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/init.h>
   6 #include <linux/module.h>
   7 #include <linux/mod_devicetable.h>
   8 #include <linux/slab.h>
   9
  10 #include <asm/errno.h>
  11
  12 /**
  13  * of_match_device - Tell if a struct device matches an of_device_id list
  14  * @ids: array of of device match structures to search in
  15  * @dev: the of device structure to match against
  16  *
  17  * Used by a driver to check whether an platform_device present in the
  18  * system is in its list of supported devices.
  19  */
  20 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  21                                            const struct device *dev)
  22 {
  23         if ((!matches) || (!dev->of_node))
  24                 return NULL;
  25         return of_match_node(matches, dev->of_node);
  26 }
  27 EXPORT_SYMBOL(of_match_device);
  28
  29 struct platform_device *of_dev_get(struct platform_device *dev)
  30 {
  31         struct device *tmp;
  32
  33         if (!dev)
  34                 return NULL;
  35         tmp = get_device(&dev->dev);
  36         if (tmp)
  37                 return to_platform_device(tmp);
  38         else
  39                 return NULL;
  40 }
  41 EXPORT_SYMBOL(of_dev_get);
  42
  43 void of_dev_put(struct platform_device *dev)
  44 {
  45         if (dev)
  46                 put_device(&dev->dev);
  47 }
  48 EXPORT_SYMBOL(of_dev_put);
  49
  50 int of_device_add(struct platform_device *ofdev)
  51 {
  52         BUG_ON(ofdev->dev.of_node == NULL);
  53
  54         /* name and id have to be set so that the platform bus doesn't get
  55          * confused on matching */
  56         ofdev->name = dev_name(&ofdev->dev);
  57         ofdev->id = -1;
  58
  59         /* device_add will assume that this device is on the same node as
  60          * the parent. If there is no parent defined, set the node
  61          * explicitly */
  62         if (!ofdev->dev.parent)
  63                 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  64
  65         return device_add(&ofdev->dev);
  66 }
  67
  68 int of_device_register(struct platform_device *pdev)
  69 {
  70         device_initialize(&pdev->dev);
  71         return of_device_add(pdev);
  72 }
  73 EXPORT_SYMBOL(of_device_register);
  74
  75 void of_device_unregister(struct platform_device *ofdev)
  76 {
  77         device_unregister(&ofdev->dev);
  78 }
  79 EXPORT_SYMBOL(of_device_unregister);
  80
  81 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
  82 {
  83         const char *compat;
  84         int cplen, i;
  85         ssize_t tsize, csize, repend;
  86
  87         /* Name & Type */
  88         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
  89                          dev->of_node->type);
  90
  91         /* Get compatible property if any */
  92         compat = of_get_property(dev->of_node, "compatible", &cplen);
  93         if (!compat)
  94                 return csize;
  95
  96         /* Find true end (we tolerate multiple \0 at the end */
  97         for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
  98                 cplen--;
  99         if (!cplen)
 100                 return csize;
 101         cplen++;
 102
 103         /* Check space (need cplen+1 chars including final \0) */
 104         tsize = csize + cplen;
 105         repend = tsize;
 106
 107         if (csize >= len)               /* @ the limit, all is already filled */
 108                 return tsize;
 109
 110         if (tsize >= len) {             /* limit compat list */
 111                 cplen = len - csize - 1;
 112                 repend = len;
 113         }
 114
 115         /* Copy and do char replacement */
 116         memcpy(&str[csize + 1], compat, cplen);
 117         for (i = csize; i < repend; i++) {
 118                 char c = str[i];
 119                 if (c == '\0')
 120                         str[i] = 'C';
 121                 else if (c == ' ')
 122                         str[i] = '_';
 123         }
 124
 125         return tsize;
 126 }
 127
 128 /**
 129  * of_device_uevent - Display OF related uevent information
 130  */
 131 int of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 132 {
 133         const char *compat;
 134         int seen = 0, cplen, sl;
 135
 136         if ((!dev) || (!dev->of_node))
 137                 return -ENODEV;
 138
 139         if (add_uevent_var(env, "OF_NAME=%s", dev->of_node->name))
 140                 return -ENOMEM;
 141
 142         if (add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type))
 143                 return -ENOMEM;
 144
 145         /* Since the compatible field can contain pretty much anything
 146          * it's not really legal to split it out with commas. We split it
 147          * up using a number of environment variables instead. */
 148
 149         compat = of_get_property(dev->of_node, "compatible", &cplen);
 150         while (compat && *compat && cplen > 0) {
 151                 if (add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat))
 152                         return -ENOMEM;
 153
 154                 sl = strlen(compat) + 1;
 155                 compat += sl;
 156                 cplen -= sl;
 157                 seen++;
 158         }
 159
 160         if (add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen))
 161                 return -ENOMEM;
 162
 163         /* modalias is trickier, we add it in 2 steps */
 164         if (add_uevent_var(env, "MODALIAS="))
 165                 return -ENOMEM;
 166
 167         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 168                                     sizeof(env->buf) - env->buflen);
 169         if (sl >= (sizeof(env->buf) - env->buflen))
 170                 return -ENOMEM;
 171         env->buflen += sl;
 172
 173         return 0;
 174 }