1 /* 2 * Copyright (C) 2006 PA Semi, Inc 3 * 4 * Authors: Kip Walker, PA Semi 5 * Olof Johansson, PA Semi 6 * 7 * Maintained by: Olof Johansson <olof@lixom.net> 8 * 9 * Based on arch/powerpc/platforms/maple/pci.c 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 23 */ 24 25 26 #include <linux/kernel.h> 27 #include <linux/pci.h> 28 29 #include <asm/pci-bridge.h> 30 #include <asm/machdep.h> 31 32 #include <asm/ppc-pci.h> 33 34 #include "pasemi.h" 35 36 #define PA_PXP_CFA(bus, devfn, off) (((bus) << 20) | ((devfn) << 12) | (off)) 37 38 static inline int pa_pxp_offset_valid(u8 bus, u8 devfn, int offset) 39 { 40 /* Device 0 Function 0 is special: It's config space spans function 1 as 41 * well, so allow larger offset. It's really a two-function device but the 42 * second function does not probe. 43 */ 44 if (bus == 0 && devfn == 0) 45 return offset < 8192; 46 else 47 return offset < 4096; 48 } 49 50 static void volatile __iomem *pa_pxp_cfg_addr(struct pci_controller *hose, 51 u8 bus, u8 devfn, int offset) 52 { 53 return hose->cfg_data + PA_PXP_CFA(bus, devfn, offset); 54 } 55 56 static inline int is_root_port(int busno, int devfn) 57 { 58 return ((busno == 0) && (PCI_FUNC(devfn) < 4) && 59 ((PCI_SLOT(devfn) == 16) || (PCI_SLOT(devfn) == 17))); 60 } 61 62 static inline int is_5945_reg(int reg) 63 { 64 return (((reg >= 0x18) && (reg < 0x34)) || 65 ((reg >= 0x158) && (reg < 0x178))); 66 } 67 68 static int workaround_5945(struct pci_bus *bus, unsigned int devfn, 69 int offset, int len, u32 *val) 70 { 71 struct pci_controller *hose; 72 void volatile __iomem *addr, *dummy; 73 int byte; 74 u32 tmp; 75 76 if (!is_root_port(bus->number, devfn) || !is_5945_reg(offset)) 77 return 0; 78 79 hose = pci_bus_to_host(bus); 80 81 addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset & ~0x3); 82 byte = offset & 0x3; 83 84 /* Workaround bug 5945: write 0 to a dummy register before reading, 85 * and write back what we read. We must read/write the full 32-bit 86 * contents so we need to shift and mask by hand. 87 */ 88 dummy = pa_pxp_cfg_addr(hose, bus->number, devfn, 0x10); 89 out_le32(dummy, 0); 90 tmp = in_le32(addr); 91 out_le32(addr, tmp); 92 93 switch (len) { 94 case 1: 95 *val = (tmp >> (8*byte)) & 0xff; 96 break; 97 case 2: 98 if (byte == 0) 99 *val = tmp & 0xffff; 100 else 101 *val = (tmp >> 16) & 0xffff; 102 break; 103 default: 104 *val = tmp; 105 break; 106 } 107 108 return 1; 109 } 110 111 static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn, 112 int offset, int len, u32 *val) 113 { 114 struct pci_controller *hose; 115 void volatile __iomem *addr; 116 117 hose = pci_bus_to_host(bus); 118 if (!hose) 119 return PCIBIOS_DEVICE_NOT_FOUND; 120 121 if (!pa_pxp_offset_valid(bus->number, devfn, offset)) 122 return PCIBIOS_BAD_REGISTER_NUMBER; 123 124 if (workaround_5945(bus, devfn, offset, len, val)) 125 return PCIBIOS_SUCCESSFUL; 126 127 addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset); 128 129 /* 130 * Note: the caller has already checked that offset is 131 * suitably aligned and that len is 1, 2 or 4. 132 */ 133 switch (len) { 134 case 1: 135 *val = in_8(addr); 136 break; 137 case 2: 138 *val = in_le16(addr); 139 break; 140 default: 141 *val = in_le32(addr); 142 break; 143 } 144 145 return PCIBIOS_SUCCESSFUL; 146 } 147 148 static int pa_pxp_write_config(struct pci_bus *bus, unsigned int devfn, 149 int offset, int len, u32 val) 150 { 151 struct pci_controller *hose; 152 void volatile __iomem *addr; 153 154 hose = pci_bus_to_host(bus); 155 if (!hose) 156 return PCIBIOS_DEVICE_NOT_FOUND; 157 158 if (!pa_pxp_offset_valid(bus->number, devfn, offset)) 159 return PCIBIOS_BAD_REGISTER_NUMBER; 160 161 addr = pa_pxp_cfg_addr(hose, bus->number, devfn, offset); 162 163 /* 164 * Note: the caller has already checked that offset is 165 * suitably aligned and that len is 1, 2 or 4. 166 */ 167 switch (len) { 168 case 1: 169 out_8(addr, val); 170 break; 171 case 2: 172 out_le16(addr, val); 173 break; 174 default: 175 out_le32(addr, val); 176 break; 177 } 178 return PCIBIOS_SUCCESSFUL; 179 } 180 181 static struct pci_ops pa_pxp_ops = { 182 .read = pa_pxp_read_config, 183 .write = pa_pxp_write_config, 184 }; 185 186 static void __init setup_pa_pxp(struct pci_controller *hose) 187 { 188 hose->ops = &pa_pxp_ops; 189 hose->cfg_data = ioremap(0xe0000000, 0x10000000); 190 } 191 192 static int __init pas_add_bridge(struct device_node *dev) 193 { 194 struct pci_controller *hose; 195 196 pr_debug("Adding PCI host bridge %pOF\n", dev); 197 198 hose = pcibios_alloc_controller(dev); 199 if (!hose) 200 return -ENOMEM; 201 202 hose->first_busno = 0; 203 hose->last_busno = 0xff; 204 hose->controller_ops = pasemi_pci_controller_ops; 205 206 setup_pa_pxp(hose); 207 208 printk(KERN_INFO "Found PA-PXP PCI host bridge.\n"); 209 210 /* Interpret the "ranges" property */ 211 pci_process_bridge_OF_ranges(hose, dev, 1); 212 213 return 0; 214 } 215 216 void __init pas_pci_init(void) 217 { 218 struct device_node *np, *root; 219 220 root = of_find_node_by_path("/"); 221 if (!root) { 222 printk(KERN_CRIT "pas_pci_init: can't find root " 223 "of device tree\n"); 224 return; 225 } 226 227 for (np = NULL; (np = of_get_next_child(root, np)) != NULL;) 228 if (np->name && !strcmp(np->name, "pxp") && !pas_add_bridge(np)) 229 of_node_get(np); 230 231 of_node_put(root); 232 } 233 234 void __iomem *pasemi_pci_getcfgaddr(struct pci_dev *dev, int offset) 235 { 236 struct pci_controller *hose; 237 238 hose = pci_bus_to_host(dev->bus); 239 240 return (void __iomem *)pa_pxp_cfg_addr(hose, dev->bus->number, dev->devfn, offset); 241 } 242 243 struct pci_controller_ops pasemi_pci_controller_ops; 244