Re: [PATCH v6 04/17] iio: adc: adi-axi-adc: Add support for CRC

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] CRC operations are not hooked up for all AXI ADC IP core variants
--

commit 432feaef6b44e5ab8e03ad8059b2636d78ecf5d5
Author: Janani Sunil <janani.sunil@analog.com>

    iio: adc: adi-axi-adc: Add support for CRC
    
    Add support for enabling and disabling Cyclic Redundancy Check (CRC)
    processing in the AXI ADC backend. CRC provides data integrity verification
    for high-speed ADC data streams, ensuring reliable data transfer between
    the ADC frontend and backend processing systems.

> diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
> index fc7cc92b35f0a..8b7c45d51dbe8 100644
> --- a/drivers/iio/adc/adi-axi-adc.c
> +++ b/drivers/iio/adc/adi-axi-adc.c
[ ... ]
> @@ -47,6 +47,9 @@
>  #define    ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK	BIT(1)
>  
>  #define ADI_AXI_ADC_REG_CNTRL_3			0x004c
> +/* Bit 8 is common to all AXI ADC cores; bits 7-0 are per-HDL-project. */
> +#define    ADI_AXI_ADC_CNTRL_3_CRC_EN_MASK	BIT(8)
> +
>  #define   AXI_AD485X_CNTRL_3_OS_EN_MSK		BIT(2)
>  #define   AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK	GENMASK(1, 0)
>  #define   AXI_AD485X_PACKET_FORMAT_20BIT	0x0
[ ... ]
> @@ -644,6 +663,8 @@ static const struct iio_backend_ops adi_axi_adc_ops = {
>  	.num_lanes_set = axi_adc_num_lanes_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),
> +	.crc_enable = axi_adc_crc_enable,
> +	.crc_disable = axi_adc_crc_disable,
>  };

[Severity: Medium]
If the CRC enable bit is common to all AXI ADC cores as the comment above
suggests, should these callbacks also be added to adi_ad485x_ops and
adi_ad408x_ops in the same file?

For example:

drivers/iio/adc/adi-axi-adc.c:adi_ad485x_ops {
	.enable = axi_adc_enable,
	.disable = axi_adc_disable,
	...
}

If a frontend driver paired with an axi-ad485x or axi-ad408x backend attempts
to call iio_backend_crc_enable(), the call will fail with -EOPNOTSUPP because
the function pointers in those backend ops structures are NULL.

If the feature is intentionally unsupported on those variants, the code comment
claiming it is "common to all" seems misleading.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260904-ad7768-driver-v6-0-e4378f946bfb@analog.com?part=4