On Fri, Apr 08, 2016 at 04:34:25PM +0200, Martin Pieuchot wrote:
> On 08/04/16(Fri) 14:46, Patrick Wildt wrote:
> > Hi,
> >
> > so that we can easily check if a node is compatible or to find nodes
> > that are compatible, I would like to add helpers to the fdt routines.
> >
> > This way the drivers can check if they "match" to a node by simply
> > calling:
> >
> > if (fdt_node_compatible(ma->ma_node, "samsung,exynos4210-ehci"))
> > return (1);
> >
> > Sometimes it's helpful to find any node that is compatible. It can
> > be helpful for instance on finding the early uart. Simplified example:
> >
> > if ((node = fdt_find_compatible("arm,pl011")) != NULL)
> > pl011cnattach(...);
> >
> > Thoughts? ok?
>
> Always hard to comment without seeing which code would use that.
>
> Is a custom function really needed? Why not do like sparc64 and macppc,
> for example your ehci_match() could be:
>
> {
> char compat[32];
> ...
>
> if (OF_getprop(ma->ma_node, "compatible", compat, sizeof(compat)) == -1)
> return 0;
>
> if (strcmp(compat, "samsung,exynos4210-ehci") == 0
> return 1;
>
> return 0;
> }
>
The compatible attribute can be a list of strings:
compatible = "grinn,am335x-chiliboard", "grinn,am335x-chilisom",
"ti,am33xx";
Implementing parsing multiple strings in a buffer and checking it in
every _match function seemed a bit too much overhead. Imagine 20 drivers
doing the same code over and over again.
Especially if you're also are not looking for one compatible, but
multiple compatibles:
static char *ampintc_compatibles[] = {
"arm,gic",
"arm,cortex-a7-gic",
"arm,cortex-a9-gic",
"arm,cortex-a15-gic",
NULL
};
for (int i = 0; ampintc_compatibles[i]; i++)
if (fdt_node_compatible(ia->ca_node,
ampintc_compatibles[i]))
return (1);
