iio:ad7476: Add ad7940 support

The AD7940 is a single channel 14 bit ADC similar to the ADCs already supported
by the ad7476 driver, but it does have a different shift factor.

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

2 files changed, 16 insertions, 6 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index c71a0009cc79..e2e696395ac8 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -37,8 +37,8 @@ config AD7476
         select IIO_TRIGGERED_BUFFER
         help
           Say yes here to build support for Analog Devices AD7475, AD7476, AD7477,
-          AD7478, AD7466, AD7467, AD7468, AD7495, AD7910, AD7920 SPI analog to
-          digital converters (ADC).
+          AD7478, AD7466, AD7467, AD7468, AD7495, AD7910, AD7920, AD7920 SPI analog
+          to digital converters (ADC).
 
           If unsure, say N (but it's safe to say "Y").
 
diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
index 093a4ed900d8..be22757d54e4 100644
--- a/drivers/iio/adc/ad7476.c
+++ b/drivers/iio/adc/ad7476.c
@@ -48,7 +48,8 @@ enum ad7476_supported_device_ids {
         ID_AD7466,
         ID_AD7467,
         ID_AD7468,
-        ID_AD7495
+        ID_AD7495,
+        ID_AD7940,
 };
 
 static irqreturn_t ad7476_trigger_handler(int irq, void  *p)
@@ -126,7 +127,7 @@ static int ad7476_read_raw(struct iio_dev *indio_dev,
         return -EINVAL;
 }
 
-#define AD7476_CHAN(bits)                                       \
+#define _AD7476_CHAN(bits, _shift)                              \
         {                                                       \
         .type = IIO_VOLTAGE,                                    \
         .indexed = 1,                                           \
@@ -134,12 +135,16 @@ static int ad7476_read_raw(struct iio_dev *indio_dev,
         IIO_CHAN_INFO_SCALE_SHARED_BIT,                         \
         .scan_type = {                                          \
                 .sign = 'u',                                    \
-                .realbits = bits,                               \
+                .realbits = (bits),                             \
                 .storagebits = 16,                              \
-                .shift = 13 - bits,                             \
+                .shift = (_shift),                              \
+                .endianness = IIO_BE,                           \
         },                                                      \
 }
 
+#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits))
+#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits))
+
 static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
         [ID_AD7466] = {
                 .channel[0] = AD7476_CHAN(12),
@@ -158,6 +163,10 @@ static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
                 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
                 .int_vref_uv = 2500000,
         },
+        [ID_AD7940] = {
+                .channel[0] = AD7940_CHAN(14),
+                .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+        },
 };
 
 static const struct iio_info ad7476_info = {
@@ -260,6 +269,7 @@ static const struct spi_device_id ad7476_id[] = {
         {"ad7495", ID_AD7495},
         {"ad7910", ID_AD7467},
         {"ad7920", ID_AD7466},
+        {"ad7940", ID_AD7940},
         {}
 };
 MODULE_DEVICE_TABLE(spi, ad7476_id);