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Diffstat (limited to 'arch/arm/mach-integrator/pci.c')
-rw-r--r-- | arch/arm/mach-integrator/pci.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/arm/mach-integrator/pci.c b/arch/arm/mach-integrator/pci.c new file mode 100644 index 000000000000..394ec9261c4e --- /dev/null +++ b/arch/arm/mach-integrator/pci.c @@ -0,0 +1,132 @@ +/* + * linux/arch/arm/mach-integrator/pci-integrator.c + * + * Copyright (C) 1999 ARM Limited + * Copyright (C) 2000 Deep Blue Solutions Ltd + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * + * PCI functions for Integrator + */ +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/ptrace.h> +#include <linux/interrupt.h> +#include <linux/init.h> + +#include <asm/irq.h> +#include <asm/system.h> +#include <asm/mach/pci.h> +#include <asm/mach-types.h> + +/* + * A small note about bridges and interrupts. The DECchip 21050 (and + * later) adheres to the PCI-PCI bridge specification. This says that + * the interrupts on the other side of a bridge are swizzled in the + * following manner: + * + * Dev Interrupt Interrupt + * Pin on Pin on + * Device Connector + * + * 4 A A + * B B + * C C + * D D + * + * 5 A B + * B C + * C D + * D A + * + * 6 A C + * B D + * C A + * D B + * + * 7 A D + * B A + * C B + * D C + * + * Where A = pin 1, B = pin 2 and so on and pin=0 = default = A. + * Thus, each swizzle is ((pin-1) + (device#-4)) % 4 + * + * The following code swizzles for exactly one bridge. + */ +static inline int bridge_swizzle(int pin, unsigned int slot) +{ + return (pin + slot) & 3; +} + +/* + * This routine handles multiple bridges. + */ +static u8 __init integrator_swizzle(struct pci_dev *dev, u8 *pinp) +{ + int pin = *pinp; + + if (pin == 0) + pin = 1; + + pin -= 1; + while (dev->bus->self) { + pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn)); + /* + * move up the chain of bridges, swizzling as we go. + */ + dev = dev->bus->self; + } + *pinp = pin + 1; + + return PCI_SLOT(dev->devfn); +} + +static int irq_tab[4] __initdata = { + IRQ_AP_PCIINT0, IRQ_AP_PCIINT1, IRQ_AP_PCIINT2, IRQ_AP_PCIINT3 +}; + +/* + * map the specified device/slot/pin to an IRQ. This works out such + * that slot 9 pin 1 is INT0, pin 2 is INT1, and slot 10 pin 1 is INT1. + */ +static int __init integrator_map_irq(struct pci_dev *dev, u8 slot, u8 pin) +{ + int intnr = ((slot - 9) + (pin - 1)) & 3; + + return irq_tab[intnr]; +} + +extern void pci_v3_init(void *); + +static struct hw_pci integrator_pci __initdata = { + .swizzle = integrator_swizzle, + .map_irq = integrator_map_irq, + .setup = pci_v3_setup, + .nr_controllers = 1, + .scan = pci_v3_scan_bus, + .preinit = pci_v3_preinit, + .postinit = pci_v3_postinit, +}; + +static int __init integrator_pci_init(void) +{ + if (machine_is_integrator()) + pci_common_init(&integrator_pci); + return 0; +} + +subsys_initcall(integrator_pci_init); |