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
  13 #include <asm/errno.h>
  14 #include "of_private.h"
  15
  16 /**
  17  * of_match_device - Tell if a struct device matches an of_device_id list
  18  * @ids: array of of device match structures to search in
  19  * @dev: the of device structure to match against
  20  *
  21  * Used by a driver to check whether an platform_device present in the
  22  * system is in its list of supported devices.
  23  */
  24 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  25                                            const struct device *dev)
  26 {
  27         if ((!matches) || (!dev->of_node))
  28                 return NULL;
  29         return of_match_node(matches, dev->of_node);
  30 }
  31 EXPORT_SYMBOL(of_match_device);
  32
  33 struct platform_device *of_dev_get(struct platform_device *dev)
  34 {
  35         struct device *tmp;
  36
  37         if (!dev)
  38                 return NULL;
  39         tmp = get_device(&dev->dev);
  40         if (tmp)
  41                 return to_platform_device(tmp);
  42         else
  43                 return NULL;
  44 }
  45 EXPORT_SYMBOL(of_dev_get);
  46
  47 void of_dev_put(struct platform_device *dev)
  48 {
  49         if (dev)
  50                 put_device(&dev->dev);
  51 }
  52 EXPORT_SYMBOL(of_dev_put);
  53
  54 int of_device_add(struct platform_device *ofdev)
  55 {
  56         BUG_ON(ofdev->dev.of_node == NULL);
  57
  58         /* name and id have to be set so that the platform bus doesn't get
  59          * confused on matching */
  60         ofdev->name = dev_name(&ofdev->dev);
  61         ofdev->id = -1;
  62
  63         /*
  64          * If this device has not binding numa node in devicetree, that is
  65          * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
  66          * device is on the same node as the parent.
  67          */
  68         set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  69
  70         return device_add(&ofdev->dev);
  71 }
  72
  73 /**
  74  * of_dma_configure - Setup DMA configuration
  75  * @dev:        Device to apply DMA configuration
  76  * @np:         Pointer to OF node having DMA configuration
  77  *
  78  * Try to get devices's DMA configuration from DT and update it
  79  * accordingly.
  80  *
  81  * If platform code needs to use its own special DMA configuration, it
  82  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  83  * to fix up DMA configuration.
  84  */
  85 int of_dma_configure(struct device *dev, struct device_node *np)
  86 {
  87         u64 dma_addr, paddr, size;
  88         int ret;
  89         bool coherent;
  90         unsigned long offset;
  91         const struct iommu_ops *iommu;
  92         u64 mask;
  93
  94         /*
  95          * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
  96          * setup the correct supported mask.
  97          */
  98         if (!dev->coherent_dma_mask)
  99                 dev->coherent_dma_mask = DMA_BIT_MASK(32);
 100
 101         /*
 102          * Set it to coherent_dma_mask by default if the architecture
 103          * code has not set it.
 104          */
 105         if (!dev->dma_mask)
 106                 dev->dma_mask = &dev->coherent_dma_mask;
 107
 108         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
 109         if (ret < 0) {
 110                 dma_addr = offset = 0;
 111                 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 112         } else {
 113                 offset = PFN_DOWN(paddr - dma_addr);
 114
 115                 /*
 116                  * Add a work around to treat the size as mask + 1 in case
 117                  * it is defined in DT as a mask.
 118                  */
 119                 if (size & 1) {
 120                         dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
 121                                  size);
 122                         size = size + 1;
 123                 }
 124
 125                 if (!size) {
 126                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 127                         return -EINVAL;
 128                 }
 129                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 130         }
 131
 132         dev->dma_pfn_offset = offset;
 133
 134         /*
 135          * Limit coherent and dma mask based on size and default mask
 136          * set by the driver.
 137          */
 138         mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
 139         dev->coherent_dma_mask &= mask;
 140         *dev->dma_mask &= mask;
 141
 142         coherent = of_dma_is_coherent(np);
 143         dev_dbg(dev, "device is%sdma coherent\n",
 144                 coherent ? " " : " not ");
 145
 146         iommu = of_iommu_configure(dev, np);
 147         if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
 148                 return -EPROBE_DEFER;
 149
 150         dev_dbg(dev, "device is%sbehind an iommu\n",
 151                 iommu ? " " : " not ");
 152
 153         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 154
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(of_dma_configure);
 158
 159 /**
 160  * of_dma_deconfigure - Clean up DMA configuration
 161  * @dev:        Device for which to clean up DMA configuration
 162  *
 163  * Clean up all configuration performed by of_dma_configure_ops() and free all
 164  * resources that have been allocated.
