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 54 static void *ht_cfg_space; 55 56 #define PCI_BUS_ENABLED 1 57 #define PCI_DEVICE_MODE 2 58 59 static 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 */ 68 unsigned long ht_eoi_space; 69 70 /* 71 * Read/write 32-bit values in config space. 72 */ 73 static inline u32 READCFG32(u32 addr) 74 { 75 return *(u32 *)(ht_cfg_space + (addr&~3)); 76 } 77 78 static 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 */ 88 static 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 */ 108 109 static 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 } 133 134 static 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 } 163 164 static int bcm1480ht_pcibios_get_busno(void) 165 { 166 return 0; 167 } 168 169 struct pci_ops bcm1480ht_pci_ops = { 170 .read = bcm1480ht_pcibios_read, 171 .write = bcm1480ht_pcibios_write, 172 }; 173 174 static struct resource bcm1480ht_mem_resource = { 175 .name = "BCM1480 HT MEM", 176 .start = 0x40000000UL, 177 .end = 0x5fffffffUL, 178 .flags = IORESOURCE_MEM, 179 }; 180 181 static struct resource bcm1480ht_io_resource = { 182 .name = "BCM1480 HT I/O", 183 .start = 0x00000000UL, 184 .end = 0x01ffffffUL, 185 .flags = IORESOURCE_IO, 186 }; 187 188 struct 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 }; 195 196 static 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; /* XXX */ 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 } 222 223 arch_initcall(bcm1480ht_pcibios_init); 224