drivers/mtd/maps/physmap_of_core.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/device.h>
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/map.h>
  21 #include <linux/mtd/partitions.h>
  22 #include <linux/mtd/concat.h>
  23 #include <linux/mtd/cfi_endian.h>
  24 #include <linux/of.h>
  25 #include <linux/of_address.h>
  26 #include <linux/of_platform.h>
  27 #include <linux/slab.h>
  28 #include "physmap_of_gemini.h"
  29 #include "physmap_of_versatile.h"
  30
  31 struct of_flash_list {
  32         struct mtd_info *mtd;
  33         struct map_info map;
  34 };
  35
  36 struct of_flash {
  37         struct mtd_info         *cmtd;
  38         int list_size; /* number of elements in of_flash_list */
  39         struct of_flash_list    list[0];
  40 };
  41
  42 static int of_flash_remove(struct platform_device *dev)
  43 {
  44         struct of_flash *info;
  45         int i;
  46
  47         info = dev_get_drvdata(&dev->dev);
  48         if (!info)
  49                 return 0;
  50         dev_set_drvdata(&dev->dev, NULL);
  51
  52         if (info->cmtd) {
  53                 mtd_device_unregister(info->cmtd);
  54                 if (info->cmtd != info->list[0].mtd)
  55                         mtd_concat_destroy(info->cmtd);
  56         }
  57
  58         for (i = 0; i < info->list_size; i++)
  59                 if (info->list[i].mtd)
  60                         map_destroy(info->list[i].mtd);
  61
  62         return 0;
  63 }
  64
  65 static const char * const rom_probe_types[] = {
  66         "cfi_probe", "jedec_probe", "map_rom" };
  67
  68 /* Helper function to handle probing of the obsolete "direct-mapped"
  69  * compatible binding, which has an extra "probe-type" property
  70  * describing the type of flash probe necessary. */
  71 static struct mtd_info *obsolete_probe(struct platform_device *dev,
  72                                        struct map_info *map)
  73 {
  74         struct device_node *dp = dev->dev.of_node;
  75         const char *of_probe;
  76         struct mtd_info *mtd;
  77         int i;
  78
  79         dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
  80                  "flash binding\n");
  81
  82         of_probe = of_get_property(dp, "probe-type", NULL);
  83         if (!of_probe) {
  84                 for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
  85                         mtd = do_map_probe(rom_probe_types[i], map);
  86                         if (mtd)
  87                                 return mtd;
  88                 }
  89                 return NULL;
  90         } else if (strcmp(of_probe, "CFI") == 0) {
  91                 return do_map_probe("cfi_probe", map);
  92         } else if (strcmp(of_probe, "JEDEC") == 0) {
  93                 return do_map_probe("jedec_probe", map);
  94         } else {
  95                 if (strcmp(of_probe, "ROM") != 0)
  96                         dev_warn(&dev->dev, "obsolete_probe: don't know probe "
  97                                  "type '%s', mapping as rom\n", of_probe);
  98                 return do_map_probe("map_rom", map);
  99         }
 100 }
 101
 102 /* When partitions are set we look for a linux,part-probe property which
 103    specifies the list of partition probers to use. If none is given then the
 104    default is use. These take precedence over other device tree
 105    information. */
 106 static const char * const part_probe_types_def[] = {
 107         "cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
 108
 109 static const char * const *of_get_probes(struct device_node *dp)
 110 {
 111         const char **res;
 112         int count;
 113
 114         count = of_property_count_strings(dp, "linux,part-probe");
 115         if (count < 0)
 116                 return part_probe_types_def;
 117
 118         res = kcalloc(count + 1, sizeof(*res), GFP_KERNEL);
 119         if (!res)
 120                 return NULL;
 121
 122         count = of_property_read_string_array(dp, "linux,part-probe", res,
 123                                               count);
 124         if (count < 0)
 125                 return NULL;
 126
 127         return res;
 128 }
 129
 130 static void of_free_probes(const char * const *probes)
 131 {
 132         if (probes != part_probe_types_def)
 133                 kfree(probes);
 134 }
 135
 136 static const struct of_device_id of_flash_match[];
 137 static int of_flash_probe(struct platform_device *dev)
 138 {
 139         const char * const *part_probe_types;
 140         const struct of_device_id *match;
 141         struct device_node *dp = dev->dev.of_node;
 142         struct resource res;
 143         struct of_flash *info;
 144         const char *probe_type;
 145         const __be32 *width;
 146         int err;
 147         int i;
 148         int count;
 149         const __be32 *p;
 150         int reg_tuple_size;
 151         struct mtd_info **mtd_list = NULL;
 152         resource_size_t res_size;
 153         bool map_indirect;
 154         const char *mtd_name = NULL;
 155
 156         match = of_match_device(of_flash_match, &dev->dev);
 157         if (!match)
 158                 return -EINVAL;
 159         probe_type = match->data;
 160
 161         reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
 162
 163         of_property_read_string(dp, "linux,mtd-name", &mtd_name);
 164
 165         /*
 166          * Get number of "reg" tuples. Scan for MTD devices on area's
 167          * described by each "reg" region. This makes it possible (including
 168          * the concat support) to support the Intel P30 48F4400 chips which
 169          * consists internally of 2 non-identical NOR chips on one die.
