1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * OLPC-specific OFW device tree support code. 4 * 5 * Paul Mackerras August 1996. 6 * Copyright (C) 1996-2005 Paul Mackerras. 7 * 8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. 9 * {engebret|bergner}@us.ibm.com 10 * 11 * Adapted for sparc by David S. Miller davem@davemloft.net 12 * Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net> 13 */ 14 15 #include <linux/kernel.h> 16 #include <linux/memblock.h> 17 #include <linux/of.h> 18 #include <linux/of_pdt.h> 19 #include <asm/olpc.h> 20 #include <asm/olpc_ofw.h> 21 22 static phandle __init olpc_dt_getsibling(phandle node) 23 { 24 const void *args[] = { (void *)node }; 25 void *res[] = { &node }; 26 27 if ((s32)node == -1) 28 return 0; 29 30 if (olpc_ofw("peer", args, res) || (s32)node == -1) 31 return 0; 32 33 return node; 34 } 35 36 static phandle __init olpc_dt_getchild(phandle node) 37 { 38 const void *args[] = { (void *)node }; 39 void *res[] = { &node }; 40 41 if ((s32)node == -1) 42 return 0; 43 44 if (olpc_ofw("child", args, res) || (s32)node == -1) { 45 pr_err("PROM: %s: fetching child failed!\n", __func__); 46 return 0; 47 } 48 49 return node; 50 } 51 52 static int __init olpc_dt_getproplen(phandle node, const char *prop) 53 { 54 const void *args[] = { (void *)node, prop }; 55 int len; 56 void *res[] = { &len }; 57 58 if ((s32)node == -1) 59 return -1; 60 61 if (olpc_ofw("getproplen", args, res)) { 62 pr_err("PROM: %s: getproplen failed!\n", __func__); 63 return -1; 64 } 65 66 return len; 67 } 68 69 static int __init olpc_dt_getproperty(phandle node, const char *prop, 70 char *buf, int bufsize) 71 { 72 int plen; 73 74 plen = olpc_dt_getproplen(node, prop); 75 if (plen > bufsize || plen < 1) { 76 return -1; 77 } else { 78 const void *args[] = { (void *)node, prop, buf, (void *)plen }; 79 void *res[] = { &plen }; 80 81 if (olpc_ofw("getprop", args, res)) { 82 pr_err("PROM: %s: getprop failed!\n", __func__); 83 return -1; 84 } 85 } 86 87 return plen; 88 } 89 90 static int __init olpc_dt_nextprop(phandle node, char *prev, char *buf) 91 { 92 const void *args[] = { (void *)node, prev, buf }; 93 int success; 94 void *res[] = { &success }; 95 96 buf[0] = '\0'; 97 98 if ((s32)node == -1) 99 return -1; 100 101 if (olpc_ofw("nextprop", args, res) || success != 1) 102 return -1; 103 104 return 0; 105 } 106 107 static int __init olpc_dt_pkg2path(phandle node, char *buf, 108 const int buflen, int *len) 109 { 110 const void *args[] = { (void *)node, buf, (void *)buflen }; 111 void *res[] = { len }; 112 113 if ((s32)node == -1) 114 return -1; 115 116 if (olpc_ofw("package-to-path", args, res) || *len < 1) 117 return -1; 118 119 return 0; 120 } 121 122 static unsigned int prom_early_allocated __initdata; 123 124 void * __init prom_early_alloc(unsigned long size) 125 { 126 static u8 *mem; 127 static size_t free_mem; 128 void *res; 129 130 if (free_mem < size) { 131 const size_t chunk_size = max(PAGE_SIZE, size); 132 133 /* 134 * To minimize the number of allocations, grab at least 135 * PAGE_SIZE of memory (that's an arbitrary choice that's 136 * fast enough on the platforms we care about while minimizing 137 * wasted bootmem) and hand off chunks of it to callers. 138 */ 139 res = memblock_alloc(chunk_size, SMP_CACHE_BYTES); 140 if (!res) 141 panic("%s: Failed to allocate %zu bytes\n", __func__, 142 chunk_size); 143 BUG_ON(!res); 144 prom_early_allocated += chunk_size; 145 memset(res, 0, chunk_size); 146 free_mem = chunk_size; 147 mem = res; 148 } 149 150 /* allocate from the local cache */ 151 free_mem -= size; 152 res = mem; 153 mem += size; 154 return res; 155 } 156 157 static struct of_pdt_ops prom_olpc_ops __initdata = { 158 .nextprop = olpc_dt_nextprop, 159 .getproplen = olpc_dt_getproplen, 160 .getproperty = olpc_dt_getproperty, 161 .getchild = olpc_dt_getchild, 162 .getsibling = olpc_dt_getsibling, 163 .pkg2path = olpc_dt_pkg2path, 164 }; 165 166 static phandle __init olpc_dt_finddevice(const char *path) 167 { 168 phandle node; 169 const void *args[] = { path }; 170 void *res[] = { &node }; 171 172 if (olpc_ofw("finddevice", args, res)) { 173 pr_err("olpc_dt: finddevice failed!