Re: [PATCH v4 06/10] iio: adc: adi-axi-adc: add data align process

["Nuno Sá" <noname.nuno@gmail.com>]

On Fri, 2025-05-02 at 11:59 +0300, Antoniu Miclaus wrote:
> Add support for starting the sync process used for data
> capture alignment.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
> changes in v4:
>  - rework data_align function.
>  - rename bit definitions/functions.
>  drivers/iio/adc/adi-axi-adc.c | 37 +++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
> index 2a3a6c3f5e59..2a79c043c0de 100644
> --- a/drivers/iio/adc/adi-axi-adc.c
> +++ b/drivers/iio/adc/adi-axi-adc.c
> @@ -44,6 +44,7 @@
>  #define   ADI_AXI_ADC_REG_CONFIG_CMOS_OR_LVDS_N	BIT(7)
>  
>  #define ADI_AXI_ADC_REG_CTRL			0x0044
> +#define    ADI_AXI_ADC_CTRL_SYNC_MSK		BIT(3)
>  #define    ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK	BIT(1)
>  
>  #define ADI_AXI_ADC_REG_CNTRL_3			0x004c
> @@ -54,6 +55,9 @@
>  #define   AXI_AD485X_PACKET_FORMAT_32BIT	0x2
>  #define   AXI_AD408X_CNTRL_3_FILTER_EN_MSK	BIT(0)
>  
> +#define ADI_AXI_ADC_REG_SYNC_STATUS		0x0068
> +#define   ADI_AXI_ADC_SYNC_STATUS_ADC_SYNC_MSK	BIT(0)
> +
>  #define ADI_AXI_ADC_REG_DRP_STATUS		0x0074
>  #define   ADI_AXI_ADC_DRP_LOCKED		BIT(17)
>  
> @@ -416,6 +420,38 @@ static int axi_adc_ad408x_filter_type_set(struct
> iio_backend *back,
>  				 AXI_AD408X_CNTRL_3_FILTER_EN_MSK);
>  }
>  
> +static int axi_adc_ad408x_interface_data_align(struct iio_backend *back,
> +					       u32 timeout)
> +{
> +	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
> +	bool sync_en;
> +	u32 val;
> +	int ret;
> +
> +	ret = regmap_set_bits(st->regmap, ADI_AXI_ADC_REG_CTRL,
> +			      ADI_AXI_ADC_CTRL_SYNC_MSK);
> +	if (ret)
> +		return ret;
> +
> +	do {
> +		ret = regmap_read(st->regmap, ADI_AXI_ADC_REG_SYNC_STATUS,
> &val);
> +		if (ret)
> +			return ret;
> +
> +		sync_en = FIELD_GET(ADI_AXI_ADC_SYNC_STATUS_ADC_SYNC_MSK,
> val);
> +
> +		if (!sync_en)
> +			dev_dbg(st->dev, "Not Locked: Running Bit Slip\n");
> +
> +		fsleep(500);
> +	} while (--timeout && !sync_en);

Why not regmap_read_poll_timeout()?

- Nuno Sá
> +
> +	if (!timeout)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
>  static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
>  						 struct iio_dev *indio_dev)
>  {
> @@ -605,6 +641,7 @@ static const struct iio_backend_ops adi_ad408x_ops = {
>  	.free_buffer = axi_adc_free_buffer,
>  	.data_sample_trigger = axi_adc_data_sample_trigger,
>  	.filter_type_set = axi_adc_ad408x_filter_type_set,
> +	.interface_data_align = axi_adc_ad408x_interface_data_align,
>  	.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),
>  };