xref: /linux/arch/sh/drivers/pci/ops-sh4.c (revision b6706ef10f75921733d7275fd45d268f2f6254c8)
1 /*
2  * Generic SH-4 / SH-4A PCIC operations (SH7751, SH7780).
3  *
4  * Copyright (C) 2002 - 2006  Paul Mundt
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License v2. See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 #include <linux/pci.h>
11 #include <asm/addrspace.h>
12 #include <asm/io.h>
13 #include "pci-sh4.h"
14 
15 /*
16  * Direct access to PCI hardware...
17  */
18 #define CONFIG_CMD(bus, devfn, where) \
19 	P1SEGADDR((bus->number << 16) | (devfn << 8) | (where & ~3))
20 
21 static DEFINE_SPINLOCK(sh4_pci_lock);
22 
23 /*
24  * Functions for accessing PCI configuration space with type 1 accesses
25  */
26 static int sh4_pci_read(struct pci_bus *bus, unsigned int devfn,
27 			   int where, int size, u32 *val)
28 {
29 	struct pci_channel *chan = bus->sysdata;
30 	unsigned long flags;
31 	u32 data;
32 
33 	/*
34 	 * PCIPDR may only be accessed as 32 bit words,
35 	 * so we must do byte alignment by hand
36 	 */
37 	spin_lock_irqsave(&sh4_pci_lock, flags);
38 	pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
39 	data = pci_read_reg(chan, SH4_PCIPDR);
40 	spin_unlock_irqrestore(&sh4_pci_lock, flags);
41 
42 	switch (size) {
43 	case 1:
44 		*val = (data >> ((where & 3) << 3)) & 0xff;
45 		break;
46 	case 2:
47 		*val = (data >> ((where & 2) << 3)) & 0xffff;
48 		break;
49 	case 4:
50 		*val = data;
51 		break;
52 	default:
53 		return PCIBIOS_FUNC_NOT_SUPPORTED;
54 	}
55 
56 	return PCIBIOS_SUCCESSFUL;
57 }
58 
59 /*
60  * Since SH4 only does 32bit access we'll have to do a read,
61  * mask,write operation.
62  * We'll allow an odd byte offset, though it should be illegal.
63  */
64 static int sh4_pci_write(struct pci_bus *bus, unsigned int devfn,
65 			 int where, int size, u32 val)
66 {
67 	struct pci_channel *chan = bus->sysdata;
68 	unsigned long flags;
69 	int shift;
70 	u32 data;
71 
72 	spin_lock_irqsave(&sh4_pci_lock, flags);
73 	pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR);
74 	data = pci_read_reg(chan, SH4_PCIPDR);
75 	spin_unlock_irqrestore(&sh4_pci_lock, flags);
76 
77 	switch (size) {
78 	case 1:
79 		shift = (where & 3) << 3;
80 		data &= ~(0xff << shift);
81 		data |= ((val & 0xff) << shift);
82 		break;
83 	case 2:
84 		shift = (where & 2) << 3;
85 		data &= ~(0xffff << shift);
86 		data |= ((val & 0xffff) << shift);
87 		break;
88 	case 4:
89 		data = val;
90 		break;
91 	default:
92 		return PCIBIOS_FUNC_NOT_SUPPORTED;
93 	}
94 
95 	pci_write_reg(chan, data, SH4_PCIPDR);
96 
97 	return PCIBIOS_SUCCESSFUL;
98 }
99 
100 struct pci_ops sh4_pci_ops = {
101 	.read		= sh4_pci_read,
102 	.write		= sh4_pci_write,
103 };
104 
105 /*
106  * Not really related to pci_ops, but it's common and not worth shoving
107  * somewhere else for now..
108  */
109 static unsigned int pci_probe = PCI_PROBE_CONF1;
110 
111 int __init sh4_pci_check_direct(struct pci_channel *chan)
112 {
113 	/*
114 	 * Check if configuration works.
115 	 */
116 	if (pci_probe & PCI_PROBE_CONF1) {
117 		unsigned int tmp = pci_read_reg(chan, SH4_PCIPAR);
118 
119 		pci_write_reg(chan, P1SEG, SH4_PCIPAR);
120 
121 		if (pci_read_reg(chan, SH4_PCIPAR) == P1SEG) {
122 			pci_write_reg(chan, tmp, SH4_PCIPAR);
123 			printk(KERN_INFO "PCI: Using configuration type 1\n");
124 			request_region(PCI_REG(SH4_PCIPAR), 8, "PCI conf1");
125 
126 			return 0;
127 		}
128 
129 		pci_write_reg(chan, tmp, SH4_PCIPAR);
130 	}
131 
132 	pr_debug("PCI: pci_check_direct failed\n");
133 	return -EINVAL;
134 }
135 
136 /* Handle generic fixups */
137 static void __init pci_fixup_ide_bases(struct pci_dev *d)
138 {
139 	int i;
140 
141 	/*
142 	 * PCI IDE controllers use non-standard I/O port decoding, respect it.
143 	 */
144 	if ((d->class >> 8) != PCI_CLASS_STORAGE_IDE)
145 		return;
146 	pr_debug("PCI: IDE base address fixup for %s\n", pci_name(d));
147 	for(i = 0; i < 4; i++) {
148 		struct resource *r = &d->resource[i];
149 
150 		if ((r->start & ~0x80) == 0x374) {
151 			r->start |= 2;
152 			r->end = r->start;
153 		}
154 	}
155 }
156 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_ide_bases);
157 
158 char * __devinit pcibios_setup(char *str)
159 {
160 	if (!strcmp(str, "off")) {
161 		pci_probe = 0;
162 		return NULL;
163 	}
164 
165 	return str;
166 }
167 
168 int __attribute__((weak)) pci_fixup_pcic(struct pci_channel *chan)
169 {
170 	/* Nothing to do. */
171 	return 0;
172 }
173