board/karo/common/fdt.c

   1 /*
   2  * (C) Copyright 2012,2013 Lothar Waßmann <LW@KARO-electronics.de>
   3  *
   4  * See file CREDITS for list of people who contributed to this
   5  * project.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16 */
  17
  18 #include <common.h>
  19 #include <errno.h>
  20 #include <libfdt.h>
  21 #include <fdt_support.h>
  22 #include <nand.h>
  23 #include <mxcfb.h>
  24 #include <linux/list.h>
  25 #include <linux/fb.h>
  26 #include <jffs2/load_kernel.h>
  27
  28 #include "karo.h"
  29
  30 #ifdef CONFIG_MAX_DTB_SIZE
  31 #define MAX_DTB_SIZE    CONFIG_MAX_DTB_SIZE
  32 #else
  33 #define MAX_DTB_SIZE    SZ_64K
  34 #endif
  35
  36 DECLARE_GLOBAL_DATA_PTR;
  37
  38 static void karo_set_fdtsize(void *fdt)
  39 {
  40         char fdt_size[9];
  41         size_t fdtsize = getenv_ulong("fdtsize", 16, 0);
  42
  43         if (fdtsize == fdt_totalsize(fdt)) {
  44                 return;
  45         }
  46         debug("FDT size changed from %u to %u\n",
  47                 fdtsize, fdt_totalsize(fdt));
  48
  49         snprintf(fdt_size, sizeof(fdt_size), "%08x", fdt_totalsize(fdt));
  50         setenv("fdtsize", fdt_size);
  51 }
  52
  53 void karo_fdt_move_fdt(void)
  54 {
  55         void *fdt;
  56         unsigned long fdt_addr = getenv_ulong("fdtaddr", 16, 0);
  57
  58         if (working_fdt) {
  59                 debug("DTB already loaded\n");
  60                 return;
  61         }
  62
  63         if (!fdt_addr) {
  64                 fdt_addr = CONFIG_SYS_FDT_ADDR;
  65                 printf("fdtaddr is not set; using default: %08lx\n",
  66                         fdt_addr);
  67         }
  68
  69         fdt = karo_fdt_load_dtb();
  70         if (fdt == NULL) {
  71                 fdt = (void *)gd->fdt_blob;
  72                 if (fdt == NULL) {
  73                         printf("Compiled in FDT not found\n");
  74                         return;
  75                 }
  76                 debug("Checking FDT header @ %p\n", fdt);
  77                 if (fdt_check_header(fdt)) {
  78                         printf("ERROR: No valid DTB found at %p\n", fdt);
  79                         return;
  80                 }
  81                 printf("No DTB in flash; using default DTB\n");
  82                 debug("Moving FDT from %p..%p to %08lx..%08lx\n",
  83                         fdt, fdt + fdt_totalsize(fdt) - 1,
  84                         fdt_addr, fdt_addr + fdt_totalsize(fdt) - 1);
  85                 memmove((void *)fdt_addr, fdt, fdt_totalsize(fdt));
  86         }
  87         set_working_fdt_addr((void *)fdt_addr);
  88         gd->fdt_blob = fdt;
  89         karo_set_fdtsize(fdt);
  90 }
  91
  92 void karo_fdt_remove_node(void *blob, const char *node)
  93 {
  94         int off = fdt_path_offset(blob, node);
  95         int ret;
  96
  97         debug("Removing node '%s' from DT\n", node);
  98
  99         if (off < 0) {
 100                 printf("Could not find node '%s': %d\n", node, off);
 101         } else {
 102                 ret = fdt_del_node(blob, off);
 103                 if (ret)
 104                         printf("Failed to remove node '%s': %d\n",
 105                                 node, ret);
 106         }
 107         karo_set_fdtsize(blob);
 108 }
 109
 110 void karo_fdt_enable_node(void *blob, const char *node, int enable)
 111 {
 112         int off = fdt_path_offset(blob, node);
 113
 114         debug("%sabling node '%s'\n", enable ? "En" : "Dis", node);
 115         if (off < 0) {
 116                 printf("Could not find node '%s': %d\n", node, off);
 117                 return;
 118         }
 119         fdt_set_node_status(blob, off,
 120                         enable ? FDT_STATUS_OKAY : FDT_STATUS_DISABLED, 0);
 121
 122         karo_set_fdtsize(blob);
 123 }
