1 /* 2 * OLPC-specific OFW device tree support code. 3 * 4 * Paul Mackerras August 1996. 5 * Copyright (C) 1996-2005 Paul Mackerras. 6 * 7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. 8 * {engebret|bergner}@us.ibm.com 9 * 10 * Adapted for sparc by David S. Miller davem@davemloft.net 11 * Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net> 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 */ 18 19 #include <linux/kernel.h> 20 #include <linux/bootmem.h> 21 #include <linux/of.h> 22 #include <linux/of_platform.h> 23 #include <linux/of_pdt.h> 24 #include <asm/olpc.h> 25 #include <asm/olpc_ofw.h> 26 27 static phandle __init olpc_dt_getsibling(phandle node) 28 { 29 const void *args[] = { (void *)node }; 30 void *res[] = { &node }; 31 32 if ((s32)node == -1) 33 return 0; 34 35 if (olpc_ofw("peer", args, res) || (s32)node == -1) 36 return 0; 37 38 return node; 39 } 40 41 static phandle __init olpc_dt_getchild(phandle node) 42 { 43 const void *args[] = { (void *)node }; 44 void *res[] = { &node }; 45 46 if ((s32)node == -1) 47 return 0; 48 49 if (olpc_ofw("child", args, res) || (s32)node == -1) { 50 pr_err("PROM: %s: fetching child failed!\n", __func__); 51 return 0; 52 } 53 54 return node; 55 } 56 57 static int __init olpc_dt_getproplen(phandle node, const char *prop) 58 { 59 const void *args[] = { (void *)node, prop }; 60 int len; 61 void *res[] = { &len }; 62 63 if ((s32)node == -1) 64 return -1; 65 66 if (olpc_ofw("getproplen", args, res)) { 67 pr_err("PROM: %s: getproplen failed!\n", __func__); 68 return -1; 69 } 70 71 return len; 72 } 73 74 static int __init olpc_dt_getproperty(phandle node, const char *prop, 75 char *buf, int bufsize) 76 { 77 int plen; 78 79 plen = olpc_dt_getproplen(node, prop); 80 if (plen > bufsize || plen < 1) { 81 return -1; 82 } else { 83 const void *args[] = { (void *)node, prop, buf, (void *)plen }; 84 void *res[] = { &plen }; 85 86 if (olpc_ofw("getprop", args, res)) { 87 pr_err("PROM: %s: getprop failed!\n", __func__); 88 return -1; 89 } 90 } 91 92 return plen; 93 } 94 95 static int __init olpc_dt_nextprop(phandle node, char *prev, char *buf) 96 { 97 const void *args[] = { (void *)node, prev, buf }; 98 int success; 99 void *res[] = { &success }; 100 101 buf[0] = '\0'; 102 103 if ((s32)node == -1) 104 return -1; 105 106 if (olpc_ofw("nextprop", args, res) || success != 1) 107 return -1; 108 109 return 0; 110 } 111 112 static int __init olpc_dt_pkg2path(phandle node, char *buf, 113 const int buflen, int *len) 114 { 115 const void *args[] = { (void *)node, buf, (void *)buflen }; 116 void *res[] = { len }; 117 118 if ((s32)node == -1) 119 return -1; 120 121 if (olpc_ofw("package-to-path", args, res) || *len < 1) 122 return -1; 123 124 return 0; 125 } 126 127 static unsigned int prom_early_allocated __initdata; 128 129 void * __init prom_early_alloc(unsigned long size) 130 { 131 static u8 *mem; 132 static size_t free_mem; 133 void *res; 134 135 if (free_mem < size) { 136 const size_t chunk_size = max(PAGE_SIZE, size); 137 138 /* 139 * To mimimize the number of allocations, grab at least 140 * PAGE_SIZE of memory (that's an arbitrary choice that's 141 * fast enough on the platforms we care about while minimizing 142 * wasted bootmem) and hand off chunks of it to callers. 