drivers/mtd/maps/physmap-core.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Normal mappings of chips in physical memory
   4  *
   5  * Copyright (C) 2003 MontaVista Software Inc.
   6  * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
   7  *
   8  * 031022 - [jsun] add run-time configure and partition setup
   9  *
  10  * Device tree support:
  11  *    Copyright (C) 2006 MontaVista Software Inc.
  12  *    Author: Vitaly Wool <vwool@ru.mvista.com>
  13  *
  14  *    Revised to handle newer style flash binding by:
  15  *    Copyright (C) 2007 David Gibson, IBM Corporation.
  16  *
  17  * GPIO address extension:
  18  *    Handle the case where a flash device is mostly addressed using physical
  19  *    line and supplemented by GPIOs.  This way you can hook up say a 8MiB flash
  20  *    to a 2MiB memory range and use the GPIOs to select a particular range.
  21  *
  22  *    Copyright © 2000 Nicolas Pitre <nico@cam.org>
  23  *    Copyright © 2005-2009 Analog Devices Inc.
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/device.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/property.h>
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/map.h>
  36 #include <linux/mtd/partitions.h>
  37 #include <linux/mtd/physmap.h>
  38 #include <linux/mtd/concat.h>
  39 #include <linux/mtd/cfi_endian.h>
  40 #include <linux/io.h>
  41 #include <linux/of.h>
  42 #include <linux/pm_runtime.h>
  43 #include <linux/gpio/consumer.h>
  44
  45 #include "physmap-bt1-rom.h"
  46 #include "physmap-gemini.h"
  47 #include "physmap-ixp4xx.h"
  48 #include "physmap-versatile.h"
  49
  50 struct physmap_flash_info {
  51         unsigned int            nmaps;
  52         struct mtd_info         **mtds;
  53         struct mtd_info         *cmtd;
  54         struct map_info         *maps;
  55         spinlock_t              vpp_lock;
  56         int                     vpp_refcnt;
  57         const char              *probe_type;
  58         const char * const      *part_types;
  59         unsigned int            nparts;
  60         const struct mtd_partition *parts;
  61         struct gpio_descs       *gpios;
  62         unsigned int            gpio_values;
  63         unsigned int            win_order;
  64 };
  65
  66 static void physmap_flash_remove(struct platform_device *dev)
  67 {
  68         struct physmap_flash_info *info;
  69         struct physmap_flash_data *physmap_data;
  70         int i;
  71
  72         info = platform_get_drvdata(dev);
  73
  74         if (info->cmtd) {
  75                 WARN_ON(mtd_device_unregister(info->cmtd));
  76
  77                 if (info->cmtd != info->mtds[0])
  78                         mtd_concat_destroy(info->cmtd);
  79         }
  80
  81         for (i = 0; i < info->nmaps; i++) {
  82                 if (info->mtds[i])
  83                         map_destroy(info->mtds[i]);
  84         }
  85
  86         physmap_data = dev_get_platdata(&dev->dev);
  87         if (physmap_data && physmap_data->exit)
  88                 physmap_data->exit(dev);
  89
  90         pm_runtime_put(&dev->dev);
  91         pm_runtime_disable(&dev->dev);
  92 }
  93
  94 static void physmap_set_vpp(struct map_info *map, int state)
  95 {
  96         struct platform_device *pdev;
  97         struct physmap_flash_data *physmap_data;
  98         struct physmap_flash_info *info;
  99         unsigned long flags;
 100
 101         pdev = (struct platform_device *)map->map_priv_1;
 102         physmap_data = dev_get_platdata(&pdev->dev);
 103
 104         if (!physmap_data->set_vpp)
 105                 return;
 106
 107         info = platform_get_drvdata(pdev);
 108
 109         spin_lock_irqsave(&info->vpp_lock, flags);
 110         if (state) {
 111                 if (++info->vpp_refcnt == 1)    /* first nested 'on' */
 112                         physmap_data->set_vpp(pdev, 1);
 113         } else {
 114                 if (--info->vpp_refcnt == 0)    /* last nested 'off' */
 115                         physmap_data->set_vpp(pdev, 0);
 116         }
 117         spin_unlock_irqrestore(&info->vpp_lock, flags);
 118 }
 119
 120 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_GPIO_ADDR)
 121 static void physmap_set_addr_gpios(struct physmap_flash_info *info,
 122                                    unsigned long ofs)
 123 {
 124         unsigned int i;
 125
 126         ofs >>= info->win_order;
 127         if (info->gpio_values == ofs)
 128                 return;
 129
