drivers/mtd/maps/physmap_of.c

   1 /*
   2  * Flash mappings described by the OF (or flattened) device tree
   3  *
   4  * Copyright (C) 2006 MontaVista Software Inc.
   5  * Author: Vitaly Wool <vwool@ru.mvista.com>
   6  *
   7  * Revised to handle newer style flash binding by:
   8  *   Copyright (C) 2007 David Gibson, IBM Corporation.
   9  *
  10  * This program is free software; you can redistribute  it and/or modify it
  11  * under  the terms of  the GNU General  Public License as published by the
  12  * Free Software Foundation;  either version 2 of the  License, or (at your
  13  * option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/init.h>
  19 #include <linux/device.h>
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/mtd/map.h>
  22 #include <linux/mtd/partitions.h>
  23 #include <linux/mtd/concat.h>
  24 #include <linux/of.h>
  25 #include <linux/of_address.h>
  26 #include <linux/of_platform.h>
  27 #include <linux/slab.h>
  28
  29 struct of_flash_list {
  30         struct mtd_info *mtd;
  31         struct map_info map;
  32         struct resource *res;
  33 };
  34
  35 struct of_flash {
  36         struct mtd_info         *cmtd;
  37 #ifdef CONFIG_MTD_PARTITIONS
  38         struct mtd_partition    *parts;
  39 #endif
  40         int list_size; /* number of elements in of_flash_list */
  41         struct of_flash_list    list[0];
  42 };
  43
  44 #ifdef CONFIG_MTD_PARTITIONS
  45 #define OF_FLASH_PARTS(info)    ((info)->parts)
  46
  47 static int parse_obsolete_partitions(struct platform_device *dev,
  48                                      struct of_flash *info,
  49                                      struct device_node *dp)
  50 {
  51         int i, plen, nr_parts;
  52         const struct {
  53                 __be32 offset, len;
  54         } *part;
  55         const char *names;
  56
  57         part = of_get_property(dp, "partitions", &plen);
  58         if (!part)
  59                 return 0; /* No partitions found */
  60
  61         dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
  62
  63         nr_parts = plen / sizeof(part[0]);
  64
  65         info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
  66         if (!info->parts)
  67                 return -ENOMEM;
  68
  69         names = of_get_property(dp, "partition-names", &plen);
  70
  71         for (i = 0; i < nr_parts; i++) {
  72                 info->parts[i].offset = be32_to_cpu(part->offset);
  73                 info->parts[i].size   = be32_to_cpu(part->len) & ~1;
  74                 if (be32_to_cpu(part->len) & 1) /* bit 0 set signifies read only partition */
  75                         info->parts[i].mask_flags = MTD_WRITEABLE;
  76
  77                 if (names && (plen > 0)) {
  78                         int len = strlen(names) + 1;
  79
  80                         info->parts[i].name = (char *)names;
  81                         plen -= len;
  82                         names += len;
  83                 } else {
  84                         info->parts[i].name = "unnamed";
  85                 }
  86
  87                 part++;
  88         }
  89
  90         return nr_parts;
  91 }
  92 #else /* MTD_PARTITIONS */
  93 #define OF_FLASH_PARTS(info)            (0)
  94 #define parse_partitions(info, dev)     (0)
  95 #endif /* MTD_PARTITIONS */
  96
  97 static int of_flash_remove(struct platform_device *dev)
  98 {
  99         struct of_flash *info;
 100         int i;
 101
 102         info = dev_get_drvdata(&dev->dev);
 103         if (!info)
 104                 return 0;
 105         dev_set_drvdata(&dev->dev, NULL);
 106
 107         if (info->cmtd != info->list[0].mtd) {
 108                 del_mtd_device(info->cmtd);
 109                 mtd_concat_destroy(info->cmtd);
 110         }
 111
 112         if (info->cmtd) {
 113                 if (OF_FLASH_PARTS(info)) {
 114                         del_mtd_partitions(info->cmtd);
 115                         kfree(OF_FLASH_PARTS(info));
 116                 } else {
 117                         del_mtd_device(info->cmtd);
 118                 }
 119         }
 120
 121         for (i = 0; i < info->list_size; i++) {
 122                 if (info->list[i].mtd)
 123                         map_destroy(info->list[i].mtd);
 124
 125                 if (info->list[i].map.virt)
 126                         iounmap(info->list[i].map.virt);
 127
 128                 if (info->list[i].res) {
 129                         release_resource(info->list[i].res);
 130                         kfree(info->list[i].res);
 131                 }
 132         }
 133
 134         kfree(info);
 135
 136         return 0;
 137 }
 138
 139 /* Helper function to handle probing of the obsolete "direct-mapped"
 140  * compatible binding, which has an extra "probe-type" property
 141  * describing the type of flash probe necessary. */
 142 static struct mtd_info * __devinit obsolete_probe(struct platform_device *dev,
 143                                                   struct map_info *map)
 144 {
 145         struct device_node *dp = dev->dev.of_node;
 146         const char *of_probe;
 147         struct mtd_info *mtd;
 148         static const char *rom_probe_types[]
 149                 = { "cfi_probe", "jedec_probe", "map_rom"};
 150         int i;
 151
 152         dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
 153                  "flash binding\n");
 154