 124
 125 static const char *karo_touchpanels[] = {
 126         "ti,tsc2007",
 127         "edt,edt-ft5x06",
 128 #ifdef CONFIG_MX28
 129         "fsl,imx28-lradc",
 130 #endif
 131 };
 132
 133 static void fdt_disable_tp_node(void *blob, const char *name)
 134 {
 135         int offs = fdt_node_offset_by_compatible(blob, -1, name);
 136
 137         if (offs < 0) {
 138                 debug("node '%s' not found: %d\n", name, offs);
 139                 return;
 140         }
 141
 142         debug("Disabling node '%s'\n", name);
 143         fdt_set_node_status(blob, offs, FDT_STATUS_DISABLED, 0);
 144 }
 145
 146 void karo_fdt_fixup_touchpanel(void *blob)
 147 {
 148         int i;
 149         const char *model = getenv("touchpanel");
 150
 151         for (i = 0; i < ARRAY_SIZE(karo_touchpanels); i++) {
 152                 const char *tp = karo_touchpanels[i];
 153
 154                 if (model != NULL && strcmp(model, tp) == 0)
 155                         continue;
 156
 157                 if (model != NULL) {
 158                         if (strcmp(model, tp) == 0)
 159                                 continue;
 160                         tp = strchr(tp, ',');
 161                         if (tp != NULL && *tp != '\0' && strcmp(model, tp + 1) == 0)
 162                                 continue;
 163                 }
 164                 fdt_disable_tp_node(blob, karo_touchpanels[i]);
 165         }
 166         karo_set_fdtsize(blob);
 167 }
 168
 169 void karo_fdt_fixup_usb_otg(void *blob, const char *node, const char *phy)
 170 {
 171         const char *otg_mode = getenv("otg_mode");
 172         int off;
 173         int ret;
 174         const uint32_t *ph;
 175         int disable_otg = 0;
 176         int disable_phy_pins = 1;
 177
 178         debug("OTG mode is '%s'\n", otg_mode ? otg_mode : "<UNSET>");
 179
 180         off = fdt_path_offset(blob, node);
 181         if (off < 0) {
 182                 debug("Failed to find node %s\n", node);
 183                 return;
 184         }
 185
 186         if (otg_mode && (strcmp(otg_mode, "device") == 0 ||
 187                                 strcmp(otg_mode, "gadget") == 0)) {
 188                 debug("Setting dr_mode to 'peripheral'\n");
 189                 ret = fdt_setprop_string(blob, off, "dr_mode", "peripheral");
 190         } else if (otg_mode && strcmp(otg_mode, "host") == 0) {
 191                 debug("Setting dr_mode to 'host'\n");
 192                 ret = fdt_setprop_string(blob, off, "dr_mode", "host");
 193                 disable_phy_pins = 0;
 194         } else if (otg_mode && strcmp(otg_mode, "otg") == 0) {
 195                 debug("Setting dr_mode to 'host'\n");
 196                 ret = fdt_setprop_string(blob, off, "dr_mode", "otg");
 197         } else {
 198                 if (otg_mode && strcmp(otg_mode, "none") != 0)
 199                         printf("Invalid 'otg_mode' setting '%s'; disabling usbotg port\n",
 200                                 otg_mode);
 201                 disable_otg = 1;
 202                 ret = 0;
 203         }
 204
 205         if ((!disable_phy_pins && !disable_otg) || ret)
 206                 goto out;
 207
 208         if (disable_otg) {
 209                 ret = fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
 210                 if (ret)
 211                         goto out;
 212         }
 213
 214         ph = fdt_getprop(blob, off, phy, NULL);
 215         if (ph == NULL) {
 216                 printf("Failed to find '%s' phandle in node '%s'\n", phy,
 217                         fdt_get_name(blob, off, NULL));
 218                 goto out;
 219         }
 220
 221         off = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*ph));
 222         if (off <= 0) {
 223                 printf("Failed to find '%s' node via phandle %04x\n",
