[PATCH v2 1/1] dt: Add general DMA window parser

[swarren@wwwdotorg.org (Stephen Warren)]

On 04/23/2012 05:53 AM, Hiroshi Doyu wrote:
> From: Hiroshi DOYU <hdoyu@nvidia.com>
> 
> This code was based on:
> 	"arch/microblaze/kernel/prom_parse.c"
> 	"arch/powerpc/kernel/prom_parse.c"
> 
> "ibm," prefix could be supported with some modification.

That'd probably be a good idea. If it isn't supported, then this code
can't be used as a replacement for the PPC and Microblaze code.

> +int of_parse_dma_window(struct device_node *dn,
> +			const char *propname, int index,
> +			unsigned long *busno,
> +			dma_addr_t *addr, size_t *size)
> +{
> +	const __be32 *dma_window, *end;
> +	int bytes, cur_index = 0;
> +
> +	if (!dn || !propname || !addr || !size)
> +		return -EINVAL;

Instead of erroring out if (!propname), perhaps:

if (!propname)
    propname = "dma-window";

so that only drivers using bindings before this common binding was
defined actually need to write out the property name?

> diff --git a/include/linux/of_address.h b/include/linux/of_address.h
...
> +extern int of_parse_dma_window(struct device_node *dev,
> +			       const char *propname, int index,
> +			       unsigned long *busno,
> +			       dma_addr_t *phys, size_t *size);

This function has the same name as the PPC and Microblaze code it's
based on. Is that going to cause compile and link errors due to
duplicate symbol definitions?