iio: adc: ad9088: Add support for CNCO and FNCO mixer mode configuration

This patch introduces support for configuring the mixer modes of both
coarse (CNCO) and fine (FNCO) NCOs via IIO attributes. It adds read and
write handlers for both RX and TX paths, allowing user-space control over
mixer behavior.

The supported mixer modes include:
- Variable IF
- Zero IF
- Fs/4 IF
- Test tone

New IIO attributes:
- main_nco_mixer_mode
- channel_nco_mixer_mode
- *_available variants for both

These attributes are exposed per channel and allow fine-grained control
over signal path configuration, improving flexibility for diverse RF
applications.

Signed-off-by: Michael Hennerich <[email protected]>

Author: mhennerich

drivers/iio/adc/apollo/ad9088.c

@@ -1550,7 +1550,116 @@ static const struct iio_enum ad9088_loopback_modes_enum = {
 	.get = ad9088_loopback_mode_read,
 };
 
+static int ad9088_cnco_mixer_mode_read(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan)
+{
+	struct axiadc_converter *conv = iio_device_get_drvdata(indio_dev);
+	struct ad9088_phy *phy = conv->phy;
+	u8 cddc_num, fddc_num, side, mode;
+	u32 cddc_mask, fddc_mask;
+	int ret;
+
+	ad9088_iiochan_to_fddc_cddc(phy, chan, &fddc_num,
+				    &fddc_mask, &cddc_num, &cddc_mask, &side);
+
+	ret = adi_apollo_hal_bf_get(&phy->ad9088,
+		BF_DRC_IF_MODE_TXRX_COARSE_NCO_INFO(chan->output ? calc_tx_cnco_base(cddc_num) : calc_rx_cnco_base(cddc_num)),
+		&mode, 1);
+	if (ret)
+		return ret;
+
+	return mode & 0x3;
+}
+
+static int ad9088_cnco_mixer_mode_write(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      unsigned int item)
+{
+	struct axiadc_converter *conv = iio_device_get_drvdata(indio_dev);
+	struct ad9088_phy *phy = conv->phy;
+	u8 cddc_num, fddc_num, side;
+	u32 cddc_mask, fddc_mask;
+	int ret = 0;
+
+	ad9088_iiochan_to_fddc_cddc(phy, chan, &fddc_num,
+				    &fddc_mask, &cddc_num, &cddc_mask, &side);
+
+	guard(mutex)(&phy->lock);
+
+	return adi_apollo_cnco_mode_set(&phy->ad9088, chan->output ? ADI_APOLLO_TX : ADI_APOLLO_RX,
+					cddc_mask, item);
+
+	return ret;
+}
+
+static int ad9088_fnco_mixer_mode_read(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan)
+{
+	struct axiadc_converter *conv = iio_device_get_drvdata(indio_dev);
+	struct ad9088_phy *phy = conv->phy;
+	u8 cddc_num, fddc_num, side, mode;
+	u32 cddc_mask, fddc_mask;
+	int ret;
+
+	ad9088_iiochan_to_fddc_cddc(phy, chan, &fddc_num,
+				    &fddc_mask, &cddc_num, &cddc_mask, &side);
+
+	ret = adi_apollo_hal_bf_get(&phy->ad9088,
+		BF_DRC_IF_MODE_TXRX_FINE_NCO_INFO(chan->output ? calc_tx_fnco_base(fddc_num) : calc_rx_fnco_base(fddc_num)),
+		&mode, 1);
+	if (ret)
+		return ret;
+
+	return mode & 0x3;
+}
+
+static int ad9088_fnco_mixer_mode_write(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      unsigned int item)
+{
+	struct axiadc_converter *conv = iio_device_get_drvdata(indio_dev);
+	struct ad9088_phy *phy = conv->phy;
+	u8 cddc_num, fddc_num, side;
+	u32 cddc_mask, fddc_mask;
+	int ret = 0;
+
+	ad9088_iiochan_to_fddc_cddc(phy, chan, &fddc_num,
+				    &fddc_mask, &cddc_num, &cddc_mask, &side);
+
+	guard(mutex)(&phy->lock);
+
+	return adi_apollo_fnco_mode_set(&phy->ad9088, chan->output ? ADI_APOLLO_TX : ADI_APOLLO_RX,
+					fddc_mask, item);
+
+	return ret;
+}
+
+static const char *const ad9088_mixer_modes[] = {
+	[ADI_APOLLO_MXR_VAR_IF_MODE] = "var_IF",
+	[ADI_APOLLO_MXR_ZERO_IF_MODE] = "zero_IF",
+	[ADI_APOLLO_MXR_FS_BY_4_MODE] = "fs/4_IF",
+	[ADI_APOLLO_MXR_TEST_MODE] = "test_tone",
+};
+
+static const struct iio_enum ad9088_cnco_mixer_modes_enum = {
+	.items = ad9088_mixer_modes,
+	.num_items = ARRAY_SIZE(ad9088_mixer_modes),
+	.set = ad9088_cnco_mixer_mode_write,
+	.get = ad9088_cnco_mixer_mode_read,
+};
+
+static const struct iio_enum ad9088_fnco_mixer_modes_enum = {
+	.items = ad9088_mixer_modes,
+	.num_items = ARRAY_SIZE(ad9088_mixer_modes),
+	.set = ad9088_fnco_mixer_mode_write,
+	.get = ad9088_fnco_mixer_mode_read,
+};
+
 static struct iio_chan_spec_ext_info rxadc_ext_info[] = {
+	IIO_ENUM("main_nco_mixer_mode", IIO_SEPARATE, &ad9088_cnco_mixer_modes_enum),
+	IIO_ENUM_AVAILABLE("main_nco_mixer_mode", IIO_SHARED_BY_TYPE, &ad9088_fnco_mixer_modes_enum),
+	IIO_ENUM("channel_nco_mixer_mode", IIO_SEPARATE, &ad9088_cnco_mixer_modes_enum),
+	IIO_ENUM_AVAILABLE("channel_nco_mixer_mode", IIO_SHARED_BY_TYPE, &ad9088_fnco_mixer_modes_enum),
 	IIO_ENUM("test_mode", IIO_SEPARATE, &ad9088_testmode_enum),
 	IIO_ENUM_AVAILABLE("test_mode", IIO_SHARED_BY_TYPE, &ad9088_testmode_enum),
 	IIO_ENUM("loopback", IIO_SEPARATE, &ad9088_loopback_modes_enum),
@@ -1700,6 +1809,10 @@ static struct iio_chan_spec_ext_info rxadc_ext_info[] = {
 };
 
 static struct iio_chan_spec_ext_info txdac_ext_info[] = {
+	IIO_ENUM("main_nco_mixer_mode", IIO_SEPARATE, &ad9088_cnco_mixer_modes_enum),
+	IIO_ENUM_AVAILABLE("main_nco_mixer_mode", IIO_SHARED_BY_TYPE, &ad9088_fnco_mixer_modes_enum),
+	IIO_ENUM("channel_nco_mixer_mode", IIO_SEPARATE, &ad9088_cnco_mixer_modes_enum),
+	IIO_ENUM_AVAILABLE("channel_nco_mixer_mode", IIO_SHARED_BY_TYPE, &ad9088_fnco_mixer_modes_enum),
 	{
 		.name = "main_nco_frequency",
 		.read = ad9088_ext_info_read,