kernel/drivers/acpi/glue.c

   1 /*
   2  * Link physical devices with ACPI devices support
   3  *
   4  * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
   5  * Copyright (c) 2005 Intel Corp.
   6  *
   7  * This file is released under the GPLv2.
   8  */
   9 #include <linux/export.h>
  10 #include <linux/init.h>
  11 #include <linux/list.h>
  12 #include <linux/device.h>
  13 #include <linux/slab.h>
  14 #include <linux/rwsem.h>
  15 #include <linux/acpi.h>
  16
  17 #include "internal.h"
  18
  19 #define ACPI_GLUE_DEBUG 0
  20 #if ACPI_GLUE_DEBUG
  21 #define DBG(fmt, ...)                                           \
  22         printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
  23 #else
  24 #define DBG(fmt, ...)                                           \
  25 do {                                                            \
  26         if (0)                                                  \
  27                 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);   \
  28 } while (0)
  29 #endif
  30 static LIST_HEAD(bus_type_list);
  31 static DECLARE_RWSEM(bus_type_sem);
  32
  33 #define PHYSICAL_NODE_STRING "physical_node"
  34 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
  35
  36 int register_acpi_bus_type(struct acpi_bus_type *type)
  37 {
  38         if (acpi_disabled)
  39                 return -ENODEV;
  40         if (type && type->match && type->find_companion) {
  41                 down_write(&bus_type_sem);
  42                 list_add_tail(&type->list, &bus_type_list);
  43                 up_write(&bus_type_sem);
  44                 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
  45                 return 0;
  46         }
  47         return -ENODEV;
  48 }
  49 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  50
  51 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  52 {
  53         if (acpi_disabled)
  54                 return 0;
  55         if (type) {
  56                 down_write(&bus_type_sem);
  57                 list_del_init(&type->list);
  58                 up_write(&bus_type_sem);
  59                 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
  60                        type->name);
  61                 return 0;
  62         }
  63         return -ENODEV;
  64 }
  65 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  66
  67 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
  68 {
  69         struct acpi_bus_type *tmp, *ret = NULL;
  70
  71         down_read(&bus_type_sem);
  72         list_for_each_entry(tmp, &bus_type_list, list) {
  73                 if (tmp->match(dev)) {
  74                         ret = tmp;
  75                         break;
  76                 }
  77         }
  78         up_read(&bus_type_sem);
  79         return ret;
  80 }
  81
  82 #define FIND_CHILD_MIN_SCORE    1
  83 #define FIND_CHILD_MAX_SCORE    2
  84
  85 static int find_child_checks(struct acpi_device *adev, bool check_children)
  86 {
  87         bool sta_present = true;
  88         unsigned long long sta;
  89         acpi_status status;
  90
  91         status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
  92         if (status == AE_NOT_FOUND)
  93                 sta_present = false;
  94         else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
  95                 return -ENODEV;
  96
  97         if (check_children && list_empty(&adev->children))
  98                 return -ENODEV;
  99
 100         return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 101 }
 102
 103 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
 104                                            u64 address, bool check_children)
 105 {
 106         struct acpi_device *adev, *ret = NULL;
 107         int ret_score = 0;
 108
 109         if (!parent)
 110                 return NULL;
 111
 112         list_for_each_entry(adev, &parent->children, node) {
 113                 unsigned long long addr;
 114                 acpi_status status;
 115                 int score;
 116
 117                 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
 118                                                NULL, &addr);
 119                 if (ACPI_FAILURE(status) || addr != address)
 120                         continue;
 121
 122                 if (!ret) {
 123                         /* This is the first matching object.  Save it. */
 124                         ret = adev;
 125                         continue;
 126                 }
 127                 /*
 128                  * There is more than one matching device object with the same
 129                  * _ADR value.  That really is unexpected, so we are kind of
 130                  * beyond the scope of the spec here.  We have to choose which
 131                  * one to return, though.
 132                  *
 133                  * First, check if the previously found object is good enough
 134                  * and return it if so.  Second, do the same for the object that
 135                  * we've just found.
 136                  */
 137                 if (!ret_score) {
 138                         ret_score = find_child_checks(ret, check_children);
 139                         if (ret_score == FIND_CHILD_MAX_SCORE)
 140                                 return ret;
 141                 }
 142                 score = find_child_checks(adev, check_children);
 143                 if (score == FIND_CHILD_MAX_SCORE) {
 144                         return adev;
 145                 } else if (score > ret_score) {
 146                         ret = adev;
 147                         ret_score = score;
 148                 }
 149         }
 150         return ret;
 151 }
 152 EXPORT_SYMBOL_GPL(acpi_find_child_device);
 153
 154 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 155 {
 156         if (node_id > 0)
 157                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 158                          PHYSICAL_NODE_STRING "%u", node_id);
 159         else
 160                 strcpy(buf, PHYSICAL_NODE_STRING);
 161 }
 162
 163 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 164 {
 165         struct acpi_device_physical_node *physical_node, *pn;
 166         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 167         struct list_head *physnode_list;
 168         unsigned int node_id;
 169         int retval = -EINVAL;
 170
 171         if (has_acpi_companion(dev)) {
 172                 if (acpi_dev) {
 173                         dev_warn(dev, "ACPI companion already set\n");
 174                         return -EINVAL;
 175                 } else {
 176                         acpi_dev = ACPI_COMPANION(dev);
 177                 }
 178         }
 179         if (!acpi_dev)
 180                 return -EINVAL;
 181
 182         get_device(&acpi_dev->dev);
 183         get_device(dev);
 184         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 185         if (!physical_node) {
 186                 retval = -ENOMEM;
 187                 goto err;
 188         }
 189
 190         mutex_lock(&acpi_dev->physical_node_lock);
 191
 192         /*
 193          * Keep the list sorted by node_id so that the IDs of removed nodes can
 194          * be recycled easily.
