Re: [PATCH V2 3/6] pinctrl: core device tree mapping table parsing support

[Dong Aisheng <aisheng.dong@freescale.com>]

On Thu, Mar 22, 2012 at 01:25:25AM +0800, Stephen Warren wrote:
> On 03/21/2012 09:48 AM, Stephen Warren wrote:
> > On 03/21/2012 01:31 AM, Dong Aisheng wrote:
> >> On Wed, Mar 21, 2012 at 01:44:36AM +0800, Stephen Warren wrote:
> ...
> >>> +int pinctrl_dt_to_map(struct pinctrl *p)
> >>> +{
> >>> +	struct device_node *np = p->dev->of_node;
> >>> +	int state, ret;
> >>> +	char *propname;
> >>> +	struct property *prop;
> >>> +	const char *statename;
> >>> +	const __be32 *list;
> >>> +	int size, config;
> >>> +	phandle phandle;
> >>> +	struct device_node *np_config;
> >>> +	struct pinctrl_dt_map *dt_map;
> >>
> >> Add NULL np checking?
> > 
> > Oops yes. I though I had that somewhere, but evidently not...
> 
> It turns out this isn't needed; of_node_get() and of_find_property()
> both handle a NULL np just fine. Still, I suppose this might not always
> be true for arbitrary code that's in pinctrl_dt_to_map(), so perhaps we
> should add this anyway.
> 
Yes, and it's meaningless to keep going forward if np is NULL.

> >>> +		}
> >>> +
> >>> +		/* For every referenced pin configuration node in it */
> >>> +		for (config = 0; config < size; config++) {
> >>> +			phandle = be32_to_cpup(list++);
> >>> +
> >>> +			/* Look up the pin configuration node */
> >>> +			np_config = of_find_node_by_phandle(phandle);
> >>
> >> One option is using of_parse_phandle, then we do not need calculate
> >> the phandle offset by ourselves.
> >> Like:
> >> np_config = of_parse_phandle(propname , config);
> > 
> > Yes, that's a good idea. I'll try that.
> 
> I looked at this more, and the existing code is a lot more efficient;
> of_parse_phandle() internally calls of_find_property() each time, which
> this pinctrl code has already done. I'd rather just leave this as it is.
> Are you OK with that?
> 
Yes, i'm ok with it.

Regards
Dong Aisheng