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 static ssize_t devspec_show(struct device *dev,
  51                                 struct device_attribute *attr, char *buf)
  52 {
  53         struct platform_device *ofdev;
  54
  55         ofdev = to_platform_device(dev);
  56         return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
  57 }
  58
  59 static ssize_t name_show(struct device *dev,
  60                                 struct device_attribute *attr, char *buf)
  61 {
  62         struct platform_device *ofdev;
  63
  64         ofdev = to_platform_device(dev);
  65         return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
  66 }
  67
  68 static ssize_t modalias_show(struct device *dev,
  69                                 struct device_attribute *attr, char *buf)
  70 {
  71         ssize_t len = of_device_get_modalias(dev, buf, PAGE_SIZE - 2);
  72         buf[len] = '\n';
  73         buf[len+1] = 0;
  74         return len+1;
  75 }
  76
  77 struct device_attribute of_platform_device_attrs[] = {
  78         __ATTR_RO(devspec),
  79         __ATTR_RO(name),
  80         __ATTR_RO(modalias),
  81         __ATTR_NULL
  82 };
  83
  84 int of_device_add(struct platform_device *ofdev)
  85 {
  86         BUG_ON(ofdev->dev.of_node == NULL);
  87
  88         /* name and id have to be set so that the platform bus doesn't get
  89          * confused on matching */
  90         ofdev->name = dev_name(&ofdev->dev);
  91         ofdev->id = -1;
  92
  93         /* device_add will assume that this device is on the same node as
  94          * the parent. If there is no parent defined, set the node
  95          * explicitly */
  96         if (!ofdev->dev.parent)
  97                 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  98
  99         return device_add(&ofdev->dev);
 100 }
 101
 102 int of_device_register(struct platform_device *pdev)
 103 {
 104         device_initialize(&pdev->dev);
 105         return of_device_add(pdev);
 106 }
 107 EXPORT_SYMBOL(of_device_register);
 108
 109 void of_device_unregister(struct platform_device *ofdev)
 110 {
 111         device_unregister(&ofdev->dev);
 112 }
 113 EXPORT_SYMBOL(of_device_unregister);
 114
 115 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 116 {
 117         const char *compat;
 118         int cplen, i;
 119         ssize_t tsize, csize, repend;
 120
 121         /* Name & Type */
 122         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 123                          dev->of_node->type);
 124
 125         /* Get compatible property if any */
 126         compat = of_get_property(dev->of_node, "compatible", &cplen);
 127         if (!compat)
 128                 return csize;
 129
 130         /* Find true end (we tolerate multiple \0 at the end */
 131         for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
 132                 cplen--;
 133         if (!cplen)
 134                 return csize;
 135         cplen++;
 136
 137         /* Check space (need cplen+1 chars including final \0) */
 138         tsize = csize + cplen;
 139         repend = tsize;
 140
 141         if (csize >= len)               /* @ the limit, all is already filled */
 142                 return tsize;
 143
 144         if (tsize >= len) {             /* limit compat list */
 145                 cplen = len - csize - 1;
 146                 repend = len;
 147         }
 148
 149         /* Copy and do char replacement */
 150         memcpy(&str[csize + 1], compat, cplen);
 151         for (i = csize; i < repend; i++) {
 152                 char c = str[i];
 153                 if (c == '\0')
 154                         str[i] = 'C';
 155                 else if (c == ' ')
 156                         str[i] = '_';
 157         }
 158
 159         return tsize;
 160 }
 161
 162 /**
 163  * of_device_uevent - Display OF related uevent information
 164  */
 165 int of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 166 {
 167         const char *compat;
 168         int seen = 0, cplen, sl;
 169
 170         if ((!dev) || (!dev->of_node))
 171                 return -ENODEV;
 172
 173         if (add_uevent_var(env, "OF_NAME=%s", dev->of_node->name))
 174                 return -ENOMEM;
 175
 176         if (add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type))
 177                 return -ENOMEM;
 178
 179         /* Since the compatible field can contain pretty much anything
 180          * it's not really legal to split it out with commas. We split it
 181          * up using a number of environment variables instead. */
 182
 183         compat = of_get_property(dev->of_node, "compatible", &cplen);
 184         while (compat && *compat && cplen > 0) {
 185                 if (add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat))
 186                         return -ENOMEM;
 187
 188                 sl = strlen(compat) + 1;
 189                 compat += sl;
 190                 cplen -= sl;
 191                 seen++;
 192         }
 193
 194         if (add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen))
 195                 return -ENOMEM;
 196
 197         /* modalias is trickier, we add it in 2 steps */
 198         if (add_uevent_var(env, "MODALIAS="))
 199                 return -ENOMEM;
 200
 201         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 202                                     sizeof(env->buf) - env->buflen);
 203         if (sl >= (sizeof(env->buf) - env->buflen))
 204                 return -ENOMEM;
 205         env->buflen += sl;
 206
 207         return 0;
 208 }