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 = {
  86        .id = GENL_ID_GENERATE,
  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        int result;
 104
 105        /* allocate memory */
 106        size = nla_total_size(sizeof(struct acpi_genl_event)) +
 107            nla_total_size(0);
 108
 109        skb = genlmsg_new(size, GFP_ATOMIC);
 110        if (!skb)
 111                return -ENOMEM;
 112
 113        /* add the genetlink message header */
 114        msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
 115                                 &acpi_event_genl_family, 0,
 116                                 ACPI_GENL_CMD_EVENT);
 117        if (!msg_header) {
 118                nlmsg_free(skb);
 119                return -ENOMEM;
 120        }
 121
 122        /* fill the data */
 123        attr =
 124            nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
 125                        sizeof(struct acpi_genl_event));
 126        if (!attr) {
 127                nlmsg_free(skb);
 128                return -EINVAL;
 129        }
 130
 131        event = nla_data(attr);
 132        memset(event, 0, sizeof(struct acpi_genl_event));
 133
 134        strcpy(event->device_class, device_class);
 135        strcpy(event->bus_id, bus_id);
 136        event->type = type;
 137        event->data = data;
 138
 139        /* send multicast genetlink message */
 140        result = genlmsg_end(skb, msg_header);
 141        if (result < 0) {
 142                nlmsg_free(skb);
 143                return result;
 144        }
 145
 146        genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
 147        return 0;
 148}
 149
 150EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 151
 152static int acpi_event_genetlink_init(void)
 153{
 154        return genl_register_family(&acpi_event_genl_family);
 155}
 156
 157#else
 158int acpi_bus_generate_netlink_event(const char *device_class,
 159                                      const char *bus_id,
 160                                      u8 type, int data)
 161{
 162        return 0;
 163}
 164
 165EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 166
 167static int acpi_event_genetlink_init(void)
 168{
 169        return -ENODEV;
 170}
 171#endif
 172
 173static int __init acpi_event_init(void)
 174{
 175        int error = 0;
 176
 177        if (acpi_disabled)
 178                return 0;
 179
 180        /* create genetlink for acpi event */
 181        error = acpi_event_genetlink_init();
 182        if (error)
 183                printk(KERN_WARNING PREFIX
 184                       "Failed to create genetlink family for ACPI event\n");
 185        return 0;
 186}
 187
 188fs_initcall(acpi_event_init);
 189