Re: [PATCH] iio: kfifo: add devm_iio_triggered_buffer_setup_ext variant

[Alexandru Ardelean <ardeleanalex@gmail.com>]

On Thu, Mar 11, 2021 at 11:14 AM Alexandru Ardelean
<aardelean@deviqon.com> wrote:
>
> This is similar to the {devm_}iio_triggered_buffer_setup_ext variants added
> via commit 5164c7889857 ("iio: triggered-buffer: add
> {devm_}iio_triggered_buffer_setup_ext variants").
>
> These can be used to pass extra buffer attributes to the buffer object.
> This is a bit of temporary mechanism (hopefully) so that drivers that want
> to allocate a kfifo buffer with extra buffer attributes, don't need to
> include 'buffer_impl.h' directly. This can also become an API function (in
> it's own right, unfortunately), but it may be a little less bad vs drivers
> having to include 'buffer_impl.h'.
>
> So, far the drivers that want to pass buffer attributes, all have to do
> with some HW FIFO attributes, so there may be a chance of unifying them
> into IIO core somehow (as some standard API). But, until that happens, we
> just need to let them register their HW FIFO attributes directly (without
> having to let them include 'buffer_impl.h' directly).
>

This isn't required anymore.
Please disregard.
Apologies for the noise

> Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
> ---
>
> Related to the discussion here:
>   https://lore.kernel.org/linux-iio/CA+U=Dspk3cWjiiRmDrgfHAY6houjr-KtSD3u4BssUcb=c2ujpQ@mail.gmail.com/T/#mcfda9d6cb6426caefa4a5db6d634640bfdbe328e
>
>  drivers/iio/buffer/kfifo_buf.c | 16 ++++++++++------
>  include/linux/iio/kfifo_buf.h  | 12 ++++++++----
>  2 files changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/iio/buffer/kfifo_buf.c b/drivers/iio/buffer/kfifo_buf.c
> index 4ecfa0ec3016..13eea2e11cbc 100644
> --- a/drivers/iio/buffer/kfifo_buf.c
> +++ b/drivers/iio/buffer/kfifo_buf.c
> @@ -206,22 +206,24 @@ static struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
>  }
>
>  /**
> - * devm_iio_kfifo_buffer_setup - Allocate a kfifo buffer & attach it to an IIO device
> + * devm_iio_kfifo_buffer_setup_ext - Allocate a kfifo buffer & attach it to an IIO device
>   * @dev: Device object to which to attach the life-time of this kfifo buffer
>   * @indio_dev: The device the buffer should be attached to
>   * @mode_flags: The mode flags for this buffer (INDIO_BUFFER_SOFTWARE and/or
>   *             INDIO_BUFFER_TRIGGERED).
>   * @setup_ops: The setup_ops required to configure the HW part of the buffer (optional)
> + * @buffer_attrs: Extra sysfs buffer attributes for this IIO buffer
>   *
>   * This function allocates a kfifo buffer via devm_iio_kfifo_allocate() and
>   * attaches it to the IIO device via iio_device_attach_buffer().
>   * This is meant to be a bit of a short-hand/helper function as there are a few
>   * drivers that seem to do this.
>   */
> -int devm_iio_kfifo_buffer_setup(struct device *dev,
> -                               struct iio_dev *indio_dev,
> -                               int mode_flags,
> -                               const struct iio_buffer_setup_ops *setup_ops)
> +int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
> +                                   struct iio_dev *indio_dev,
> +                                   int mode_flags,
> +                                   const struct iio_buffer_setup_ops *setup_ops,
> +                                   const struct attribute **buffer_attrs)
>  {
>         struct iio_buffer *buffer;
>
> @@ -237,8 +239,10 @@ int devm_iio_kfifo_buffer_setup(struct device *dev,
>         indio_dev->modes |= mode_flags;
>         indio_dev->setup_ops = setup_ops;
>
> +       buffer->attrs = buffer_attrs;
> +
>         return iio_device_attach_buffer(indio_dev, buffer);
>  }
> -EXPORT_SYMBOL_GPL(devm_iio_kfifo_buffer_setup);
> +EXPORT_SYMBOL_GPL(devm_iio_kfifo_buffer_setup_ext);
>
>  MODULE_LICENSE("GPL");
> diff --git a/include/linux/iio/kfifo_buf.h b/include/linux/iio/kfifo_buf.h
> index 1522896e1daf..ccd2ceae7b25 100644
> --- a/include/linux/iio/kfifo_buf.h
> +++ b/include/linux/iio/kfifo_buf.h
> @@ -10,9 +10,13 @@ struct device;
>  struct iio_buffer *iio_kfifo_allocate(void);
>  void iio_kfifo_free(struct iio_buffer *r);
>
> -int devm_iio_kfifo_buffer_setup(struct device *dev,
> -                               struct iio_dev *indio_dev,
> -                               int mode_flags,
> -                               const struct iio_buffer_setup_ops *setup_ops);
> +int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
> +                                   struct iio_dev *indio_dev,
> +                                   int mode_flags,
> +                                   const struct iio_buffer_setup_ops *setup_ops,
> +                                   const struct attribute **buffer_attrs);
> +
> +#define devm_iio_kfifo_buffer_setup(dev, indio_dev, mode_flags, setup_ops)     \
> +       devm_iio_kfifo_buffer_setup_ext((dev), (indio_dev), (mode_flags), (setup_ops), NULL)
>
>  #endif
> --
> 2.29.2
>