 155         of_probe = of_get_property(dp, "probe-type", NULL);
 156         if (!of_probe) {
 157                 for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
 158                         mtd = do_map_probe(rom_probe_types[i], map);
 159                         if (mtd)
 160                                 return mtd;
 161                 }
 162                 return NULL;
 163         } else if (strcmp(of_probe, "CFI") == 0) {
 164                 return do_map_probe("cfi_probe", map);
 165         } else if (strcmp(of_probe, "JEDEC") == 0) {
 166                 return do_map_probe("jedec_probe", map);
 167         } else {
 168                 if (strcmp(of_probe, "ROM") != 0)
 169                         dev_warn(&dev->dev, "obsolete_probe: don't know probe "
 170                                  "type '%s', mapping as rom\n", of_probe);
 171                 return do_map_probe("mtd_rom", map);
 172         }
 173 }
 174
 175 #ifdef CONFIG_MTD_PARTITIONS
 176 /* When partitions are set we look for a linux,part-probe property which
 177    specifies the list of partition probers to use. If none is given then the
 178    default is use. These take precedence over other device tree
 179    information. */
 180 static const char *part_probe_types_def[] = { "cmdlinepart", "RedBoot", NULL };
 181 static const char ** __devinit of_get_probes(struct device_node *dp)
 182 {
 183         const char *cp;
 184         int cplen;
 185         unsigned int l;
 186         unsigned int count;
 187         const char **res;
 188
 189         cp = of_get_property(dp, "linux,part-probe", &cplen);
 190         if (cp == NULL)
 191                 return part_probe_types_def;
 192
 193         count = 0;
 194         for (l = 0; l != cplen; l++)
 195                 if (cp[l] == 0)
 196                         count++;
 197
 198         res = kzalloc((count + 1)*sizeof(*res), GFP_KERNEL);
 199         count = 0;
 200         while (cplen > 0) {
 201                 res[count] = cp;
 202                 l = strlen(cp) + 1;
 203                 cp += l;
 204                 cplen -= l;
 205                 count++;
 206         }
 207         return res;
 208 }
 209
 210 static void __devinit of_free_probes(const char **probes)
 211 {
 212         if (probes != part_probe_types_def)
 213                 kfree(probes);
 214 }
 215 #endif
 216
 217 static int __devinit of_flash_probe(struct platform_device *dev)
 218 {
 219 #ifdef CONFIG_MTD_PARTITIONS
 220         const char **part_probe_types;
 221 #endif
 222         struct device_node *dp = dev->dev.of_node;
 223         struct resource res;
 224         struct of_flash *info;
 225         const char *probe_type;
 226         const __be32 *width;
 227         int err;
 228         int i;
 229         int count;
 230         const __be32 *p;
 231         int reg_tuple_size;
 232         struct mtd_info **mtd_list = NULL;
 233         resource_size_t res_size;
 234
 235         if (!dev->dev.of_match)
 236                 return -EINVAL;
 237         probe_type = dev->dev.of_match->data;
 238
 239         reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
 240
 241         /*
 242          * Get number of "reg" tuples. Scan for MTD devices on area's
 243          * described by each "reg" region. This makes it possible (including
 244          * the concat support) to support the Intel P30 48F4400 chips which
 245          * consists internally of 2 non-identical NOR chips on one die.
 246          */
 247         p = of_get_property(dp, "reg", &count);
 248         if (count % reg_tuple_size != 0) {
 249                 dev_err(&dev->dev, "Malformed reg property on %s\n",
 250                                 dev->dev.of_node->full_name);
 251                 err = -EINVAL;
 252                 goto err_flash_remove;
 253         }
 254         count /= reg_tuple_size;
 255
 256         err = -ENOMEM;
 257         info = kzalloc(sizeof(struct of_flash) +
 258                        sizeof(struct of_flash_list) * count, GFP_KERNEL);
 259         if (!info)
 260                 goto err_flash_remove;
 261
 262         dev_set_drvdata(&dev->dev, info);
 263
 264         mtd_list = kzalloc(sizeof(*mtd_list) * count, GFP_KERNEL);
 265         if (!mtd_list)
 266                 goto err_flash_remove;
 267
 268         for (i = 0; i < count; i++) {
 269                 err = -ENXIO;
 270                 if (of_address_to_resource(dp, i, &res)) {
 271                         /*
 272                          * Continue with next register tuple if this
 273                          * one is not mappable
 274                          */
 275                         continue;
 276                 }
 277
 278                 dev_dbg(&dev->dev, "of_flash device: %pR\n", &res);
 279
 280                 err = -EBUSY;
 281                 res_size = resource_size(&res);
 282                 info->list[i].res = request_mem_region(res.start, res_size,
 283                                                        dev_name(&dev->dev));
 284                 if (!info->list[i].res)
 285                         goto err_out;
 286
 287                 err = -ENXIO;
 288                 width = of_get_property(dp, "bank-width", NULL);
 289                 if (!width) {
 290                         dev_err(&dev->dev, "Can't get bank width from device"
 291                                 " tree\n");
 292                         goto err_out;
 293                 }
 294