 224                         phy, fdt32_to_cpu(*ph));
 225                 goto out;
 226         }
 227
 228         if (disable_otg) {
 229                 debug("Disabling usbphy\n");
 230                 ret = fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
 231         }
 232 out:
 233         if (ret)
 234                 printf("Failed to update usbotg: %d\n", ret);
 235         else
 236                 debug("node '%s' updated\n", node);
 237         karo_set_fdtsize(blob);
 238 }
 239
 240 static int karo_fdt_flexcan_enabled(void *blob)
 241 {
 242         const char *can_ifs[] = {
 243                 "can0",
 244                 "can1",
 245         };
 246         size_t i;
 247
 248         for (i = 0; i < ARRAY_SIZE(can_ifs); i++) {
 249                 const char *status;
 250                 int off = fdt_path_offset(blob, can_ifs[i]);
 251
 252                 if (off < 0) {
 253                         debug("node '%s' not found\n", can_ifs[i]);
 254                         continue;
 255                 }
 256                 status = fdt_getprop(blob, off, "status", NULL);
 257                 if (status && strcmp(status, "okay") == 0) {
 258                         debug("%s is enabled\n", can_ifs[i]);
 259                         return 1;
 260                 }
 261         }
 262         debug("can driver is disabled\n");
 263         return 0;
 264 }
 265
 266 static void karo_fdt_set_lcd_pins(void *blob, const char *name)
 267 {
 268         int off = fdt_path_offset(blob, name);
 269         u32 ph;
 270         const struct fdt_property *pc;
 271         int len;
 272
 273         if (off < 0)
 274                 return;
 275
 276         ph = fdt_create_phandle(blob, off);
 277         if (!ph)
 278                 return;
 279
 280         off = fdt_path_offset(blob, "display");
 281         if (off < 0)
 282                 return;
 283
 284         pc = fdt_get_property(blob, off, "pinctrl-0", &len);
 285         if (!pc || len < sizeof(ph))
 286                 return;
 287
 288         memcpy((void *)pc->data, &ph, sizeof(ph));
 289         fdt_setprop_cell(blob, off, "pinctrl-0", ph);
 290 }
 291
 292 void karo_fdt_fixup_flexcan(void *blob, int xcvr_present)
 293 {
 294         const char *xcvr_status = "disabled";
 295
 296         if (xcvr_present) {
 297                 if (karo_fdt_flexcan_enabled(blob)) {
 298                         karo_fdt_set_lcd_pins(blob, "lcdif_23bit_pins_a");
 299                         xcvr_status = "okay";
 300                 } else {
 301                         karo_fdt_set_lcd_pins(blob, "lcdif_24bit_pins_a");
 302                 }
 303         } else {
 304                 const char *otg_mode = getenv("otg_mode");
 305
 306                 if (otg_mode && (strcmp(otg_mode, "host") == 0))
 307                         karo_fdt_enable_node(blob, "can1", 0);
 308
 309                 karo_fdt_set_lcd_pins(blob, "lcdif_24bit_pins_a");
 310         }
 311         fdt_find_and_setprop(blob, "/regulators/can-xcvr", "status",
 312                         xcvr_status, strlen(xcvr_status) + 1, 1);
 313 }
 314
 315 void karo_fdt_del_prop(void *blob, const char *compat, phys_addr_t offs,
 316                         const char *prop)
 317 {
 318         int ret;
 319         int offset;
 320         const uint32_t *phandle;
 321         uint32_t ph = 0;
 322
 323         offset = fdt_node_offset_by_compat_reg(blob, compat, offs);
 324         if (offset <= 0)
 325                 return;
 326
 327         phandle = fdt_getprop(blob, offset, prop, NULL);
 328         if (phandle) {
 329                 ph = fdt32_to_cpu(*phandle);
 330         }
 331
 332         debug("Removing property '%s' from node %s@%08lx\n", prop, compat, offs);
 333         ret = fdt_delprop(blob, offset, prop);
 334         if (ret == 0)
