aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-ixp2000/pci.c
blob: 0788fb2b5c10e6ae6e2023649930205cc3afb016 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/*
 * arch/arm/mach-ixp2000/pci.c
 *
 * PCI routines for IXDP2400/IXDP2800 boards
 *
 * Original Author: Naeem Afzal <naeem.m.afzal@intel.com>
 * Maintained by: Deepak Saxena <dsaxena@plexity.net>
 *
 * Copyright 2002 Intel Corp.
 * Copyright (C) 2003-2004 MontaVista Software, Inc.
 *
 *  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.
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/mach-types.h>
#include <asm/hardware.h>

#include <asm/mach/pci.h>

static int pci_master_aborts = 0;

static int clear_master_aborts(void);

u32 *
ixp2000_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
{
	u32 *paddress;

	if (PCI_SLOT(devfn) > 7)
		return 0;

	/* Must be dword aligned */
	where &= ~3;

	/*
	 * For top bus, generate type 0, else type 1
	 */
	if (!bus_nr) {
		/* only bits[23:16] are used for IDSEL */
		paddress = (u32 *) (IXP2000_PCI_CFG0_VIRT_BASE
				    | (1 << (PCI_SLOT(devfn) + 16))
				    | (PCI_FUNC(devfn) << 8) | where);
	} else {
		paddress = (u32 *) (IXP2000_PCI_CFG1_VIRT_BASE 
				    | (bus_nr << 16)
				    | (PCI_SLOT(devfn) << 11)
				    | (PCI_FUNC(devfn) << 8) | where);
	}

	return paddress;
}

/*
 * Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
 * 0 and 3 are not valid indexes...
 */
static u32 bytemask[] = {
	/*0*/	0,
	/*1*/	0xff,
	/*2*/	0xffff,
	/*3*/	0,
	/*4*/	0xffffffff,
};


int ixp2000_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where,
				int size, u32 *value)
{
	u32 n;
	u32 *addr;

	n = where % 4;

	addr = ixp2000_pci_config_addr(bus->number, devfn, where);
	if (!addr)
		return PCIBIOS_DEVICE_NOT_FOUND;

	pci_master_aborts = 0;
	*value = (*addr >> (8*n)) & bytemask[size];
	if (pci_master_aborts) {
		pci_master_aborts = 0;
		*value = 0xffffffff;
		return PCIBIOS_DEVICE_NOT_FOUND;
	}

	return PCIBIOS_SUCCESSFUL;
}

/*
 * We don't do error checks by callling clear_master_aborts() b/c the
 * assumption is that the caller did a read first to make sure a device
 * exists.
 */
int ixp2000_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where,
				int size, u32 value)
{
	u32 mask;
	u32 *addr;
	u32 temp;

	mask = ~(bytemask[size] << ((where % 0x4) * 8));
	addr = ixp2000_pci_config_addr(bus->number, devfn, where);
	if (!addr)
		return PCIBIOS_DEVICE_NOT_FOUND;
	temp = (u32) (value) << ((where % 0x4) * 8);
	*addr = (*addr & mask) | temp;

	clear_master_aborts();

	return PCIBIOS_SUCCESSFUL;
}


static struct pci_ops ixp2000_pci_ops = {
	.read	= ixp2000_pci_read_config,
	.write	= ixp2000_pci_write_config
};

struct pci_bus *ixp2000_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
{
	return pci_scan_bus(sysdata->busnr, &ixp2000_pci_ops, sysdata);
}


int ixp2000_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{

	volatile u32 temp;
	unsigned long flags;

	pci_master_aborts = 1;

	local_irq_save(flags);
	temp = *(IXP2000_PCI_CONTROL);
	if (temp & ((1 << 8) | (1 << 5))) {
		ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
	}

	temp = *(IXP2000_PCI_CMDSTAT);
	if (temp & (1 << 29)) {
		while (temp & (1 << 29)) {	
			ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
			temp = *(IXP2000_PCI_CMDSTAT);
		}
	}
	local_irq_restore(flags);

	/*
	 * If it was an imprecise abort, then we need to correct the
	 * return address to be _after_ the instruction.
	 */
	if (fsr & (1 << 10))
		regs->ARM_pc += 4;

	return 0;
}

int
clear_master_aborts(void)
{
	volatile u32 temp;
	unsigned long flags;

	local_irq_save(flags);
	temp = *(IXP2000_PCI_CONTROL);
	if (temp & ((1 << 8) | (1 << 5))) {	
		ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
	}

	temp = *(IXP2000_PCI_CMDSTAT);
	if (temp & (1 << 29)) {
		while (temp & (1 << 29)) {
			ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
			temp = *(IXP2000_PCI_CMDSTAT);
		}
	}
	local_irq_restore(flags);

	return 0;
}

void __init
ixp2000_pci_preinit(void)
{
#ifndef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO
	/*
	 * Configure the PCI unit to properly byteswap I/O transactions,
	 * and verify that it worked.
	 */
	ixp2000_reg_write(IXP2000_PCI_CONTROL,
			  (*IXP2000_PCI_CONTROL | PCI_CONTROL_IEE));

	if ((*IXP2000_PCI_CONTROL & PCI_CONTROL_IEE) == 0)
		panic("IXP2000: PCI I/O is broken on this ixp model, and "
			"the needed workaround has not been configured in");
#endif

	hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS,
				"PCI config cycle to non-existent device");
}


/*
 * IXP2000 systems often have large resource requirements, so we just
 * use our own resource space.
 */
static struct resource ixp2000_pci_mem_space = {
	.start	= 0xe0000000,
	.end	= 0xffffffff,
	.flags	= IORESOURCE_MEM,
	.name	= "PCI Mem Space"
};

static struct resource ixp2000_pci_io_space = {
	.start	= 0x00010000,
	.end	= 0x0001ffff,
	.flags	= IORESOURCE_IO,
	.name	= "PCI I/O Space"
};

int ixp2000_pci_setup(int nr, struct pci_sys_data *sys)
{
	if (nr >= 1)
		return 0;

	sys->resource[0] = &ixp2000_pci_io_space;
	sys->resource[1] = &ixp2000_pci_mem_space;
	sys->resource[2] = NULL;

	return 1;
}