1/*
2 * Copyright (C) 2001,2002,2005 Broadcom Corporation
3 * Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
18 */
19
20/*
21 * BCM1480/1455-specific HT support (looking like PCI)
22 *
23 * This module provides the glue between Linux's PCI subsystem
24 * and the hardware.  We basically provide glue for accessing
25 * configuration space, and set up the translation for I/O
26 * space accesses.
27 *
28 * To access configuration space, we use ioremap.  In the 32-bit
29 * kernel, this consumes either 4 or 8 page table pages, and 16MB of
30 * kernel mapped memory.  Hopefully neither of these should be a huge
31 * problem.
32 *
33 */
34#include <linux/types.h>
35#include <linux/pci.h>
36#include <linux/kernel.h>
37#include <linux/init.h>
38#include <linux/mm.h>
39#include <linux/console.h>
40#include <linux/tty.h>
41
42#include <asm/sibyte/bcm1480_regs.h>
43#include <asm/sibyte/bcm1480_scd.h>
44#include <asm/sibyte/board.h>
45#include <asm/io.h>
46
47/*
48 * Macros for calculating offsets into config space given a device
49 * structure or dev/fun/reg
50 */
51#define CFGOFFSET(bus,devfn,where) (((bus)<<16)+((devfn)<<8)+(where))
52#define CFGADDR(bus,devfn,where)   CFGOFFSET((bus)->number,(devfn),where)
53
54static void *ht_cfg_space;
55
56#define PCI_BUS_ENABLED	1
57#define PCI_DEVICE_MODE	2
58
59static int bcm1480ht_bus_status = 0;
60
61#define PCI_BRIDGE_DEVICE  0
62#define HT_BRIDGE_DEVICE   1
63
64/*
65 * HT's level-sensitive interrupts require EOI, which is generated
66 * through a 4MB memory-mapped region
67 */
68unsigned long ht_eoi_space;
69
70/*
71 * Read/write 32-bit values in config space.
72 */
73static inline u32 READCFG32(u32 addr)
74{
75	return *(u32 *)(ht_cfg_space + (addr&~3));
76}
77
78static inline void WRITECFG32(u32 addr, u32 data)
79{
80	*(u32 *)(ht_cfg_space + (addr & ~3)) = data;
81}
82
83/*
84 * Some checks before doing config cycles:
85 * In PCI Device Mode, hide everything on bus 0 except the LDT host
86 * bridge.  Otherwise, access is controlled by bridge MasterEn bits.
87 */
88static int bcm1480ht_can_access(struct pci_bus *bus, int devfn)
89{
90	u32 devno;
91
92	if (!(bcm1480ht_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
93		return 0;
94
95	if (bus->number == 0) {
96		devno = PCI_SLOT(devfn);
97		if (bcm1480ht_bus_status & PCI_DEVICE_MODE)
98			return 0;
99	}
100	return 1;
101}
102
103/*
104 * Read/write access functions for various sizes of values
105 * in config space.  Return all 1's for disallowed accesses
106 * for a kludgy but adequate simulation of master aborts.
107 */
108
109static int bcm1480ht_pcibios_read(struct pci_bus *bus, unsigned int devfn,
110				  int where, int size, u32 * val)
111{
112	u32 data = 0;
113
114	if ((size == 2) && (where & 1))
115		return PCIBIOS_BAD_REGISTER_NUMBER;
116	else if ((size == 4) && (where & 3))
117		return PCIBIOS_BAD_REGISTER_NUMBER;
118
119	if (bcm1480ht_can_access(bus, devfn))
120		data = READCFG32(CFGADDR(bus, devfn, where));
121	else
122		data = 0xFFFFFFFF;
123
124	if (size == 1)
125		*val = (data >> ((where & 3) << 3)) & 0xff;
126	else if (size == 2)
127		*val = (data >> ((where & 3) << 3)) & 0xffff;
128	else
129		*val = data;
130
131	return PCIBIOS_SUCCESSFUL;
132}
133
134static int bcm1480ht_pcibios_write(struct pci_bus *bus, unsigned int devfn,
135				   int where, int size, u32 val)
136{
137	u32 cfgaddr = CFGADDR(bus, devfn, where);
138	u32 data = 0;
139
140	if ((size == 2) && (where & 1))
141		return PCIBIOS_BAD_REGISTER_NUMBER;
142	else if ((size == 4) && (where & 3))
143		return PCIBIOS_BAD_REGISTER_NUMBER;
144
145	if (!bcm1480ht_can_access(bus, devfn))
146		return PCIBIOS_BAD_REGISTER_NUMBER;
147
148	data = READCFG32(cfgaddr);
149
150	if (size == 1)
151		data = (data & ~(0xff << ((where & 3) << 3))) |
152		    (val << ((where & 3) << 3));
153	else if (size == 2)
154		data = (data & ~(0xffff << ((where & 3) << 3))) |
155		    (val << ((where & 3) << 3));
156	else
157		data = val;
158
159	WRITECFG32(cfgaddr, data);
160
161	return PCIBIOS_SUCCESSFUL;
162}
163
164static int bcm1480ht_pcibios_get_busno(void)
165{
166	return 0;
167}
168
169struct pci_ops bcm1480ht_pci_ops = {
170	.read	= bcm1480ht_pcibios_read,
171	.write	= bcm1480ht_pcibios_write,
172};
173
174static struct resource bcm1480ht_mem_resource = {
175	.name	= "BCM1480 HT MEM",
176	.start	= 0x40000000UL,
177	.end	= 0x5fffffffUL,
178	.flags	= IORESOURCE_MEM,
179};
180
181static struct resource bcm1480ht_io_resource = {
182	.name	= "BCM1480 HT I/O",
183	.start	= 0x00000000UL,
184	.end	= 0x01ffffffUL,
185	.flags	= IORESOURCE_IO,
186};
187
188struct pci_controller bcm1480ht_controller = {
189	.pci_ops	= &bcm1480ht_pci_ops,
190	.mem_resource	= &bcm1480ht_mem_resource,
191	.io_resource	= &bcm1480ht_io_resource,
192	.index		= 1,
193	.get_busno	= bcm1480ht_pcibios_get_busno,
194};
195
196static int __init bcm1480ht_pcibios_init(void)
197{
198	uint32_t cmdreg;
199
200	ht_cfg_space = ioremap(A_BCM1480_PHYS_HT_CFG_MATCH_BITS, 16*1024*1024);
201
202	/*
203	 * See if the PCI bus has been configured by the firmware.
204	 */
205	cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
206				     PCI_COMMAND));
207	if (!(cmdreg & PCI_COMMAND_MASTER)) {
208		printk("HT: Skipping HT probe. Bus is not initialized.\n");
209		iounmap(ht_cfg_space);
210		return 1;
211	}
212	bcm1480ht_bus_status |= PCI_BUS_ENABLED;
213
214	ht_eoi_space = (unsigned long)
215		ioremap(A_BCM1480_PHYS_HT_SPECIAL_MATCH_BYTES,
216			4 * 1024 * 1024);
217
218	register_pci_controller(&bcm1480ht_controller);
219
220	return 0;
221}
222
223arch_initcall(bcm1480ht_pcibios_init);
224