 295                 info->list[i].map.name = dev_name(&dev->dev);
 296                 info->list[i].map.phys = res.start;
 297                 info->list[i].map.size = res_size;
 298                 info->list[i].map.bankwidth = be32_to_cpup(width);
 299
 300                 err = -ENOMEM;
 301                 info->list[i].map.virt = ioremap(info->list[i].map.phys,
 302                                                  info->list[i].map.size);
 303                 if (!info->list[i].map.virt) {
 304                         dev_err(&dev->dev, "Failed to ioremap() flash"
 305                                 " region\n");
 306                         goto err_out;
 307                 }
 308
 309                 simple_map_init(&info->list[i].map);
 310
 311                 if (probe_type) {
 312                         info->list[i].mtd = do_map_probe(probe_type,
 313                                                          &info->list[i].map);
 314                 } else {
 315                         info->list[i].mtd = obsolete_probe(dev,
 316                                                            &info->list[i].map);
 317                 }
 318                 mtd_list[i] = info->list[i].mtd;
 319
 320                 err = -ENXIO;
 321                 if (!info->list[i].mtd) {
 322                         dev_err(&dev->dev, "do_map_probe() failed\n");
 323                         goto err_out;
 324                 } else {
 325                         info->list_size++;
 326                 }
 327                 info->list[i].mtd->owner = THIS_MODULE;
 328                 info->list[i].mtd->dev.parent = &dev->dev;
 329         }
 330
 331         err = 0;
 332         if (info->list_size == 1) {
 333                 info->cmtd = info->list[0].mtd;
 334         } else if (info->list_size > 1) {
 335                 /*
 336                  * We detected multiple devices. Concatenate them together.
 337                  */
 338                 info->cmtd = mtd_concat_create(mtd_list, info->list_size,
 339                                                dev_name(&dev->dev));
 340                 if (info->cmtd == NULL)
 341                         err = -ENXIO;
 342         }
 343         if (err)
 344                 goto err_out;
 345
 346 #ifdef CONFIG_MTD_PARTITIONS
 347         part_probe_types = of_get_probes(dp);
 348         err = parse_mtd_partitions(info->cmtd, part_probe_types,
 349                                    &info->parts, 0);
 350         if (err < 0) {
 351                 of_free_probes(part_probe_types);
 352                 goto err_out;
 353         }
 354         of_free_probes(part_probe_types);
 355
 356 #ifdef CONFIG_MTD_OF_PARTS
 357         if (err == 0) {
 358                 err = of_mtd_parse_partitions(&dev->dev, dp, &info->parts);
 359                 if (err < 0)
 360                         goto err_out;
 361         }
 362 #endif
 363
 364         if (err == 0) {
 365                 err = parse_obsolete_partitions(dev, info, dp);
 366                 if (err < 0)
 367                         goto err_out;
 368         }
 369
 370         if (err > 0)
 371                 add_mtd_partitions(info->cmtd, info->parts, err);
 372         else
 373 #endif
 374                 add_mtd_device(info->cmtd);
 375
 376         kfree(mtd_list);
 377
 378         return 0;
 379
 380 err_out:
 381         kfree(mtd_list);
 382 err_flash_remove:
 383         of_flash_remove(dev);
 384
 385         return err;
 386 }
 387
 388 static struct of_device_id of_flash_match[] = {
 389         {
 390                 .compatible     = "cfi-flash",
 391                 .data           = (void *)"cfi_probe",
 392         },
 393         {
 394                 /* FIXME: JEDEC chips can't be safely and reliably
 395                  * probed, although the mtd code gets it right in
 396                  * practice most of the time.  We should use the
 397                  * vendor and device ids specified by the binding to
 398                  * bypass the heuristic probe code, but the mtd layer
 399                  * provides, at present, no interface for doing so
 400                  * :(. */
 401                 .compatible     = "jedec-flash",
 402                 .data           = (void *)"jedec_probe",
 403         },
 404         {
 405                 .compatible     = "mtd-ram",
 406                 .data           = (void *)"map_ram",
 407         },
 408         {
 409                 .type           = "rom",
 410                 .compatible     = "direct-mapped"
 411         },
 412         { },
 413 };
 414 MODULE_DEVICE_TABLE(of, of_flash_match);
 415
 416 static struct platform_driver of_flash_driver = {
 417         .driver = {
 418                 .name = "of-flash",
 419                 .owner = THIS_MODULE,
 420                 .of_match_table = of_flash_match,
 421         },
 422         .probe          = of_flash_probe,
 423         .remove         = of_flash_remove,
 424 };
 425
 426 static int __init of_flash_init(void)
 427 {
 428         return platform_driver_register(&of_flash_driver);
 429 }
 430
 431 static void __exit of_flash_exit(void)
 432 {
 433         platform_driver_unregister(&of_flash_driver);
 434 }
 435
 436 module_init(of_flash_init);
 437 module_exit(of_flash_exit);
 438
 439 MODULE_LICENSE("GPL");
 440 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
 441 MODULE_DESCRIPTION("Device tree based MTD map driver");