 165  */
 166 void of_dma_deconfigure(struct device *dev)
 167 {
 168         arch_teardown_dma_ops(dev);
 169 }
 170
 171 int of_device_register(struct platform_device *pdev)
 172 {
 173         device_initialize(&pdev->dev);
 174         return of_device_add(pdev);
 175 }
 176 EXPORT_SYMBOL(of_device_register);
 177
 178 void of_device_unregister(struct platform_device *ofdev)
 179 {
 180         device_unregister(&ofdev->dev);
 181 }
 182 EXPORT_SYMBOL(of_device_unregister);
 183
 184 const void *of_device_get_match_data(const struct device *dev)
 185 {
 186         const struct of_device_id *match;
 187
 188         match = of_match_device(dev->driver->of_match_table, dev);
 189         if (!match)
 190                 return NULL;
 191
 192         return match->data;
 193 }
 194 EXPORT_SYMBOL(of_device_get_match_data);
 195
 196 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 197 {
 198         const char *compat;
 199         int cplen, i;
 200         ssize_t tsize, csize, repend;
 201
 202         if ((!dev) || (!dev->of_node))
 203                 return -ENODEV;
 204
 205         /* Name & Type */
 206         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 207                          dev->of_node->type);
 208
 209         /* Get compatible property if any */
 210         compat = of_get_property(dev->of_node, "compatible", &cplen);
 211         if (!compat)
 212                 return csize;
 213
 214         /* Find true end (we tolerate multiple \0 at the end */
 215         for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
 216                 cplen--;
 217         if (!cplen)
 218                 return csize;
 219         cplen++;
 220
 221         /* Check space (need cplen+1 chars including final \0) */
 222         tsize = csize + cplen;
 223         repend = tsize;
 224
 225         if (csize >= len)               /* @ the limit, all is already filled */
 226                 return tsize;
 227
 228         if (tsize >= len) {             /* limit compat list */
 229                 cplen = len - csize - 1;
 230                 repend = len;
 231         }
 232
 233         /* Copy and do char replacement */
 234         memcpy(&str[csize + 1], compat, cplen);
 235         for (i = csize; i < repend; i++) {
 236                 char c = str[i];
 237                 if (c == '\0')
 238                         str[i] = 'C';
 239                 else if (c == ' ')
 240                         str[i] = '_';
 241         }
 242
 243         return repend;
 244 }
 245
 246 int of_device_request_module(struct device *dev)
 247 {
 248         char *str;
 249         ssize_t size;
 250         int ret;
 251
 252         size = of_device_get_modalias(dev, NULL, 0);
 253         if (size < 0)
 254                 return size;
 255
 256         str = kmalloc(size + 1, GFP_KERNEL);
 257         if (!str)
 258                 return -ENOMEM;
 259
 260         of_device_get_modalias(dev, str, size);
 261         str[size] = '\0';
 262         ret = request_module(str);
 263         kfree(str);
 264
 265         return ret;
 266 }
 267 EXPORT_SYMBOL_GPL(of_device_request_module);
 268
 269 /**
 270  * of_device_modalias - Fill buffer with newline terminated modalias string
 271  */
 272 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 273 {
 274         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 275         if (sl < 0)
 276                 return sl;
 277         if (sl > len - 2)
 278                 return -ENOMEM;
 279
 280         str[sl++] = '\n';
 281         str[sl] = 0;
 282         return sl;
 283 }
 284 EXPORT_SYMBOL_GPL(of_device_modalias);
 285
 286 /**
 287  * of_device_uevent - Display OF related uevent information
 288  */
 289 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 290 {
 291         const char *compat;
 292         struct alias_prop *app;
 293         int seen = 0, cplen, sl;
 294
 295         if ((!dev) || (!dev->of_node))
 296                 return;
 297
 298         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 299         add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
 300         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 301                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 302
 303         /* Since the compatible field can contain pretty much anything
 304          * it's not really legal to split it out with commas. We split it
 305          * up using a number of environment variables instead. */
 306         compat = of_get_property(dev->of_node, "compatible", &cplen);
 307         while (compat && *compat && cplen > 0) {
 308                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 309                 sl = strlen(compat) + 1;
 310                 compat += sl;
 311                 cplen -= sl;
 312                 seen++;
 313         }
 314         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 315
 316         seen = 0;
 317         mutex_lock(&of_mutex);
 318         list_for_each_entry(app, &aliases_lookup, link) {
 319                 if (dev->of_node == app->np) {
 320                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 321                                        app->alias);
 322                         seen++;
 323                 }
 324         }
 325         mutex_unlock(&of_mutex);
 326 }
 327
 328 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 329 {
 330         int sl;
 331
 332         if ((!dev) || (!dev->of_node))
 333                 return -ENODEV;
 334
 335         /* Devicetree modalias is tricky, we add it in 2 steps */
 336         if (add_uevent_var(env, "MODALIAS="))
 337                 return -ENOMEM;
 338
 339         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 340                                     sizeof(env->buf) - env->buflen);
 341         if (sl >= (sizeof(env->buf) - env->buflen))
 342                 return -ENOMEM;
 343         env->buflen += sl;
 344
 345         return 0;
 346 }
 347 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);