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 void 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
  93         /*
  94          * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
  95          * setup the correct supported mask.
  96          */
  97         if (!dev->coherent_dma_mask)
  98                 dev->coherent_dma_mask = DMA_BIT_MASK(32);
  99
 100         /*
 101          * Set it to coherent_dma_mask by default if the architecture
 102          * code has not set it.
 103          */
 104         if (!dev->dma_mask)
 105                 dev->dma_mask = &dev->coherent_dma_mask;
 106
 107         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
 108         if (ret < 0) {
 109                 dma_addr = offset = 0;
 110                 size = dev->coherent_dma_mask + 1;
 111         } else {
 112                 offset = PFN_DOWN(paddr - dma_addr);
 113
 114                 /*
 115                  * Add a work around to treat the size as mask + 1 in case
 116                  * it is defined in DT as a mask.
 117                  */
 118                 if (size & 1) {
 119                         dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
 120                                  size);
 121                         size = size + 1;
 122                 }
 123
 124                 if (!size) {
 125                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 126                         return;
 127                 }
 128                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 129         }
 130
 131         dev->dma_pfn_offset = offset;
 132
 133         /*
 134          * Limit coherent and dma mask based on size and default mask
 135          * set by the driver.
 136          */
 137         dev->coherent_dma_mask = min(dev->coherent_dma_mask,
 138                                      DMA_BIT_MASK(ilog2(dma_addr + size)));
 139         *dev->dma_mask = min((*dev->dma_mask),
 140                              DMA_BIT_MASK(ilog2(dma_addr + size)));
 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         dev_dbg(dev, "device is%sbehind an iommu\n",
 148                 iommu ? " " : " not ");
 149
 150         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 151 }
 152 EXPORT_SYMBOL_GPL(of_dma_configure);
 153
 154 int of_device_register(struct platform_device *pdev)
 155 {
 156         device_initialize(&pdev->dev);
 157         return of_device_add(pdev);
 158 }
 159 EXPORT_SYMBOL(of_device_register);
 160
 161 void of_device_unregister(struct platform_device *ofdev)
 162 {
 163         device_unregister(&ofdev->dev);
 164 }
 165 EXPORT_SYMBOL(of_device_unregister);
 166
 167 const void *of_device_get_match_data(const struct device *dev)
 168 {
 169         const struct of_device_id *match;
 170
 171         match = of_match_device(dev->driver->of_match_table, dev);
 172         if (!match)
 173                 return NULL;
 174
 175         return match->data;
 176 }
 177 EXPORT_SYMBOL(of_device_get_match_data);
 178
 179 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 180 {
 181         const char *compat;
 182         int cplen, i;
 183         ssize_t tsize, csize, repend;
 184
 185         if ((!dev) || (!dev->of_node))
 186                 return -ENODEV;
 187
 188         /* Name & Type */
 189         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 190                          dev->of_node->type);
 191
 192         /* Get compatible property if any */
 193         compat = of_get_property(dev->of_node, "compatible", &cplen);
 194         if (!compat)
 195                 return csize;
 196
 197         /* Find true end (we tolerate multiple \0 at the end */
 198         for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
 199                 cplen--;
 200         if (!cplen)
 201                 return csize;
 202         cplen++;
 203
 204         /* Check space (need cplen+1 chars including final \0) */
 205         tsize = csize + cplen;
 206         repend = tsize;
 207
 208         if (csize >= len)               /* @ the limit, all is already filled */
 209                 return tsize;
 210
 211         if (tsize >= len) {             /* limit compat list */
 212                 cplen = len - csize - 1;
 213                 repend = len;
 214         }
 215
 216         /* Copy and do char replacement */
 217         memcpy(&str[csize + 1], compat, cplen);
 218         for (i = csize; i < repend; i++) {
 219                 char c = str[i];
 220                 if (c == '\0')
 221                         str[i] = 'C';
 222                 else if (c == ' ')
 223                         str[i] = '_';
 224         }
 225
 226         return tsize;
 227 }
 228
 229 /**
 230  * of_device_uevent - Display OF related uevent information
 231  */
 232 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 233 {
 234         const char *compat;
 235         struct alias_prop *app;
 236         int seen = 0, cplen, sl;
 237
 238         if ((!dev) || (!dev->of_node))
 239                 return;
 240
 241         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 242         add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
 243         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 244                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 245
 246         /* Since the compatible field can contain pretty much anything
 247          * it's not really legal to split it out with commas. We split it
 248          * up using a number of environment variables instead. */
 249         compat = of_get_property(dev->of_node, "compatible", &cplen);
 250         while (compat && *compat && cplen > 0) {
 251                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 252                 sl = strlen(compat) + 1;
 253                 compat += sl;
 254                 cplen -= sl;
 255                 seen++;
 256         }
 257         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 258
 259         seen = 0;
 260         mutex_lock(&of_mutex);
 261         list_for_each_entry(app, &aliases_lookup, link) {
 262                 if (dev->of_node == app->np) {
 263                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 264                                        app->alias);
 265                         seen++;
 266                 }
 267         }
 268         mutex_unlock(&of_mutex);
 269 }
 270
 271 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 272 {
 273         int sl;
 274
 275         if ((!dev) || (!dev->of_node))
 276                 return -ENODEV;
 277
 278         /* Devicetree modalias is tricky, we add it in 2 steps */
 279         if (add_uevent_var(env, "MODALIAS="))
 280                 return -ENOMEM;
 281
 282         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 283                                     sizeof(env->buf) - env->buflen);
 284         if (sl >= (sizeof(env->buf) - env->buflen))
 285                 return -ENOMEM;
 286         env->buflen += sl;
 287
 288         return 0;
 289 }