1 /*
2 * arch/arm/mach-ixp2000/pci.c
3 *
4 * PCI routines for IXDP2400/IXDP2800 boards
5 *
6 * Original Author: Naeem Afzal <naeem.m.afzal@intel.com>
7 * Maintained by: Deepak Saxena <dsaxena@plexity.net>
8 *
9 * Copyright 2002 Intel Corp.
10 * Copyright (C) 2003-2004 MontaVista Software, Inc.
11 *
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.
16 */
17
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/delay.h>
26 #include <linux/io.h>
27
28 #include <asm/irq.h>
29 #include <mach/hardware.h>
30
31 #include <asm/mach/pci.h>
32
33 static volatile int pci_master_aborts = 0;
34
35 static int clear_master_aborts(void);
36
37 u32 *
ixp2000_pci_config_addr(unsigned int bus_nr,unsigned int devfn,int where)38 ixp2000_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
39 {
40 u32 *paddress;
41
42 if (PCI_SLOT(devfn) > 7)
43 return 0;
44
45 /* Must be dword aligned */
46 where &= ~3;
47
48 /*
49 * For top bus, generate type 0, else type 1
50 */
51 if (!bus_nr) {
52 /* only bits[23:16] are used for IDSEL */
53 paddress = (u32 *) (IXP2000_PCI_CFG0_VIRT_BASE
54 | (1 << (PCI_SLOT(devfn) + 16))
55 | (PCI_FUNC(devfn) << 8) | where);
56 } else {
57 paddress = (u32 *) (IXP2000_PCI_CFG1_VIRT_BASE
58 | (bus_nr << 16)
59 | (PCI_SLOT(devfn) << 11)
60 | (PCI_FUNC(devfn) << 8) | where);
61 }
62
63 return paddress;
64 }
65
66 /*
67 * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
68 * 0 and 3 are not valid indexes...
69 */
70 static u32 bytemask[] = {
71 /*0*/ 0,
72 /*1*/ 0xff,
73 /*2*/ 0xffff,
74 /*3*/ 0,
75 /*4*/ 0xffffffff,
76 };
77
78
ixp2000_pci_read_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * value)79 int ixp2000_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where,
80 int size, u32 *value)
81 {
82 u32 n;
83 u32 *addr;
84
85 n = where % 4;
86
87 addr = ixp2000_pci_config_addr(bus->number, devfn, where);
88 if (!addr)
89 return PCIBIOS_DEVICE_NOT_FOUND;
90
91 pci_master_aborts = 0;
92 *value = (*addr >> (8*n)) & bytemask[size];
93 if (pci_master_aborts) {
94 pci_master_aborts = 0;
95 *value = 0xffffffff;
96 return PCIBIOS_DEVICE_NOT_FOUND;
97 }
98
99 return PCIBIOS_SUCCESSFUL;
100 }
101
102 /*
103 * We don't do error checks by calling clear_master_aborts() b/c the
104 * assumption is that the caller did a read first to make sure a device
105 * exists.
