[PATCH 1/4] of/pci: Provide support for parsing PCI DT ranges property
Thierry Reding
thierry.reding at avionic-design.de
Tue Feb 12 17:45:23 EST 2013
On Mon, Feb 11, 2013 at 01:43:03PM -0600, Rob Herring wrote:
> On 02/11/2013 02:22 AM, Thierry Reding wrote:
> > From: Andrew Murray <andrew.murray at arm.com>
> >
> > DT bindings for PCI host bridges often use the ranges property to describe
> > memory and IO ranges - this binding tends to be the same across architectures
> > yet several parsing implementations exist, e.g. arch/mips/pci/pci.c,
> > arch/powerpc/kernel/pci-common.c, arch/sparc/kernel/pci.c and
> > arch/microblaze/pci/pci-common.c (clone of PPC). Some of these duplicate
> > functionality provided by drivers/of/address.c.
> >
> > This patch provides a common iterator-based parser for the ranges property, it
> > is hoped this will reduce DT representation differences between architectures
> > and that architectures will migrate in part to this new parser.
> >
> > It is also hoped (and the motativation for the patch) that this patch will
> > reduce duplication of code when writing host bridge drivers that are supported
> > by multiple architectures.
> >
> > This patch provides struct resources from a device tree node, e.g.:
> >
> > u32 *last = NULL;
> > struct resource res;
> > while ((last = of_pci_process_ranges(np, res, last))) {
> > //do something with res
> > }
> >
> > Platforms with quirks can then do what they like with the resource or migrate
> > common quirk handling to the parser. In an ideal world drivers can just request
> > the obtained resources and pass them on (e.g. pci_add_resource_offset).
> >
> > Signed-off-by: Andrew Murray <Andrew.Murray at arm.com>
> > Signed-off-by: Liviu Dudau <Liviu.Dudau at arm.com>
> > Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
> > ---
> > drivers/of/address.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++
> > include/linux/of_address.h | 9 +++++++
> > 2 files changed, 72 insertions(+)
> >
> > diff --git a/drivers/of/address.c b/drivers/of/address.c
> > index 04da786..f607008 100644
> > --- a/drivers/of/address.c
> > +++ b/drivers/of/address.c
> > @@ -13,6 +13,7 @@
> > #define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
> >
> > static struct of_bus *of_match_bus(struct device_node *np);
> > +static struct of_bus *of_find_bus(const char *name);
>
> Can you move this function up to avoid the forward declaration.
It needs to be defined after the of_busses structure, which is defined
below the CONFIG_PCI block where of_pci_process_ranges() is defined. I'd
have to move that one as well and add another #ifdef CONFIG_PCI section.
If you prefer that I can do that.
> > +static struct of_bus *of_find_bus(const char *name)
> > +{
> > + unsigned int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(of_busses); i++)
> > + if (strcmp(name, of_busses[i].name) == 0)
> ^
> space needed.
I don't understand. Do you want the space to go between '.' and "name"?
Thierry
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