drivers/of/device.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/string.h>
   3 #include <linux/kernel.h>
   4 #include <linux/of.h>
   5 #include <linux/of_device.h>
   6 #include <linux/of_address.h>
   7 #include <linux/of_iommu.h>
   8 #include <linux/of_reserved_mem.h>
   9 #include <linux/dma-direct.h> /* for bus_dma_region */
  10 #include <linux/dma-map-ops.h>
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/mod_devicetable.h>
  14 #include <linux/slab.h>
  15 #include <linux/platform_device.h>
  16
  17 #include <asm/errno.h>
  18 #include "of_private.h"
  19
  20 /**
  21  * of_match_device - Tell if a struct device matches an of_device_id list
  22  * @matches: array of of device match structures to search in
  23  * @dev: the of device structure to match against
  24  *
  25  * Used by a driver to check whether an platform_device present in the
  26  * system is in its list of supported devices.
  27  */
  28 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  29                                            const struct device *dev)
  30 {
  31         if ((!matches) || (!dev->of_node))
  32                 return NULL;
  33         return of_match_node(matches, dev->of_node);
  34 }
  35 EXPORT_SYMBOL(of_match_device);
  36
  37 int of_device_add(struct platform_device *ofdev)
  38 {
  39         BUG_ON(ofdev->dev.of_node == NULL);
  40
  41         /* name and id have to be set so that the platform bus doesn't get
  42          * confused on matching */
  43         ofdev->name = dev_name(&ofdev->dev);
  44         ofdev->id = PLATFORM_DEVID_NONE;
  45
  46         /*
  47          * If this device has not binding numa node in devicetree, that is
  48          * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
  49          * device is on the same node as the parent.
  50          */
  51         set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  52
  53         return device_add(&ofdev->dev);
  54 }
  55
  56 static void
  57 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
  58 {
  59         struct device_node *node, *of_node = dev->of_node;
  60         int count, i;
  61
  62         if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
  63                 return;
  64
  65         count = of_property_count_elems_of_size(of_node, "memory-region",
  66                                                 sizeof(u32));
  67         /*
  68          * If dev->of_node doesn't exist or doesn't contain memory-region, try
  69          * the OF node having DMA configuration.
  70          */
  71         if (count <= 0) {
  72                 of_node = np;
  73                 count = of_property_count_elems_of_size(
  74                         of_node, "memory-region", sizeof(u32));
  75         }
  76
  77         for (i = 0; i < count; i++) {
  78                 node = of_parse_phandle(of_node, "memory-region", i);
  79                 /*
  80                  * There might be multiple memory regions, but only one
  81                  * restricted-dma-pool region is allowed.
  82                  */
  83                 if (of_device_is_compatible(node, "restricted-dma-pool") &&
  84                     of_device_is_available(node))
  85                         break;
  86         }
  87
  88         /*
  89          * Attempt to initialize a restricted-dma-pool region if one was found.
  90          * Note that count can hold a negative error code.
  91          */
  92         if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
  93                 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
  94 }
  95
  96 /**
  97  * of_dma_configure_id - Setup DMA configuration
  98  * @dev:        Device to apply DMA configuration
  99  * @np:         Pointer to OF node having DMA configuration
 100  * @force_dma:  Whether device is to be set up by of_dma_configure() even if
 101  *              DMA capability is not explicitly described by firmware.
 102  * @id:         Optional const pointer value input id
 103  *
 104  * Try to get devices's DMA configuration from DT and update it
 105  * accordingly.
 106  *
 107  * If platform code needs to use its own special DMA configuration, it
 108  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
 109  * to fix up DMA configuration.
 110  */
 111 int of_dma_configure_id(struct device *dev, struct device_node *np,
 112                         bool force_dma, const u32 *id)
 113 {
 114         const struct iommu_ops *iommu;
 115         const struct bus_dma_region *map = NULL;
 116         u64 dma_start = 0;
 117         u64 mask, end, size = 0;
 118         bool coherent;
 119         int ret;
 120
 121         ret = of_dma_get_range(np, &map);
 122         if (ret < 0) {
 123                 /*
 124                  * For legacy reasons, we have to assume some devices need
 125                  * DMA configuration regardless of whether "dma-ranges" is
 126                  * correctly specified or not.
