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