drivers/mtd/maps/physmap_of.c

   1 /*
   2  * Normal mappings of chips in physical memory for OF devices
   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/kernel.h>
  19 #include <linux/init.h>
  20 #include <linux/slab.h>
  21 #include <linux/device.h>
  22 #include <linux/mtd/mtd.h>
  23 #include <linux/mtd/map.h>
  24 #include <linux/mtd/partitions.h>
  25 #include <linux/mtd/physmap.h>
  26 #include <asm/io.h>
  27 #include <asm/prom.h>
  28 #include <asm/of_device.h>
  29 #include <asm/of_platform.h>
  30
  31 struct physmap_flash_info {
  32         struct mtd_info         *mtd;
  33         struct map_info         map;
  34         struct resource         *res;
  35 #ifdef CONFIG_MTD_PARTITIONS
  36         struct mtd_partition    *parts;
  37 #endif
  38 };
  39
  40 #ifdef CONFIG_MTD_PARTITIONS
  41 static int parse_obsolete_partitions(struct of_device *dev,
  42                                      struct physmap_flash_info *info,
  43                                      struct device_node *dp)
  44 {
  45         int i, plen, nr_parts;
  46         const struct {
  47                 u32 offset, len;
  48         } *part;
  49         const char *names;
  50
  51         part = of_get_property(dp, "partitions", &plen);
  52         if (!part)
  53                 return -ENOENT;
  54
  55         dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
  56
  57         nr_parts = plen / sizeof(part[0]);
  58
  59         info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition), GFP_KERNEL);
  60         if (!info->parts) {
  61                 printk(KERN_ERR "Can't allocate the flash partition data!\n");
  62                 return -ENOMEM;
  63         }
  64
  65         names = of_get_property(dp, "partition-names", &plen);
  66
  67         for (i = 0; i < nr_parts; i++) {
  68                 info->parts[i].offset = part->offset;
  69                 info->parts[i].size   = part->len & ~1;
  70                 if (part->len & 1) /* bit 0 set signifies read only partition */
  71                         info->parts[i].mask_flags = MTD_WRITEABLE;
  72
  73                 if (names && (plen > 0)) {
  74                         int len = strlen(names) + 1;
  75
  76                         info->parts[i].name = (char *)names;
  77                         plen -= len;
  78                         names += len;
  79                 } else {
  80                         info->parts[i].name = "unnamed";
  81                 }
  82
  83                 part++;
  84         }
  85
  86         return nr_parts;
  87 }
  88
  89 static int __devinit process_partitions(struct physmap_flash_info *info,
  90                                         struct of_device *dev)
  91 {
  92         const char *partname;
  93         static const char *part_probe_types[]
  94                 = { "cmdlinepart", "RedBoot", NULL };
  95         struct device_node *dp = dev->node, *pp;
  96         int nr_parts, i;
  97
  98         /* First look for RedBoot table or partitions on the command
  99          * line, these take precedence over device tree information */
 100         nr_parts = parse_mtd_partitions(info->mtd, part_probe_types,
 101                                         &info->parts, 0);
 102         if (nr_parts > 0) {
 103                 add_mtd_partitions(info->mtd, info->parts, nr_parts);
 104                 return 0;
 105         }
 106
 107         /* First count the subnodes */
 108         nr_parts = 0;
 109         for (pp = dp->child; pp; pp = pp->sibling)
 110                 nr_parts++;
 111
 112         if (nr_parts) {
 113                 info->parts = kzalloc(nr_parts * sizeof(struct mtd_partition),
 114                                       GFP_KERNEL);
 115                 if (!info->parts) {
 116                         printk(KERN_ERR "Can't allocate the flash partition data!\n");
 117                         return -ENOMEM;
 118                 }
 119
 120                 for (pp = dp->child, i = 0 ; pp; pp = pp->sibling, i++) {
 121                         const u32 *reg;
 122                         int len;
 123
 124                         reg = of_get_property(pp, "reg", &len);
 125                         if (!reg || (len != 2*sizeof(u32))) {
 126                                 dev_err(&dev->dev, "Invalid 'reg' on %s\n",
 127                                         dp->full_name);
