On Mon, Sep 23, 2024 at 12:16 PM Antoniu Miclaus
<antoniu.miclaus@xxxxxxxxxx> wrote:
>
> Add support for selecting the data format within the AXI ADC ip.
>
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> ---
> drivers/iio/adc/adi-axi-adc.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
> index ff48f26e02a3..926a8902c621 100644
> --- a/drivers/iio/adc/adi-axi-adc.c
> +++ b/drivers/iio/adc/adi-axi-adc.c
> @@ -45,6 +45,8 @@
> #define ADI_AXI_ADC_REG_CTRL 0x0044
> #define ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK BIT(1)
>
> +#define ADI_AXI_ADC_REG_CNTRL_3 0x004c
> +
> #define ADI_AXI_ADC_REG_DRP_STATUS 0x0074
> #define ADI_AXI_ADC_DRP_LOCKED BIT(17)
>
> @@ -271,6 +273,24 @@ static int axi_adc_interface_type_get(struct iio_backend *back,
> return 0;
> }
>
> +static int axi_adc_data_size_set(struct iio_backend *back,
> + ssize_t size)
> +{
> + struct adi_axi_adc_state *st = iio_backend_get_priv(back);
> + unsigned int val;
> +
> + if (size <= 20)
> + val = 0;
> + else if (size <= 24)
> + val = 1;
> + else if (size <= 32)
> + val = 3;
> + else
> + return -EINVAL;
> +
> + return regmap_write(st->regmap, ADI_AXI_ADC_REG_CNTRL_3, val);
http://analogdevicesinc.github.io/hdl/library/axi_ad485x/index.html
says that bit 8 of this register is CRC_EN and bits 7 to 0 are
CUSTOM_CONTROL so we likely need a mask and regmap_write_bits() here.
Also, since the value being written here is CUSTOM_CONTROL, it makes
me wonder if this callback really belongs to adi_axi_adc_generic or if
we need a copy of that specific to the axi_ad485x project to handle
the custom meaning of this value for this family of chips. The
description of CUSTOM_CONTROL in the link is "Select output format
decode mode.(for ADAQ8092: bit 0 - enables digital output randomizer
decode , bit 1 - enables alternate bit polarity decode)." which
doesn't look like what is being done in the function above.
> +}
> +
> static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
> struct iio_dev *indio_dev)
> {
> @@ -308,6 +328,7 @@ static const struct iio_backend_ops adi_axi_adc_generic = {
> .test_pattern_set = axi_adc_test_pattern_set,
> .chan_status = axi_adc_chan_status,
> .interface_type_get = axi_adc_interface_type_get,
> + .data_size_set = axi_adc_data_size_set,
> };
>
> static int adi_axi_adc_probe(struct platform_device *pdev)
> --
> 2.46.0
>
