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         /* device_add will assume that this device is on the same node as
  64          * the parent. If there is no parent defined, set the node
  65          * explicitly */
  66         if (!ofdev->dev.parent)
  67                 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  68
  69         return device_add(&ofdev->dev);
  70 }
  71
  72 /**
  73  * of_dma_configure - Setup DMA configuration
  74  * @dev:        Device to apply DMA configuration
  75  * @np:         Pointer to OF node having DMA configuration
  76  *
  77  * Try to get devices's DMA configuration from DT and update it
  78  * accordingly.
  79  *
  80  * If platform code needs to use its own special DMA configuration, it
  81  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  82  * to fix up DMA configuration.
  83  */
  84 void of_dma_configure(struct device *dev, struct device_node *np)
  85 {
  86         u64 dma_addr, paddr, size;
  87         int ret;
  88         bool coherent;
  89         unsigned long offset;
  90         struct iommu_ops *iommu;
  91
  92         /*
  93          * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
  94          * setup the correct supported mask.
  95          */
  96         if (!dev->coherent_dma_mask)
  97                 dev->coherent_dma_mask = DMA_BIT_MASK(32);
  98
  99         /*
 100          * Set it to coherent_dma_mask by default if the architecture
 101          * code has not set it.
 102          */
 103         if (!dev->dma_mask)
 104                 dev->dma_mask = &dev->coherent_dma_mask;
 105
 106         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
 107         if (ret < 0) {
 108                 dma_addr = offset = 0;
 109                 size = dev->coherent_dma_mask + 1;
 110         } else {
 111                 offset = PFN_DOWN(paddr - dma_addr);
 112
 113                 /*
 114                  * Add a work around to treat the size as mask + 1 in case
 115                  * it is defined in DT as a mask.
 116                  */
 117                 if (size & 1) {
 118                         dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
 119                                  size);
 120                         size = size + 1;
 121                 }
 122
 123                 if (!size) {
 124                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 125                         return;
 126                 }
 127                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 128         }
 129
 130         dev->dma_pfn_offset = offset;
 131
 132         /*
 133          * Limit coherent and dma mask based on size and default mask
 134          * set by the driver.
 135          */
 136         dev->coherent_dma_mask = min(dev->coherent_dma_mask,
 137                                      DMA_BIT_MASK(ilog2(dma_addr + size)));
 138         *dev->dma_mask = min((*dev->dma_mask),
 139                              DMA_BIT_MASK(ilog2(dma_addr + size)));
 140
 141         coherent = of_dma_is_coherent(np);
 142         dev_dbg(dev, "device is%sdma coherent\n",
 143                 coherent ? " " : " not ");
 144
 145         iommu = of_iommu_configure(dev, np);
 146         dev_dbg(dev, "device is%sbehind an iommu\n",
 147                 iommu ? " " : " not ");
 148
 149         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 150 }
 151 EXPORT_SYMBOL_GPL(of_dma_configure);
 152
 153 int of_device_register(struct platform_device *pdev)
 154 {
 155         device_initialize(&pdev->dev);
 156         return of_device_add(pdev);
 157 }
 158 EXPORT_SYMBOL(of_device_register);
 159
 160 void of_device_unregister(struct platform_device *ofdev)
 161 {
 162         device_unregister(&ofdev->dev);
 163 }
 164 EXPORT_SYMBOL(of_device_unregister);
 165
 166 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 167 {
 168         const char *compat;
 169         int cplen, i;
 170         ssize_t tsize, csize, repend;
 171
 172         if ((!dev) || (!dev->of_node))
 173                 return -ENODEV;
 174
 175         /* Name & Type */
 176         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 177                          dev->of_node->type);
 178
 179         /* Get compatible property if any */
 180         compat = of_get_property(dev->of_node, "compatible", &cplen);
 181         if (!compat)
 182                 return csize;
 183
 184         /* Find true end (we tolerate multiple \0 at the end */
 185         for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
 186                 cplen--;
 187         if (!cplen)
 188                 return csize;
 189         cplen++;
 190
 191         /* Check space (need cplen+1 chars including final \0) */
 192         tsize = csize + cplen;
 193         repend = tsize;
 194
 195         if (csize >= len)               /* @ the limit, all is already filled */
 196                 return tsize;
 197
 198         if (tsize >= len) {             /* limit compat list */
 199                 cplen = len - csize - 1;
 200                 repend = len;
 201         }
 202
 203         /* Copy and do char replacement */
 204         memcpy(&str[csize + 1], compat, cplen);
 205         for (i = csize; i < repend; i++) {
 206                 char c = str[i];
 207                 if (c == '\0')
 208                         str[i] = 'C';
 209                 else if (c == ' ')
 210                         str[i] = '_';
 211         }
 212
 213         return tsize;
 214 }
 215
 216 /**
 217  * of_device_uevent - Display OF related uevent information
 218  */
 219 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 220 {
 221         const char *compat;
 222         struct alias_prop *app;
 223         int seen = 0, cplen, sl;
 224
 225         if ((!dev) || (!dev->of_node))
 226                 return;
 227
 228         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 229         add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
 230         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 231                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 232
 233         /* Since the compatible field can contain pretty much anything
 234          * it's not really legal to split it out with commas. We split it
 235          * up using a number of environment variables instead. */
 236         compat = of_get_property(dev->of_node, "compatible", &cplen);
 237         while (compat && *compat && cplen > 0) {
 238                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 239                 sl = strlen(compat) + 1;
 240                 compat += sl;
 241                 cplen -= sl;
 242                 seen++;
 243         }
 244         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 245
 246         seen = 0;
 247         mutex_lock(&of_mutex);
 248         list_for_each_entry(app, &aliases_lookup, link) {
 249                 if (dev->of_node == app->np) {
 250                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 251                                        app->alias);
 252                         seen++;
 253                 }
 254         }
 255         mutex_unlock(&of_mutex);
 256 }
 257
 258 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 259 {
 260         int sl;
 261
 262         if ((!dev) || (!dev->of_node))
 263                 return -ENODEV;
 264
 265         /* Devicetree modalias is tricky, we add it in 2 steps */
 266         if (add_uevent_var(env, "MODALIAS="))
 267                 return -ENOMEM;
 268
 269         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 270                                     sizeof(env->buf) - env->buflen);
 271         if (sl >= (sizeof(env->buf) - env->buflen))
 272                 return -ENOMEM;
 273         env->buflen += sl;
 274
 275         return 0;
 276 }