 128                                 kfree(info->parts);
 129                                 info->parts = NULL;
 130                                 return -EINVAL;
 131                         }
 132                         info->parts[i].offset = reg[0];
 133                         info->parts[i].size = reg[1];
 134
 135                         partname = of_get_property(pp, "label", &len);
 136                         if (!partname)
 137                                 partname = of_get_property(pp, "name", &len);
 138                         info->parts[i].name = (char *)partname;
 139
 140                         if (of_get_property(pp, "read-only", &len))
 141                                 info->parts[i].mask_flags = MTD_WRITEABLE;
 142                 }
 143         } else {
 144                 nr_parts = parse_obsolete_partitions(dev, info, dp);
 145         }
 146
 147         if (nr_parts < 0)
 148                 return nr_parts;
 149
 150         if (nr_parts > 0)
 151                 add_mtd_partitions(info->mtd, info->parts, nr_parts);
 152         else
 153                 add_mtd_device(info->mtd);
 154
 155         return 0;
 156 }
 157 #else /* MTD_PARTITIONS */
 158 static int __devinit process_partitions(struct physmap_flash_info *info,
 159                                         struct device_node *dev)
 160 {
 161         add_mtd_device(info->mtd);
 162         return 0;
 163 }
 164 #endif /* MTD_PARTITIONS */
 165
 166 static int of_physmap_remove(struct of_device *dev)
 167 {
 168         struct physmap_flash_info *info;
 169
 170         info = dev_get_drvdata(&dev->dev);
 171         if (info == NULL)
 172                 return 0;
 173         dev_set_drvdata(&dev->dev, NULL);
 174
 175         if (info->mtd != NULL) {
 176 #ifdef CONFIG_MTD_PARTITIONS
 177                 if (info->parts) {
 178                         del_mtd_partitions(info->mtd);
 179                         kfree(info->parts);
 180                 } else {
 181                         del_mtd_device(info->mtd);
 182                 }
 183 #else
 184                 del_mtd_device(info->mtd);
 185 #endif
 186                 map_destroy(info->mtd);
 187         }
 188
 189         if (info->map.virt != NULL)
 190                 iounmap(info->map.virt);
 191
 192         if (info->res != NULL) {
 193                 release_resource(info->res);
 194                 kfree(info->res);
 195         }
 196
 197         return 0;
 198 }
 199
 200 /* Helper function to handle probing of the obsolete "direct-mapped"
 201  * compatible binding, which has an extra "probe-type" property
 202  * describing the type of flash probe necessary. */
 203 static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
 204                                                   struct map_info *map)
 205 {
 206         struct device_node *dp = dev->node;
 207         const char *of_probe;
 208         struct mtd_info *mtd;
 209         static const char *rom_probe_types[]
 210                 = { "cfi_probe", "jedec_probe", "map_rom"};
 211         int i;
 212
 213         dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
 214                  "flash binding\n");
 215
 216         of_probe = of_get_property(dp, "probe-type", NULL);
 217         if (!of_probe) {
 218                 for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
 219                         mtd = do_map_probe(rom_probe_types[i], map);
 220                         if (mtd)
 221                                 return mtd;
 222                 }
 223                 return NULL;
 224         } else if (strcmp(of_probe, "CFI") == 0) {
 225                 return do_map_probe("cfi_probe", map);
 226         } else if (strcmp(of_probe, "JEDEC") == 0) {
 227                 return do_map_probe("jedec_probe", map);
 228         } else {
 229                 if (strcmp(of_probe, "ROM") != 0)
 230                         dev_dbg(&dev->dev, "obsolete_probe: don't know probe type "
 231                                 "'%s', mapping as rom\n", of_probe);
 232                 return do_map_probe("mtd_rom", map);
 233         }
 234 }
 235
 236 static int __devinit of_physmap_probe(struct of_device *dev, const struct of_device_id *match)
 237 {
 238         struct device_node *dp = dev->node;
 239         struct resource res;
