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 acpi_handle acpi_get_child(acpi_handle handle, u64 addr)
 155 {
 156         struct acpi_device *adev;
 157
 158         if (!handle || acpi_bus_get_device(handle, &adev))
 159                 return NULL;
 160
 161         adev = acpi_find_child_device(adev, addr, false);
 162         return adev ? adev->handle : NULL;
 163 }
 164 EXPORT_SYMBOL_GPL(acpi_get_child);
 165
 166 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 167 {
 168         if (node_id > 0)
 169                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 170                          PHYSICAL_NODE_STRING "%u", node_id);
 171         else
 172                 strcpy(buf, PHYSICAL_NODE_STRING);
 173 }
 174
 175 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 176 {
 177         struct acpi_device_physical_node *physical_node, *pn;
 178         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 179         struct list_head *physnode_list;
 180         unsigned int node_id;
 181         int retval = -EINVAL;
 182
 183         if (ACPI_COMPANION(dev)) {
 184                 if (acpi_dev) {
 185                         dev_warn(dev, "ACPI companion already set\n");
 186                         return -EINVAL;
 187                 } else {
 188                         acpi_dev = ACPI_COMPANION(dev);
 189                 }
 190         }
 191         if (!acpi_dev)
 192                 return -EINVAL;
 193
 194         get_device(&acpi_dev->dev);
 195         get_device(dev);
 196         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 197         if (!physical_node) {
 198                 retval = -ENOMEM;
 199                 goto err;
 200         }
 201
 202         mutex_lock(&acpi_dev->physical_node_lock);
 203
 204         /*
 205          * Keep the list sorted by node_id so that the IDs of removed nodes can
 206          * be recycled easily.
 207          */
 208         physnode_list = &acpi_dev->physical_node_list;
 209         node_id = 0;
 210         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 211                 /* Sanity check. */
 212                 if (pn->dev == dev) {
 213                         mutex_unlock(&acpi_dev->physical_node_lock);
 214
 215                         dev_warn(dev, "Already associated with ACPI node\n");
 216                         kfree(physical_node);
 217                         if (ACPI_COMPANION(dev) != acpi_dev)
 218                                 goto err;
 219
 220                         put_device(dev);
 221                         put_device(&acpi_dev->dev);
 222                         return 0;
 223                 }
 224                 if (pn->node_id == node_id) {
 225                         physnode_list = &pn->node;
 226                         node_id++;
 227                 }
 228         }
 229
 230         physical_node->node_id = node_id;
 231         physical_node->dev = dev;
 232         list_add(&physical_node->node, physnode_list);
 233         acpi_dev->physical_node_count++;
 234
 235         if (!ACPI_COMPANION(dev))
 236                 ACPI_COMPANION_SET(dev, acpi_dev);
 237
 238         acpi_physnode_link_name(physical_node_name, node_id);
 239         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 240                                    physical_node_name);
 241         if (retval)
 242                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 243                         physical_node_name, retval);
 244
 245         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 246                                    "firmware_node");
 247         if (retval)
 248                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 249                         retval);
 250
 251         mutex_unlock(&acpi_dev->physical_node_lock);
 252
 253         if (acpi_dev->wakeup.flags.valid)
 254                 device_set_wakeup_capable(dev, true);
 255
 256         return 0;
 257
 258  err:
 259         ACPI_COMPANION_SET(dev, NULL);
 260         put_device(dev);
 261         put_device(&acpi_dev->dev);
 262         return retval;
 263 }
 264 EXPORT_SYMBOL_GPL(acpi_bind_one);
 265
 266 int acpi_unbind_one(struct device *dev)
 267 {
 268         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 269         struct acpi_device_physical_node *entry;
 270
 271         if (!acpi_dev)
 272                 return 0;
 273
 274         mutex_lock(&acpi_dev->physical_node_lock);
 275
 276         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 277                 if (entry->dev == dev) {
 278                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 279
 280                         list_del(&entry->node);
 281                         acpi_dev->physical_node_count--;
 282
 283                         acpi_physnode_link_name(physnode_name, entry->node_id);
 284                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 285                         sysfs_remove_link(&dev->kobj, "firmware_node");
 286                         ACPI_COMPANION_SET(dev, NULL);
 287                         /* Drop references taken by acpi_bind_one(). */
 288                         put_device(dev);
 289                         put_device(&acpi_dev->dev);
 290                         kfree(entry);
 291                         break;
 292                 }
 293
 294         mutex_unlock(&acpi_dev->physical_node_lock);
 295         return 0;
 296 }
 297 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 298
 299 static int acpi_platform_notify(struct device *dev)
 300 {
 301         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 302         int ret;
 303
 304         ret = acpi_bind_one(dev, NULL);
 305         if (ret && type) {
 306                 struct acpi_device *adev;
 307
 308                 adev = type->find_companion(dev);
 309                 if (!adev) {
 310                         DBG("Unable to get handle for %s\n", dev_name(dev));
 311                         ret = -ENODEV;
 312                         goto out;
 313                 }
 314                 ret = acpi_bind_one(dev, adev);
 315                 if (ret)
 316                         goto out;
 317         }
 318
 319         if (type && type->setup)
 320                 type->setup(dev);
 321
 322  out:
 323 #if ACPI_GLUE_DEBUG
 324         if (!ret) {
 325                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 326
 327                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 328                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 329                 kfree(buffer.pointer);
 330         } else
 331                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 332 #endif
 333
 334         return ret;
 335 }
 336
 337 static int acpi_platform_notify_remove(struct device *dev)
 338 {
 339         struct acpi_bus_type *type;
 340
 341         type = acpi_get_bus_type(dev);
 342         if (type && type->cleanup)
 343                 type->cleanup(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 }