Re: [PATCH v6 5/8] iio: adc: adi-axi-adc: set data format

David Lechner
2024-11-12T20:11:07Z

On 11/11/24 6:12 AM, Antoniu Miclaus wrote:
> Add support for selecting the data format within the AXI ADC ip.
>
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> ---
> changes in v6:
> - use switch case
> - add macro definition for packet format mask and sizes
> drivers/iio/adc/adi-axi-adc.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
> index f6475bc93796..9bf967d5b730 100644
> --- a/drivers/iio/adc/adi-axi-adc.c
> +++ b/drivers/iio/adc/adi-axi-adc.c
> @@ -45,6 +45,12 @@
> #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 AD485X_CNTRL_3_CUSTOM_CTRL_PACKET_FORMAT_MSK GENMASK(1, 0)
> +#define AD485X_PACKET_FORMAT_20BIT 0x0
> +#define AD485X_PACKET_FORMAT_24BIT 0x1
> +#define AD485X_PACKET_FORMAT_32BIT 0x2
> +
> #define ADI_AXI_ADC_REG_DRP_STATUS 0x0074
> #define ADI_AXI_ADC_DRP_LOCKED BIT(17)
>
> @@ -312,6 +318,29 @@ static int axi_adc_interface_type_get(struct iio_backend *back,
> return 0;
> }
>
> +static int axi_adc_data_size_set(struct iio_backend *back, unsigned int size)
> +{
> + struct adi_axi_adc_state *st = iio_backend_get_priv(back);
> + unsigned int val;
> +
> + switch (size) {

What happened to 16 bit for 16-bit chips?

Ideally there should be an identification register we can read or
a compatible string from the devicetree that says if the HDL was
compiled for a 16-bit or 20-bit chip and we would have two different
versions of this function and pick one based on what HDL is being
used.

> + case 20:
> + val = AD485X_PACKET_FORMAT_20BIT;
> + break;
> + case 24:
> + val = AD485X_PACKET_FORMAT_24BIT;
> + break;
> + case 32:
> + val = AD485X_PACKET_FORMAT_32BIT;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
> + AD485X_CNTRL_3_CUSTOM_CTRL_PACKET_FORMAT_MSK, val);
> +}
> +
> static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
> struct iio_dev *indio_dev)
> {
> @@ -360,6 +389,7 @@ static const struct iio_backend_ops adi_axi_adc_ops = {
> .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,
> .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),
> };