 130         for (i = 0; i < info->gpios->ndescs; i++) {
 131                 if ((BIT(i) & ofs) == (BIT(i) & info->gpio_values))
 132                         continue;
 133
 134                 gpiod_set_value(info->gpios->desc[i], !!(BIT(i) & ofs));
 135         }
 136
 137         info->gpio_values = ofs;
 138 }
 139
 140 #define win_mask(order)         (BIT(order) - 1)
 141
 142 static map_word physmap_addr_gpios_read(struct map_info *map,
 143                                         unsigned long ofs)
 144 {
 145         struct platform_device *pdev;
 146         struct physmap_flash_info *info;
 147         map_word mw;
 148         u16 word;
 149
 150         pdev = (struct platform_device *)map->map_priv_1;
 151         info = platform_get_drvdata(pdev);
 152         physmap_set_addr_gpios(info, ofs);
 153
 154         word = readw(map->virt + (ofs & win_mask(info->win_order)));
 155         mw.x[0] = word;
 156         return mw;
 157 }
 158
 159 static void physmap_addr_gpios_copy_from(struct map_info *map, void *buf,
 160                                          unsigned long ofs, ssize_t len)
 161 {
 162         struct platform_device *pdev;
 163         struct physmap_flash_info *info;
 164
 165         pdev = (struct platform_device *)map->map_priv_1;
 166         info = platform_get_drvdata(pdev);
 167
 168         while (len) {
 169                 unsigned int winofs = ofs & win_mask(info->win_order);
 170                 unsigned int chunklen = min_t(unsigned int, len,
 171                                               BIT(info->win_order) - winofs);
 172
 173                 physmap_set_addr_gpios(info, ofs);
 174                 memcpy_fromio(buf, map->virt + winofs, chunklen);
 175                 len -= chunklen;
 176                 buf += chunklen;
 177                 ofs += chunklen;
 178         }
 179 }
 180
 181 static void physmap_addr_gpios_write(struct map_info *map, map_word mw,
 182                                      unsigned long ofs)
 183 {
 184         struct platform_device *pdev;
 185         struct physmap_flash_info *info;
 186         u16 word;
 187
 188         pdev = (struct platform_device *)map->map_priv_1;
 189         info = platform_get_drvdata(pdev);
 190         physmap_set_addr_gpios(info, ofs);
 191
 192         word = mw.x[0];
 193         writew(word, map->virt + (ofs & win_mask(info->win_order)));
 194 }
 195
 196 static void physmap_addr_gpios_copy_to(struct map_info *map, unsigned long ofs,
 197                                        const void *buf, ssize_t len)
 198 {
 199         struct platform_device *pdev;
 200         struct physmap_flash_info *info;
 201
 202         pdev = (struct platform_device *)map->map_priv_1;
 203         info = platform_get_drvdata(pdev);
 204
 205         while (len) {
 206                 unsigned int winofs = ofs & win_mask(info->win_order);
 207                 unsigned int chunklen = min_t(unsigned int, len,
 208                                               BIT(info->win_order) - winofs);
 209
 210                 physmap_set_addr_gpios(info, ofs);
 211                 memcpy_toio(map->virt + winofs, buf, chunklen);
 212                 len -= chunklen;
 213                 buf += chunklen;
 214                 ofs += chunklen;
 215         }
 216 }
 217
 218 static int physmap_addr_gpios_map_init(struct map_info *map)
 219 {
 220         map->phys = NO_XIP;
 221         map->read = physmap_addr_gpios_read;
 222         map->copy_from = physmap_addr_gpios_copy_from;
 223         map->write = physmap_addr_gpios_write;
 224         map->copy_to = physmap_addr_gpios_copy_to;
 225
 226         return 0;
 227 }
 228 #else
 229 static int physmap_addr_gpios_map_init(struct map_info *map)
 230 {
 231         return -ENOTSUPP;
 232 }
 233 #endif
 234
 235 #if IS_ENABLED(CONFIG_MTD_PHYSMAP_OF)
 236 static const struct of_device_id of_flash_match[] = {
 237         {
 238                 .compatible = "cfi-flash",
 239                 .data = "cfi_probe",
 240         },
 241         {
 242                 /*
 243                  * FIXME: JEDEC chips can't be safely and reliably
 244                  * probed, although the mtd code gets it right in
 245                  * practice most of the time.  We should use the
 246                  * vendor and device ids specified by the binding to
 247                  * bypass the heuristic probe code, but the mtd layer
 248                  * provides, at present, no interface for doing so
 249                  * :(.
