LXR linux/drivers/acpi/event.c

   1/*
   2 * event.c - exporting ACPI events via procfs
   3 *
   4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6 *
   7 */
   8
   9#include <linux/spinlock.h>
  10#include <linux/export.h>
  11#include <linux/proc_fs.h>
  12#include <linux/init.h>
  13#include <linux/poll.h>
  14#include <linux/gfp.h>
  15#include <linux/acpi.h>
  16#include <net/netlink.h>
  17#include <net/genetlink.h>
  18
  19#include "internal.h"
  20
  21#define _COMPONENT              ACPI_SYSTEM_COMPONENT
  22ACPI_MODULE_NAME("event");
  23
  24/* ACPI notifier chain */
  25static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
  26
  27int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
  28{
  29        struct acpi_bus_event event;
  30
  31        strcpy(event.device_class, dev->pnp.device_class);
  32        strcpy(event.bus_id, dev->pnp.bus_id);
  33        event.type = type;
  34        event.data = data;
  35        return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
  36                        == NOTIFY_BAD) ? -EINVAL : 0;
  37}
  38EXPORT_SYMBOL(acpi_notifier_call_chain);
  39
  40int register_acpi_notifier(struct notifier_block *nb)
  41{
  42        return blocking_notifier_chain_register(&acpi_chain_head, nb);
  43}
  44EXPORT_SYMBOL(register_acpi_notifier);
  45
  46int unregister_acpi_notifier(struct notifier_block *nb)
  47{
  48        return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
  49}
  50EXPORT_SYMBOL(unregister_acpi_notifier);
  51
  52#ifdef CONFIG_NET
  53static unsigned int acpi_event_seqnum;
  54struct acpi_genl_event {
  55        acpi_device_class device_class;
  56        char bus_id[15];
  57        u32 type;
  58        u32 data;
  59};
  60
  61/* attributes of acpi_genl_family */
  62enum {
  63        ACPI_GENL_ATTR_UNSPEC,
  64        ACPI_GENL_ATTR_EVENT,   /* ACPI event info needed by user space */
  65        __ACPI_GENL_ATTR_MAX,
  66};
  67#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
  68
  69/* commands supported by the acpi_genl_family */
  70enum {
  71        ACPI_GENL_CMD_UNSPEC,
  72        ACPI_GENL_CMD_EVENT,    /* kernel->user notifications for ACPI events */
  73        __ACPI_GENL_CMD_MAX,
  74};
  75#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
  76
  77#define ACPI_GENL_FAMILY_NAME           "acpi_event"
  78#define ACPI_GENL_VERSION               0x01
  79#define ACPI_GENL_MCAST_GROUP_NAME      "acpi_mc_group"
  80
  81static const struct genl_multicast_group acpi_event_mcgrps[] = {
  82        { .name = ACPI_GENL_MCAST_GROUP_NAME, },
  83};
  84
  85static struct genl_family acpi_event_genl_family __ro_after_init = {
  86        .module = THIS_MODULE,
  87        .name = ACPI_GENL_FAMILY_NAME,
  88        .version = ACPI_GENL_VERSION,
  89        .maxattr = ACPI_GENL_ATTR_MAX,
  90        .mcgrps = acpi_event_mcgrps,
  91        .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
  92};
  93
  94int acpi_bus_generate_netlink_event(const char *device_class,
  95                                      const char *bus_id,
  96                                      u8 type, int data)
  97{
  98        struct sk_buff *skb;
  99        struct nlattr *attr;
 100        struct acpi_genl_event *event;
 101        void *msg_header;
 102        int size;
 103
 104        /* allocate memory */
 105        size = nla_total_size(sizeof(struct acpi_genl_event)) +
 106            nla_total_size(0);
 107
 108        skb = genlmsg_new(size, GFP_ATOMIC);
 109        if (!skb)
 110                return -ENOMEM;
 111
 112        /* add the genetlink message header */
 113        msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
 114                                 &acpi_event_genl_family, 0,
 115                                 ACPI_GENL_CMD_EVENT);
 116        if (!msg_header) {
 117                nlmsg_free(skb);
 118                return -ENOMEM;
 119        }
 120
 121        /* fill the data */
 122        attr =
 123            nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
 124                        sizeof(struct acpi_genl_event));
 125        if (!attr) {
 126                nlmsg_free(skb);
 127                return -EINVAL;
 128        }
 129
 130        event = nla_data(attr);
 131        memset(event, 0, sizeof(struct acpi_genl_event));
 132
 133        strcpy(event->device_class, device_class);
 134        strcpy(event->bus_id, bus_id);
 135        event->type = type;
 136        event->data = data;
 137
 138        /* send multicast genetlink message */
 139        genlmsg_end(skb, msg_header);
 140
 141        genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
 142        return 0;
 143}
 144
 145EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 146
 147static int __init acpi_event_genetlink_init(void)
 148{
 149        return genl_register_family(&acpi_event_genl_family);
 150}
 151
 152#else
 153int acpi_bus_generate_netlink_event(const char *device_class,
 154                                      const char *bus_id,
 155                                      u8 type, int data)
 156{
 157        return 0;
 158}
 159
 160EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 161
 162static int acpi_event_genetlink_init(void)
 163{
 164        return -ENODEV;
 165}
 166#endif
 167
 168static int __init acpi_event_init(void)
 169{
 170        int error = 0;
 171
 172        if (acpi_disabled)
 173                return 0;
 174
 175        /* create genetlink for acpi event */
 176        error = acpi_event_genetlink_init();
 177        if (error)
 178                printk(KERN_WARNING PREFIX
 179                       "Failed to create genetlink family for ACPI event\n");
 180        return 0;
 181}
 182
 183fs_initcall(acpi_event_init);
 184