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/proc_fs.h> 11 #include <linux/init.h> 12 #include <linux/poll.h> 13 #include <acpi/acpi_drivers.h> 14 #include <net/netlink.h> 15 #include <net/genetlink.h> 16 17 #define _COMPONENT ACPI_SYSTEM_COMPONENT 18 ACPI_MODULE_NAME("event"); 19 20 /* Global vars for handling event proc entry */ 21 static DEFINE_SPINLOCK(acpi_system_event_lock); 22 int event_is_open = 0; 23 extern struct list_head acpi_bus_event_list; 24 extern wait_queue_head_t acpi_bus_event_queue; 25 26 static int acpi_system_open_event(struct inode *inode, struct file *file) 27 { 28 spin_lock_irq(&acpi_system_event_lock); 29 30 if (event_is_open) 31 goto out_busy; 32 33 event_is_open = 1; 34 35 spin_unlock_irq(&acpi_system_event_lock); 36 return 0; 37 38 out_busy: 39 spin_unlock_irq(&acpi_system_event_lock); 40 return -EBUSY; 41 } 42 43 static ssize_t 44 acpi_system_read_event(struct file *file, char __user * buffer, size_t count, 45 loff_t * ppos) 46 { 47 int result = 0; 48 struct acpi_bus_event event; 49 static char str[ACPI_MAX_STRING]; 50 static int chars_remaining = 0; 51 static char *ptr; 52 53 if (!chars_remaining) { 54 memset(&event, 0, sizeof(struct acpi_bus_event)); 55 56 if ((file->f_flags & O_NONBLOCK) 57 && (list_empty(&acpi_bus_event_list))) 58 return -EAGAIN; 59 60 result = acpi_bus_receive_event(&event); 61 if (result) 62 return result; 63 64 chars_remaining = sprintf(str, "%s %s %08x %08x\n", 65 event.device_class ? event. 66 device_class : "<unknown>", 67 event.bus_id ? event. 68 bus_id : "<unknown>", event.type, 69 event.data); 70 ptr = str; 71 } 72 73 if (chars_remaining < count) { 74 count = chars_remaining; 75 } 76 77 if (copy_to_user(buffer, ptr, count)) 78 return -EFAULT; 79 80 *ppos += count; 81 chars_remaining -= count; 82 ptr += count; 83 84 return count; 85 } 86 87 static int acpi_system_close_event(struct inode *inode, struct file *file) 88 { 89 spin_lock_irq(&acpi_system_event_lock); 90 event_is_open = 0; 91 spin_unlock_irq(&acpi_system_event_lock); 92 return 0; 93 } 94 95 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait) 96 { 97 poll_wait(file, &acpi_bus_event_queue, wait); 98 if (!list_empty(&acpi_bus_event_list)) 99 return POLLIN | POLLRDNORM; 100 return 0; 101 } 102 103 static const struct file_operations acpi_system_event_ops = { 104 .open = acpi_system_open_event, 105 .read = acpi_system_read_event, 106 .release = acpi_system_close_event, 107 .poll = acpi_system_poll_event, 108 }; 109 110 #ifdef CONFIG_NET 111 unsigned int acpi_event_seqnum; 112 struct acpi_genl_event { 113 acpi_device_class device_class; 114 char bus_id[15]; 115 u32 type; 116 u32 data; 117 }; 118 119 /* attributes of acpi_genl_family */ 120 enum { 121 ACPI_GENL_ATTR_UNSPEC, 122 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */ 123 __ACPI_GENL_ATTR_MAX, 124 }; 125 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1) 126 127 /* commands supported by the acpi_genl_family */ 128 enum { 129 ACPI_GENL_CMD_UNSPEC, 130 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */ 131 __ACPI_GENL_CMD_MAX, 132 }; 133 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1) 134 135 #define ACPI_GENL_FAMILY_NAME "acpi_event" 136 #define ACPI_GENL_VERSION 0x01 137 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group" 138 139 static struct genl_family acpi_event_genl_family = { 140 .id = GENL_ID_GENERATE, 141 .name = ACPI_GENL_FAMILY_NAME, 142 .version = ACPI_GENL_VERSION, 143 .maxattr = ACPI_GENL_ATTR_MAX, 144 }; 145 146 static struct genl_multicast_group acpi_event_mcgrp = { 147 .name = ACPI_GENL_MCAST_GROUP_NAME, 148 }; 149 150 int acpi_bus_generate_genetlink_event(struct acpi_device *device, 151 u8 type, int data) 152 { 153 struct sk_buff *skb; 154 struct nlattr *attr; 155 struct acpi_genl_event *event; 156 void *msg_header; 157 int size; 158 int result; 159 160 /* allocate memory */ 161 size = nla_total_size(sizeof(struct acpi_genl_event)) + 162 nla_total_size(0); 163 164 skb = genlmsg_new(size, GFP_ATOMIC); 165 if (!skb) 166 return -ENOMEM; 167 168 /* add the genetlink message header */ 169 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++, 170 &acpi_event_genl_family, 0, 171 ACPI_GENL_CMD_EVENT); 172 if (!msg_header) { 173 nlmsg_free(skb); 174 return -ENOMEM; 175 } 176 177 /* fill the data */ 178 attr = 179 nla_reserve(skb, ACPI_GENL_ATTR_EVENT, 180 sizeof(struct acpi_genl_event)); 181 if (!attr) { 182 nlmsg_free(skb); 183 return -EINVAL; 184 } 185 186 event = nla_data(attr); 187 if (!event) { 188 nlmsg_free(skb); 189 return -EINVAL; 190 } 191 192 memset(event, 0, sizeof(struct acpi_genl_event)); 193 194 strcpy(event->device_class, device->pnp.device_class); 195 strcpy(event->bus_id, device->dev.bus_id); 196 event->type = type; 197 event->data = data; 198 199 /* send multicast genetlink message */ 200 result = genlmsg_end(skb, msg_header); 201 if (result < 0) { 202 nlmsg_free(skb); 203 return result; 204 } 205 206 result = 207 genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC); 208 if (result) 209 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 210 "Failed to send a Genetlink message!\n")); 211 return 0; 212 } 213 214 static int acpi_event_genetlink_init(void) 215 { 216 int result; 217 218 result = genl_register_family(&acpi_event_genl_family); 219 if (result) 220 return result; 221 222 result = genl_register_mc_group(&acpi_event_genl_family, 223 &acpi_event_mcgrp); 224 if (result) 225 genl_unregister_family(&acpi_event_genl_family); 226 227 return result; 228 } 229 230 #else 231 int acpi_bus_generate_genetlink_event(struct acpi_device *device, u8 type, 232 int data) 233 { 234 return 0; 235 } 236 237 static int acpi_event_genetlink_init(void) 238 { 239 return -ENODEV; 240 } 241 #endif 242 243 static int __init acpi_event_init(void) 244 { 245 struct proc_dir_entry *entry; 246 int error = 0; 247 248 if (acpi_disabled) 249 return 0; 250 251 /* create genetlink for acpi event */ 252 error = acpi_event_genetlink_init(); 253 if (error) 254 printk(KERN_WARNING PREFIX 255 "Failed to create genetlink family for ACPI event\n"); 256 257 /* 'event' [R] */ 258 entry = create_proc_entry("event", S_IRUSR, acpi_root_dir); 259 if (entry) 260 entry->proc_fops = &acpi_system_event_ops; 261 else 262 return -ENODEV; 263 264 return 0; 265 } 266 267 fs_initcall(acpi_event_init); 268