linux/drivers/of/device.c
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   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#include "of_private.h"
  12
  13/**
  14 * of_match_device - Tell if a struct device matches an of_device_id list
  15 * @ids: array of of device match structures to search in
  16 * @dev: the of device structure to match against
  17 *
  18 * Used by a driver to check whether an platform_device present in the
  19 * system is in its list of supported devices.
  20 */
  21const struct of_device_id *of_match_device(const struct of_device_id *matches,
  22                                           const struct device *dev)
  23{
  24        if ((!matches) || (!dev->of_node))
  25                return NULL;
  26        return of_match_node(matches, dev->of_node);
  27}
  28EXPORT_SYMBOL(of_match_device);
  29
  30struct platform_device *of_dev_get(struct platform_device *dev)
  31{
  32        struct device *tmp;
  33
  34        if (!dev)
  35                return NULL;
  36        tmp = get_device(&dev->dev);
  37        if (tmp)
  38                return to_platform_device(tmp);
  39        else
  40                return NULL;
  41}
  42EXPORT_SYMBOL(of_dev_get);
  43
  44void of_dev_put(struct platform_device *dev)
  45{
  46        if (dev)
  47                put_device(&dev->dev);
  48}
  49EXPORT_SYMBOL(of_dev_put);
  50
  51int of_device_add(struct platform_device *ofdev)
  52{
  53        BUG_ON(ofdev->dev.of_node == NULL);
  54
  55        /* name and id have to be set so that the platform bus doesn't get
  56         * confused on matching */
  57        ofdev->name = dev_name(&ofdev->dev);
  58        ofdev->id = -1;
  59
  60        /* device_add will assume that this device is on the same node as
  61         * the parent. If there is no parent defined, set the node
  62         * explicitly */
  63        if (!ofdev->dev.parent)
  64                set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  65
  66        return device_add(&ofdev->dev);
  67}
  68
  69int of_device_register(struct platform_device *pdev)
  70{
  71        device_initialize(&pdev->dev);
  72        return of_device_add(pdev);
  73}
  74EXPORT_SYMBOL(of_device_register);
  75
  76void of_device_unregister(struct platform_device *ofdev)
  77{
  78        device_unregister(&ofdev->dev);
  79}
  80EXPORT_SYMBOL(of_device_unregister);
  81
  82ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
  83{
  84        const char *compat;
  85        int cplen, i;
  86        ssize_t tsize, csize, repend;
  87
  88        /* Name & Type */
  89        csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
  90                         dev->of_node->type);
  91
  92        /* Get compatible property if any */
  93        compat = of_get_property(dev->of_node, "compatible", &cplen);
  94        if (!compat)
  95                return csize;
  96
  97        /* Find true end (we tolerate multiple \0 at the end */
  98        for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
  99                cplen--;
 100        if (!cplen)
 101                return csize;
 102        cplen++;
 103
 104        /* Check space (need cplen+1 chars including final \0) */
 105        tsize = csize + cplen;
 106        repend = tsize;
 107
 108        if (csize >= len)               /* @ the limit, all is already filled */
 109                return tsize;
 110
 111        if (tsize >= len) {             /* limit compat list */
 112                cplen = len - csize - 1;
 113                repend = len;
 114        }
 115
 116        /* Copy and do char replacement */
 117        memcpy(&str[csize + 1], compat, cplen);
 118        for (i = csize; i < repend; i++) {
 119                char c = str[i];
 120                if (c == '\0')
 121                        str[i] = 'C';
 122                else if (c == ' ')
 123                        str[i] = '_';
 124        }
 125
 126        return tsize;
 127}
 128
 129/**
 130 * of_device_uevent - Display OF related uevent information
 131 */
 132void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 133{
 134        const char *compat;
 135        struct alias_prop *app;
 136        int seen = 0, cplen, sl;
 137
 138        if ((!dev) || (!dev->of_node))
 139                return;
 140
 141        add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 142        add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
 143        if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 144                add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 145
 146        /* Since the compatible field can contain pretty much anything
 147         * it's not really legal to split it out with commas. We split it
 148         * up using a number of environment variables instead. */
 149        compat = of_get_property(dev->of_node, "compatible", &cplen);
 150        while (compat && *compat && cplen > 0) {
 151                add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 152                sl = strlen(compat) + 1;
 153                compat += sl;
 154                cplen -= sl;
 155                seen++;
 156        }
 157        add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 158
 159        seen = 0;
 160        mutex_lock(&of_aliases_mutex);
 161        list_for_each_entry(app, &aliases_lookup, link) {
 162                if (dev->of_node == app->np) {
 163                        add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 164                                       app->alias);
 165                        seen++;
 166                }
 167        }
 168        mutex_unlock(&of_aliases_mutex);
 169}
 170
 171int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 172{
 173        int sl;
 174
 175        if ((!dev) || (!dev->of_node))
 176                return -ENODEV;
 177
 178        /* Devicetree modalias is tricky, we add it in 2 steps */
 179        if (add_uevent_var(env, "MODALIAS="))
 180                return -ENOMEM;
 181
 182        sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 183                                    sizeof(env->buf) - env->buflen);
 184        if (sl >= (sizeof(env->buf) - env->buflen))
 185                return -ENOMEM;
 186        env->buflen += sl;
 187
 188        return 0;
 189}
 190
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