Re: [PATCH v2 4/5] drivers: iio: adc: LTC2499 support

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 01/09/2022 15:16, Ciprian Regus wrote:
> The LTC2499 is a 16-channel (eight differential), 24-bit,
> ADC with Easy Drive technology and a 2-wire, I2C interface.
> 
> Implement support for the LTC2499 ADC by extending the LTC2497
> driver. A new chip_info struct is added to differentiate between
> chip types and resolutions when reading data from the device.
> 
> Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2499fe.pdf

Missing blank line. Use standard Git tools for handling your patches or
be sure you produce the same result when using some custom process.

> Signed-off-by: Ciprian Regus <ciprian.regus@analog.com>

(...)

> +};
> +
>  static const struct i2c_device_id ltc2497_id[] = {
> -	{ "ltc2497", 0 },
> +	{ "ltc2497", (kernel_ulong_t)&ltc2497_info[TYPE_LTC2497] },
> +	{ "ltc2499", (kernel_ulong_t)&ltc2497_info[TYPE_LTC2497] },

So they are the same, aren't they?

>  	{ }
>  };
>  MODULE_DEVICE_TABLE(i2c, ltc2497_id);
>  
>  static const struct of_device_id ltc2497_of_match[] = {
> -	{ .compatible = "lltc,ltc2497", },
> +	{ .compatible = "lltc,ltc2497", .data = &ltc2497_info[TYPE_LTC2497] },
> +	{ .compatible = "lltc,ltc2499", .data = &ltc2497_info[TYPE_LTC2499] },

I think this should be split into two patches for easier review - one
working on driver data for existing variant and second for adding new
variant 2499.

>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, ltc2497_of_match);
> diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
> index d0b42dd6b8ad..95f6a5f4d4a6 100644
> --- a/drivers/iio/adc/ltc2497.h
> +++ b/drivers/iio/adc/ltc2497.h
> @@ -4,9 +4,20 @@
>  #define LTC2497_CONFIG_DEFAULT		LTC2497_ENABLE
>  #define LTC2497_CONVERSION_TIME_MS	150ULL
>  
> +enum ltc2497_chip_type {
> +	TYPE_LTC2496,

Why having here 2496 and not using it?

> +	TYPE_LTC2497,
> +	TYPE_LTC2499,
> +};
> +
Krzysztof