From: Angelo Dureghello <adureghello@baylibre.com>

Add data source getter.

Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
---
 drivers/iio/dac/adi-axi-dac.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index 892d770aec69c4259de777058801c9ab33c79923..a6abd828ebdb34800cc08a2151e52a9acda9eba1 100644
--- a/drivers/iio/dac/adi-axi-dac.c
+++ b/drivers/iio/dac/adi-axi-dac.c
@@ -514,6 +514,32 @@ static int axi_dac_data_source_set(struct iio_backend *back, unsigned int chan,
 	}
 }
 
+static int axi_dac_data_source_get(struct iio_backend *back, unsigned int chan,
+				   enum iio_backend_data_source *data)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+	int ret;
+	u32 val;
+
+	ret = regmap_read(st->regmap, AXI_DAC_CHAN_CNTRL_7_REG(chan), &val);
+	if (ret)
+		return ret;
+
+	switch (val) {
+	case AXI_DAC_DATA_INTERNAL_TONE:
+		*data = IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE;
+		return 0;
+	case AXI_DAC_DATA_DMA:
+		*data = IIO_BACKEND_EXTERNAL;
+		return 0;
+	case AXI_DAC_DATA_INTERNAL_RAMP_16BIT:
+		*data = IIO_BACKEND_INTERNAL_RAMP_16BIT;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
 static int axi_dac_set_sample_rate(struct iio_backend *back, unsigned int chan,
 				   u64 sample_rate)
 {
@@ -794,6 +820,7 @@ static const struct iio_backend_ops axi_ad3552r_ops = {
 	.request_buffer = axi_dac_request_buffer,
 	.free_buffer = axi_dac_free_buffer,
 	.data_source_set = axi_dac_data_source_set,
+	.data_source_get = axi_dac_data_source_get,
 	.ddr_enable = axi_dac_ddr_enable,
 	.ddr_disable = axi_dac_ddr_disable,
 	.data_stream_enable = axi_dac_data_stream_enable,

-- 
2.49.0

On Fri, 2025-03-21 at 21:28 +0100, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add data source getter.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> ---
>  drivers/iio/dac/adi-axi-dac.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> index
> 892d770aec69c4259de777058801c9ab33c79923..a6abd828ebdb34800cc08a2151e52a9acda9eba1
> 100644
> --- a/drivers/iio/dac/adi-axi-dac.c
> +++ b/drivers/iio/dac/adi-axi-dac.c
> @@ -514,6 +514,32 @@ static int axi_dac_data_source_set(struct iio_backend *back,
> unsigned int chan,
>  	}
>  }
>  
> +static int axi_dac_data_source_get(struct iio_backend *back, unsigned int chan,
> +				   enum iio_backend_data_source *data)
> +{
> +	struct axi_dac_state *st = iio_backend_get_priv(back);
> +	int ret;
> +	u32 val;
> +
> +	ret = regmap_read(st->regmap, AXI_DAC_CHAN_CNTRL_7_REG(chan), &val);
> +	if (ret)
> +		return ret;

Is chan something that we can validate? Do we reliable know max number of channels?

> +
> +	switch (val) {
> +	case AXI_DAC_DATA_INTERNAL_TONE:
> +		*data = IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE;
> +		return 0;
> +	case AXI_DAC_DATA_DMA:
> +		*data = IIO_BACKEND_EXTERNAL;
> +		return 0;
> +	case AXI_DAC_DATA_INTERNAL_RAMP_16BIT:
> +		*data = IIO_BACKEND_INTERNAL_RAMP_16BIT;
> +		return 0;
> +	default:
> +		return -EINVAL;

More of a nitpick comment but I would some other error code. This is not really an
"Invalid argument" situation. Maybe -EIO as the HW is giving something unexpected? or
ENOTSUPP (likely not exactly like this)...

- Nuno Sá

>  	.ddr_disable = axi_dac_ddr_disable,
>  	.data_stream_enable = axi_dac_data_stream_enable,
> 

On 28.03.2025 08:15, Nuno Sá wrote:
> On Fri, 2025-03-21 at 21:28 +0100, Angelo Dureghello wrote:
> > From: Angelo Dureghello <adureghello@baylibre.com>
> > 
> > Add data source getter.
> > 
> > Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
> > ---
> >  drivers/iio/dac/adi-axi-dac.c | 27 +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> > 
> > diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> > index
> > 892d770aec69c4259de777058801c9ab33c79923..a6abd828ebdb34800cc08a2151e52a9acda9eba1
> > 100644
> > --- a/drivers/iio/dac/adi-axi-dac.c
> > +++ b/drivers/iio/dac/adi-axi-dac.c
> > @@ -514,6 +514,32 @@ static int axi_dac_data_source_set(struct iio_backend *back,
> > unsigned int chan,
> >  	}
> >  }
> >  
> > +static int axi_dac_data_source_get(struct iio_backend *back, unsigned int chan,
> > +				   enum iio_backend_data_source *data)
> > +{
> > +	struct axi_dac_state *st = iio_backend_get_priv(back);
> > +	int ret;
> > +	u32 val;
> > +
> > +	ret = regmap_read(st->regmap, AXI_DAC_CHAN_CNTRL_7_REG(chan), &val);
> > +	if (ret)
> > +		return ret;
> 
> Is chan something that we can validate? Do we reliable know max number of channels?
>

Ack, will set it to 15, 0 to 15 is what the documentation says.
But at this point should be set in a diffetrent patch for the "set"
too.

Btw, there is something odd here. I tested the generator and it works,
i am enabling RAMP for both channels 0 and 1.
The channel offset here is 0x40, while in ad3552r and generic dac doc
it is 0x58. So, since ramp is working i am supposing the documentation 
can be wrong. 
 
> > +
> > +	switch (val) {
> > +	case AXI_DAC_DATA_INTERNAL_TONE:
> > +		*data = IIO_BACKEND_INTERNAL_CONTINUOUS_WAVE;
> > +		return 0;
> > +	case AXI_DAC_DATA_DMA:
> > +		*data = IIO_BACKEND_EXTERNAL;
> > +		return 0;
> > +	case AXI_DAC_DATA_INTERNAL_RAMP_16BIT:
> > +		*data = IIO_BACKEND_INTERNAL_RAMP_16BIT;
> > +		return 0;
> > +	default:
> > +		return -EINVAL;
> 
> More of a nitpick comment but I would some other error code. This is not really an
> "Invalid argument" situation. Maybe -EIO as the HW is giving something unexpected? or
> ENOTSUPP (likely not exactly like this)...
>
Correct, will set EIO.
 
> - Nuno Sá
> 
> >  	.ddr_disable = axi_dac_ddr_disable,
> >  	.data_stream_enable = axi_dac_data_stream_enable,
> > 
>