 250                  */
 251                 .compatible = "jedec-flash",
 252                 .data = "jedec_probe",
 253         },
 254         {
 255                 .compatible = "mtd-ram",
 256                 .data = "map_ram",
 257         },
 258         {
 259                 .compatible = "mtd-rom",
 260                 .data = "map_rom",
 261         },
 262         {
 263                 .type = "rom",
 264                 .compatible = "direct-mapped"
 265         },
 266         { /* sentinel */ },
 267 };
 268 MODULE_DEVICE_TABLE(of, of_flash_match);
 269
 270 static const char * const of_default_part_probes[] = {
 271         "cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL
 272 };
 273
 274 static const char * const *of_get_part_probes(struct platform_device *dev)
 275 {
 276         struct device_node *dp = dev->dev.of_node;
 277         const char **res;
 278         int count;
 279
 280         count = of_property_count_strings(dp, "linux,part-probe");
 281         if (count < 0)
 282                 return of_default_part_probes;
 283
 284         res = devm_kcalloc(&dev->dev, count + 1, sizeof(*res), GFP_KERNEL);
 285         if (!res)
 286                 return NULL;
 287
 288         count = of_property_read_string_array(dp, "linux,part-probe", res,
 289                                               count);
 290         if (count < 0)
 291                 return NULL;
 292
 293         return res;
 294 }
 295
 296 static const char *of_select_probe_type(struct platform_device *dev)
 297 {
 298         struct device_node *dp = dev->dev.of_node;
 299         const char *probe_type;
 300
 301         probe_type = device_get_match_data(&dev->dev);
 302         if (probe_type)
 303                 return probe_type;
 304
 305         dev_warn(&dev->dev,
 306                  "Device tree uses obsolete \"direct-mapped\" flash binding\n");
 307
 308         of_property_read_string(dp, "probe-type", &probe_type);
 309         if (!probe_type)
 310                 return NULL;
 311
 312         if (!strcmp(probe_type, "CFI")) {
 313                 probe_type = "cfi_probe";
 314         } else if (!strcmp(probe_type, "JEDEC")) {
 315                 probe_type = "jedec_probe";
 316         } else if (!strcmp(probe_type, "ROM")) {
 317                 probe_type = "map_rom";
 318         } else {
 319                 dev_warn(&dev->dev,
 320                          "obsolete_probe: don't know probe type '%s', mapping as rom\n",
 321                          probe_type);
 322                 probe_type = "map_rom";
 323         }
 324
 325         return probe_type;
 326 }
 327
 328 static int physmap_flash_of_init(struct platform_device *dev)
 329 {
 330         struct physmap_flash_info *info = platform_get_drvdata(dev);
 331         struct device_node *dp = dev->dev.of_node;
 332         const char *mtd_name = NULL;
 333         int err, swap = 0;
 334         bool map_indirect;
 335         unsigned int i;
 336         u32 bankwidth;
 337
 338         if (!dp)
 339                 return -EINVAL;
 340
 341         info->probe_type = of_select_probe_type(dev);
 342
 343         info->part_types = of_get_part_probes(dev);
 344         if (!info->part_types)
 345                 return -ENOMEM;
 346
 347         of_property_read_string(dp, "linux,mtd-name", &mtd_name);
 348
 349         map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
 350
 351         err = of_property_read_u32(dp, "bank-width", &bankwidth);
 352         if (err) {
 353                 dev_err(&dev->dev, "Can't get bank width from device tree\n");
 354                 return err;
 355         }
 356
 357         if (of_property_read_bool(dp, "big-endian"))
 358                 swap = CFI_BIG_ENDIAN;
 359         else if (of_property_read_bool(dp, "little-endian"))
 360                 swap = CFI_LITTLE_ENDIAN;
 361
 362         for (i = 0; i < info->nmaps; i++) {
 363                 info->maps[i].name = mtd_name;
 364                 info->maps[i].swap = swap;
 365                 info->maps[i].bankwidth = bankwidth;
 366                 info->maps[i].device_node = dp;
 367
 368                 err = of_flash_probe_bt1_rom(dev, dp, &info->maps[i]);
 369                 if (err)
