| 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/of.h> |
| 24 | #include <linux/of_address.h> |
| 25 | #include <linux/of_platform.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include "physmap_of_versatile.h" |
| 28 | |
| 29 | struct of_flash_list { |
| 30 | struct mtd_info *mtd; |
| 31 | struct map_info map; |
| 32 | struct resource *res; |
| 33 | }; |
| 34 | |
| 35 | struct of_flash { |
| 36 | struct mtd_info *cmtd; |
| 37 | int list_size; /* number of elements in of_flash_list */ |
| 38 | struct of_flash_list list[0]; |
| 39 | }; |
| 40 | |
| 41 | static int of_flash_remove(struct platform_device *dev) |
| 42 | { |
| 43 | struct of_flash *info; |
| 44 | int i; |
| 45 | |
| 46 | info = dev_get_drvdata(&dev->dev); |
| 47 | if (!info) |
| 48 | return 0; |
| 49 | dev_set_drvdata(&dev->dev, NULL); |
| 50 | |
| 51 | if (info->cmtd) { |
| 52 | mtd_device_unregister(info->cmtd); |
| 53 | if (info->cmtd != info->list[0].mtd) |
| 54 | mtd_concat_destroy(info->cmtd); |
| 55 | } |
| 56 | |
| 57 | for (i = 0; i < info->list_size; i++) { |
| 58 | if (info->list[i].mtd) |
| 59 | map_destroy(info->list[i].mtd); |
| 60 | |
| 61 | if (info->list[i].map.virt) |
| 62 | iounmap(info->list[i].map.virt); |
| 63 | |
| 64 | if (info->list[i].res) { |
| 65 | release_resource(info->list[i].res); |
| 66 | kfree(info->list[i].res); |
| 67 | } |
| 68 | } |
| 69 | return 0; |
| 70 | } |
| 71 | |
| 72 | static const char * const rom_probe_types[] = { |
| 73 | "cfi_probe", "jedec_probe", "map_rom" }; |
| 74 | |
| 75 | /* Helper function to handle probing of the obsolete "direct-mapped" |
| 76 | * compatible binding, which has an extra "probe-type" property |
| 77 | * describing the type of flash probe necessary. */ |
| 78 | static struct mtd_info *obsolete_probe(struct platform_device *dev, |
| 79 | struct map_info *map) |
| 80 | { |
| 81 | struct device_node *dp = dev->dev.of_node; |
| 82 | const char *of_probe; |
| 83 | struct mtd_info *mtd; |
| 84 | int i; |
| 85 | |
| 86 | dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" " |
| 87 | "flash binding\n"); |
| 88 | |
| 89 | of_probe = of_get_property(dp, "probe-type", NULL); |
| 90 | if (!of_probe) { |
| 91 | for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) { |
| 92 | mtd = do_map_probe(rom_probe_types[i], map); |
| 93 | if (mtd) |
| 94 | return mtd; |
| 95 | } |
| 96 | return NULL; |
| 97 | } else if (strcmp(of_probe, "CFI") == 0) { |
| 98 | return do_map_probe("cfi_probe", map); |
| 99 | } else if (strcmp(of_probe, "JEDEC") == 0) { |
| 100 | return do_map_probe("jedec_probe", map); |
| 101 | } else { |
| 102 | if (strcmp(of_probe, "ROM") != 0) |
| 103 | dev_warn(&dev->dev, "obsolete_probe: don't know probe " |
| 104 | "type '%s', mapping as rom\n", of_probe); |
| 105 | return do_map_probe("map_rom", map); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | /* When partitions are set we look for a linux,part-probe property which |
| 110 | specifies the list of partition probers to use. If none is given then the |
| 111 | default is use. These take precedence over other device tree |
| 112 | information. */ |
| 113 | static const char * const part_probe_types_def[] = { |
| 114 | "cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL }; |
| 115 | |
| 116 | static const char * const *of_get_probes(struct device_node *dp) |
| 117 | { |
| 118 | const char *cp; |
| 119 | int cplen; |
| 120 | unsigned int l; |
| 121 | unsigned int count; |
| 122 | const char **res; |
| 123 | |
| 124 | cp = of_get_property(dp, "linux,part-probe", &cplen); |
| 125 | if (cp == NULL) |
| 126 | return part_probe_types_def; |
| 127 | |
| 128 | count = 0; |
| 129 | for (l = 0; l != cplen; l++) |
| 130 | if (cp[l] == 0) |
| 131 | count++; |
| 132 | |
| 133 | res = kzalloc((count + 1)*sizeof(*res), GFP_KERNEL); |
| 134 | if (!res) |
| 135 | return NULL; |
| 136 | count = 0; |
| 137 | while (cplen > 0) { |
| 138 | res[count] = cp; |
| 139 | l = strlen(cp) + 1; |
| 140 | cp += l; |
| 141 | cplen -= l; |
