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