 335                 karo_set_fdtsize(blob);
 336
 337         if (!ph)
 338                 return;
 339
 340         offset = fdt_node_offset_by_phandle(blob, ph);
 341         if (offset <= 0)
 342                 return;
 343
 344         debug("Removing node @ %08x\n", offset);
 345         fdt_del_node(blob, offset);
 346         karo_set_fdtsize(blob);
 347 }
 348
 349 static int fdt_init_fb_mode(const void *blob, int off, struct fb_videomode *fb_mode)
 350 {
 351         const uint32_t *prop;
 352
 353         memset(fb_mode, 0, sizeof(*fb_mode));
 354
 355         prop = fdt_getprop(blob, off, "clock-frequency", NULL);
 356         if (prop)
 357                 fb_mode->pixclock = KHZ2PICOS(fdt32_to_cpu(*prop) / 1000);
 358
 359         prop = fdt_getprop(blob, off, "hactive", NULL);
 360         if (prop)
 361                 fb_mode->xres = fdt32_to_cpu(*prop);
 362
 363         prop = fdt_getprop(blob, off, "vactive", NULL);
 364         if (prop)
 365                 fb_mode->yres = fdt32_to_cpu(*prop);
 366
 367         prop = fdt_getprop(blob, off, "hback-porch", NULL);
 368         if (prop)
 369                 fb_mode->left_margin = fdt32_to_cpu(*prop);
 370
 371         prop = fdt_getprop(blob, off, "hsync-len", NULL);
 372         if (prop)
 373                 fb_mode->hsync_len = fdt32_to_cpu(*prop);
 374
 375         prop = fdt_getprop(blob, off, "hfront-porch", NULL);
 376         if (prop)
 377                 fb_mode->right_margin = fdt32_to_cpu(*prop);
 378
 379         prop = fdt_getprop(blob, off, "vback-porch", NULL);
 380         if (prop)
 381                 fb_mode->upper_margin = fdt32_to_cpu(*prop);
 382
 383         prop = fdt_getprop(blob, off, "vsync-len", NULL);
 384         if (prop)
 385                 fb_mode->vsync_len = fdt32_to_cpu(*prop);
 386
 387         prop = fdt_getprop(blob, off, "vfront-porch", NULL);
 388         if (prop)
 389                 fb_mode->lower_margin = fdt32_to_cpu(*prop);
 390
 391         prop = fdt_getprop(blob, off, "hsync-active", NULL);
 392         if (prop)
 393                 fb_mode->sync |= *prop ? FB_SYNC_VERT_HIGH_ACT : 0;
 394
 395         prop = fdt_getprop(blob, off, "vsync-active", NULL);
 396         if (prop)
 397                 fb_mode->sync |= *prop ? FB_SYNC_VERT_HIGH_ACT : 0;
 398
 399         prop = fdt_getprop(blob, off, "de-active", NULL);
 400         if (prop)
 401                 fb_mode->sync |= *prop ? 0 : FB_SYNC_OE_LOW_ACT;
 402
 403         prop = fdt_getprop(blob, off, "pixelclk-active", NULL);
 404         if (prop)
 405                 fb_mode->sync |= *prop ? 0 : FB_SYNC_CLK_LAT_FALL;
 406
 407         return 0;
 408 }
 409
 410 static int fdt_update_native_fb_mode(void *blob, int off)
 411 {
 412         int ret;
 413         uint32_t ph;
 414
 415         ret = fdt_increase_size(blob, 64);
 416         if (ret) {
 417                 printf("Warning: Failed to increase FDT size: %d\n", ret);
 418         }
 419         debug("Creating phandle at offset %d\n", off);
 420         ph = fdt_create_phandle(blob, off);
 421         if (!ph) {
 422                 printf("Failed to create phandle for video timing\n");
 423                 return -ENOMEM;
 424         }
 425
 426         debug("phandle of %s @ %06x=%04x\n", fdt_get_name(blob, off, NULL),
 427                 off, ph);
 428         off = fdt_parent_offset(blob, off);
 429         if (off < 0)
 430                 return off;
 431         debug("parent offset=%06x\n", off);
 432         ret = fdt_setprop_cell(blob, off, "native-mode", ph);
 433         if (ret)
 434                 printf("Failed to set property 'native-mode': %d\n", ret);
 435         karo_set_fdtsize(blob);
 436         return ret;
 437 }
 438
 439 static int karo_fdt_find_video_timings(void *blob)
 440 {
 441         int off = fdt_path_offset(blob, "display");