 195          */
 196         physnode_list = &acpi_dev->physical_node_list;
 197         node_id = 0;
 198         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 199                 /* Sanity check. */
 200                 if (pn->dev == dev) {
 201                         mutex_unlock(&acpi_dev->physical_node_lock);
 202
 203                         dev_warn(dev, "Already associated with ACPI node\n");
 204                         kfree(physical_node);
 205                         if (ACPI_COMPANION(dev) != acpi_dev)
 206                                 goto err;
 207
 208                         put_device(dev);
 209                         put_device(&acpi_dev->dev);
 210                         return 0;
 211                 }
 212                 if (pn->node_id == node_id) {
 213                         physnode_list = &pn->node;
 214                         node_id++;
 215                 }
 216         }
 217
 218         physical_node->node_id = node_id;
 219         physical_node->dev = dev;
 220         list_add(&physical_node->node, physnode_list);
 221         acpi_dev->physical_node_count++;
 222
 223         if (!has_acpi_companion(dev))
 224                 ACPI_COMPANION_SET(dev, acpi_dev);
 225
 226         acpi_physnode_link_name(physical_node_name, node_id);
 227         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 228                                    physical_node_name);
 229         if (retval)
 230                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 231                         physical_node_name, retval);
 232
 233         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 234                                    "firmware_node");
 235         if (retval)
 236                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 237                         retval);
 238
 239         mutex_unlock(&acpi_dev->physical_node_lock);
 240
 241         if (acpi_dev->wakeup.flags.valid)
 242                 device_set_wakeup_capable(dev, true);
 243
 244         return 0;
 245
 246  err:
 247         ACPI_COMPANION_SET(dev, NULL);
 248         put_device(dev);
 249         put_device(&acpi_dev->dev);
 250         return retval;
 251 }
 252 EXPORT_SYMBOL_GPL(acpi_bind_one);
 253
 254 int acpi_unbind_one(struct device *dev)
 255 {
 256         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 257         struct acpi_device_physical_node *entry;
 258
 259         if (!acpi_dev)
 260                 return 0;
 261
 262         mutex_lock(&acpi_dev->physical_node_lock);
 263
 264         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 265                 if (entry->dev == dev) {
 266                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 267
 268                         list_del(&entry->node);
 269                         acpi_dev->physical_node_count--;
 270
 271                         acpi_physnode_link_name(physnode_name, entry->node_id);
 272                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 273                         sysfs_remove_link(&dev->kobj, "firmware_node");
 274                         ACPI_COMPANION_SET(dev, NULL);
 275                         /* Drop references taken by acpi_bind_one(). */
 276                         put_device(dev);
 277                         put_device(&acpi_dev->dev);
 278                         kfree(entry);
 279                         break;
 280                 }
 281
 282         mutex_unlock(&acpi_dev->physical_node_lock);
 283         return 0;
 284 }
 285 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 286
 287 static int acpi_platform_notify(struct device *dev)
 288 {
 289         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 290         struct acpi_device *adev;
 291         int ret;
 292
 293         ret = acpi_bind_one(dev, NULL);
 294         if (ret && type) {
 295                 struct acpi_device *adev;
 296
 297                 adev = type->find_companion(dev);
 298                 if (!adev) {
 299                         DBG("Unable to get handle for %s\n", dev_name(dev));
 300                         ret = -ENODEV;
 301                         goto out;
 302                 }
 303                 ret = acpi_bind_one(dev, adev);
 304                 if (ret)
 305                         goto out;
 306         }
 307         adev = ACPI_COMPANION(dev);
 308         if (!adev)
 309                 goto out;
 310
 311         if (type && type->setup)
 312                 type->setup(dev);
 313         else if (adev->handler && adev->handler->bind)
 314                 adev->handler->bind(dev);
 315
 316  out:
 317 #if ACPI_GLUE_DEBUG
 318         if (!ret) {
 319                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 320
 321                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 322                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 323                 kfree(buffer.pointer);
 324         } else
 325                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 326 #endif
 327
 328         return ret;
 329 }
 330
 331 static int acpi_platform_notify_remove(struct device *dev)
 332 {
 333         struct acpi_device *adev = ACPI_COMPANION(dev);
 334         struct acpi_bus_type *type;
 335
 336         if (!adev)
 337                 return 0;
 338
 339         type = acpi_get_bus_type(dev);
 340         if (type && type->cleanup)
 341                 type->cleanup(dev);
 342         else if (adev->handler && adev->handler->unbind)
 343                 adev->handler->unbind(dev);
 344
 345         acpi_unbind_one(dev);
 346         return 0;
 347 }
 348
 349 int __init init_acpi_device_notify(void)
 350 {
 351         if (platform_notify || platform_notify_remove) {
 352                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 353                 return 0;
 354         }
 355         platform_notify = acpi_platform_notify;
 356         platform_notify_remove = acpi_platform_notify_remove;
 357         return 0;
 358 }