drivers/of/device.c

   1 #include <linux/string.h>
   2 #include <linux/kernel.h>
   3 #include <linux/of.h>
   4 #include <linux/of_device.h>
   5 #include <linux/of_address.h>
   6 #include <linux/of_iommu.h>
   7 #include <linux/dma-mapping.h>
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/mod_devicetable.h>
  11 #include <linux/slab.h>
  12 #include <linux/platform_device.h>
  13
  14 #include <asm/errno.h>
  15 #include "of_private.h"
  16
  17 /**
  18  * of_match_device - Tell if a struct device matches an of_device_id list
  19  * @ids: array of of device match structures to search in
  20  * @dev: the of device structure to match against
  21  *
  22  * Used by a driver to check whether an platform_device present in the
  23  * system is in its list of supported devices.
  24  */
  25 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  26                                            const struct device *dev)
  27 {
  28         if ((!matches) || (!dev->of_node))
  29                 return NULL;
  30         return of_match_node(matches, dev->of_node);
  31 }
  32 EXPORT_SYMBOL(of_match_device);
  33
  34 struct platform_device *of_dev_get(struct platform_device *dev)
  35 {
  36         struct device *tmp;
  37
  38         if (!dev)
  39                 return NULL;
  40         tmp = get_device(&dev->dev);
  41         if (tmp)
  42                 return to_platform_device(tmp);
  43         else
  44                 return NULL;
  45 }
  46 EXPORT_SYMBOL(of_dev_get);
  47
  48 void of_dev_put(struct platform_device *dev)
  49 {
  50         if (dev)
  51                 put_device(&dev->dev);
  52 }
  53 EXPORT_SYMBOL(of_dev_put);
  54
  55 int of_device_add(struct platform_device *ofdev)
  56 {
  57         BUG_ON(ofdev->dev.of_node == NULL);
  58
  59         /* name and id have to be set so that the platform bus doesn't get
  60          * confused on matching */
  61         ofdev->name = dev_name(&ofdev->dev);
  62         ofdev->id = PLATFORM_DEVID_NONE;
  63
  64         /*
  65          * If this device has not binding numa node in devicetree, that is
  66          * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
  67          * device is on the same node as the parent.
  68          */
  69         set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  70
  71         return device_add(&ofdev->dev);
  72 }
  73
  74 /**
  75  * of_dma_configure - Setup DMA configuration
  76  * @dev:        Device to apply DMA configuration
  77  * @np:         Pointer to OF node having DMA configuration
  78  *
  79  * Try to get devices's DMA configuration from DT and update it
  80  * accordingly.
  81  *
  82  * If platform code needs to use its own special DMA configuration, it
  83  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  84  * to fix up DMA configuration.
  85  */
  86 int of_dma_configure(struct device *dev, struct device_node *np)
  87 {
  88         u64 dma_addr, paddr, size = 0;
  89         int ret;
  90         bool coherent;
  91         unsigned long offset;
  92         const struct iommu_ops *iommu;
  93         u64 mask;
  94
  95         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
  96         if (ret < 0) {
  97                 /*
  98                  * For legacy reasons, we have to assume some devices need
  99                  * DMA configuration regardless of whether "dma-ranges" is
 100                  * correctly specified or not.
 101                  */
 102                 if (!dev->bus->force_dma)
 103                         return ret == -ENODEV ? 0 : ret;
 104
 105                 dma_addr = offset = 0;
 106         } else {
 107                 offset = PFN_DOWN(paddr - dma_addr);
 108
 109                 /*
 110                  * Add a work around to treat the size as mask + 1 in case
 111                  * it is defined in DT as a mask.
 112                  */
 113                 if (size & 1) {
 114                         dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
 115                                  size);
 116                         size = size + 1;
 117                 }
 118
 119                 if (!size) {
 120                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 121                         return -EINVAL;
 122                 }
 123                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 124         }
 125
 126         /*
 127          * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
 128          * setup the correct supported mask.
 129          */
 130         if (!dev->coherent_dma_mask)
 131                 dev->coherent_dma_mask = DMA_BIT_MASK(32);
 132         /*
 133          * Set it to coherent_dma_mask by default if the architecture
 134          * code has not set it.
 135          */
 136         if (!dev->dma_mask)
 137                 dev->dma_mask = &dev->coherent_dma_mask;
 138
 139         if (!size)
 140                 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 141
 142         dev->dma_pfn_offset = offset;
 143
 144         /*
 145          * Limit coherent and dma mask based on size and default mask
 146          * set by the driver.
