drivers/mtd/mtd_uboot.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2014
   4  * Heiko Schocher, DENX Software Engineering, hs@denx.de.
   5  */
   6 #include <common.h>
   7 #include <env.h>
   8 #include <log.h>
   9 #include <malloc.h>
  10 #include <dm/device.h>
  11 #include <dm/uclass-internal.h>
  12 #include <dm/uclass.h>
  13 #include <linux/err.h>
  14 #include <linux/mtd/mtd.h>
  15 #include <linux/mtd/partitions.h>
  16 #include <asm/global_data.h>
  17 #include <mtd.h>
  18
  19 #define MTD_NAME_MAX_LEN 20
  20
  21 void board_mtdparts_default(const char **mtdids, const char **mtdparts);
  22
  23 static const char *get_mtdids(void)
  24 {
  25         __maybe_unused const char *mtdparts = NULL;
  26         const char *mtdids = env_get("mtdids");
  27
  28         if (mtdids)
  29                 return mtdids;
  30
  31 #if defined(CONFIG_SYS_MTDPARTS_RUNTIME)
  32         board_mtdparts_default(&mtdids, &mtdparts);
  33 #elif defined(CONFIG_MTDIDS_DEFAULT)
  34         mtdids = CONFIG_MTDIDS_DEFAULT;
  35 #endif
  36
  37         if (mtdids)
  38                 env_set("mtdids", mtdids);
  39
  40         return mtdids;
  41 }
  42
  43 /**
  44  * mtd_search_alternate_name - Search an alternate name for @mtdname thanks to
  45  *                             the mtdids legacy environment variable.
  46  *
  47  * The mtdids string is a list of comma-separated 'dev_id=mtd_id' tupples.
  48  * Check if one of the mtd_id matches mtdname, in this case save dev_id in
  49  * altname.
  50  *
  51  * @mtdname: Current MTD device name
  52  * @altname: Alternate name to return
  53  * @max_len: Length of the alternate name buffer
  54  *
  55  * Return: 0 on success, an error otherwise.
  56  */
  57 int mtd_search_alternate_name(const char *mtdname, char *altname,
  58                               unsigned int max_len)
  59 {
  60         const char *mtdids, *equal, *comma, *dev_id, *mtd_id;
  61         int dev_id_len, mtd_id_len;
  62
  63         mtdids = get_mtdids();
  64         if (!mtdids)
  65                 return -EINVAL;
  66
  67         do {
  68                 /* Find the '=' sign */
  69                 dev_id = mtdids;
  70                 equal = strchr(dev_id, '=');
  71                 if (!equal)
  72                         break;
  73                 dev_id_len = equal - mtdids;
  74                 mtd_id = equal + 1;
  75
  76                 /* Find the end of the tupple */
  77                 comma = strchr(mtdids, ',');
  78                 if (comma)
  79                         mtd_id_len = comma - mtd_id;
  80                 else
  81                         mtd_id_len = &mtdids[strlen(mtdids)] - mtd_id + 1;
  82
  83                 if (!dev_id_len || !mtd_id_len)
  84                         return -EINVAL;
  85
  86                 if (dev_id_len + 1 > max_len)
  87                         continue;
  88
  89                 /* Compare the name we search with the current mtd_id */
  90                 if (!strncmp(mtdname, mtd_id, mtd_id_len)) {
  91                         strncpy(altname, dev_id, dev_id_len);
  92                         altname[dev_id_len] = 0;
  93
  94                         return 0;
  95                 }
  96
  97                 /* Go to the next tupple */
  98                 mtdids = comma + 1;
  99         } while (comma);
 100
 101         return -EINVAL;
 102 }
 103
 104 #if IS_ENABLED(CONFIG_DM_MTD)
 105 static void mtd_probe_uclass_mtd_devs(void)
 106 {
 107         struct udevice *dev;
 108
 109         uclass_foreach_dev_probe(UCLASS_MTD, dev)
 110                 ;
 111 }
 112 #else
 113 static void mtd_probe_uclass_mtd_devs(void) { }
 114 #endif
 115
 116 #if IS_ENABLED(CONFIG_DM_SPI_FLASH) && IS_ENABLED(CONFIG_SPI_FLASH_MTD)
 117 static void mtd_probe_uclass_spi_nor_devs(void)
 118 {
 119         struct udevice *dev;
 120
 121         uclass_foreach_dev_probe(UCLASS_SPI_FLASH, dev)
 122                 ;
 123 }
 124 #else
 125 static void mtd_probe_uclass_spi_nor_devs(void) { }
 126 #endif
 127
 128 #if defined(CONFIG_MTD_PARTITIONS)
 129
 130 #define MTDPARTS_MAXLEN         512
 131
 132 static const char *get_mtdparts(void)
 133 {
 134         __maybe_unused const char *mtdids = NULL;
 135         static char tmp_parts[MTDPARTS_MAXLEN];
 136         const char *mtdparts = NULL;
 137
 138         if (gd->flags & GD_FLG_ENV_READY)