 127                  */
 128                 if (!force_dma)
 129                         return ret == -ENODEV ? 0 : ret;
 130         } else {
 131                 const struct bus_dma_region *r = map;
 132                 u64 dma_end = 0;
 133
 134                 /* Determine the overall bounds of all DMA regions */
 135                 for (dma_start = ~0; r->size; r++) {
 136                         /* Take lower and upper limits */
 137                         if (r->dma_start < dma_start)
 138                                 dma_start = r->dma_start;
 139                         if (r->dma_start + r->size > dma_end)
 140                                 dma_end = r->dma_start + r->size;
 141                 }
 142                 size = dma_end - dma_start;
 143
 144                 /*
 145                  * Add a work around to treat the size as mask + 1 in case
 146                  * it is defined in DT as a mask.
 147                  */
 148                 if (size & 1) {
 149                         dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
 150                                  size);
 151                         size = size + 1;
 152                 }
 153
 154                 if (!size) {
 155                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 156                         kfree(map);
 157                         return -EINVAL;
 158                 }
 159         }
 160
 161         /*
 162          * If @dev is expected to be DMA-capable then the bus code that created
 163          * it should have initialised its dma_mask pointer by this point. For
 164          * now, we'll continue the legacy behaviour of coercing it to the
 165          * coherent mask if not, but we'll no longer do so quietly.
 166          */
 167         if (!dev->dma_mask) {
 168                 dev_warn(dev, "DMA mask not set\n");
 169                 dev->dma_mask = &dev->coherent_dma_mask;
 170         }
 171
 172         if (!size && dev->coherent_dma_mask)
 173                 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 174         else if (!size)
 175                 size = 1ULL << 32;
 176
 177         /*
 178          * Limit coherent and dma mask based on size and default mask
 179          * set by the driver.
 180          */
 181         end = dma_start + size - 1;
 182         mask = DMA_BIT_MASK(ilog2(end) + 1);
 183         dev->coherent_dma_mask &= mask;
 184         *dev->dma_mask &= mask;
 185         /* ...but only set bus limit and range map if we found valid dma-ranges earlier */
 186         if (!ret) {
 187                 dev->bus_dma_limit = end;
 188                 dev->dma_range_map = map;
 189         }
 190
 191         coherent = of_dma_is_coherent(np);
 192         dev_dbg(dev, "device is%sdma coherent\n",
 193                 coherent ? " " : " not ");
 194
 195         iommu = of_iommu_configure(dev, np, id);
 196         if (PTR_ERR(iommu) == -EPROBE_DEFER) {
 197                 /* Don't touch range map if it wasn't set from a valid dma-ranges */
 198                 if (!ret)
 199                         dev->dma_range_map = NULL;
 200                 kfree(map);
 201                 return -EPROBE_DEFER;
 202         }
 203
 204         dev_dbg(dev, "device is%sbehind an iommu\n",
 205                 iommu ? " " : " not ");
 206
 207         arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
 208
 209         if (!iommu)
 210                 of_dma_set_restricted_buffer(dev, np);
 211
 212         return 0;
 213 }
 214 EXPORT_SYMBOL_GPL(of_dma_configure_id);
 215
 216 int of_device_register(struct platform_device *pdev)
 217 {
 218         device_initialize(&pdev->dev);
 219         return of_device_add(pdev);
 220 }
 221 EXPORT_SYMBOL(of_device_register);
 222
 223 void of_device_unregister(struct platform_device *ofdev)
 224 {
 225         device_unregister(&ofdev->dev);
 226 }
 227 EXPORT_SYMBOL(of_device_unregister);
 228
 229 const void *of_device_get_match_data(const struct device *dev)
 230 {
 231         const struct of_device_id *match;
 232
 233         match = of_match_device(dev->driver->of_match_table, dev);
 234         if (!match)
 235                 return NULL;
 236
 237         return match->data;
 238 }
 239 EXPORT_SYMBOL(of_device_get_match_data);
 240
 241 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 242 {
 243         const char *compat;
 244         char *c;
 245         struct property *p;
 246         ssize_t csize;
 247         ssize_t tsize;
 248
 249         if ((!dev) || (!dev->of_node))
 250                 return -ENODEV;
