialio-core.c

@@ -90,6 +90,7 @@ static const char * const iio_chan_info_postfix[] = {
 	[IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 	[IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 	= "filter_low_pass_3db_frequency",
+	[IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 };
 
 const struct iio_chan_spec