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/pci.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/amba/bus.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  * @ids: 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  *
  81  * Try to get devices's DMA configuration from DT and update it
  82  * accordingly.
  83  *
  84  * If platform code needs to use its own special DMA configuration, it
  85  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  86  * to fix up DMA configuration.
  87  */
  88 int of_dma_configure(struct device *dev, struct device_node *np)
  89 {
  90         u64 dma_addr, paddr, size = 0;
  91         int ret;
  92         bool coherent;
  93         unsigned long offset;
  94         const struct iommu_ops *iommu;
  95         u64 mask;
  96
  97         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
  98         if (ret < 0) {
  99                 /*
 100                  * For legacy reasons, we have to assume some devices need
 101                  * DMA configuration regardless of whether "dma-ranges" is
 102                  * correctly specified or not.
 103                  */
 104                 if (!dev_is_pci(dev) &&
 105 #ifdef CONFIG_ARM_AMBA
 106                     dev->bus != &amba_bustype &&
 107 #endif
 108                     dev->bus != &platform_bus_type)
 109                         return ret == -ENODEV ? 0 : ret;
 110
 111                 dma_addr = offset = 0;
 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         /*
 133          * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
 134          * setup the correct supported mask.
 135          */
 136         if (!dev->coherent_dma_mask)
 137                 dev->coherent_dma_mask = DMA_BIT_MASK(32);
 138         /*
 139          * Set it to coherent_dma_mask by default if the architecture
 140          * code has not set it.
 141          */
 142         if (!dev->dma_mask)
 143                 dev->dma_mask = &dev->coherent_dma_mask;
 144
 145         if (!size)
 146                 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 147
 148         dev->dma_pfn_offset = offset;
 149
 150         /*
 151          * Limit coherent and dma mask based on size and default mask
 152          * set by the driver.
 153          */
 154         mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
 155         dev->coherent_dma_mask &= mask;
 156         *dev->dma_mask &= mask;
 157
 158         coherent = of_dma_is_coherent(np);
 159         dev_dbg(dev, "device is%sdma coherent\n",
 160                 coherent ? " " : " not ");
 161
 162         iommu = of_iommu_configure(dev, np);
 163         if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
 164                 return -EPROBE_DEFER;
 165
 166         dev_dbg(dev, "device is%sbehind an iommu\n",
 167                 iommu ? " " : " not ");
 168
 169         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 170
 171         return 0;
 172 }
 173 EXPORT_SYMBOL_GPL(of_dma_configure);
 174
 175 /**
 176  * of_dma_deconfigure - Clean up DMA configuration
 177  * @dev:        Device for which to clean up DMA configuration
 178  *
 179  * Clean up all configuration performed by of_dma_configure_ops() and free all
 180  * resources that have been allocated.
 181  */
 182 void of_dma_deconfigure(struct device *dev)
 183 {
 184         arch_teardown_dma_ops(dev);
 185 }
 186
 187 int of_device_register(struct platform_device *pdev)
 188 {
 189         device_initialize(&pdev->dev);
 190         return of_device_add(pdev);
 191 }
 192 EXPORT_SYMBOL(of_device_register);
 193
 194 void of_device_unregister(struct platform_device *ofdev)
 195 {
 196         device_unregister(&ofdev->dev);
 197 }
 198 EXPORT_SYMBOL(of_device_unregister);
 199
 200 const void *of_device_get_match_data(const struct device *dev)
 201 {
 202         const struct of_device_id *match;
 203
 204         match = of_match_device(dev->driver->of_match_table, dev);
 205         if (!match)
 206                 return NULL;
 207
 208         return match->data;
 209 }
 210 EXPORT_SYMBOL(of_device_get_match_data);
 211
 212 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 213 {
 214         const char *compat;
 215         char *c;
 216         struct property *p;
 217         ssize_t csize;
 218         ssize_t tsize;
 219
 220         if ((!dev) || (!dev->of_node))
 221                 return -ENODEV;
 222
 223         /* Name & Type */
 224         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 225                          dev->of_node->type);
 226         tsize = csize;
 227         len -= csize;
 228         if (str)
 229                 str += csize;
 230
 231         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 232                 csize = strlen(compat) + 1;
 233                 tsize += csize;
 234                 if (csize > len)
 235                         continue;
 236
 237                 csize = snprintf(str, len, "C%s", compat);
 238                 for (c = str; c; ) {
 239                         c = strchr(c, ' ');
 240                         if (c)
 241                                 *c++ = '_';
 242                 }
 243                 len -= csize;
 244                 str += csize;
 245         }
 246
 247         return tsize;
 248 }
 249
 250 int of_device_request_module(struct device *dev)
 251 {
 252         char *str;
 253         ssize_t size;
 254         int ret;
 255
 256         size = of_device_get_modalias(dev, NULL, 0);
 257         if (size < 0)
 258                 return size;
 259
 260         str = kmalloc(size + 1, GFP_KERNEL);
 261         if (!str)
 262                 return -ENOMEM;
 263
 264         of_device_get_modalias(dev, str, size);
 265         str[size] = '\0';
 266         ret = request_module(str);
 267         kfree(str);
 268
 269         return ret;
 270 }
 271 EXPORT_SYMBOL_GPL(of_device_request_module);
 272
 273 /**
 274  * of_device_modalias - Fill buffer with newline terminated modalias string
 275  */
 276 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 277 {
 278         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 279         if (sl < 0)
 280                 return sl;
 281         if (sl > len - 2)
 282                 return -ENOMEM;
 283
 284         str[sl++] = '\n';
 285         str[sl] = 0;
 286         return sl;
 287 }
 288 EXPORT_SYMBOL_GPL(of_device_modalias);
 289
 290 /**
 291  * of_device_uevent - Display OF related uevent information
 292  */
 293 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 294 {
 295         const char *compat;
 296         struct alias_prop *app;
 297         struct property *p;
 298         int seen = 0;
 299
 300         if ((!dev) || (!dev->of_node))
 301                 return;
 302
 303         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 304         add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 305         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 306                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 307
 308         /* Since the compatible field can contain pretty much anything
 309          * it's not really legal to split it out with commas. We split it
 310          * up using a number of environment variables instead. */
 311         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 312                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 313                 seen++;
 314         }
 315         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 316
 317         seen = 0;
 318         mutex_lock(&of_mutex);
 319         list_for_each_entry(app, &aliases_lookup, link) {
 320                 if (dev->of_node == app->np) {
 321                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 322                                        app->alias);
 323                         seen++;
 324                 }
 325         }
 326         mutex_unlock(&of_mutex);
 327 }
 328
 329 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 330 {
 331         int sl;
 332
 333         if ((!dev) || (!dev->of_node))
 334                 return -ENODEV;
 335
 336         /* Devicetree modalias is tricky, we add it in 2 steps */
 337         if (add_uevent_var(env, "MODALIAS="))
 338                 return -ENOMEM;
 339
 340         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 341                                     sizeof(env->buf) - env->buflen);
 342         if (sl >= (sizeof(env->buf) - env->buflen))
 343                 return -ENOMEM;
 344         env->buflen += sl;
 345
 346         return 0;
 347 }
 348 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);