[PATCH v12 7/9] iio: adc: adi-axi-adc: add oversampling

[Antoniu Miclaus <antoniu.miclaus@analog.com>]

Add support for enabling/disabling oversampling.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
no changes in v12.
 drivers/iio/adc/adi-axi-adc.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 272d82c6e887..872ff51e08a7 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -46,6 +46,7 @@
 #define    ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK	BIT(1)
 
 #define ADI_AXI_ADC_REG_CNTRL_3			0x004c
+#define   AD485X_CNTRL_3_OS_EN_MSK		BIT(2)
 #define   AD485X_CNTRL_3_PACKET_FORMAT_MSK	GENMASK(1, 0)
 #define   AD485X_PACKET_FORMAT_20BIT		0x0
 #define   AD485X_PACKET_FORMAT_24BIT		0x1
@@ -363,6 +364,28 @@ static int axi_adc_data_size_set(struct iio_backend *back, unsigned int size)
 				  FIELD_PREP(AD485X_CNTRL_3_PACKET_FORMAT_MSK, val));
 }
 
+static int axi_adc_oversampling_ratio_set(struct iio_backend *back,
+					  unsigned int ratio)
+{
+	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+
+	/* The current state of the function enables or disables the
+	 * oversampling in REG_CNTRL_3 register. A ratio equal to 1 implies no
+	 * oversampling, while a value greater than 1 implies oversampling being
+	 * enabled.
+	 */
+	switch (ratio) {
+	case 0:
+		return -EINVAL;
+	case 1:
+		return regmap_clear_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
+					 AD485X_CNTRL_3_OS_EN_MSK);
+	default:
+		return regmap_set_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
+				       AD485X_CNTRL_3_OS_EN_MSK);
+	}
+}
+
 static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
 						 struct iio_dev *indio_dev)
 {
@@ -428,6 +451,7 @@ static const struct iio_backend_ops adi_ad485x_ops = {
 	.chan_status = axi_adc_chan_status,
 	.interface_type_get = axi_adc_interface_type_get,
 	.data_size_set = axi_adc_data_size_set,
+	.oversampling_ratio_set = axi_adc_oversampling_ratio_set,
 	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_adc_reg_access),
 	.debugfs_print_chan_status = iio_backend_debugfs_ptr(axi_adc_debugfs_print_chan_status),
 };
-- 
2.48.1