Re: [PATCH v2 1/8] iio: add read raw service to iio backend framework

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 25 Jun 2024 17:07:09 +0200
Olivier Moysan <olivier.moysan@foss.st.com> wrote:

> Add iio_backend_read_raw() service to support attributes read
> from an IIO backend.
> 
> Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
> Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Other than line wrapping moans this looks good to me.

J
> ---
>  drivers/iio/industrialio-backend.c | 21 +++++++++++++++++++++
>  include/linux/iio/backend.h        |  6 +++++-
>  2 files changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/industrialio-backend.c b/drivers/iio/industrialio-backend.c
> index 929aff4040ed..0e2653de1956 100644
> --- a/drivers/iio/industrialio-backend.c
> +++ b/drivers/iio/industrialio-backend.c
> @@ -357,6 +357,27 @@ int devm_iio_backend_request_buffer(struct device *dev,
>  }
>  EXPORT_SYMBOL_NS_GPL(devm_iio_backend_request_buffer, IIO_BACKEND);
>  
> +/**
> + * iio_backend_read_raw - Request a channel attribute from the IIO backend.
> + * @back:	Backend device
> + * @chan:	IIO channel reference
> + * @val:	First element of the returned value
> + * @val2:	Second element of the returned value
> + * @mask:	Specify value to retrieve
> + *
> + * This callback replicates the read_raw callback of the IIO framework, and is intended to
> + * request miscellaneous channel attributes from the backend device.

For IIO code, please still wrap at 80 chars unless there is a good reason to
got longer.

> + *
> + * RETURNS:
> + * 0 on success, negative error number on failure.
> + */
> +int iio_backend_read_raw(struct iio_backend *back, struct iio_chan_spec const *chan, int *val,
Likewise. Wrap this shorter.

> +			 int *val2, long mask)
> +{
> +	return iio_backend_op_call(back, read_raw, chan, val, val2, mask);
> +}
> +EXPORT_SYMBOL_NS_GPL(iio_backend_read_raw, IIO_BACKEND);
> +
>  static struct iio_backend *iio_backend_from_indio_dev_parent(const struct device *dev)
>  {
>  	struct iio_backend *back = ERR_PTR(-ENODEV), *iter;
> diff --git a/include/linux/iio/backend.h b/include/linux/iio/backend.h
> index 8099759d7242..24185718b20d 100644
> --- a/include/linux/iio/backend.h
> +++ b/include/linux/iio/backend.h
> @@ -81,6 +81,7 @@ enum iio_backend_sample_trigger {
>   * @extend_chan_spec: Extend an IIO channel.
>   * @ext_info_set: Extended info setter.
>   * @ext_info_get: Extended info getter.
> + * @read_raw: Read value from a backend device
>   **/
>  struct iio_backend_ops {
>  	int (*enable)(struct iio_backend *back);
> @@ -113,6 +114,8 @@ struct iio_backend_ops {
>  			    const char *buf, size_t len);
>  	int (*ext_info_get)(struct iio_backend *back, uintptr_t private,
>  			    const struct iio_chan_spec *chan, char *buf);
> +	int (*read_raw)(struct iio_backend *back, struct iio_chan_spec const *chan, int *val,
And here.
> +			int *val2, long mask);
>  };
>  
>  int iio_backend_chan_enable(struct iio_backend *back, unsigned int chan);
> @@ -141,7 +144,8 @@ ssize_t iio_backend_ext_info_set(struct iio_dev *indio_dev, uintptr_t private,
>  				 const char *buf, size_t len);
>  ssize_t iio_backend_ext_info_get(struct iio_dev *indio_dev, uintptr_t private,
>  				 const struct iio_chan_spec *chan, char *buf);
> -
> +int iio_backend_read_raw(struct iio_backend *back, struct iio_chan_spec const *chan, int *val,
and here.

> +			 int *val2, long mask);
>  int iio_backend_extend_chan_spec(struct iio_dev *indio_dev,
>  				 struct iio_backend *back,
>  				 struct iio_chan_spec *chan);