143 */ 144 res = alloc_bootmem(chunk_size); 145 BUG_ON(!res); 146 prom_early_allocated += chunk_size; 147 memset(res, 0, chunk_size); 148 free_mem = chunk_size; 149 mem = res; 150 } 151 152 /* allocate from the local cache */ 153 free_mem -= size; 154 res = mem; 155 mem += size; 156 return res; 157 } 158 159 static struct of_pdt_ops prom_olpc_ops __initdata = { 160 .nextprop = olpc_dt_nextprop, 161 .getproplen = olpc_dt_getproplen, 162 .getproperty = olpc_dt_getproperty, 163 .getchild = olpc_dt_getchild, 164 .getsibling = olpc_dt_getsibling, 165 .pkg2path = olpc_dt_pkg2path, 166 }; 167 168 static phandle __init olpc_dt_finddevice(const char *path) 169 { 170 phandle node; 171 const void *args[] = { path }; 172 void *res[] = { &node }; 173 174 if (olpc_ofw("finddevice", args, res)) { 175 pr_err("olpc_dt: finddevice failed!\n"); 176 return 0; 177 } 178 179 if ((s32) node == -1) 180 return 0; 181 182 return node; 183 } 184 185 static int __init olpc_dt_interpret(const char *words) 186 { 187 int result; 188 const void *args[] = { words }; 189 void *res[] = { &result }; 190 191 if (olpc_ofw("interpret", args, res)) { 192 pr_err("olpc_dt: interpret failed!\n"); 193 return -1; 194 } 195 196 return result; 197 } 198 199 /* 200 * Extract board revision directly from OFW device tree. 201 * We can't use olpc_platform_info because that hasn't been set up yet. 202 */ 203 static u32 __init olpc_dt_get_board_revision(void) 204 { 205 phandle node; 206 __be32 rev; 207 int r; 208 209 node = olpc_dt_finddevice("/"); 210 if (!node) 211 return 0; 212 213 r = olpc_dt_getproperty(node, "board-revision-int", 214 (char *) &rev, sizeof(rev)); 215 if (r < 0) 216 return 0; 217 218 return be32_to_cpu(rev); 219 } 220 221 void __init olpc_dt_fixup(void) 222 { 223 int r; 224 char buf[64]; 225 phandle node; 226 u32 board_rev; 227 228 node = olpc_dt_finddevice("/battery@0"); 229 if (!node) 230 return; 231 232 /* 233 * If the battery node has a compatible property, we are running a new 234 * enough firmware and don't have fixups to make. 235 */ 236 r = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf)); 237 if (r > 0) 238 return; 239 240 pr_info("PROM DT: Old firmware detected, applying fixes\n"); 241 242 /* Add olpc,xo1-battery compatible marker to battery node */ 243 olpc_dt_interpret("\" /battery@0\" find-device" 244 " \" olpc,xo1-battery\" +compatible" 245 " device-end"); 246 247 board_rev = olpc_dt_get_board_revision(); 248 if (!board_rev) 249 return; 250 251 if (board_rev >= olpc_board_pre(0xd0)) { 252 /* XO-1.5: add dcon device */ 253 olpc_dt_interpret("\" /pci/display@1\" find-device" 254 " new-device" 255 " \" dcon\" device-name \" olpc,xo1-dcon\" +compatible" 256 " finish-device device-end"); 257 } else { 258 /* XO-1: add dcon device, mark RTC as olpc,xo1-rtc */ 259 olpc_dt_interpret("\" /pci/display@1,1\" find-device" 260 " new-device" 261 " \" dcon\" device-name \" olpc,xo1-dcon\" +compatible" 262 " finish-device device-end" 263 " \" /rtc\" find-device" 264 " \" olpc,xo1-rtc\" +compatible" 265 " device-end"); 266 } 267 } 268 269 void __init olpc_dt_build_devicetree(void) 270 { 271 phandle root; 272 273 if (!olpc_ofw_is_installed()) 274 return; 275 276 olpc_dt_fixup(); 277 278 root = olpc_dt_getsibling(0); 279 if (!root) { 280 pr_err("PROM: unable to get root node from OFW!\n"); 281 return; 282 } 283 of_pdt_build_devicetree(root, &prom_olpc_ops); 284 285 pr_info("PROM DT: Built device tree with %u bytes of memory.\n", 286 prom_early_allocated); 287 } 288 289 /* A list of DT node/bus matches that we want to expose as platform devices */ 290 static struct of_device_id __initdata of_ids[] = { 291 { .compatible = "olpc,xo1-battery" }, 292 { .compatible = "olpc,xo1-dcon" }, 293 { .compatible = "olpc,xo1-rtc" }, 294 {}, 295 }; 296 297 static int __init olpc_create_platform_devices(void) 298 { 299 if (machine_is_olpc()) 300 return of_platform_bus_probe(NULL, of_ids, NULL); 301 else 302 return 0; 303 } 304 device_initcall(olpc_create_platform_devices); 305