Re: [PATCH v3] iio: adc: ad7173: fix num_slots

["Nuno Sá" <noname.nuno@gmail.com>]

On Sun, 2025-07-06 at 13:53 -0500, David Lechner wrote:
> Fix the num_slots value for most chips in the ad7173 driver. The correct
> value is the number of CHANNELx registers on the chip.
> 
> In commit 4310e15b3140 ("iio: adc: ad7173: don't make copy of
> ad_sigma_delta_info struct"), we refactored struct ad_sigma_delta_info
> to be static const data instead of being dynamically populated during
> driver probe. However, there was an existing bug in commit 76a1e6a42802
> ("iio: adc: ad7173: add AD7173 driver") where num_slots was incorrectly
> set to the number of CONFIGx registers instead of the number of
> CHANNELx registers. This bug was partially propagated to the refactored
> code in that the 16-channel chips were only given 8 slots instead of
> 16 although we did managed to fix the 8-channel chips and one of the
> 4-channel chips in that commit. However, we botched two of the 4-channel
> chips and ended up incorrectly giving them 8 slots during the
> refactoring.
> 
> This patch fixes that mistake on the 4-channel chips and also
> corrects the 16-channel chips to have 16 slots.
> 
> Fixes: 4310e15b3140 ("iio: adc: ad7173: don't make copy of ad_sigma_delta_info
> struct")
> Signed-off-by: David Lechner <dlechner@baylibre.com>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

> Here is the patch that actually compiles on the fixes-togreg branch.
> ---
> Changes in v3:
> - Drop supports_spi_offload field.
> - Link to v2:
> https://lore.kernel.org/r/20250704-iio-adc-ad7173-fix-num_slots-on-most-chips-v2-1-a74941609143@baylibre.com
> 
> Changes in v2:
> - Improve commit message.
> - Link to v1:
> https://lore.kernel.org/r/20250703-iio-adc-ad7173-fix-num_slots-on-most-chips-v1-1-326c5d113e15@baylibre.com
> ---
>  drivers/iio/adc/ad7173.c | 36 ++++++++++++++++++++++++++----------
>  1 file changed, 26 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
> index
> 1966a9bc331401af118334a7be4c1a5b8d381473..c41bc5b9ac597f57eea6a097cc3a118de7b4
> 2210 100644
> --- a/drivers/iio/adc/ad7173.c
> +++ b/drivers/iio/adc/ad7173.c
> @@ -772,10 +772,26 @@ static const struct ad_sigma_delta_info
> ad7173_sigma_delta_info_8_slots = {
>  	.num_slots = 8,
>  };
>  
> +static const struct ad_sigma_delta_info ad7173_sigma_delta_info_16_slots = {
> +	.set_channel = ad7173_set_channel,
> +	.append_status = ad7173_append_status,
> +	.disable_all = ad7173_disable_all,
> +	.disable_one = ad7173_disable_one,
> +	.set_mode = ad7173_set_mode,
> +	.has_registers = true,
> +	.has_named_irqs = true,
> +	.addr_shift = 0,
> +	.read_mask = BIT(6),
> +	.status_ch_mask = GENMASK(3, 0),
> +	.data_reg = AD7173_REG_DATA,
> +	.num_resetclks = 64,
> +	.num_slots = 16,
> +};
> +
>  static const struct ad7173_device_info ad4111_device_info = {
>  	.name = "ad4111",
>  	.id = AD4111_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in_div = 8,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -797,7 +813,7 @@ static const struct ad7173_device_info ad4111_device_info
> = {
>  static const struct ad7173_device_info ad4112_device_info = {
>  	.name = "ad4112",
>  	.id = AD4112_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in_div = 8,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -818,7 +834,7 @@ static const struct ad7173_device_info ad4112_device_info
> = {
>  static const struct ad7173_device_info ad4113_device_info = {
>  	.name = "ad4113",
>  	.id = AD4113_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in_div = 8,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -837,7 +853,7 @@ static const struct ad7173_device_info ad4113_device_info
> = {
>  static const struct ad7173_device_info ad4114_device_info = {
>  	.name = "ad4114",
>  	.id = AD4114_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in_div = 16,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -856,7 +872,7 @@ static const struct ad7173_device_info ad4114_device_info
> = {
>  static const struct ad7173_device_info ad4115_device_info = {
>  	.name = "ad4115",
>  	.id = AD4115_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in_div = 16,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -875,7 +891,7 @@ static const struct ad7173_device_info ad4115_device_info
> = {
>  static const struct ad7173_device_info ad4116_device_info = {
>  	.name = "ad4116",
>  	.id = AD4116_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in_div = 11,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -894,7 +910,7 @@ static const struct ad7173_device_info ad4116_device_info
> = {
>  static const struct ad7173_device_info ad7172_2_device_info = {
>  	.name = "ad7172-2",
>  	.id = AD7172_2_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_4_slots,
>  	.num_voltage_in = 5,
>  	.num_channels = 4,
>  	.num_configs = 4,
> @@ -927,7 +943,7 @@ static const struct ad7173_device_info
> ad7172_4_device_info = {
>  static const struct ad7173_device_info ad7173_8_device_info = {
>  	.name = "ad7173-8",
>  	.id = AD7173_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in = 17,
>  	.num_channels = 16,
>  	.num_configs = 8,
> @@ -944,7 +960,7 @@ static const struct ad7173_device_info
> ad7173_8_device_info = {
>  static const struct ad7173_device_info ad7175_2_device_info = {
>  	.name = "ad7175-2",
>  	.id = AD7175_2_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_4_slots,
>  	.num_voltage_in = 5,
>  	.num_channels = 4,
>  	.num_configs = 4,
> @@ -961,7 +977,7 @@ static const struct ad7173_device_info
> ad7175_2_device_info = {
>  static const struct ad7173_device_info ad7175_8_device_info = {
>  	.name = "ad7175-8",
>  	.id = AD7175_8_ID,
> -	.sd_info = &ad7173_sigma_delta_info_8_slots,
> +	.sd_info = &ad7173_sigma_delta_info_16_slots,
>  	.num_voltage_in = 17,
>  	.num_channels = 16,
>  	.num_configs = 8,
> 
> ---
> base-commit: 731bfc181896a4dfd20a8c219bef1c205dd1d708
> change-id: 20250703-iio-adc-ad7173-fix-num_slots-on-most-chips-b982206a20b1
> 
> Best regards,