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 <acpi/acpi_drivers.h>
  16 #include <net/netlink.h>
  17 #include <net/genetlink.h>
  18
  19 #include "internal.h"
  20
  21 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
  22 ACPI_MODULE_NAME("event");
  23
  24 /* ACPI notifier chain */
  25 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
  26
  27 int 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 }
  38 EXPORT_SYMBOL(acpi_notifier_call_chain);
  39
  40 int register_acpi_notifier(struct notifier_block *nb)
  41 {
  42         return blocking_notifier_chain_register(&acpi_chain_head, nb);
  43 }
  44 EXPORT_SYMBOL(register_acpi_notifier);
  45
  46 int unregister_acpi_notifier(struct notifier_block *nb)
  47 {
  48         return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
  49 }
  50 EXPORT_SYMBOL(unregister_acpi_notifier);
  51
  52 #ifdef CONFIG_NET
  53 static unsigned int acpi_event_seqnum;
  54 struct 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 */
  62 enum {
  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 */
  70 enum {
  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
  81 static struct genl_family acpi_event_genl_family = {
  82         .id = GENL_ID_GENERATE,
  83         .name = ACPI_GENL_FAMILY_NAME,
  84         .version = ACPI_GENL_VERSION,
  85         .maxattr = ACPI_GENL_ATTR_MAX,
  86 };
  87
  88 static struct genl_multicast_group acpi_event_mcgrp = {
  89         .name = ACPI_GENL_MCAST_GROUP_NAME,
  90 };
  91
  92 int acpi_bus_generate_netlink_event(const char *device_class,
  93                                       const char *bus_id,
  94                                       u8 type, int data)
  95 {
  96         struct sk_buff *skb;
  97         struct nlattr *attr;
  98         struct acpi_genl_event *event;
  99         void *msg_header;
 100         int size;
 101         int result;
 102
 103         /* allocate memory */
 104         size = nla_total_size(sizeof(struct acpi_genl_event)) +
 105             nla_total_size(0);
 106
 107         skb = genlmsg_new(size, GFP_ATOMIC);
 108         if (!skb)
 109                 return -ENOMEM;
 110
 111         /* add the genetlink message header */
 112         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
 113                                  &acpi_event_genl_family, 0,
 114                                  ACPI_GENL_CMD_EVENT);
 115         if (!msg_header) {
 116                 nlmsg_free(skb);
 117                 return -ENOMEM;
 118         }
 119
 120         /* fill the data */
 121         attr =
 122             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
 123                         sizeof(struct acpi_genl_event));
 124         if (!attr) {
 125                 nlmsg_free(skb);
 126                 return -EINVAL;
 127         }
 128
 129         event = nla_data(attr);
 130         if (!event) {
 131                 nlmsg_free(skb);
 132                 return -EINVAL;
 133         }
 134
 135         memset(event, 0, sizeof(struct acpi_genl_event));
 136
 137         strcpy(event->device_class, device_class);
 138         strcpy(event->bus_id, bus_id);
 139         event->type = type;
 140         event->data = data;
 141
 142         /* send multicast genetlink message */
 143         result = genlmsg_end(skb, msg_header);
 144         if (result < 0) {
 145                 nlmsg_free(skb);
 146                 return result;
 147         }
 148
 149         genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
 150         return 0;
 151 }
 152
 153 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 154
 155 static int acpi_event_genetlink_init(void)
 156 {
 157         int result;
 158
 159         result = genl_register_family(&acpi_event_genl_family);
 160         if (result)
 161                 return result;
 162
 163         result = genl_register_mc_group(&acpi_event_genl_family,
 164                                         &acpi_event_mcgrp);
 165         if (result)
 166                 genl_unregister_family(&acpi_event_genl_family);
 167
 168         return result;
 169 }
 170
 171 #else
 172 int acpi_bus_generate_netlink_event(const char *device_class,
 173                                       const char *bus_id,
 174                                       u8 type, int data)
 175 {
 176         return 0;
 177 }
 178
 179 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 180
 181 static int acpi_event_genetlink_init(void)
 182 {
 183         return -ENODEV;
 184 }
 185 #endif
 186
 187 static int __init acpi_event_init(void)
 188 {
 189         int error = 0;
 190
 191         if (acpi_disabled)
 192                 return 0;
 193
 194         /* create genetlink for acpi event */
 195         error = acpi_event_genetlink_init();
 196         if (error)
 197                 printk(KERN_WARNING PREFIX
 198                        "Failed to create genetlink family for ACPI event\n");
 199         return 0;
 200 }
 201
 202 fs_initcall(acpi_event_init);