 139                 mtdparts = env_get("mtdparts");
 140         else if (env_get_f("mtdparts", tmp_parts, sizeof(tmp_parts)) != -1)
 141                 mtdparts = tmp_parts;
 142
 143         if (mtdparts)
 144                 return mtdparts;
 145
 146 #if defined(CONFIG_SYS_MTDPARTS_RUNTIME)
 147         board_mtdparts_default(&mtdids, &mtdparts);
 148 #elif defined(CONFIG_MTDPARTS_DEFAULT)
 149         mtdparts = CONFIG_MTDPARTS_DEFAULT;
 150 #endif
 151
 152         if (mtdparts)
 153                 env_set("mtdparts", mtdparts);
 154
 155         return mtdparts;
 156 }
 157
 158 static int mtd_del_parts(struct mtd_info *mtd, bool quiet)
 159 {
 160         int ret;
 161
 162         if (!mtd_has_partitions(mtd))
 163                 return 0;
 164
 165         /* do not delete partitions if they are in use. */
 166         if (mtd_partitions_used(mtd)) {
 167                 if (!quiet)
 168                         printf("\"%s\" partitions still in use, can't delete them\n",
 169                                mtd->name);
 170                 return -EACCES;
 171         }
 172
 173         ret = del_mtd_partitions(mtd);
 174         if (ret)
 175                 return ret;
 176
 177         return 1;
 178 }
 179
 180 static bool mtd_del_all_parts_failed;
 181
 182 static void mtd_del_all_parts(void)
 183 {
 184         struct mtd_info *mtd;
 185         int ret = 0;
 186
 187         mtd_del_all_parts_failed = false;
 188
 189         /*
 190          * It is not safe to remove entries from the mtd_for_each_device loop
 191          * as it uses idr indexes and the partitions removal is done in bulk
 192          * (all partitions of one device at the same time), so break and
 193          * iterate from start each time a new partition is found and deleted.
 194          */
 195         do {
 196                 mtd_for_each_device(mtd) {
 197                         ret = mtd_del_parts(mtd, false);
 198                         if (ret > 0)
 199                                 break;
 200                         else if (ret < 0)
 201                                 mtd_del_all_parts_failed = true;
 202                 }
 203         } while (ret > 0);
 204 }
 205
 206 static int parse_mtdparts(const char *mtdparts, const char *mtdids)
 207 {
 208         const char *mtdparts_next;
 209         struct mtd_info *mtd;
 210
 211         /* Start the parsing by ignoring the extra 'mtdparts=' prefix, if any */
 212         if (!strncmp(mtdparts, "mtdparts=", sizeof("mtdparts=") - 1))
 213                 mtdparts += 9;
 214
 215         /* For each MTD device in mtdparts */
 216         for (; mtdparts[0] != '\0'; mtdparts = mtdparts_next) {
 217                 char mtd_name[MTD_NAME_MAX_LEN], *colon;
 218                 struct mtd_partition *parts;
 219                 unsigned int mtd_name_len;
 220                 int nparts, ret;
 221
 222                 mtdparts_next = strchr(mtdparts, ';');
 223                 if (!mtdparts_next)
 224                         mtdparts_next = mtdparts + strlen(mtdparts);
 225                 else
 226                         mtdparts_next++;
 227
 228                 colon = strchr(mtdparts, ':');
 229                 if (colon > mtdparts_next)
 230                         colon = NULL;
 231
 232                 if (!colon) {
 233                         printf("Wrong mtdparts: %s\n", mtdparts);
 234                         return -EINVAL;
 235                 }
 236
 237                 mtd_name_len = (unsigned int)(colon - mtdparts);
 238                 if (mtd_name_len + 1 > sizeof(mtd_name)) {
 239                         printf("MTD name too long: %s\n", mtdparts);
 240                         return -EINVAL;
 241                 }
 242
 243                 strncpy(mtd_name, mtdparts, mtd_name_len);
 244                 mtd_name[mtd_name_len] = '\0';
 245                 /* Move the pointer forward (including the ':') */
 246                 mtdparts += mtd_name_len + 1;
 247                 mtd = get_mtd_device_nm(mtd_name);
 248                 if (IS_ERR_OR_NULL(mtd)) {
 249                         char linux_name[MTD_NAME_MAX_LEN];
 250
 251                         /*
 252                          * The MTD device named "mtd_name" does not exist. Try
 253                          * to find a correspondance with an MTD device having
 254                          * the same type and number as defined in the mtdids.