| 142 | count++; |
| 143 | } |
| 144 | return res; |
| 145 | } |
| 146 | |
| 147 | static void of_free_probes(const char * const *probes) |
| 148 | { |
| 149 | if (probes != part_probe_types_def) |
| 150 | kfree(probes); |
| 151 | } |
| 152 | |
| 153 | static const struct of_device_id of_flash_match[]; |
| 154 | static int of_flash_probe(struct platform_device *dev) |
| 155 | { |
| 156 | const char * const *part_probe_types; |
| 157 | const struct of_device_id *match; |
| 158 | struct device_node *dp = dev->dev.of_node; |
| 159 | struct resource res; |
| 160 | struct of_flash *info; |
| 161 | const char *probe_type; |
| 162 | const __be32 *width; |
| 163 | int err; |
| 164 | int i; |
| 165 | int count; |
| 166 | const __be32 *p; |
| 167 | int reg_tuple_size; |
| 168 | struct mtd_info **mtd_list = NULL; |
| 169 | resource_size_t res_size; |
| 170 | bool map_indirect; |
| 171 | const char *mtd_name = NULL; |
| 172 | |
| 173 | match = of_match_device(of_flash_match, &dev->dev); |
| 174 | if (!match) |
| 175 | return -EINVAL; |
| 176 | probe_type = match->data; |
| 177 | |
| 178 | reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32); |
| 179 | |
| 180 | of_property_read_string(dp, "linux,mtd-name", &mtd_name); |
| 181 | |
| 182 | /* |
| 183 | * Get number of "reg" tuples. Scan for MTD devices on area's |
| 184 | * described by each "reg" region. This makes it possible (including |
| 185 | * the concat support) to support the Intel P30 48F4400 chips which |
| 186 | * consists internally of 2 non-identical NOR chips on one die. |
| 187 | */ |
| 188 | p = of_get_property(dp, "reg", &count); |
| 189 | if (!p || count % reg_tuple_size != 0) { |
| 190 | dev_err(&dev->dev, "Malformed reg property on %s\n", |
| 191 | dev->dev.of_node->full_name); |
| 192 | err = -EINVAL; |
| 193 | goto err_flash_remove; |
| 194 | } |
| 195 | count /= reg_tuple_size; |
| 196 | |
| 197 | map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access"); |
| 198 | |
| 199 | err = -ENOMEM; |
| 200 | info = devm_kzalloc(&dev->dev, |
| 201 | sizeof(struct of_flash) + |
| 202 | sizeof(struct of_flash_list) * count, GFP_KERNEL); |
| 203 | if (!info) |
| 204 | goto err_flash_remove; |
| 205 | |
| 206 | dev_set_drvdata(&dev->dev, info); |
| 207 | |
| 208 | mtd_list = kzalloc(sizeof(*mtd_list) * count, GFP_KERNEL); |
| 209 | if (!mtd_list) |
| 210 | goto err_flash_remove; |
| 211 | |
| 212 | for (i = 0; i < count; i++) { |
| 213 | err = -ENXIO; |
| 214 | if (of_address_to_resource(dp, i, &res)) { |
| 215 | /* |
| 216 | * Continue with next register tuple if this |
| 217 | * one is not mappable |
| 218 | */ |
| 219 | continue; |
| 220 | } |
| 221 | |
| 222 | dev_dbg(&dev->dev, "of_flash device: %pR\n", &res); |
| 223 | |
| 224 | err = -EBUSY; |
| 225 | res_size = resource_size(&res); |
| 226 | info->list[i].res = request_mem_region(res.start, res_size, |
| 227 | dev_name(&dev->dev)); |
| 228 | if (!info->list[i].res) |
| 229 | goto err_out; |
| 230 | |
| 231 | err = -ENXIO; |
| 232 | width = of_get_property(dp, "bank-width", NULL); |
| 233 | if (!width) { |
| 234 | dev_err(&dev->dev, "Can't get bank width from device" |
| 235 | " tree\n"); |
| 236 | goto err_out; |
| 237 | } |
| 238 | |
| 239 | info->list[i].map.name = mtd_name ?: dev_name(&dev->dev); |
| 240 | info->list[i].map.phys = res.start; |
| 241 | info->list[i].map.size = res_size; |
| 242 | info->list[i].map.bankwidth = be32_to_cpup(width); |
| 243 | info->list[i].map.device_node = dp; |
| 244 | err = of_flash_probe_versatile(dev, dp, &info->list[i].map); |
| 245 | if (err) { |
| 246 | dev_err(&dev->dev, "Can't probe Versatile VPP\n"); |
| 247 | return err; |
| 248 | } |
| 249 | |
| 250 | err = -ENOMEM; |
| 251 | info->list[i].map.virt = ioremap(info->list[i].map.phys, |
| 252 | info->list[i].map.size); |
| 253 | if (!info->list[i].map.virt) { |
| 254 | dev_err(&dev->dev, "Failed to ioremap() flash" |
| 255 | " region\n"); |
| 256 | goto err_out; |
| 257 | } |
| 258 | |
