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