Re: [PATCH v2 2/6] iio: imu: bmi270: Provide chip info as configuration structure

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 18 Oct 2024 16:36:08 -0700
Justin Weiss <justin@justinweiss.com> wrote:

> Prepare the bmi270 driver to support similar devices like the bmi260.
> 
> Signed-off-by: Justin Weiss <justin@justinweiss.com>
One thing in here.  The enum ID thing tends to end up costing more than
the benefit it brings, so for newer drivers preferred option is separate
structure instances rather than an array.

> ---
>  drivers/iio/imu/bmi270/bmi270.h      | 15 ++++++++++++++-
>  drivers/iio/imu/bmi270/bmi270_core.c | 18 +++++++++++++++---
>  drivers/iio/imu/bmi270/bmi270_i2c.c  | 11 ++++++++---
>  drivers/iio/imu/bmi270/bmi270_spi.c  | 11 ++++++++---
>  4 files changed, 45 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iio/imu/bmi270/bmi270.h b/drivers/iio/imu/bmi270/bmi270.h
> index 8ac20ad7ee94..2e8d85a4e419 100644
> --- a/drivers/iio/imu/bmi270/bmi270.h
> +++ b/drivers/iio/imu/bmi270/bmi270.h
> @@ -10,10 +10,23 @@ struct device;
>  struct bmi270_data {
>  	struct device *dev;
>  	struct regmap *regmap;
> +	const struct bmi270_chip_info *chip_info;
> +};
> +
> +enum bmi270_device_type {
> +	BMI270,

Whilst quite a few drivers do it this way, over time we've found that it's
much easier to just skip the array of structures and have independent ones.
Increase the extern lines to one per supported device, but removes
need for an enum here and generally gives slightly more readable code.


> +};

>  };
>  
>  static const struct of_device_id bmi270_of_match[] = {
> -	{ .compatible = "bosch,bmi270" },
> +	{ .compatible = "bosch,bmi270", .data = &bmi270_chip_info[BMI270] },

After dropping the enum this just becomes &bmi270_chip_info
and later you'll add bmi260_chip_info etc.

>  	{ }
>  };
>