diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/of/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/of/Makefile | 1 | ||||
| -rw-r--r-- | drivers/of/of_pci.c | 91 |
3 files changed, 98 insertions, 0 deletions
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 3c6e100a3ad0..efabbf9dd607 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -69,4 +69,10 @@ config OF_MDIO help OpenFirmware MDIO bus (Ethernet PHY) accessors +config OF_PCI + def_tristate PCI + depends on PCI && (PPC || MICROBLAZE) + help + OpenFirmware PCI bus accessors + endmenu # OF diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 3ab21a0a4907..f7861ed2f287 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_OF_I2C) += of_i2c.o obj-$(CONFIG_OF_NET) += of_net.o obj-$(CONFIG_OF_SPI) += of_spi.o obj-$(CONFIG_OF_MDIO) += of_mdio.o +obj-$(CONFIG_OF_PCI) += of_pci.o diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c new file mode 100644 index 000000000000..314535fa32c1 --- /dev/null +++ b/drivers/of/of_pci.c @@ -0,0 +1,91 @@ +#include <linux/kernel.h> +#include <linux/of_pci.h> +#include <asm/prom.h> + +/** + * of_irq_map_pci - Resolve the interrupt for a PCI device + * @pdev: the device whose interrupt is to be resolved + * @out_irq: structure of_irq filled by this function + * + * This function resolves the PCI interrupt for a given PCI device. If a + * device-node exists for a given pci_dev, it will use normal OF tree + * walking. If not, it will implement standard swizzling and walk up the + * PCI tree until an device-node is found, at which point it will finish + * resolving using the OF tree walking. + */ +int of_irq_map_pci(struct pci_dev *pdev, struct of_irq *out_irq) +{ + struct device_node *dn, *ppnode; + struct pci_dev *ppdev; + u32 lspec; + __be32 lspec_be; + __be32 laddr[3]; + u8 pin; + int rc; + + /* Check if we have a device node, if yes, fallback to standard + * device tree parsing + */ + dn = pci_device_to_OF_node(pdev); + if (dn) { + rc = of_irq_map_one(dn, 0, out_irq); + if (!rc) + return rc; + } + + /* Ok, we don't, time to have fun. Let's start by building up an + * interrupt spec. we assume #interrupt-cells is 1, which is standard + * for PCI. If you do different, then don't use that routine. + */ + rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin); + if (rc != 0) + return rc; + /* No pin, exit */ + if (pin == 0) + return -ENODEV; + + /* Now we walk up the PCI tree */ + lspec = pin; + for (;;) { + /* Get the pci_dev of our parent */ + ppdev = pdev->bus->self; + + /* Ouch, it's a host bridge... */ + if (ppdev == NULL) { + ppnode = pci_bus_to_OF_node(pdev->bus); + + /* No node for host bridge ? give up */ + if (ppnode == NULL) + return -EINVAL; + } else { + /* We found a P2P bridge, check if it has a node */ + ppnode = pci_device_to_OF_node(ppdev); + } + + /* Ok, we have found a parent with a device-node, hand over to + * the OF parsing code. + * We build a unit address from the linux device to be used for + * resolution. Note that we use the linux bus number which may + * not match your firmware bus numbering. + * Fortunately, in most cases, interrupt-map-mask doesn't + * include the bus number as part of the matching. + * You should still be careful about that though if you intend + * to rely on this function (you ship a firmware that doesn't + * create device nodes for all PCI devices). + */ + if (ppnode) + break; + + /* We can only get here if we hit a P2P bridge with no node, + * let's do standard swizzling and try again + */ + lspec = pci_swizzle_interrupt_pin(pdev, lspec); + pdev = ppdev; + } + + lspec_be = cpu_to_be32(lspec); + laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); + laddr[1] = laddr[2] = cpu_to_be32(0); + return of_irq_map_raw(ppnode, &lspec_be, 1, laddr, out_irq); +} +EXPORT_SYMBOL_GPL(of_irq_map_pci); |