\n"); 174 return 0; 175 } 176 177 if ((s32) node == -1) 178 return 0; 179 180 return node; 181 } 182 183 static int __init olpc_dt_interpret(const char *words) 184 { 185 int result; 186 const void *args[] = { words }; 187 void *res[] = { &result }; 188 189 if (olpc_ofw("interpret", args, res)) { 190 pr_err("olpc_dt: interpret failed!\n"); 191 return -1; 192 } 193 194 return result; 195 } 196 197 /* 198 * Extract board revision directly from OFW device tree. 199 * We can't use olpc_platform_info because that hasn't been set up yet. 200 */ 201 static u32 __init olpc_dt_get_board_revision(void) 202 { 203 phandle node; 204 __be32 rev; 205 int r; 206 207 node = olpc_dt_finddevice("/"); 208 if (!node) 209 return 0; 210 211 r = olpc_dt_getproperty(node, "board-revision-int", 212 (char *) &rev, sizeof(rev)); 213 if (r < 0) 214 return 0; 215 216 return be32_to_cpu(rev); 217 } 218 219 static int __init olpc_dt_compatible_match(phandle node, const char *compat) 220 { 221 char buf[64], *p; 222 int plen, len; 223 224 plen = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf)); 225 if (plen <= 0) 226 return 0; 227 228 len = strlen(compat); 229 for (p = buf; p < buf + plen; p += strlen(p) + 1) { 230 if (strcmp(p, compat) == 0) 231 return 1; 232 } 233 234 return 0; 235 } 236 237 static void __init olpc_dt_fixup(void) 238 { 239 phandle node; 240 u32 board_rev; 241 242 node = olpc_dt_finddevice("/battery@0"); 243 if (!node) 244 return; 245 246 board_rev = olpc_dt_get_board_revision(); 247 if (!board_rev) 248 return; 249 250 if (board_rev >= olpc_board_pre(0xd0)) { 251 /* XO-1.5 */ 252 253 if (olpc_dt_compatible_match(node, "olpc,xo1.5-battery")) 254 return; 255 256 /* Add olpc,xo1.5-battery compatible marker to battery node */ 257 olpc_dt_interpret("\" /battery@0\" find-device"); 258 olpc_dt_interpret(" \" olpc,xo1.5-battery\" +compatible"); 259 olpc_dt_interpret("device-end"); 260 261 if (olpc_dt_compatible_match(node, "olpc,xo1-battery")) { 262 /* 263 * If we have a olpc,xo1-battery compatible, then we're 264 * running a new enough firmware that already has 265 * the dcon node. 266 */ 267 return; 268 } 269 270 /* Add dcon device */ 271 olpc_dt_interpret("\" /pci/display@1\" find-device"); 272 olpc_dt_interpret(" new-device"); 273 olpc_dt_interpret(" \" dcon\" device-name"); 274 olpc_dt_interpret(" \" olpc,xo1-dcon\" +compatible"); 275 olpc_dt_interpret(" finish-device"); 276 olpc_dt_interpret("device-end"); 277 } else { 278 /* XO-1 */ 279 280 if (olpc_dt_compatible_match(node, "olpc,xo1-battery")) { 281 /* 282 * If we have a olpc,xo1-battery compatible, then we're 283 * running a new enough firmware that already has 284 * the dcon and RTC nodes. 285 */ 286 return; 287 } 288 289 /* Add dcon device, mark RTC as olpc,xo1-rtc */ 290 olpc_dt_interpret("\" /pci/display@1,1\" find-device"); 291 olpc_dt_interpret(" new-device"); 292 olpc_dt_interpret(" \" dcon\" device-name"); 293 olpc_dt_interpret(" \" olpc,xo1-dcon\" +compatible"); 294 olpc_dt_interpret(" finish-device"); 295 olpc_dt_interpret("device-end"); 296 297 olpc_dt_interpret("\" /rtc\" find-device"); 298 olpc_dt_interpret(" \" olpc,xo1-rtc\" +compatible"); 299 olpc_dt_interpret("device-end"); 300 } 301 302 /* Add olpc,xo1-battery compatible marker to battery node */ 303 olpc_dt_interpret("\" /battery@0\" find-device"); 304 olpc_dt_interpret(" \" olpc,xo1-battery\" +compatible"); 305 olpc_dt_interpret("device-end"); 306 } 307 308 void __init olpc_dt_build_devicetree(void) 309 { 310 phandle root; 311 312 if (!olpc_ofw_is_installed()) 313 return; 314 315 olpc_dt_fixup(); 316 317 root = olpc_dt_getsibling(0); 318 if (!root) { 319 pr_err("PROM: unable to get root node from OFW!\n"); 320 return; 321 } 322 of_pdt_build_devicetree(root, &prom_olpc_ops); 323 324 pr_info("PROM DT: Built device tree with %u bytes of memory.\n", 325 prom_early_allocated); 326 } 327