Linux-2.6.12-rc2
[linux-2.6/kvm.git] / arch / arm / mach-ixp2000 / pci.c
blob831f8ffb6b61d200cf535637e612c4dbfc3ee917
1 /*
2 * arch/arm/mach-ixp2000/pci.c
4 * PCI routines for IXDP2400/IXDP2800 boards
6 * Original Author: Naeem Afzal <naeem.m.afzal@intel.com>
7 * Maintained by: Deepak Saxena <dsaxena@plexity.net>
9 * Copyright 2002 Intel Corp.
10 * Copyright (C) 2003-2004 MontaVista Software, Inc.
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version.
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/pci.h>
21 #include <linux/interrupt.h>
22 #include <linux/mm.h>
23 #include <linux/init.h>
24 #include <linux/ioport.h>
25 #include <linux/slab.h>
26 #include <linux/delay.h>
28 #include <asm/io.h>
29 #include <asm/irq.h>
30 #include <asm/system.h>
31 #include <asm/mach-types.h>
32 #include <asm/hardware.h>
34 #include <asm/mach/pci.h>
36 static int pci_master_aborts = 0;
38 static int clear_master_aborts(void);
40 static u32 *
41 ixp2000_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
43 u32 *paddress;
45 if (PCI_SLOT(devfn) > 7)
46 return 0;
48 /* Must be dword aligned */
49 where &= ~3;
52 * For top bus, generate type 0, else type 1
54 if (!bus_nr) {
55 /* only bits[23:16] are used for IDSEL */
56 paddress = (u32 *) (IXP2000_PCI_CFG0_VIRT_BASE
57 | (1 << (PCI_SLOT(devfn) + 16))
58 | (PCI_FUNC(devfn) << 8) | where);
59 } else {
60 paddress = (u32 *) (IXP2000_PCI_CFG1_VIRT_BASE
61 | (bus_nr << 16)
62 | (PCI_SLOT(devfn) << 11)
63 | (PCI_FUNC(devfn) << 8) | where);
66 return paddress;
70 * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
71 * 0 and 3 are not valid indexes...
73 static u32 bytemask[] = {
74 /*0*/ 0,
75 /*1*/ 0xff,
76 /*2*/ 0xffff,
77 /*3*/ 0,
78 /*4*/ 0xffffffff,
82 int ixp2000_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where,
83 int size, u32 *value)
85 u32 n;
86 u32 *addr;
88 n = where % 4;
90 addr = ixp2000_pci_config_addr(bus->number, devfn, where);
91 if (!addr)
92 return PCIBIOS_DEVICE_NOT_FOUND;
94 pci_master_aborts = 0;
95 *value = (*addr >> (8*n)) & bytemask[size];
96 if (pci_master_aborts) {
97 pci_master_aborts = 0;
98 *value = 0xffffffff;
99 return PCIBIOS_DEVICE_NOT_FOUND;
102 return PCIBIOS_SUCCESSFUL;
106 * We don't do error checks by callling clear_master_aborts() b/c the
107 * assumption is that the caller did a read first to make sure a device
108 * exists.
110 int ixp2000_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where,
111 int size, u32 value)
113 u32 mask;
114 u32 *addr;
115 u32 temp;
117 mask = ~(bytemask[size] << ((where % 0x4) * 8));
118 addr = ixp2000_pci_config_addr(bus->number, devfn, where);
119 if (!addr)
120 return PCIBIOS_DEVICE_NOT_FOUND;
121 temp = (u32) (value) << ((where % 0x4) * 8);
122 *addr = (*addr & mask) | temp;
124 clear_master_aborts();
126 return PCIBIOS_SUCCESSFUL;
130 static struct pci_ops ixp2000_pci_ops = {
131 .read = ixp2000_pci_read_config,
132 .write = ixp2000_pci_write_config
135 struct pci_bus *ixp2000_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
137 return pci_scan_bus(sysdata->busnr, &ixp2000_pci_ops, sysdata);
141 int ixp2000_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
144 volatile u32 temp;
145 unsigned long flags;
147 pci_master_aborts = 1;
149 local_irq_save(flags);
150 temp = *(IXP2000_PCI_CONTROL);
151 if (temp & ((1 << 8) | (1 << 5))) {
152 ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
155 temp = *(IXP2000_PCI_CMDSTAT);
156 if (temp & (1 << 29)) {
157 while (temp & (1 << 29)) {
158 ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
159 temp = *(IXP2000_PCI_CMDSTAT);
162 local_irq_restore(flags);
165 * If it was an imprecise abort, then we need to correct the
166 * return address to be _after_ the instruction.
168 if (fsr & (1 << 10))
169 regs->ARM_pc += 4;
171 return 0;
175 clear_master_aborts(void)
177 volatile u32 temp;
178 unsigned long flags;
180 local_irq_save(flags);
181 temp = *(IXP2000_PCI_CONTROL);
182 if (temp & ((1 << 8) | (1 << 5))) {
183 ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
186 temp = *(IXP2000_PCI_CMDSTAT);
187 if (temp & (1 << 29)) {
188 while (temp & (1 << 29)) {
189 ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
190 temp = *(IXP2000_PCI_CMDSTAT);
193 local_irq_restore(flags);
195 return 0;
198 void __init
199 ixp2000_pci_preinit(void)
201 hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS,
202 "PCI config cycle to non-existent device");
207 * IXP2000 systems often have large resource requirements, so we just
208 * use our own resource space.
210 static struct resource ixp2000_pci_mem_space = {
211 .start = 0x00000000,
212 .end = 0xffffffff,
213 .flags = IORESOURCE_MEM,
214 .name = "PCI Mem Space"
217 static struct resource ixp2000_pci_io_space = {
218 .start = 0x00000000,
219 .end = 0xffffffff,
220 .flags = IORESOURCE_IO,
221 .name = "PCI I/O Space"
224 int ixp2000_pci_setup(int nr, struct pci_sys_data *sys)
226 if (nr >= 1)
227 return 0;
229 sys->resource[0] = &ixp2000_pci_io_space;
230 sys->resource[1] = &ixp2000_pci_mem_space;
231 sys->resource[2] = NULL;
233 return 1;