| 259 | simple_map_init(&info->list[i].map); |
| 260 | |
| 261 | /* |
| 262 | * On some platforms (e.g. MPC5200) a direct 1:1 mapping |
| 263 | * may cause problems with JFFS2 usage, as the local bus (LPB) |
| 264 | * doesn't support unaligned accesses as implemented in the |
| 265 | * JFFS2 code via memcpy(). By setting NO_XIP, the |
| 266 | * flash will not be exposed directly to the MTD users |
| 267 | * (e.g. JFFS2) any more. |
| 268 | */ |
| 269 | if (map_indirect) |
| 270 | info->list[i].map.phys = NO_XIP; |
| 271 | |
| 272 | if (probe_type) { |
| 273 | info->list[i].mtd = do_map_probe(probe_type, |
| 274 | &info->list[i].map); |
| 275 | } else { |
| 276 | info->list[i].mtd = obsolete_probe(dev, |
| 277 | &info->list[i].map); |
| 278 | } |
| 279 | |
| 280 | /* Fall back to mapping region as ROM */ |
| 281 | if (!info->list[i].mtd) { |
| 282 | dev_warn(&dev->dev, |
| 283 | "do_map_probe() failed for type %s\n", |
| 284 | probe_type); |
| 285 | |
| 286 | info->list[i].mtd = do_map_probe("map_rom", |
| 287 | &info->list[i].map); |
| 288 | } |
| 289 | mtd_list[i] = info->list[i].mtd; |
| 290 | |
| 291 | err = -ENXIO; |
| 292 | if (!info->list[i].mtd) { |
| 293 | dev_err(&dev->dev, "do_map_probe() failed\n"); |
| 294 | goto err_out; |
| 295 | } else { |
| 296 | info->list_size++; |
| 297 | } |
| 298 | info->list[i].mtd->dev.parent = &dev->dev; |
| 299 | } |
| 300 | |
| 301 | err = 0; |
| 302 | info->cmtd = NULL; |
| 303 | if (info->list_size == 1) { |
| 304 | info->cmtd = info->list[0].mtd; |
| 305 | } else if (info->list_size > 1) { |
| 306 | /* |
| 307 | * We detected multiple devices. Concatenate them together. |
| 308 | */ |
| 309 | info->cmtd = mtd_concat_create(mtd_list, info->list_size, |
| 310 | dev_name(&dev->dev)); |
| 311 | } |
| 312 | if (info->cmtd == NULL) |
| 313 | err = -ENXIO; |
| 314 | |
| 315 | if (err) |
| 316 | goto err_out; |
| 317 | |
| 318 | info->cmtd->dev.parent = &dev->dev; |
| 319 | mtd_set_of_node(info->cmtd, dp); |
| 320 | part_probe_types = of_get_probes(dp); |
| 321 | if (!part_probe_types) { |
| 322 | err = -ENOMEM; |
| 323 | goto err_out; |
| 324 | } |
| 325 | mtd_device_parse_register(info->cmtd, part_probe_types, NULL, |
| 326 | NULL, 0); |
| 327 | of_free_probes(part_probe_types); |
| 328 | |
| 329 | kfree(mtd_list); |
| 330 | |
| 331 | return 0; |
| 332 | |
| 333 | err_out: |
| 334 | kfree(mtd_list); |
| 335 | err_flash_remove: |
| 336 | of_flash_remove(dev); |
| 337 | |
| 338 | return err; |
| 339 | } |
| 340 | |
| 341 | static const struct of_device_id of_flash_match[] = { |
| 342 | { |
| 343 | .compatible = "cfi-flash", |
| 344 | .data = (void *)"cfi_probe", |
| 345 | }, |
| 346 | { |
| 347 | /* FIXME: JEDEC chips can't be safely and reliably |
| 348 | * probed, although the mtd code gets it right in |
| 349 | * practice most of the time. We should use the |
| 350 | * vendor and device ids specified by the binding to |
| 351 | * bypass the heuristic probe code, but the mtd layer |
| 352 | * provides, at present, no interface for doing so |
| 353 | * :(. */ |
| 354 | .compatible = "jedec-flash", |
| 355 | .data = (void *)"jedec_probe", |
| 356 | }, |
| 357 | { |
| 358 | .compatible = "mtd-ram", |
| 359 | .data = (void *)"map_ram", |
| 360 | }, |
| 361 | { |
| 362 | .compatible = "mtd-rom", |
| 363 | .data = (void *)"map_rom", |
| 364 | }, |
| 365 | { |
| 366 | .type = "rom", |
| 367 | .compatible = "direct-mapped" |
| 368 | }, |
| 369 | { }, |
| 370 | }; |
| 371 | MODULE_DEVICE_TABLE(of, of_flash_match); |
| 372 | |
| 373 | static struct platform_driver of_flash_driver = { |
| 374 | .driver = { |
| 375 | .name = "of-flash", |
| 376 | .of_match_table = of_flash_match, |
| 377 | }, |
| 378 | .probe = of_flash_probe, |
| 379 | .remove = of_flash_remove, |
| 380 | }; |
| 381 | |
| 382 | module_platform_driver(of_flash_driver); |
| 383 | |
| 384 | MODULE_LICENSE("GPL"); |
| 385 | MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>"); |
| 386 | MODULE_DESCRIPTION("Device tree based MTD map driver"); |