[PATCH 01/15] staging: comedi: comedi_isadma: introduce helper module for ISA DMA

Ian Abbott abbotti at mev.co.uk
Thu Jan 15 10:51:03 UTC 2015


On 14/01/15 17:05, H Hartley Sweeten wrote:
> Introduce a new helper module to consolidate all the ISA DMA code. This will
> allow removing the "depends on ISA_DMA_API" from the legacy drivers that can
> use DMA for async command support.
>
> This module is complete based on the various uses of ISA DMA in the comedi
> drivers.
>
> Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
> Cc: Ian Abbott <abbotti at mev.co.uk>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> ---
[snip]
> diff --git a/drivers/staging/comedi/drivers/comedi_isadma.c b/drivers/staging/comedi/drivers/comedi_isadma.c
> new file mode 100644
> index 0000000..dbdea71
> --- /dev/null
> +++ b/drivers/staging/comedi/drivers/comedi_isadma.c
[snip]
> +/**
> + * comedi_isadma_set_mode - set the ISA DMA transfer direction
> + * @desc:	the ISA DMA cookie to set
> + * @dma_dir:	the DMA direction
> + */

I think it's worth documenting the values of dma_dir there, i.e. 
COMEDI_ISADMA_READ or COMEDI_ISADMA_WRITE.

> +void comedi_isadma_set_mode(struct comedi_isadma_desc *desc, char dma_dir)
> +{
> +	desc->mode = (dma_dir == COMEDI_ISADMA_READ) ? DMA_MODE_READ
> +						     : DMA_MODE_WRITE;
> +}
> +EXPORT_SYMBOL_GPL(comedi_isadma_set_mode);
> +
> +/**
> + * comedi_isadma_alloc - allocate and initialize the ISA DMA
> + * @dev:	comedi_device struct
> + * @n_desc:	the number of cookies to allocate
> + * @dma_chan:	DMA channel for the first cookie
> + * @dma_chan2:	DMA channel for the second cookie
> + * @maxsize:	the size of the buffer to allocate for each cookie
> + * @dma_dir:	the DMA direction
> + *
> + * Returns the allocated and initialized ISA DMA or NULL if anything fails.
> + */

Ditto.

-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbotti at mev.co.uk> )=-
-=(                          Web: http://www.mev.co.uk/  )=-


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