[PATCH] dmaengine: fsl-edma: fixup reg offset and hw S/G support in big-endian model

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Sep 23 03:37:21 PDT 2014


On Tue, Sep 23, 2014 at 05:15:19PM +0800, Jingchang Lu wrote:
>  static u16 edma_readw(struct fsl_edma_engine *edma, void __iomem *addr)
>  {
> -	if (edma->big_endian)
> -		return ioread16be(addr);
> -	else
> +	u32 dst;

This should be unsigned long, if it needs to exist.

> +	/* swap the reg offset for these in big-endian mode */
> +	if (edma->big_endian) {
> +		dst = ((u32)addr & ~0x3) | (((u32)addr & 0x3) ^ 0x2);

This can be simplified to:

		addr = (void __iomem *)((unsigned long)addr ^ 2);

Ditto for all the other cases.

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