 255                          */
 256                         debug("No device named %s\n", mtd_name);
 257                         ret = mtd_search_alternate_name(mtd_name, linux_name,
 258                                                         MTD_NAME_MAX_LEN);
 259                         if (!ret)
 260                                 mtd = get_mtd_device_nm(linux_name);
 261
 262                         /*
 263                          * If no device could be found, move the mtdparts
 264                          * pointer forward until the next set of partitions.
 265                          */
 266                         if (ret || IS_ERR_OR_NULL(mtd)) {
 267                                 printf("Could not find a valid device for %s\n",
 268                                        mtd_name);
 269                                 mtdparts = mtdparts_next;
 270                                 continue;
 271                         }
 272                 }
 273
 274                 /*
 275                  * Call mtd_del_parts() again, even if it's already been called
 276                  * in mtd_del_all_parts(). We need to know if old partitions are
 277                  * still around (because they are still being used by someone),
 278                  * and if they are, we shouldn't create new partitions, so just
 279                  * skip this MTD device and try the next one.
 280                  */
 281                 ret = mtd_del_parts(mtd, true);
 282                 if (ret < 0)
 283                         continue;
 284
 285                 /*
 286                  * Parse the MTD device partitions. It will update the mtdparts
 287                  * pointer, create an array of parts (that must be freed), and
 288                  * return the number of partition structures in the array.
 289                  */
 290                 ret = mtd_parse_partitions(mtd, &mtdparts, &parts, &nparts);
 291                 if (ret) {
 292                         printf("Could not parse device %s\n", mtd->name);
 293                         put_mtd_device(mtd);
 294                         return -EINVAL;
 295                 }
 296
 297                 if (!nparts)
 298                         continue;
 299
 300                 /* Create the new MTD partitions */
 301                 add_mtd_partitions(mtd, parts, nparts);
 302
 303                 /* Free the structures allocated during the parsing */
 304                 mtd_free_parsed_partitions(parts, nparts);
 305
 306                 put_mtd_device(mtd);
 307         }
 308
 309         return 0;
 310 }
 311
 312 int mtd_probe_devices(void)
 313 {
 314         static char *old_mtdparts;
 315         static char *old_mtdids;
 316         const char *mtdparts = get_mtdparts();
 317         const char *mtdids = get_mtdids();
 318         struct mtd_info *mtd;
 319
 320         mtd_probe_uclass_mtd_devs();
 321         mtd_probe_uclass_spi_nor_devs();
 322
 323         /*
 324          * Check if mtdparts/mtdids changed, if the MTD dev list was updated
 325          * or if our previous attempt to delete existing partititions failed.
 326          * In any of these cases we want to update the partitions, otherwise,
 327          * everything is up-to-date and we can return 0 directly.
 328          */
 329         if ((!mtdparts && !old_mtdparts && !mtdids && !old_mtdids) ||
 330             (mtdparts && old_mtdparts && mtdids && old_mtdids &&
 331              !mtd_dev_list_updated() && !mtd_del_all_parts_failed &&
 332              !strcmp(mtdparts, old_mtdparts) &&
 333              !strcmp(mtdids, old_mtdids)))
 334                 return 0;
 335
 336         /* Update the local copy of mtdparts */
 337         free(old_mtdparts);
 338         free(old_mtdids);
 339         old_mtdparts = strdup(mtdparts);
 340         old_mtdids = strdup(mtdids);
 341
 342         /*
 343          * Remove all old parts. Note that partition removal can fail in case
 344          * one of the partition is still being used by an MTD user, so this
 345          * does not guarantee that all old partitions are gone.
 346          */
 347         mtd_del_all_parts();
 348
 349         /*
 350          * Call mtd_dev_list_updated() to clear updates generated by our own
 351          * parts removal loop.
 352          */
 353         mtd_dev_list_updated();
 354
 355         /* If both mtdparts and mtdids are non-empty, parse */
 356         if (mtdparts && mtdids) {
 357                 if (parse_mtdparts(mtdparts, mtdids) < 0)
 358                         printf("Failed parsing MTD partitions from mtdparts!\n");
 359         }
 360
 361         /* Fallback to OF partitions */
 362         mtd_for_each_device(mtd) {
 363                 if (list_empty(&mtd->partitions)) {
 364                         if (add_mtd_partitions_of(mtd) < 0)
 365                                 printf("Failed parsing MTD %s OF partitions!\n",
 366                                         mtd->name);
 367                 }
 368         }
 369
 370         /*
 371          * Call mtd_dev_list_updated() to clear updates generated by our own
 372          * parts registration loop.
 373          */
 374         mtd_dev_list_updated();
 375
 376         return 0;
 377 }
 378 #else
 379 int mtd_probe_devices(void)
 380 {
 381         mtd_probe_uclass_mtd_devs();
 382         mtd_probe_uclass_spi_nor_devs();
 383
 384         return 0;
 385 }
 386 #endif /* defined(CONFIG_MTD_PARTITIONS) */