 251
 252         /* Name & Type */
 253         /* %p eats all alphanum characters, so %c must be used here */
 254         csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T',
 255                          of_node_get_device_type(dev->of_node));
 256         tsize = csize;
 257         len -= csize;
 258         if (str)
 259                 str += csize;
 260
 261         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 262                 csize = strlen(compat) + 1;
 263                 tsize += csize;
 264                 if (csize > len)
 265                         continue;
 266
 267                 csize = snprintf(str, len, "C%s", compat);
 268                 for (c = str; c; ) {
 269                         c = strchr(c, ' ');
 270                         if (c)
 271                                 *c++ = '_';
 272                 }
 273                 len -= csize;
 274                 str += csize;
 275         }
 276
 277         return tsize;
 278 }
 279
 280 int of_device_request_module(struct device *dev)
 281 {
 282         char *str;
 283         ssize_t size;
 284         int ret;
 285
 286         size = of_device_get_modalias(dev, NULL, 0);
 287         if (size < 0)
 288                 return size;
 289
 290         str = kmalloc(size + 1, GFP_KERNEL);
 291         if (!str)
 292                 return -ENOMEM;
 293
 294         of_device_get_modalias(dev, str, size);
 295         str[size] = '\0';
 296         ret = request_module(str);
 297         kfree(str);
 298
 299         return ret;
 300 }
 301 EXPORT_SYMBOL_GPL(of_device_request_module);
 302
 303 /**
 304  * of_device_modalias - Fill buffer with newline terminated modalias string
 305  * @dev:        Calling device
 306  * @str:        Modalias string
 307  * @len:        Size of @str
 308  */
 309 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 310 {
 311         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 312         if (sl < 0)
 313                 return sl;
 314         if (sl > len - 2)
 315                 return -ENOMEM;
 316
 317         str[sl++] = '\n';
 318         str[sl] = 0;
 319         return sl;
 320 }
 321 EXPORT_SYMBOL_GPL(of_device_modalias);
 322
 323 /**
 324  * of_device_uevent - Display OF related uevent information
 325  * @dev:        Device to apply DMA configuration
 326  * @env:        Kernel object's userspace event reference
 327  */
 328 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 329 {
 330         const char *compat, *type;
 331         struct alias_prop *app;
 332         struct property *p;
 333         int seen = 0;
 334
 335         if ((!dev) || (!dev->of_node))
 336                 return;
 337
 338         add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
 339         add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 340         type = of_node_get_device_type(dev->of_node);
 341         if (type)
 342                 add_uevent_var(env, "OF_TYPE=%s", type);
 343
 344         /* Since the compatible field can contain pretty much anything
 345          * it's not really legal to split it out with commas. We split it
 346          * up using a number of environment variables instead. */
 347         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 348                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 349                 seen++;
 350         }
 351         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 352
 353         seen = 0;
 354         mutex_lock(&of_mutex);
 355         list_for_each_entry(app, &aliases_lookup, link) {
 356                 if (dev->of_node == app->np) {
 357                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 358                                        app->alias);
 359                         seen++;
 360                 }
 361         }
 362         mutex_unlock(&of_mutex);
 363 }
 364
 365 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 366 {
 367         int sl;
 368
 369         if ((!dev) || (!dev->of_node))
 370                 return -ENODEV;
 371
 372         /* Devicetree modalias is tricky, we add it in 2 steps */
 373         if (add_uevent_var(env, "MODALIAS="))
 374                 return -ENOMEM;
 375
 376         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 377                                     sizeof(env->buf) - env->buflen);
 378         if (sl >= (sizeof(env->buf) - env->buflen))
 379                 return -ENOMEM;
 380         env->buflen += sl;
 381
 382         return 0;
 383 }
 384 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);