Subject: Re: [PATCH 5/5] Add DMA engine driver for Freescale MPC85xx processors.

From: Randy Dunlap <[email-masked]>
Date: Fri, 7 Sep 2007 08:58:45 -0700

On Fri,  7 Sep 2007 18:54:18 +0800 Zhang Wei wrote:

> Signed-off-by: Zhang Wei <[email-masked]>
> Signed-off-by: Ebony Zhu <[email-masked]>
> ---
>  drivers/dma/Kconfig  |    8 +
>  drivers/dma/Makefile |    1 +
>  drivers/dma/fsldma.c |  995 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/dma/fsldma.h |  188 ++++++++++
>  4 files changed, 1192 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/dma/fsldma.c
>  create mode 100644 drivers/dma/fsldma.h
> 
> --- /dev/null
> +++ b/drivers/dma/fsldma.c
> @@ -0,0 +1,995 @@

Thanks for using kernel-doc notation.  However, ...

> +/**
> + * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.

Function parameters need to be listed & described here.
See Documentation/kernel-doc-nano-HOWTO.txt or other source files
for examples.

(Applies to all documented function interfaces here.)

> + *
> + * Return - The descriptor allocated. NULL for failed.
> + */
> +static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
> +					struct fsl_dma_chan *fsl_chan,
> +					gfp_t flags)
> +{
...
> +}

> +/**
> + * fsl_chan_xfer_ld_queue -- Transfer the link descriptors in channel
> + *                           ld_queue.

The function's "short description" (unfortunately) must be on only one
line.  E.g.:

 * fsl_chan_xfer_ld_queue - Transfer link descriptors in channel ld_queue.

> + */
> +static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
> +{
...
> +}

> diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h
> new file mode 100644
> index 0000000..05be9ed
> --- /dev/null
> +++ b/drivers/dma/fsldma.h
> @@ -0,0 +1,188 @@
> +struct fsl_dma_chan_regs {
> +	__mix32	mr;		/* 0x00 - Mode Register */
> +	__mix32	sr;		/* 0x04 - Status Register */
> +	__mix64	cdar;		/* 0x08 - Cureent descriptor address register */

                                          Current

> +	__mix64	sar;		/* 0x10 - Source Address Register */
> +	__mix64	dar;		/* 0x18 - Destination Address Register */
> +	__mix32	bcr;		/* 0x20 - Byte Count Register */
> +	__mix64	ndar;		/* 0x24 - Next Descriptor Address Register */
> +};

---
~Randy
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