LXR linux/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 */
  20const 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}
  27EXPORT_SYMBOL(of_match_device);
  28
  29struct 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}
  41EXPORT_SYMBOL(of_dev_get);
  42
  43void of_dev_put(struct platform_device *dev)
  44{
  45        if (dev)
  46                put_device(&dev->dev);
  47}
  48EXPORT_SYMBOL(of_dev_put);
  49
  50int 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
  68int of_device_register(struct platform_device *pdev)
  69{
  70        device_initialize(&pdev->dev);
  71        return of_device_add(pdev);
  72}
  73EXPORT_SYMBOL(of_device_register);
  74
  75void of_device_unregister(struct platform_device *ofdev)
  76{
  77        device_unregister(&ofdev->dev);
  78}
  79EXPORT_SYMBOL(of_device_unregister);
  80
  81ssize_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 */
 131void 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;
 138
 139        add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 140        add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
 141        if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 142                add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 143
 144        /* Since the compatible field can contain pretty much anything
 145         * it's not really legal to split it out with commas. We split it
 146         * up using a number of environment variables instead. */
 147        compat = of_get_property(dev->of_node, "compatible", &cplen);
 148        while (compat && *compat && cplen > 0) {
 149                add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 150                sl = strlen(compat) + 1;
 151                compat += sl;
 152                cplen -= sl;
 153                seen++;
 154        }
 155        add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 156}
 157
 158int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 159{
 160        int sl;
 161
 162        if ((!dev) || (!dev->of_node))
 163                return -ENODEV;
 164
 165        /* Devicetree modalias is tricky, we add it in 2 steps */
 166        if (add_uevent_var(env, "MODALIAS="))
 167                return -ENOMEM;
 168
 169        sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 170                                    sizeof(env->buf) - env->buflen);
 171        if (sl >= (sizeof(env->buf) - env->buflen))
 172                return -ENOMEM;
 173        env->buflen += sl;
 174
 175        return 0;
 176}
 177