 170          */
 171         p = of_get_property(dp, "reg", &count);
 172         if (!p || count % reg_tuple_size != 0) {
 173                 dev_err(&dev->dev, "Malformed reg property on %pOF\n",
 174                                 dev->dev.of_node);
 175                 err = -EINVAL;
 176                 goto err_flash_remove;
 177         }
 178         count /= reg_tuple_size;
 179
 180         map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access");
 181
 182         err = -ENOMEM;
 183         info = devm_kzalloc(&dev->dev,
 184                             sizeof(struct of_flash) +
 185                             sizeof(struct of_flash_list) * count, GFP_KERNEL);
 186         if (!info)
 187                 goto err_flash_remove;
 188
 189         dev_set_drvdata(&dev->dev, info);
 190
 191         mtd_list = kcalloc(count, sizeof(*mtd_list), GFP_KERNEL);
 192         if (!mtd_list)
 193                 goto err_flash_remove;
 194
 195         for (i = 0; i < count; i++) {
 196                 err = -ENXIO;
 197                 if (of_address_to_resource(dp, i, &res)) {
 198                         /*
 199                          * Continue with next register tuple if this
 200                          * one is not mappable
 201                          */
 202                         continue;
 203                 }
 204
 205                 dev_dbg(&dev->dev, "of_flash device: %pR\n", &res);
 206
 207                 err = -EBUSY;
 208                 res_size = resource_size(&res);
 209                 info->list[i].map.virt = devm_ioremap_resource(&dev->dev, &res);
 210                 if (IS_ERR(info->list[i].map.virt)) {
 211                         err = PTR_ERR(info->list[i].map.virt);
 212                         goto err_out;
 213                 }
 214
 215                 err = -ENXIO;
 216                 width = of_get_property(dp, "bank-width", NULL);
 217                 if (!width) {
 218                         dev_err(&dev->dev, "Can't get bank width from device"
 219                                 " tree\n");
 220                         goto err_out;
 221                 }
 222
 223                 info->list[i].map.name = mtd_name ?: dev_name(&dev->dev);
 224                 info->list[i].map.phys = res.start;
 225                 info->list[i].map.size = res_size;
 226                 info->list[i].map.bankwidth = be32_to_cpup(width);
 227                 info->list[i].map.device_node = dp;
 228
 229                 if (of_property_read_bool(dp, "big-endian"))
 230                         info->list[i].map.swap = CFI_BIG_ENDIAN;
 231                 else if (of_property_read_bool(dp, "little-endian"))
 232                         info->list[i].map.swap = CFI_LITTLE_ENDIAN;
 233
 234                 err = of_flash_probe_gemini(dev, dp, &info->list[i].map);
 235                 if (err)
 236                         goto err_out;
 237                 err = of_flash_probe_versatile(dev, dp, &info->list[i].map);
 238                 if (err)
 239                         goto err_out;
 240
 241                 simple_map_init(&info->list[i].map);
 242
 243                 /*
 244                  * On some platforms (e.g. MPC5200) a direct 1:1 mapping
 245                  * may cause problems with JFFS2 usage, as the local bus (LPB)
 246                  * doesn't support unaligned accesses as implemented in the
 247                  * JFFS2 code via memcpy(). By setting NO_XIP, the
 248                  * flash will not be exposed directly to the MTD users
 249                  * (e.g. JFFS2) any more.