 370                         return err;
 371
 372                 err = of_flash_probe_gemini(dev, dp, &info->maps[i]);
 373                 if (err)
 374                         return err;
 375
 376                 err = of_flash_probe_ixp4xx(dev, dp, &info->maps[i]);
 377                 if (err)
 378                         return err;
 379
 380                 err = of_flash_probe_versatile(dev, dp, &info->maps[i]);
 381                 if (err)
 382                         return err;
 383
 384                 /*
 385                  * On some platforms (e.g. MPC5200) a direct 1:1 mapping
 386                  * may cause problems with JFFS2 usage, as the local bus (LPB)
 387                  * doesn't support unaligned accesses as implemented in the
 388                  * JFFS2 code via memcpy(). By setting NO_XIP, the
 389                  * flash will not be exposed directly to the MTD users
 390                  * (e.g. JFFS2) any more.
 391                  */
 392                 if (map_indirect)
 393                         info->maps[i].phys = NO_XIP;
 394         }
 395
 396         return 0;
 397 }
 398 #else /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
 399 #define of_flash_match NULL
 400
 401 static int physmap_flash_of_init(struct platform_device *dev)
 402 {
 403         return -ENOTSUPP;
 404 }
 405 #endif /* IS_ENABLED(CONFIG_MTD_PHYSMAP_OF) */
 406
 407 static const char * const rom_probe_types[] = {
 408         "cfi_probe", "jedec_probe", "qinfo_probe", "map_rom",
 409 };
 410
 411 static const char * const part_probe_types[] = {
 412         "cmdlinepart", "RedBoot", "afs", NULL
 413 };
 414
 415 static int physmap_flash_pdata_init(struct platform_device *dev)
 416 {
 417         struct physmap_flash_info *info = platform_get_drvdata(dev);
 418         struct physmap_flash_data *physmap_data;
 419         unsigned int i;
 420         int err;
 421
 422         physmap_data = dev_get_platdata(&dev->dev);
 423         if (!physmap_data)
 424                 return -EINVAL;
 425
 426         info->probe_type = physmap_data->probe_type;
 427         info->part_types = physmap_data->part_probe_types ? : part_probe_types;
 428         info->parts = physmap_data->parts;
 429         info->nparts = physmap_data->nr_parts;
 430
 431         if (physmap_data->init) {
 432                 err = physmap_data->init(dev);
 433                 if (err)
 434                         return err;
 435         }
 436
 437         for (i = 0; i < info->nmaps; i++) {
 438                 info->maps[i].bankwidth = physmap_data->width;
 439                 info->maps[i].pfow_base = physmap_data->pfow_base;
 440                 info->maps[i].set_vpp = physmap_set_vpp;
 441         }
 442
 443         return 0;
 444 }
 445
 446 static int physmap_flash_probe(struct platform_device *dev)
 447 {
 448         struct physmap_flash_info *info;
 449         int err = 0;
 450         int i;
 451
 452         if (!dev->dev.of_node && !dev_get_platdata(&dev->dev))
 453                 return -EINVAL;
 454
 455         info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
 456         if (!info)
 457                 return -ENOMEM;
 458
 459         while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
 460                 info->nmaps++;
 461
 462         if (!info->nmaps)
 463                 return -ENODEV;
 464
 465         info->maps = devm_kzalloc(&dev->dev,
 466                                   sizeof(*info->maps) * info->nmaps,
 467                                   GFP_KERNEL);
 468         if (!info->maps)
 469                 return -ENOMEM;
 470
 471         info->mtds = devm_kzalloc(&dev->dev,
 472                                   sizeof(*info->mtds) * info->nmaps,
 473                                   GFP_KERNEL);
 474         if (!info->mtds)
 475                 return -ENOMEM;
 476
 477         platform_set_drvdata(dev, info);
 478
 479         info->gpios = devm_gpiod_get_array_optional(&dev->dev, "addr",
 480                                                     GPIOD_OUT_LOW);
 481         if (IS_ERR(info->gpios))
 482                 return PTR_ERR(info->gpios);
 483
 484         if (info->gpios && info->nmaps > 1) {