 240         struct physmap_flash_info *info;
 241         const char *probe_type = (const char *)match->data;
 242         const u32 *width;
 243         int err;
 244
 245         if (of_address_to_resource(dp, 0, &res)) {
 246                 dev_err(&dev->dev, "Can't get the flash mapping!\n");
 247                 err = -EINVAL;
 248                 goto err_out;
 249         }
 250
 251         dev_dbg(&dev->dev, "physmap flash device: %.8llx at %.8llx\n",
 252             (unsigned long long)res.end - res.start + 1,
 253             (unsigned long long)res.start);
 254
 255         info = kzalloc(sizeof(struct physmap_flash_info), GFP_KERNEL);
 256         if (info == NULL) {
 257                 err = -ENOMEM;
 258                 goto err_out;
 259         }
 260         memset(info, 0, sizeof(*info));
 261
 262         dev_set_drvdata(&dev->dev, info);
 263
 264         info->res = request_mem_region(res.start, res.end - res.start + 1,
 265                         dev->dev.bus_id);
 266         if (info->res == NULL) {
 267                 dev_err(&dev->dev, "Could not reserve memory region\n");
 268                 err = -ENOMEM;
 269                 goto err_out;
 270         }
 271
 272         width = of_get_property(dp, "bank-width", NULL);
 273         if (width == NULL) {
 274                 dev_err(&dev->dev, "Can't get the flash bank width!\n");
 275                 err = -EINVAL;
 276                 goto err_out;
 277         }
 278
 279         info->map.name = dev->dev.bus_id;
 280         info->map.phys = res.start;
 281         info->map.size = res.end - res.start + 1;
 282         info->map.bankwidth = *width;
 283
 284         info->map.virt = ioremap(info->map.phys, info->map.size);
 285         if (info->map.virt == NULL) {
 286                 dev_err(&dev->dev, "Failed to ioremap flash region\n");
 287                 err = EIO;
 288                 goto err_out;
 289         }
 290
 291         simple_map_init(&info->map);
 292
 293         if (probe_type)
 294                 info->mtd = do_map_probe(probe_type, &info->map);
 295         else
 296                 info->mtd = obsolete_probe(dev, &info->map);
 297
 298         if (info->mtd == NULL) {
 299                 dev_err(&dev->dev, "map_probe failed\n");
 300                 err = -ENXIO;
 301                 goto err_out;
 302         }
 303         info->mtd->owner = THIS_MODULE;
 304
 305         return process_partitions(info, dev);
 306
 307 err_out:
 308         of_physmap_remove(dev);
 309         return err;
 310
 311         return 0;
 312
 313
 314 }
 315
 316 static struct of_device_id of_physmap_match[] = {
 317         {
 318                 .compatible     = "cfi-flash",
 319                 .data           = (void *)"cfi_probe",
 320         },
 321         {
 322                 /* FIXME: JEDEC chips can't be safely and reliably
 323                  * probed, although the mtd code gets it right in
 324                  * practice most of the time.  We should use the
 325                  * vendor and device ids specified by the binding to
 326                  * bypass the heuristic probe code, but the mtd layer
 327                  * provides, at present, no interface for doing so
 328                  * :(. */
 329                 .compatible     = "jedec-flash",
 330                 .data           = (void *)"jedec_probe",
 331         },
 332         {
 333                 .type           = "rom",
 334                 .compatible     = "direct-mapped"
 335         },
 336         { },
 337 };
 338
 339 MODULE_DEVICE_TABLE(of, of_physmap_match);
 340
 341
 342 static struct of_platform_driver of_physmap_flash_driver = {
 343         .name           = "physmap-flash",
 344         .match_table    = of_physmap_match,
 345         .probe          = of_physmap_probe,
 346         .remove         = of_physmap_remove,
 347 };
 348
 349 static int __init of_physmap_init(void)
 350 {
 351         return of_register_platform_driver(&of_physmap_flash_driver);
 352 }
 353
 354 static void __exit of_physmap_exit(void)
 355 {
 356         of_unregister_platform_driver(&of_physmap_flash_driver);
 357 }
 358
 359 module_init(of_physmap_init);
 360 module_exit(of_physmap_exit);
 361
 362 MODULE_LICENSE("GPL");
 363 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
 364 MODULE_DESCRIPTION("Configurable MTD map driver for OF");