Re: [PATCH v2 5/6] iio: imu: bmi270: Add triggered buffer for Bosch BMI270 IMU

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 18 Oct 2024 16:36:11 -0700
Justin Weiss <justin@justinweiss.com> wrote:

> Set up a triggered buffer for the accel and angl_vel values.
> 
> Signed-off-by: Justin Weiss <justin@justinweiss.com>
Looks good. One trivial comment inline.

Thanks,

Jonathan

> ---
>  drivers/iio/imu/bmi270/Kconfig       |  1 +
>  drivers/iio/imu/bmi270/bmi270.h      |  9 +++++
>  drivers/iio/imu/bmi270/bmi270_core.c | 56 ++++++++++++++++++++++++++++
>  3 files changed, 66 insertions(+)
> 
> diff --git a/drivers/iio/imu/bmi270/Kconfig b/drivers/iio/imu/bmi270/Kconfig
> index 0ffd29794fda..6362acc706da 100644
> --- a/drivers/iio/imu/bmi270/Kconfig
> +++ b/drivers/iio/imu/bmi270/Kconfig
> @@ -6,6 +6,7 @@
>  config BMI270
>  	tristate
>  	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
>  
>  config BMI270_I2C
>  	tristate "Bosch BMI270 I2C driver"
> diff --git a/drivers/iio/imu/bmi270/bmi270.h b/drivers/iio/imu/bmi270/bmi270.h
> index 51e374fd4290..844d70a7d32e 100644
> --- a/drivers/iio/imu/bmi270/bmi270.h
> +++ b/drivers/iio/imu/bmi270/bmi270.h
> @@ -11,6 +11,15 @@ struct bmi270_data {
>  	struct device *dev;
>  	struct regmap *regmap;
>  	const struct bmi270_chip_info *chip_info;
> +
> +	/*
> +	 * Where IIO_DMA_MINALIGN is larger than 8 bytes, align to that

maybe larger than 8 bytes
on x86_64 I think it is 8 bytes exactly, though I could be remembering that wrong.

> +	 * to ensure a DMA safe buffer.
> +	 */
> +	struct {
> +		__le16 channels[6];
> +		aligned_s64 timestamp;
> +	} data __aligned(IIO_DMA_MINALIGN);
>  };
>