summaryrefslogtreecommitdiffstats
path: root/arch/mips/pci/pci-bcm1480ht.c
blob: aca4a2e7a1c6893693d34aa248a90a7bf03eb39e (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
/*
 * Copyright (C) 2001,2002,2005 Broadcom Corporation
 * Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/*
 * BCM1480/1455-specific HT support (looking like PCI)
 *
 * This module provides the glue between Linux's PCI subsystem
 * and the hardware.  We basically provide glue for accessing
 * configuration space, and set up the translation for I/O
 * space accesses.
 *
 * To access configuration space, we use ioremap.  In the 32-bit
 * kernel, this consumes either 4 or 8 page table pages, and 16MB of
 * kernel mapped memory.  Hopefully neither of these should be a huge
 * problem.
 *
 */
#include <linux/config.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/tty.h>

#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/bcm1480_scd.h>
#include <asm/sibyte/board.h>
#include <asm/io.h>

/*
 * Macros for calculating offsets into config space given a device
 * structure or dev/fun/reg
 */
#define CFGOFFSET(bus,devfn,where) (((bus)<<16)+((devfn)<<8)+(where))
#define CFGADDR(bus,devfn,where)   CFGOFFSET((bus)->number,(devfn),where)

static void *ht_cfg_space;

#define PCI_BUS_ENABLED	1
#define PCI_DEVICE_MODE	2

static int bcm1480ht_bus_status = 0;

#define PCI_BRIDGE_DEVICE  0
#define HT_BRIDGE_DEVICE   1

/*
 * HT's level-sensitive interrupts require EOI, which is generated
 * through a 4MB memory-mapped region
 */
unsigned long ht_eoi_space;

/*
 * Read/write 32-bit values in config space.
 */
static inline u32 READCFG32(u32 addr)
{
	return *(u32 *)(ht_cfg_space + (addr&~3));
}

static inline void WRITECFG32(u32 addr, u32 data)
{
	*(u32 *)(ht_cfg_space + (addr & ~3)) = data;
}

/*
 * Some checks before doing config cycles:
 * In PCI Device Mode, hide everything on bus 0 except the LDT host
 * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
 */
static int bcm1480ht_can_access(struct pci_bus *bus, int devfn)
{
	u32 devno;

	if (!(bcm1480ht_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
		return 0;

	if (bus->number == 0) {
		devno = PCI_SLOT(devfn);
 		if (bcm1480ht_bus_status & PCI_DEVICE_MODE)
			return 0;
	}
	return 1;
}

/*
 * Read/write access functions for various sizes of values
 * in config space.  Return all 1's for disallowed accesses
 * for a kludgy but adequate simulation of master aborts.
 */

static int bcm1480ht_pcibios_read(struct pci_bus *bus, unsigned int devfn,
				  int where, int size, u32 * val)
{
	u32 data = 0;

	if ((size == 2) && (where & 1))
		return PCIBIOS_BAD_REGISTER_NUMBER;
	else if ((size == 4) && (where & 3))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (bcm1480ht_can_access(bus, devfn))
		data = READCFG32(CFGADDR(bus, devfn, where));
	else
		data = 0xFFFFFFFF;

	if (size == 1)
		*val = (data >> ((where & 3) << 3)) & 0xff;
	else if (size == 2)
		*val = (data >> ((where & 3) << 3)) & 0xffff;
	else
		*val = data;

	return PCIBIOS_SUCCESSFUL;
}

static int bcm1480ht_pcibios_write(struct pci_bus *bus, unsigned int devfn,
				   int where, int size, u32 val)
{
	u32 cfgaddr = CFGADDR(bus, devfn, where);
	u32 data = 0;

	if ((size == 2) && (where & 1))
		return PCIBIOS_BAD_REGISTER_NUMBER;
	else if ((size == 4) && (where & 3))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (!bcm1480ht_can_access(bus, devfn))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	data = READCFG32(cfgaddr);

	if (size == 1)
		data = (data & ~(0xff << ((where & 3) << 3))) |
		    (val << ((where & 3) << 3));
	else if (size == 2)
		data = (data & ~(0xffff << ((where & 3) << 3))) |
		    (val << ((where & 3) << 3));
	else
		data = val;

	WRITECFG32(cfgaddr, data);

	return PCIBIOS_SUCCESSFUL;
}

static int bcm1480ht_pcibios_get_busno(void)
{
	return 0;
}

struct pci_ops bcm1480ht_pci_ops = {
	.read	= bcm1480ht_pcibios_read,
	.write	= bcm1480ht_pcibios_write,
};

static struct resource bcm1480ht_mem_resource = {
	.name	= "BCM1480 HT MEM",
	.start	= 0x40000000UL,
	.end	= 0x5fffffffUL,
	.flags	= IORESOURCE_MEM,
};

static struct resource bcm1480ht_io_resource = {
	.name	= "BCM1480 HT I/O",
	.start	= 0x00000000UL,
	.end	= 0x01ffffffUL,
	.flags	= IORESOURCE_IO,
};

struct pci_controller bcm1480ht_controller = {
	.pci_ops	= &bcm1480ht_pci_ops,
	.mem_resource	= &bcm1480ht_mem_resource,
	.io_resource	= &bcm1480ht_io_resource,
	.index		= 1,
	.get_busno	= bcm1480ht_pcibios_get_busno,
};

static int __init bcm1480ht_pcibios_init(void)
{
	uint32_t cmdreg;

	ht_cfg_space = ioremap(A_BCM1480_PHYS_HT_CFG_MATCH_BITS, 16*1024*1024);

	/*
	 * See if the PCI bus has been configured by the firmware.
	 */
	cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
				     PCI_COMMAND));
	if (!(cmdreg & PCI_COMMAND_MASTER)) {
		printk("HT: Skipping HT probe. Bus is not initialized.\n");
		iounmap(ht_cfg_space);
		return 1; /* XXX */
	}
	bcm1480ht_bus_status |= PCI_BUS_ENABLED;

	ht_eoi_space = (unsigned long)
		ioremap(A_BCM1480_PHYS_HT_SPECIAL_MATCH_BYTES,
			4 * 1024 * 1024);

	register_pci_controller(&bcm1480ht_controller);

	return 0;
}

arch_initcall(bcm1480ht_pcibios_init);