aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sh/drivers/pci/ops-sh4.c
blob: 78bebebdc99c33aa3fd1970a3a533f25f0180d81 (plain) (blame)
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
/*
 * Generic SH-4 / SH-4A PCIC operations (SH7751, SH7780).
 *
 * Copyright (C) 2002 - 2009  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License v2. See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/pci.h>
#include <linux/io.h>
#include <asm/addrspace.h>
#include "pci-sh4.h"

/*
 * Direct access to PCI hardware...
 */
#define CONFIG_CMD(bus, devfn, where) \
	(P1SEG | (bus->number << 16) | (devfn << 8) | (where & ~3))

static DEFINE_SPINLOCK(sh4_pci_lock);

/*
 * Functions for accessing PCI configuration space with type 1 accesses
 */
static int sh4_pci_read(struct pci_bus *bus, unsigned int devfn,
			   int where, int size, u32 *val)
{
	struct pci_channel *chan = bus->sysdata;
	unsigned long flags;
	u32 data;

	/*
	 * PCIPDR may only be accessed as 32 bit words,
	 * so we must do byte alignment by hand
	 */
	spin_lock_irqsave(&sh4_pci_lock, flags);
	pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
	data = pci_read_reg(chan, SH4_PCIPDR);
	spin_unlock_irqrestore(&sh4_pci_lock, flags);

	switch (size) {
	case 1:
		*val = (data >> ((where & 3) << 3)) & 0xff;
		break;
	case 2:
		*val = (data >> ((where & 2) << 3)) & 0xffff;
		break;
	case 4:
		*val = data;
		break;
	default:
		return PCIBIOS_FUNC_NOT_SUPPORTED;
	}

	return PCIBIOS_SUCCESSFUL;
}

/*
 * Since SH4 only does 32bit access we'll have to do a read,
 * mask,write operation.
 * We'll allow an odd byte offset, though it should be illegal.
 */
static int sh4_pci_write(struct pci_bus *bus, unsigned int devfn,
			 int where, int size, u32 val)
{
	struct pci_channel *chan = bus->sysdata;
	unsigned long flags;
	int shift;
	u32 data;

	spin_lock_irqsave(&sh4_pci_lock, flags);
	pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
	data = pci_read_reg(chan, SH4_PCIPDR);
	spin_unlock_irqrestore(&sh4_pci_lock, flags);

	switch (size) {
	case 1:
		shift = (where & 3) << 3;
		data &= ~(0xff << shift);
		data |= ((val & 0xff) << shift);
		break;
	case 2:
		shift = (where & 2) << 3;
		data &= ~(0xffff << shift);
		data |= ((val & 0xffff) << shift);
		break;
	case 4:
		data = val;
		break;
	default:
		return PCIBIOS_FUNC_NOT_SUPPORTED;
	}

	pci_write_reg(chan, data, SH4_PCIPDR);

	return PCIBIOS_SUCCESSFUL;
}

struct pci_ops sh4_pci_ops = {
	.read		= sh4_pci_read,
	.write		= sh4_pci_write,
};

/*
 * Not really related to pci_ops, but it's common and not worth shoving
 * somewhere else for now..
 */
int __init sh4_pci_check_direct(struct pci_channel *chan)
{
	/*
	 * Check if configuration works.
	 */
	unsigned int tmp = pci_read_reg(chan, SH4_PCIPAR);

	pci_write_reg(chan, P1SEG, SH4_PCIPAR);

	if (pci_read_reg(chan, SH4_PCIPAR) == P1SEG) {
		pci_write_reg(chan, tmp, SH4_PCIPAR);
		printk(KERN_INFO "PCI: Using configuration type 1\n");
		request_region(chan->reg_base + SH4_PCIPAR, 8,
			       "PCI conf1");
		return 0;
	}

	pci_write_reg(chan, tmp, SH4_PCIPAR);

	printk(KERN_ERR "PCI: %s failed\n", __func__);

	return -EINVAL;
}

int __attribute__((weak)) pci_fixup_pcic(struct pci_channel *chan)
{
	/* Nothing to do. */
	return 0;
}