 485                 dev_err(&dev->dev, "addr-gpios only supported for nmaps == 1\n");
 486                 return -EINVAL;
 487         }
 488
 489         pm_runtime_enable(&dev->dev);
 490         pm_runtime_get_sync(&dev->dev);
 491
 492         if (dev->dev.of_node)
 493                 err = physmap_flash_of_init(dev);
 494         else
 495                 err = physmap_flash_pdata_init(dev);
 496
 497         if (err) {
 498                 pm_runtime_put(&dev->dev);
 499                 pm_runtime_disable(&dev->dev);
 500                 return err;
 501         }
 502
 503         for (i = 0; i < info->nmaps; i++) {
 504                 struct resource *res;
 505
 506                 info->maps[i].virt = devm_platform_get_and_ioremap_resource(dev, i, &res);
 507                 if (IS_ERR(info->maps[i].virt)) {
 508                         err = PTR_ERR(info->maps[i].virt);
 509                         goto err_out;
 510                 }
 511
 512                 dev_notice(&dev->dev, "physmap platform flash device: %pR\n",
 513                            res);
 514
 515                 if (!info->maps[i].name)
 516                         info->maps[i].name = dev_name(&dev->dev);
 517
 518                 if (!info->maps[i].phys)
 519                         info->maps[i].phys = res->start;
 520
 521                 info->win_order = get_bitmask_order(resource_size(res)) - 1;
 522                 info->maps[i].size = BIT(info->win_order +
 523                                          (info->gpios ?
 524                                           info->gpios->ndescs : 0));
 525
 526                 info->maps[i].map_priv_1 = (unsigned long)dev;
 527
 528                 if (info->gpios) {
 529                         err = physmap_addr_gpios_map_init(&info->maps[i]);
 530                         if (err)
 531                                 goto err_out;
 532                 }
 533
 534 #ifdef CONFIG_MTD_COMPLEX_MAPPINGS
 535                 /*
 536                  * Only use the simple_map implementation if map hooks are not
 537                  * implemented. Since map->read() is mandatory checking for its
 538                  * presence is enough.
 539                  */
 540                 if (!info->maps[i].read)
 541                         simple_map_init(&info->maps[i]);
 542 #else
 543                 simple_map_init(&info->maps[i]);
 544 #endif
 545
 546                 if (info->probe_type) {
 547                         info->mtds[i] = do_map_probe(info->probe_type,
 548                                                      &info->maps[i]);
 549
 550                         /* Fall back to mapping region as ROM */
 551                         if (!info->mtds[i] && IS_ENABLED(CONFIG_MTD_ROM) &&
 552                             strcmp(info->probe_type, "map_rom")) {
 553                                 dev_warn(&dev->dev,
 554                                          "map_probe() failed for type %s\n",
 555                                          info->probe_type);
 556
 557                                 info->mtds[i] = do_map_probe("map_rom",
 558                                                              &info->maps[i]);
 559                         }
 560                 } else {
 561                         int j;
 562
 563                         for (j = 0; j < ARRAY_SIZE(rom_probe_types); j++) {
 564                                 info->mtds[i] = do_map_probe(rom_probe_types[j],
 565                                                              &info->maps[i]);
 566                                 if (info->mtds[i])
 567                                         break;
 568                         }
 569                 }
 570
 571                 if (!info->mtds[i]) {
 572                         dev_err(&dev->dev, "map_probe failed\n");
 573                         err = -ENXIO;
 574                         goto err_out;
 575                 }
 576                 info->mtds[i]->dev.parent = &dev->dev;
 577         }
 578
 579         if (info->nmaps == 1) {
 580                 info->cmtd = info->mtds[0];
 581         } else {
 582                 /*
 583                  * We detected multiple devices. Concatenate them together.
