1 /*
2 * Copyright (C) 2001,2002,2003 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 * BCM1250-specific PCI support
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 #include <linux/types.h>
34 #include <linux/pci.h>
35 #include <linux/kernel.h>
36 #include <linux/init.h>
37 #include <linux/mm.h>
38 #include <linux/console.h>
39 #include <linux/tty.h>
40
41 #include <asm/io.h>
42
43 #include <asm/sibyte/sb1250_defs.h>
44 #include <asm/sibyte/sb1250_regs.h>
45 #include <asm/sibyte/sb1250_scd.h>
46 #include <asm/sibyte/board.h>
47
48 /*
49 * Macros for calculating offsets into config space given a device
50 * structure or dev/fun/reg
51 */
52 #define CFGOFFSET(bus, devfn, where) (((bus)<<16) + ((devfn)<<8) + (where))
53 #define CFGADDR(bus, devfn, where) CFGOFFSET((bus)->number, (devfn), where)
54
55 static void *cfg_space;
56
57 #define PCI_BUS_ENABLED 1
58 #define LDT_BUS_ENABLED 2
59 #define PCI_DEVICE_MODE 4
60
61 static int sb1250_bus_status = 0;
62
63 #define PCI_BRIDGE_DEVICE 0
64 #define LDT_BRIDGE_DEVICE 1
65
66 #ifdef CONFIG_SIBYTE_HAS_LDT
67 /*
68 * HT's level-sensitive interrupts require EOI, which is generated
69 * through a 4MB memory-mapped region
70 */
71 unsigned long ldt_eoi_space;
72 #endif
73
74 /*
75 * Read/write 32-bit values in config space.
76 */
READCFG32(u32 addr)77 static inline u32 READCFG32(u32 addr)
78 {
79 return *(u32 *) (cfg_space + (addr & ~3));
80 }
81
WRITECFG32(u32 addr,u32 data)82 static inline void WRITECFG32(u32 addr, u32 data)
83 {
84 *(u32 *) (cfg_space + (addr & ~3)) = data;
85 }
86
pcibios_map_irq(const struct pci_dev * dev,u8 slot,u8 pin)87 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
88 {
89 return dev->irq;
90 }
91
92 /* Do platform specific device initialization at pci_enable_device() time */
pcibios_plat_dev_init(struct pci_dev * dev)93 int pcibios_plat_dev_init(struct pci_dev *dev)
94 {
95 return 0;
96 }
97
98 /*
99 * Some checks before doing config cycles:
100 * In PCI Device Mode, hide everything on bus 0 except the LDT host
101 * bridge. Otherwise, access is controlled by bridge MasterEn bits.
102 */
sb1250_pci_can_access(struct pci_bus * bus,int devfn)103 static int sb1250_pci_can_access(struct pci_bus *bus, int devfn)
104 {
105 u32 devno;
106
107 if (!(sb1250_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
108 return 0;
109
110 if (bus->number == 0) {
111 devno = PCI_SLOT(devfn);
112 if (devno == LDT_BRIDGE_DEVICE)
113 return (sb1250_bus_status & LDT_BUS_ENABLED) != 0;
114 else if (sb1250_bus_status & PCI_DEVICE_MODE)
115 return 0;
116 else
117 return 1;
118 } else
119 return 1;
120 }
121
122 /*
123 * Read/write access functions for various sizes of values
124 * in config space. Return all 1's for disallowed accesses
125 * for a kludgy but adequate simulation of master aborts.