 442         const char *subnode = "display-timings";
 443
 444         if (off < 0) {
 445                 debug("Could not find node 'display' in FDT: %d\n", off);
 446                 return off;
 447         }
 448
 449         off = fdt_subnode_offset(blob, off, subnode);
 450         if (off < 0) {
 451                 debug("Could not find node '%s' in FDT: %d\n", subnode, off);
 452         }
 453         return off;
 454 }
 455
 456 int karo_fdt_get_fb_mode(void *blob, const char *name, struct fb_videomode *fb_mode)
 457 {
 458         int off = karo_fdt_find_video_timings(blob);
 459
 460         if (off < 0)
 461                 return off;
 462         while (off > 0) {
 463                 const char *n, *endp;
 464                 int len, d = 1;
 465
 466                 off = fdt_next_node(blob, off, &d);
 467                 if (off < 0)
 468                         return off;
 469                 if (d < 1)
 470                         return -EINVAL;
 471                 if (d > 2) {
 472                         debug("Skipping node @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
 473                         continue;
 474                 }
 475                 debug("parsing subnode @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
 476
 477                 n = fdt_getprop(blob, off, "panel-name", &len);
 478                 if (!n) {
 479                         n = fdt_get_name(blob, off, NULL);
 480                         if (strcasecmp(n, name) == 0) {
 481                                 break;
 482                         }
 483                 } else {
 484                         int found = 0;
 485
 486                         for (endp = n + len; n < endp; n += strlen(n) + 1) {
 487                                 debug("Checking panel-name '%s'\n", n);
 488                                 if (strcasecmp(n, name) == 0) {
 489                                         debug("Using node %s @ %04x\n",
 490                                                 fdt_get_name(blob, off, NULL), off);
 491                                         found = 1;
 492                                         break;
 493                                 }
 494                         }
 495                         if (found)
 496                                 break;
 497                 }
 498         }
 499         if (off > 0) {
 500                 return fdt_init_fb_mode(blob, off, fb_mode);
 501         }
 502         return -EINVAL;
 503 }
 504
 505 #define SET_FB_PROP(n, v) ({                                            \
 506         int ret;                                                        \
 507         ret = fdt_setprop_u32(blob, off, n, v);                         \
 508         if (ret) {                                                      \
 509                 printf("Failed to set property %s: %d\n", name, ret);   \
 510         }                                                               \
 511         ret;                                                            \
 512 })
 513
 514
 515 int karo_fdt_create_fb_mode(void *blob, const char *name,
 516                         struct fb_videomode *fb_mode)
 517 {
 518         int off = fdt_path_offset(blob, "display");
 519         int ret;
 520         const char *subnode = "display-timings";
 521
 522         if (off < 0) {
 523                 printf("'display' node not found in FDT\n");
 524                 return off;
 525         }
 526
 527         ret = fdt_increase_size(blob, 512);
 528         if (ret) {
 529                 printf("Failed to increase FDT size: %d\n", ret);
 530                 return ret;
 531         }
 532
 533         printf("node '%s' offset=%d\n", "display", off);
 534         ret = fdt_subnode_offset(blob, off, subnode);
 535         if (ret < 0) {
