[PATCH v3 4/6] iio: adc: ad7173: add support for special inputs

[Dumitru Ceclan via B4 Relay <devnull+dumitru.ceclan.analog.com@kernel.org>]

From: Dumitru Ceclan <dumitru.ceclan@analog.com>

 Add support for selecting REF+ and REF- inputs on all models.
 Add support for selecting ((AVDD1 − AVSS)/5) inputs
  on supported models.

Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
---
 drivers/iio/adc/ad7173.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 8a53821c8e58..106a50dbabd4 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -65,6 +65,10 @@
 	 FIELD_PREP(AD7173_CH_SETUP_AINNEG_MASK, neg))
 #define AD7173_AIN_TEMP_POS	17
 #define AD7173_AIN_TEMP_NEG	18
+#define AD7173_AIN_COM_IN_POS	19
+#define AD7173_AIN_COM_IN_NEG	20
+#define AD7173_AIN_REF_POS	21
+#define AD7173_AIN_REF_NEG	22
 
 #define AD7172_2_ID			0x00d0
 #define AD7175_ID			0x0cd0
@@ -145,6 +149,8 @@ struct ad7173_device_info {
 	unsigned int id;
 	char *name;
 	bool has_temp;
+	/* ((AVDD1 − AVSS)/5) */
+	bool has_common_input;
 	bool has_input_buf;
 	bool has_int_ref;
 	bool has_ref2;
@@ -215,6 +221,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_temp = true,
 		.has_input_buf = true,
 		.has_int_ref = true,
+		.has_common_input = true,
 		.clock = 2 * HZ_PER_MHZ,
 		.sinc5_data_rates = ad7173_sinc5_data_rates,
 		.num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
@@ -229,6 +236,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_temp = false,
 		.has_input_buf = true,
 		.has_ref2 = true,
+		.has_common_input = true,
 		.clock = 2 * HZ_PER_MHZ,
 		.sinc5_data_rates = ad7173_sinc5_data_rates,
 		.num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
@@ -244,6 +252,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_input_buf = true,
 		.has_int_ref = true,
 		.has_ref2 = true,
+		.has_common_input = false,
 		.clock = 2 * HZ_PER_MHZ,
 		.sinc5_data_rates = ad7173_sinc5_data_rates,
 		.num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
@@ -258,6 +267,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_temp = true,
 		.has_input_buf = true,
 		.has_int_ref = true,
+		.has_common_input = true,
 		.clock = 16 * HZ_PER_MHZ,
 		.sinc5_data_rates = ad7175_sinc5_data_rates,
 		.num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
@@ -273,6 +283,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_input_buf = true,
 		.has_int_ref = true,
 		.has_ref2 = true,
+		.has_common_input = true,
 		.clock = 16 * HZ_PER_MHZ,
 		.sinc5_data_rates = ad7175_sinc5_data_rates,
 		.num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
@@ -287,6 +298,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_temp = false,
 		.has_input_buf = false,
 		.has_int_ref = true,
+		.has_common_input = false,
 		.clock = 16 * HZ_PER_MHZ,
 		.sinc5_data_rates = ad7175_sinc5_data_rates,
 		.num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
@@ -301,6 +313,7 @@ static const struct ad7173_device_info ad7173_device_info[] = {
 		.has_temp = true,
 		.has_input_buf = true,
 		.has_int_ref = true,
+		.has_common_input = true,
 		.clock = 16 * HZ_PER_MHZ,
 		.odr_start_value = AD7177_ODR_START_VALUE,
 		.sinc5_data_rates = ad7175_sinc5_data_rates,
@@ -915,6 +928,14 @@ static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
 		if (ain[i] < st->info->num_inputs)
 			continue;
 
+		if (ain[i] == AD7173_AIN_REF_POS || ain[i] == AD7173_AIN_REF_NEG)
+			continue;
+
+		if ((ain[i] == AD7173_AIN_COM_IN_POS ||
+		     ain[i] == AD7173_AIN_COM_IN_NEG) &&
+		    st->info->has_common_input)
+			continue;
+
 		return dev_err_probe(dev, -EINVAL,
 			"Input pin number out of range for pair (%d %d).\n",
 			ain[0], ain[1]);

-- 
2.43.0