Re: [PATCH 01/27] iio: iio_push_to_buffers(): Change type of 'data' to const void *

[Jonathan Cameron <jic23@kernel.org>]

On 09/15/13 17:50, Lars-Peter Clausen wrote:
> Change the type of the 'data' parameter for iio_push_to_buffers() from 'u8 *' to
> 'const void *'. Drivers typically use the correct type (e.g. __be16 *) for their
> data buffer. When passing the buffer to iio_push_to_buffers() it needs to be
> cast to 'u8 *' for the compiler to not complain (and also having to add __force
> if we want to keep sparse happy as well). Since the buffer implementation should
> not care about the data layout (except the size of one sample) using a void
> pointer is the correct thing to do. Also make it const as the buffer
> implementations are not supposed to modify it.
> 
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Nice little cleanup.  I can't for the life of me remember how
we ended up with that being u8 *.  Probably something to do with the
original sw_ring buffer implementation.

Applied to the togreg branch of iio.git

Thanks,
> ---
>  drivers/iio/buffer_cb.c           |  6 +++---
>  drivers/iio/industrialio-buffer.c | 10 +++++-----
>  drivers/iio/kfifo_buf.c           |  2 +-
>  include/linux/iio/buffer.h        |  6 +++---
>  include/linux/iio/consumer.h      |  2 +-
>  5 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/iio/buffer_cb.c b/drivers/iio/buffer_cb.c
> index 9d19ba7..5f40b3a 100644
> --- a/drivers/iio/buffer_cb.c
> +++ b/drivers/iio/buffer_cb.c
> @@ -7,12 +7,12 @@
>  
>  struct iio_cb_buffer {
>  	struct iio_buffer buffer;
> -	int (*cb)(u8 *data, void *private);
> +	int (*cb)(const void *data, void *private);
>  	void *private;
>  	struct iio_channel *channels;
>  };
>  
> -static int iio_buffer_cb_store_to(struct iio_buffer *buffer, u8 *data)
> +static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
>  {
>  	struct iio_cb_buffer *cb_buff = container_of(buffer,
>  						     struct iio_cb_buffer,
> @@ -26,7 +26,7 @@ static struct iio_buffer_access_funcs iio_cb_access = {
>  };
>  
>  struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
> -					     int (*cb)(u8 *data,
> +					     int (*cb)(const void *data,
>  						       void *private),
>  					     void *private)
>  {
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index 7ea2edb..a7ac4b5 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -769,8 +769,8 @@ struct iio_demux_table {
>  	struct list_head l;
>  };
>  
> -static unsigned char *iio_demux(struct iio_buffer *buffer,
> -				 unsigned char *datain)
> +static const void *iio_demux(struct iio_buffer *buffer,
> +				 const void *datain)
>  {
>  	struct iio_demux_table *t;
>  
> @@ -783,9 +783,9 @@ static unsigned char *iio_demux(struct iio_buffer *buffer,
>  	return buffer->demux_bounce;
>  }
>  
> -static int iio_push_to_buffer(struct iio_buffer *buffer, unsigned char *data)
> +static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
>  {
> -	unsigned char *dataout = iio_demux(buffer, data);
> +	const void *dataout = iio_demux(buffer, data);
>  
>  	return buffer->access->store_to(buffer, dataout);
>  }
> @@ -800,7 +800,7 @@ static void iio_buffer_demux_free(struct iio_buffer *buffer)
>  }
>  
>  
> -int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data)
> +int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
>  {
>  	int ret;
>  	struct iio_buffer *buf;
> diff --git a/drivers/iio/kfifo_buf.c b/drivers/iio/kfifo_buf.c
> index 1bea41b..538d461 100644
> --- a/drivers/iio/kfifo_buf.c
> +++ b/drivers/iio/kfifo_buf.c
> @@ -95,7 +95,7 @@ static int iio_set_length_kfifo(struct iio_buffer *r, int length)
>  }
>  
>  static int iio_store_to_kfifo(struct iio_buffer *r,
> -			      u8 *data)
> +			      const void *data)
>  {
>  	int ret;
>  	struct iio_kfifo *kf = iio_to_kfifo(r);
> diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h
> index 2bac0eb..e5507e9 100644
> --- a/include/linux/iio/buffer.h
> +++ b/include/linux/iio/buffer.h
> @@ -36,7 +36,7 @@ struct iio_buffer;
>   * any of them not existing.
>   **/
>  struct iio_buffer_access_funcs {
> -	int (*store_to)(struct iio_buffer *buffer, u8 *data);
> +	int (*store_to)(struct iio_buffer *buffer, const void *data);
>  	int (*read_first_n)(struct iio_buffer *buffer,
>  			    size_t n,
>  			    char __user *buf);
> @@ -81,7 +81,7 @@ struct iio_buffer {
>  	bool					stufftoread;
>  	const struct attribute_group *attrs;
>  	struct list_head			demux_list;
> -	unsigned char				*demux_bounce;
> +	void					*demux_bounce;
>  	struct list_head			buffer_list;
>  };
>  
> @@ -120,7 +120,7 @@ int iio_scan_mask_set(struct iio_dev *indio_dev,
>   * @indio_dev:		iio_dev structure for device.
>   * @data:		Full scan.
>   */
> -int iio_push_to_buffers(struct iio_dev *indio_dev, unsigned char *data);
> +int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data);
>  
>  int iio_update_demux(struct iio_dev *indio_dev);
>  
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index 833926c..2752b1f 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -77,7 +77,7 @@ struct iio_cb_buffer;
>   * fail.
>   */
>  struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
> -					     int (*cb)(u8 *data,
> +					     int (*cb)(const void *data,
>  						       void *private),
>  					     void *private);
>  /**
>