 536                 debug("Could not find node '%s' in FDT: %d\n", subnode, ret);
 537                 ret = fdt_add_subnode(blob, off, subnode);
 538                 if (ret < 0) {
 539                         printf("Failed to add %s subnode: %d\n", subnode, ret);
 540                         return ret;
 541                 }
 542         }
 543
 544         printf("node '%s' offset=%d\n", subnode, ret);
 545         ret = fdt_add_subnode(blob, ret, name);
 546         if (ret < 0) {
 547                 printf("Failed to add %s subnode: %d\n", name, ret);
 548                 return ret;
 549         }
 550         off = ret;
 551
 552         ret = SET_FB_PROP("clock-frequency",
 553                         PICOS2KHZ(fb_mode->pixclock) * 1000);
 554         if (ret)
 555                 goto out;
 556         ret = SET_FB_PROP("hactive", fb_mode->xres);
 557         if (ret)
 558                 goto out;
 559         ret = SET_FB_PROP("vactive", fb_mode->yres);
 560         if (ret)
 561                 goto out;
 562         ret = SET_FB_PROP("hback-porch", fb_mode->left_margin);
 563         if (ret)
 564                 goto out;
 565         ret = SET_FB_PROP("hsync-len", fb_mode->hsync_len);
 566         if (ret)
 567                 goto out;
 568         ret = SET_FB_PROP("hfront-porch", fb_mode->right_margin);
 569         if (ret)
 570                 goto out;
 571         ret = SET_FB_PROP("vback-porch", fb_mode->upper_margin);
 572         if (ret)
 573                 goto out;
 574         ret = SET_FB_PROP("vsync-len", fb_mode->vsync_len);
 575         if (ret)
 576                 goto out;
 577         ret = SET_FB_PROP("vfront-porch", fb_mode->lower_margin);
 578         if (ret)
 579                 goto out;
 580         ret = SET_FB_PROP("hsync-active",
 581                         fb_mode->sync & FB_SYNC_VERT_HIGH_ACT ? 1 : 0);
 582         if (ret)
 583                 goto out;
 584         ret = SET_FB_PROP("vsync-active",
 585                         fb_mode->sync & FB_SYNC_VERT_HIGH_ACT ? 1 : 0);
 586         if (ret)
 587                 goto out;
 588         ret = SET_FB_PROP("de-active",
 589                         !(fb_mode->sync & FB_SYNC_OE_LOW_ACT));
 590         if (ret)
 591                 goto out;
 592         ret = SET_FB_PROP("pixelclk-active",
 593                         !(fb_mode->sync & FB_SYNC_CLK_LAT_FALL));
 594 out:
 595         karo_set_fdtsize(blob);
 596         return ret;
 597 }
 598
 599 int karo_fdt_update_fb_mode(void *blob, const char *name)
 600 {
 601         int off = fdt_path_offset(blob, "display");
 602         const char *subnode = "display-timings";
 603
 604         if (off < 0)
 605                 return off;
 606
 607         if (name == NULL) {
 608                 int ret;
 609
 610                 debug("Disabling node '%s' at %03x\n",
 611                         fdt_get_name(blob, off, NULL), off);
 612                 ret = fdt_set_node_status(blob, off, FDT_STATUS_DISABLED, 0);
 613                 return ret;
 614         }
 615
 616         off = fdt_subnode_offset(blob, off, subnode);
 617         if (off < 0) {
 618                 debug("Could not find node '%s' in FDT: %d\n", subnode, off);
 619                 return off;
 620         }
 621         while (off > 0) {
 622                 const char *n, *endp;
 623                 int len, d = 1;
 624
 625                 off = fdt_next_node(blob, off, &d);
 626                 if (off < 0)
 627                         return off;
 628                 if (d < 1)
 629                         return -EINVAL;
 630                 if (d > 2) {
 631                         debug("Skipping node @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
 632                         continue;
 633                 }
 634                 debug("parsing subnode @ %04x %s depth %d\n", off, fdt_get_name(blob, off, NULL), d);
