iio:adc:ad799x: Add helper function to read/write config register

16-bit on ad7997/ad7998, 8-bit elsewhere

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c
index 92401c958ea244ef971caf1ee2e128131855928c..fe2a9b1170b0c1413572737421ad7ce33fd788f8 100644 (file)
--- a/drivers/iio/adc/ad799x.c
+++ b/drivers/iio/adc/ad799x.c
@@ -136,6 +136,30 @@ struct ad799x_state {
        unsigned int                    transfer_size;
 };
 
+static int ad799x_write_config(struct ad799x_state *st, u16 val)
+{
+       switch (st->id) {
+       case ad7997:
+       case ad7998:
+               return i2c_smbus_write_word_swapped(st->client, AD7998_CONF_REG,
+                       val);
+       default:
+               return i2c_smbus_write_byte_data(st->client, AD7998_CONF_REG,
+                       val);
+       }
+}
+
+static int ad799x_read_config(struct ad799x_state *st)
+{
+       switch (st->id) {
+       case ad7997:
+       case ad7998:
+               return i2c_smbus_read_word_swapped(st->client, AD7998_CONF_REG);
+       default:
+               return i2c_smbus_read_byte_data(st->client, AD7998_CONF_REG);
+       }
+}
+
 /**
  * ad799x_trigger_handler() bh of trigger launched polling to ring buffer
  *