106 */
ixp2000_pci_write_config(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 value)107 int ixp2000_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where,
108 int size, u32 value)
109 {
110 u32 mask;
111 u32 *addr;
112 u32 temp;
113
114 mask = ~(bytemask[size] << ((where % 0x4) * 8));
115 addr = ixp2000_pci_config_addr(bus->number, devfn, where);
116 if (!addr)
117 return PCIBIOS_DEVICE_NOT_FOUND;
118 temp = (u32) (value) << ((where % 0x4) * 8);
119 *addr = (*addr & mask) | temp;
120
121 clear_master_aborts();
122
123 return PCIBIOS_SUCCESSFUL;
124 }
125
126
127 static struct pci_ops ixp2000_pci_ops = {
128 .read = ixp2000_pci_read_config,
129 .write = ixp2000_pci_write_config
130 };
131
ixp2000_pci_scan_bus(int nr,struct pci_sys_data * sysdata)132 struct pci_bus *ixp2000_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
133 {
134 return pci_scan_root_bus(NULL, sysdata->busnr, &ixp2000_pci_ops,
135 sysdata, &sysdata->resources);
136 }
137
138
ixp2000_pci_abort_handler(unsigned long addr,unsigned int fsr,struct pt_regs * regs)139 int ixp2000_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
140 {
141
142 volatile u32 temp;
143 unsigned long flags;
144
145 pci_master_aborts = 1;
146
147 local_irq_save(flags);
148 temp = *(IXP2000_PCI_CONTROL);
149 if (temp & ((1 << 8) | (1 << 5))) {
150 ixp2000_reg_wrb(IXP2000_PCI_CONTROL, temp);
151 }
152
153 temp = *(IXP2000_PCI_CMDSTAT);
154 if (temp & (1 << 29)) {
155 while (temp & (1 << 29)) {
156 ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
157 temp = *(IXP2000_PCI_CMDSTAT);
158 }
159 }
160 local_irq_restore(flags);
161
162 /*
163 * If it was an imprecise abort, then we need to correct the
164 * return address to be _after_ the instruction.
165 */
166 if (fsr & (1 << 10))
167 regs->ARM_pc += 4;
168
169 return 0;
170 }
171
172 int
clear_master_aborts(void)173 clear_master_aborts(void)
174 {
175 volatile u32 temp;
176 unsigned long flags;
177
178 local_irq_save(flags);
179 temp = *(IXP2000_PCI_CONTROL);
180 if (temp & ((1 << 8) | (1 << 5))) {
181 ixp2000_reg_wrb(IXP2000_PCI_CONTROL, temp);
182 }
183
184 temp = *(IXP2000_PCI_CMDSTAT);
185 if (temp & (1 << 29)) {
186 while (temp & (1 << 29)) {
187 ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
188 temp = *(IXP2000_PCI_CMDSTAT);
189 }
190 }
191 local_irq_restore(flags);
192
193 return 0;
194 }
195
196 void __init
ixp2000_pci_preinit(void)197 ixp2000_pci_preinit(void)
198 {
199 pci_set_flags(0);
200
201 pcibios_min_io = 0;
202 pcibios_min_mem = 0;
203
204 #ifndef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
205 /*
206 * Configure the PCI unit to properly byteswap I/O transactions,
207 * and verify that it worked.
208 */
209 ixp2000_reg_write(IXP2000_PCI_CONTROL,
210 (*IXP2000_PCI_CONTROL | PCI_CONTROL_IEE));
211
212 if ((*IXP2000_PCI_CONTROL & PCI_CONTROL_IEE) == 0)
213 panic("IXP2000: PCI I/O is broken on this ixp model, and "
214 "the needed workaround has not been configured in");
215 #endif
216
217 hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS, 0,
218 "PCI config cycle to non-existent device");
219 }
220
221
222 /*
223 * IXP2000 systems often have large resource requirements, so we just
224 * use our own resource space.
225 */
226 static struct resource ixp2000_pci_mem_space = {
227 .start = 0xe0000000,
228 .end = 0xffffffff,
229 .flags = IORESOURCE_MEM,
230 .name = "PCI Mem Space"
231 };
232
233 static struct resource ixp2000_pci_io_space = {
234 .start = 0x00010000,
235 .end = 0x0001ffff,
236 .flags = IORESOURCE_IO,
237 .name = "PCI I/O Space"
238 };
239
ixp2000_pci_setup(int nr,struct pci_sys_data * sys)240 int ixp2000_pci_setup(int nr, struct pci_sys_data *sys)
241 {
242 if (nr >= 1)
243 return 0;
244
245 pci_add_resource_offset(&sys->resources,
246 &ixp2000_pci_io_space, sys->io_offset);
247 pci_add_resource_offset(&sys->resources,
248 &ixp2000_pci_mem_space, sys->mem_offset);
249
250 return 1;
251 }
252
253