 635
 636                 n = fdt_getprop(blob, off, "panel-name", &len);
 637                 if (!n) {
 638                         n = fdt_get_name(blob, off, NULL);
 639                         if (strcasecmp(n, name) == 0) {
 640                                 break;
 641                         }
 642                 } else {
 643                         int found = 0;
 644
 645                         for (endp = n + len; n < endp; n += strlen(n) + 1) {
 646                                 debug("Checking panel-name '%s'\n", n);
 647                                 if (strcasecmp(n, name) == 0) {
 648                                         debug("Using node %s @ %04x\n",
 649                                                 fdt_get_name(blob, off, NULL), off);
 650                                         found = 1;
 651                                         break;
 652                                 }
 653                         }
 654                         if (found)
 655                                 break;
 656                 }
 657         }
 658         if (off > 0)
 659                 return fdt_update_native_fb_mode(blob, off);
 660         return off;
 661 }
 662
 663 static int karo_load_part(const char *part, void *addr, size_t len)
 664 {
 665         int ret;
 666         struct mtd_device *dev;
 667         struct part_info *part_info;
 668         u8 part_num;
 669         size_t actual;
 670
 671         debug("Initializing mtd_parts\n");
 672         ret = mtdparts_init();
 673         if (ret)
 674                 return ret;
 675
 676         debug("Trying to find NAND partition '%s'\n", part);
 677         ret = find_dev_and_part(part, &dev, &part_num, &part_info);
 678         if (ret) {
 679                 printf("Failed to find flash partition '%s': %d\n",
 680                         part, ret);
 681
 682                 return ret;
 683         }
 684         debug("Found partition '%s': offset=%08x size=%08x\n",
 685                 part, part_info->offset, part_info->size);
 686         if (part_info->size < len) {
 687                 printf("Warning: partition '%s' smaller than requested size: %u; truncating data to %u byte\n",
 688                         part, len, part_info->size);
 689                 len = part_info->size;
 690         }
 691         debug("Reading NAND partition '%s' to %p\n", part, addr);
 692         ret = nand_read_skip_bad(&nand_info[0], part_info->offset, &len,
 693                                 &actual, len, addr);
 694         if (ret) {
 695                 printf("Failed to load partition '%s' to %p\n", part, addr);
 696                 return ret;
 697         }
 698         if (actual < len)
 699                 printf("Read only %u of %u bytes due to bad blocks\n",
 700                         actual, len);
 701
 702         debug("Read %u byte from partition '%s' @ offset %08x\n",
 703                 len, part, part_info->offset);
 704         return 0;
 705 }
 706
 707 void *karo_fdt_load_dtb(void)
 708 {
 709         int ret;
 710         void *fdt = (void *)getenv_ulong("fdtaddr", 16, CONFIG_SYS_FDT_ADDR);
 711
 712         if (tstc()) {
 713                 debug("aborting DTB load\n");
 714                 return NULL;
 715         }
 716
 717         /* clear FDT header in memory */
 718         memset(fdt, 0, 4);
 719
 720         ret = karo_load_part("dtb", fdt, MAX_DTB_SIZE);
 721         if (ret) {
 722                 printf("Failed to load dtb from flash: %d\n", ret);
 723                 return NULL;
 724         }
 725
 726         if (fdt_check_header(fdt)) {
 727                 debug("No valid DTB in flash\n");
 728                 return NULL;
 729         }
 730         debug("Using DTB from flash\n");
 731         karo_set_fdtsize(fdt);
 732         return fdt;
 733 }