 250                  */
 251                 if (map_indirect)
 252                         info->list[i].map.phys = NO_XIP;
 253
 254                 if (probe_type) {
 255                         info->list[i].mtd = do_map_probe(probe_type,
 256                                                          &info->list[i].map);
 257                 } else {
 258                         info->list[i].mtd = obsolete_probe(dev,
 259                                                            &info->list[i].map);
 260                 }
 261
 262                 /* Fall back to mapping region as ROM */
 263                 if (!info->list[i].mtd) {
 264                         dev_warn(&dev->dev,
 265                                 "do_map_probe() failed for type %s\n",
 266                                  probe_type);
 267
 268                         info->list[i].mtd = do_map_probe("map_rom",
 269                                                          &info->list[i].map);
 270                 }
 271                 mtd_list[i] = info->list[i].mtd;
 272
 273                 err = -ENXIO;
 274                 if (!info->list[i].mtd) {
 275                         dev_err(&dev->dev, "do_map_probe() failed\n");
 276                         goto err_out;
 277                 } else {
 278                         info->list_size++;
 279                 }
 280                 info->list[i].mtd->dev.parent = &dev->dev;
 281         }
 282
 283         err = 0;
 284         info->cmtd = NULL;
 285         if (info->list_size == 1) {
 286                 info->cmtd = info->list[0].mtd;
 287         } else if (info->list_size > 1) {
 288                 /*
 289                  * We detected multiple devices. Concatenate them together.
 290                  */
 291                 info->cmtd = mtd_concat_create(mtd_list, info->list_size,
 292                                                dev_name(&dev->dev));
 293         }
 294         if (info->cmtd == NULL)
 295                 err = -ENXIO;
 296
 297         if (err)
 298                 goto err_out;
 299
 300         info->cmtd->dev.parent = &dev->dev;
 301         mtd_set_of_node(info->cmtd, dp);
 302         part_probe_types = of_get_probes(dp);
 303         if (!part_probe_types) {
 304                 err = -ENOMEM;
 305                 goto err_out;
 306         }
 307         mtd_device_parse_register(info->cmtd, part_probe_types, NULL,
 308                         NULL, 0);
 309         of_free_probes(part_probe_types);
 310
 311         kfree(mtd_list);
 312
 313         return 0;
 314
 315 err_out:
 316         kfree(mtd_list);
 317 err_flash_remove:
 318         of_flash_remove(dev);
 319
 320         return err;
 321 }
 322
 323 static const struct of_device_id of_flash_match[] = {
 324         {
 325                 .compatible     = "cfi-flash",
 326                 .data           = (void *)"cfi_probe",
 327         },
 328         {
 329                 /* FIXME: JEDEC chips can't be safely and reliably
 330                  * probed, although the mtd code gets it right in
 331                  * practice most of the time.  We should use the
 332                  * vendor and device ids specified by the binding to
 333                  * bypass the heuristic probe code, but the mtd layer
 334                  * provides, at present, no interface for doing so
 335                  * :(. */
 336                 .compatible     = "jedec-flash",
 337                 .data           = (void *)"jedec_probe",
 338         },
 339         {
 340                 .compatible     = "mtd-ram",
 341                 .data           = (void *)"map_ram",
 342         },
 343         {
 344                 .compatible     = "mtd-rom",
 345                 .data           = (void *)"map_rom",
 346         },
 347         {
 348                 .type           = "rom",
 349                 .compatible     = "direct-mapped"
 350         },
 351         { },
 352 };
 353 MODULE_DEVICE_TABLE(of, of_flash_match);
 354
 355 static struct platform_driver of_flash_driver = {
 356         .driver = {
 357                 .name = "of-flash",
 358                 .of_match_table = of_flash_match,
 359         },
 360         .probe          = of_flash_probe,
 361         .remove         = of_flash_remove,
 362 };
 363
 364 module_platform_driver(of_flash_driver);
 365
 366 MODULE_LICENSE("GPL");
 367 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
 368 MODULE_DESCRIPTION("Device tree based MTD map driver");