 147          */
 148         mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
 149         dev->coherent_dma_mask &= mask;
 150         *dev->dma_mask &= mask;
 151
 152         coherent = of_dma_is_coherent(np);
 153         dev_dbg(dev, "device is%sdma coherent\n",
 154                 coherent ? " " : " not ");
 155
 156         iommu = of_iommu_configure(dev, np);
 157         if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
 158                 return -EPROBE_DEFER;
 159
 160         dev_dbg(dev, "device is%sbehind an iommu\n",
 161                 iommu ? " " : " not ");
 162
 163         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 164
 165         return 0;
 166 }
 167 EXPORT_SYMBOL_GPL(of_dma_configure);
 168
 169 /**
 170  * of_dma_deconfigure - Clean up DMA configuration
 171  * @dev:        Device for which to clean up DMA configuration
 172  *
 173  * Clean up all configuration performed by of_dma_configure_ops() and free all
 174  * resources that have been allocated.
 175  */
 176 void of_dma_deconfigure(struct device *dev)
 177 {
 178         arch_teardown_dma_ops(dev);
 179 }
 180
 181 int of_device_register(struct platform_device *pdev)
 182 {
 183         device_initialize(&pdev->dev);
 184         return of_device_add(pdev);
 185 }
 186 EXPORT_SYMBOL(of_device_register);
 187
 188 void of_device_unregister(struct platform_device *ofdev)
 189 {
 190         device_unregister(&ofdev->dev);
 191 }
 192 EXPORT_SYMBOL(of_device_unregister);
 193
 194 const void *of_device_get_match_data(const struct device *dev)
 195 {
 196         const struct of_device_id *match;
 197
 198         match = of_match_device(dev->driver->of_match_table, dev);
 199         if (!match)
 200                 return NULL;
 201
 202         return match->data;
 203 }
 204 EXPORT_SYMBOL(of_device_get_match_data);
 205
 206 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 207 {
 208         const char *compat;
 209         char *c;
 210         struct property *p;
 211         ssize_t csize;
 212         ssize_t tsize;
 213
 214         if ((!dev) || (!dev->of_node))
 215                 return -ENODEV;
 216
 217         /* Name & Type */
 218         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 219                          dev->of_node->type);
 220         tsize = csize;
 221         len -= csize;
 222         if (str)
 223                 str += csize;
 224
 225         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 226                 csize = strlen(compat) + 1;
 227                 tsize += csize;
 228                 if (csize > len)
 229                         continue;
 230
 231                 csize = snprintf(str, len, "C%s", compat);
 232                 for (c = str; c; ) {
 233                         c = strchr(c, ' ');
 234                         if (c)
 235                                 *c++ = '_';
 236                 }
 237                 len -= csize;
 238                 str += csize;
 239         }
 240
 241         return tsize;
 242 }
 243
 244 int of_device_request_module(struct device *dev)
 245 {
 246         char *str;
 247         ssize_t size;
 248         int ret;
 249
 250         size = of_device_get_modalias(dev, NULL, 0);
 251         if (size < 0)
 252                 return size;
 253
 254         str = kmalloc(size + 1, GFP_KERNEL);
 255         if (!str)
 256                 return -ENOMEM;
 257
 258         of_device_get_modalias(dev, str, size);
 259         str[size] = '\0';
 260         ret = request_module(str);
 261         kfree(str);
 262
 263         return ret;
 264 }
 265 EXPORT_SYMBOL_GPL(of_device_request_module);
 266
 267 /**
 268  * of_device_modalias - Fill buffer with newline terminated modalias string
 269  */
 270 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 271 {
 272         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 273         if (sl < 0)
 274                 return sl;
 275         if (sl > len - 2)
 276                 return -ENOMEM;
 277
 278         str[sl++] = '\n';
 279         str[sl] = 0;
 280         return sl;
 281 }
 282 EXPORT_SYMBOL_GPL(of_device_modalias);
 283
 284 /**
 285  * of_device_uevent - Display OF related uevent information
 286  */
 287 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 288 {
 289         const char *compat;
 290         struct alias_prop *app;
 291         struct property *p;
 292         int seen = 0;
 293
 294         if ((!dev) || (!dev->of_node))
 295                 return;
 296
 297         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 298         add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 299         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 300                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 301
 302         /* Since the compatible field can contain pretty much anything
 303          * it's not really legal to split it out with commas. We split it
 304          * up using a number of environment variables instead. */
 305         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 306                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 307                 seen++;
 308         }
 309         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 310
 311         seen = 0;
 312         mutex_lock(&of_mutex);
 313         list_for_each_entry(app, &aliases_lookup, link) {
 314                 if (dev->of_node == app->np) {
 315                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 316                                        app->alias);
 317                         seen++;
 318                 }
 319         }
 320         mutex_unlock(&of_mutex);
 321 }
 322
 323 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 324 {
 325         int sl;
 326
 327         if ((!dev) || (!dev->of_node))
 328                 return -ENODEV;
 329
 330         /* Devicetree modalias is tricky, we add it in 2 steps */
 331         if (add_uevent_var(env, "MODALIAS="))
 332                 return -ENOMEM;
 333
 334         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 335                                     sizeof(env->buf) - env->buflen);
 336         if (sl >= (sizeof(env->buf) - env->buflen))
 337                 return -ENOMEM;
 338         env->buflen += sl;
 339
 340         return 0;
 341 }
 342 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);