Messages in this thread | | | Date | Mon, 11 Feb 2013 13:43:03 -0600 | From | Rob Herring <> | Subject | Re: [PATCH 1/4] of/pci: Provide support for parsing PCI DT ranges property |
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On 02/11/2013 02:22 AM, Thierry Reding wrote: > From: Andrew Murray <andrew.murray@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@arm.com> > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> > Signed-off-by: Thierry Reding <thierry.reding@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.
> static int __of_address_to_resource(struct device_node *dev, > const __be32 *addrp, u64 size, unsigned int flags, > const char *name, struct resource *r); > @@ -227,6 +228,57 @@ int of_pci_address_to_resource(struct device_node *dev, int bar, > return __of_address_to_resource(dev, addrp, size, flags, NULL, r); > } > EXPORT_SYMBOL_GPL(of_pci_address_to_resource); > + > +const __be32 *of_pci_process_ranges(struct device_node *node, > + struct resource *res, const __be32 *from) > +{ > + const __be32 *start, *end; > + int na, ns, np, pna; > + int rlen; > + struct of_bus *bus; > + > + WARN_ON(!res); > + > + bus = of_find_bus("pci"); > + bus->count_cells(node, &na, &ns); > + if (!OF_CHECK_COUNTS(na, ns)) { > + pr_err("Bad cell count for %s\n", node->full_name); > + return NULL; > + } > + > + pna = of_n_addr_cells(node); > + np = pna + na + ns; > + > + start = of_get_property(node, "ranges", &rlen); > + if (start == NULL) > + return NULL; > + > + end = start + rlen / sizeof(__be32); > + > + if (!from) > + from = start; > + > + while (from + np <= end) { > + u64 cpu_addr, size; > + > + cpu_addr = of_translate_address(node, from + na); > + size = of_read_number(from + na + pna, ns); > + res->flags = bus->get_flags(from); > + from += np; > + > + if (cpu_addr == OF_BAD_ADDR || size == 0) > + continue; > + > + res->name = node->full_name; > + res->start = cpu_addr; > + res->end = res->start + size - 1; > + res->parent = res->child = res->sibling = NULL; > + return from; > + } > + > + return NULL; > +} > +EXPORT_SYMBOL_GPL(of_pci_process_ranges); > #endif /* CONFIG_PCI */ > > /* > @@ -337,6 +389,17 @@ static struct of_bus *of_match_bus(struct device_node *np) > return NULL; > } > > +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.
> + return &of_busses[i]; > + > + return NULL; > +} > + > static int of_translate_one(struct device_node *parent, struct of_bus *bus, > struct of_bus *pbus, __be32 *addr, > int na, int ns, int pna, const char *rprop) > diff --git a/include/linux/of_address.h b/include/linux/of_address.h > index 0506eb5..751e889 100644 > --- a/include/linux/of_address.h > +++ b/include/linux/of_address.h > @@ -27,6 +27,8 @@ static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; } > #define pci_address_to_pio pci_address_to_pio > #endif > > +const __be32 *of_pci_process_ranges(struct device_node *node, > + struct resource *res, const __be32 *from); > #else /* CONFIG_OF_ADDRESS */ > #ifndef of_address_to_resource > static inline int of_address_to_resource(struct device_node *dev, int index, > @@ -53,6 +55,13 @@ static inline const __be32 *of_get_address(struct device_node *dev, int index, > { > return NULL; > } > + > +static inline const __be32 *of_pci_process_ranges(struct device_node *node, > + struct resource *res, > + const __be32 *from) > +{ > + return NULL; > +} > #endif /* CONFIG_OF_ADDRESS */ > > >
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