 584                  */
 585                 info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
 586                                                dev_name(&dev->dev));
 587                 if (!info->cmtd)
 588                         err = -ENXIO;
 589         }
 590         if (err)
 591                 goto err_out;
 592
 593         spin_lock_init(&info->vpp_lock);
 594
 595         mtd_set_of_node(info->cmtd, dev->dev.of_node);
 596         err = mtd_device_parse_register(info->cmtd, info->part_types, NULL,
 597                                         info->parts, info->nparts);
 598         if (err)
 599                 goto err_out;
 600
 601         return 0;
 602
 603 err_out:
 604         physmap_flash_remove(dev);
 605         return err;
 606 }
 607
 608 #ifdef CONFIG_PM
 609 static void physmap_flash_shutdown(struct platform_device *dev)
 610 {
 611         struct physmap_flash_info *info = platform_get_drvdata(dev);
 612         int i;
 613
 614         for (i = 0; i < info->nmaps && info->mtds[i]; i++)
 615                 if (mtd_suspend(info->mtds[i]) == 0)
 616                         mtd_resume(info->mtds[i]);
 617 }
 618 #else
 619 #define physmap_flash_shutdown NULL
 620 #endif
 621
 622 static struct platform_driver physmap_flash_driver = {
 623         .probe          = physmap_flash_probe,
 624         .remove_new     = physmap_flash_remove,
 625         .shutdown       = physmap_flash_shutdown,
 626         .driver         = {
 627                 .name   = "physmap-flash",
 628                 .of_match_table = of_flash_match,
 629         },
 630 };
 631
 632 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
 633 static struct physmap_flash_data physmap_flash_data = {
 634         .width          = CONFIG_MTD_PHYSMAP_BANKWIDTH,
 635 };
 636
 637 static struct resource physmap_flash_resource = {
 638         .start          = CONFIG_MTD_PHYSMAP_START,
 639         .end            = CONFIG_MTD_PHYSMAP_START + CONFIG_MTD_PHYSMAP_LEN - 1,
 640         .flags          = IORESOURCE_MEM,
 641 };
 642
 643 static struct platform_device physmap_flash = {
 644         .name           = "physmap-flash",
 645         .id             = 0,
 646         .dev            = {
 647                 .platform_data  = &physmap_flash_data,
 648         },
 649         .num_resources  = 1,
 650         .resource       = &physmap_flash_resource,
 651 };
 652 #endif
 653
 654 static int __init physmap_init(void)
 655 {
 656         int err;
 657
 658         err = platform_driver_register(&physmap_flash_driver);
 659 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
 660         if (err == 0) {
 661                 err = platform_device_register(&physmap_flash);
 662                 if (err)
 663                         platform_driver_unregister(&physmap_flash_driver);
 664         }
 665 #endif
 666
 667         return err;
 668 }
 669
 670 static void __exit physmap_exit(void)
 671 {
 672 #ifdef CONFIG_MTD_PHYSMAP_COMPAT
 673         platform_device_unregister(&physmap_flash);
 674 #endif
 675         platform_driver_unregister(&physmap_flash_driver);
 676 }
 677
 678 module_init(physmap_init);
 679 module_exit(physmap_exit);
 680
 681 MODULE_LICENSE("GPL");
 682 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 683 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
 684 MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
 685 MODULE_DESCRIPTION("Generic configurable MTD map driver");
 686
 687 /* legacy platform drivers can't hotplug or coldplg */
 688 #ifndef CONFIG_MTD_PHYSMAP_COMPAT
 689 /* work with hotplug and coldplug */
 690 MODULE_ALIAS("platform:physmap-flash");
 691 #endif