126 */
127
sb1250_pcibios_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)128 static int sb1250_pcibios_read(struct pci_bus *bus, unsigned int devfn,
129 int where, int size, u32 * val)
130 {
131 u32 data = 0;
132
133 if ((size == 2) && (where & 1))
134 return PCIBIOS_BAD_REGISTER_NUMBER;
135 else if ((size == 4) && (where & 3))
136 return PCIBIOS_BAD_REGISTER_NUMBER;
137
138 if (sb1250_pci_can_access(bus, devfn))
139 data = READCFG32(CFGADDR(bus, devfn, where));
140 else
141 data = 0xFFFFFFFF;
142
143 if (size == 1)
144 *val = (data >> ((where & 3) << 3)) & 0xff;
145 else if (size == 2)
146 *val = (data >> ((where & 3) << 3)) & 0xffff;
147 else
148 *val = data;
149
150 return PCIBIOS_SUCCESSFUL;
151 }
152
sb1250_pcibios_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)153 static int sb1250_pcibios_write(struct pci_bus *bus, unsigned int devfn,
154 int where, int size, u32 val)
155 {
156 u32 cfgaddr = CFGADDR(bus, devfn, where);
157 u32 data = 0;
158
159 if ((size == 2) && (where & 1))
160 return PCIBIOS_BAD_REGISTER_NUMBER;
161 else if ((size == 4) && (where & 3))
162 return PCIBIOS_BAD_REGISTER_NUMBER;
163
164 if (!sb1250_pci_can_access(bus, devfn))
165 return PCIBIOS_BAD_REGISTER_NUMBER;
166
167 data = READCFG32(cfgaddr);
168
169 if (size == 1)
170 data = (data & ~(0xff << ((where & 3) << 3))) |
171 (val << ((where & 3) << 3));
172 else if (size == 2)
173 data = (data & ~(0xffff << ((where & 3) << 3))) |
174 (val << ((where & 3) << 3));
175 else
176 data = val;
177
178 WRITECFG32(cfgaddr, data);
179
180 return PCIBIOS_SUCCESSFUL;
181 }
182
183 struct pci_ops sb1250_pci_ops = {
184 .read = sb1250_pcibios_read,
185 .write = sb1250_pcibios_write,
186 };
187
188 static struct resource sb1250_mem_resource = {
189 .name = "SB1250 PCI MEM",
190 .start = 0x40000000UL,
191 .end = 0x5fffffffUL,
192 .flags = IORESOURCE_MEM,
193 };
194
195 static struct resource sb1250_io_resource = {
196 .name = "SB1250 PCI I/O",
197 .start = 0x00000000UL,
198 .end = 0x01ffffffUL,
199 .flags = IORESOURCE_IO,
200 };
201
202 struct pci_controller sb1250_controller = {
203 .pci_ops = &sb1250_pci_ops,
204 .mem_resource = &sb1250_mem_resource,
205 .io_resource = &sb1250_io_resource,
206 };
207
sb1250_pcibios_init(void)208 static int __init sb1250_pcibios_init(void)
209 {
210 void __iomem *io_map_base;
211 uint32_t cmdreg;
212 uint64_t reg;
213
214 /* CFE will assign PCI resources */
215 pci_probe_only = 1;
216
217 /* Avoid ISA compat ranges. */
218 PCIBIOS_MIN_IO = 0x00008000UL;
219 PCIBIOS_MIN_MEM = 0x01000000UL;
220
221 /* Set I/O resource limits. */
222 ioport_resource.end = 0x01ffffffUL; /* 32MB accessible by sb1250 */
223 iomem_resource.end = 0xffffffffUL; /* no HT support yet */
224
225 cfg_space =
226 ioremap(A_PHYS_LDTPCI_CFG_MATCH_BITS, 16 * 1024 * 1024);
227
228 /*
229 * See if the PCI bus has been configured by the firmware.
230 */
231 reg = __raw_readq(IOADDR(A_SCD_SYSTEM_CFG));
232 if (!(reg & M_SYS_PCI_HOST)) {
233 sb1250_bus_status |= PCI_DEVICE_MODE;
234 } else {
235 cmdreg =
236 READCFG32(CFGOFFSET
237 (0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0),
238 PCI_COMMAND));
239 if (!(cmdreg & PCI_COMMAND_MASTER)) {
240 printk
241 ("PCI: Skipping PCI probe. Bus is not initialized.\n");
242 iounmap(cfg_space);
243 return 0;
244 }
245 sb1250_bus_status |= PCI_BUS_ENABLED;
246 }
247
248 /*
249 * Establish mappings in KSEG2 (kernel virtual) to PCI I/O
250 * space. Use "match bytes" policy to make everything look
251 * little-endian. So, you need to also set
252 * CONFIG_SWAP_IO_SPACE, but this is the combination that
253 * works correctly with most of Linux's drivers.
254 * XXX ehs: Should this happen in PCI Device mode?
255 */
256 io_map_base = ioremap(A_PHYS_LDTPCI_IO_MATCH_BYTES, 1024 * 1024);
257 sb1250_controller.io_map_base = io_map_base;
258 set_io_port_base((unsigned long)io_map_base);
259
260 #ifdef CONFIG_SIBYTE_HAS_LDT
261 /*
262 * Also check the LDT bridge's enable, just in case we didn't
263 * initialize that one.
264 */
265
266 cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(LDT_BRIDGE_DEVICE, 0),
267 PCI_COMMAND));
268 if (cmdreg & PCI_COMMAND_MASTER) {
269 sb1250_bus_status |= LDT_BUS_ENABLED;
270
271 /*
272 * Need bits 23:16 to convey vector number. Note that
273 * this consumes 4MB of kernel-mapped memory
274 * (Kseg2/Kseg3) for 32-bit kernel.
275 */
276 ldt_eoi_space = (unsigned long)
277 ioremap(A_PHYS_LDT_SPECIAL_MATCH_BYTES,
278 4 * 1024 * 1024);
279 }
280 #endif
281
282 register_pci_controller(&sb1250_controller);
283
284 #ifdef CONFIG_VGA_CONSOLE
285 take_over_console(&vga_con, 0, MAX_NR_CONSOLES - 1, 1);
286 #endif
287 return 0;
288 }
289 arch_initcall(sb1250_pcibios_init);
290