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_device) {
  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         list_for_each_entry(adev, &parent->children, node) {
 110                 unsigned long long addr;
 111                 acpi_status status;
 112                 int score;
 113
 114                 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
 115                                                NULL, &addr);
 116                 if (ACPI_FAILURE(status) || addr != address)
 117                         continue;
 118
 119                 if (!ret) {
 120                         /* This is the first matching object.  Save it. */
 121                         ret = adev;
 122                         continue;
 123                 }
 124                 /*
 125                  * There is more than one matching device object with the same
 126                  * _ADR value.  That really is unexpected, so we are kind of
 127                  * beyond the scope of the spec here.  We have to choose which
 128                  * one to return, though.
 129                  *
 130                  * First, check if the previously found object is good enough
 131                  * and return it if so.  Second, do the same for the object that
 132                  * we've just found.
 133                  */
 134                 if (!ret_score) {
 135                         ret_score = find_child_checks(ret, check_children);
 136                         if (ret_score == FIND_CHILD_MAX_SCORE)
 137                                 return ret;
 138                 }
 139                 score = find_child_checks(adev, check_children);
 140                 if (score == FIND_CHILD_MAX_SCORE) {
 141                         return adev;
 142                 } else if (score > ret_score) {
 143                         ret = adev;
 144                         ret_score = score;
 145                 }
 146         }
 147         return ret;
 148 }
 149
 150 acpi_handle acpi_find_child(acpi_handle handle, u64 addr, bool is_bridge)
 151 {
 152         struct acpi_device *adev;
 153
 154         if (!handle || acpi_bus_get_device(handle, &adev))
 155                 return NULL;
 156
 157         adev = acpi_find_child_device(adev, addr, is_bridge);
 158         return adev ? adev->handle : NULL;
 159 }
 160 EXPORT_SYMBOL_GPL(acpi_find_child);
 161
 162 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 163 {
 164         if (node_id > 0)
 165                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 166                          PHYSICAL_NODE_STRING "%u", node_id);
 167         else
 168                 strcpy(buf, PHYSICAL_NODE_STRING);
 169 }
 170
 171 int acpi_bind_one(struct device *dev, acpi_handle handle)
 172 {
 173         struct acpi_device *acpi_dev = NULL;
 174         struct acpi_device_physical_node *physical_node, *pn;
 175         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 176         struct list_head *physnode_list;
 177         unsigned int node_id;
 178         int retval = -EINVAL;
 179
 180         if (ACPI_COMPANION(dev)) {
 181                 if (handle) {
 182                         dev_warn(dev, "ACPI companion already set\n");
 183                         return -EINVAL;
 184                 } else {
 185                         acpi_dev = ACPI_COMPANION(dev);
 186                 }
 187         } else {
 188                 acpi_bus_get_device(handle, &acpi_dev);
 189         }
 190         if (!acpi_dev)
 191                 return -EINVAL;
 192
 193         get_device(&acpi_dev->dev);
 194         get_device(dev);
 195         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 196         if (!physical_node) {
 197                 retval = -ENOMEM;
 198                 goto err;
 199         }
 200
 201         mutex_lock(&acpi_dev->physical_node_lock);
 202
 203         /*
 204          * Keep the list sorted by node_id so that the IDs of removed nodes can
 205          * be recycled easily.
 206          */
 207         physnode_list = &acpi_dev->physical_node_list;
 208         node_id = 0;
 209         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 210                 /* Sanity check. */
 211                 if (pn->dev == dev) {
 212                         mutex_unlock(&acpi_dev->physical_node_lock);
 213
 214                         dev_warn(dev, "Already associated with ACPI node\n");
 215                         kfree(physical_node);
 216                         if (ACPI_COMPANION(dev) != acpi_dev)
 217                                 goto err;
 218
 219                         put_device(dev);
 220                         put_device(&acpi_dev->dev);
 221                         return 0;
 222                 }
 223                 if (pn->node_id == node_id) {
 224                         physnode_list = &pn->node;
 225                         node_id++;
 226                 }
 227         }
 228
 229         physical_node->node_id = node_id;
 230         physical_node->dev = dev;
 231         list_add(&physical_node->node, physnode_list);
 232         acpi_dev->physical_node_count++;
 233
 234         if (!ACPI_COMPANION(dev))
 235                 ACPI_COMPANION_SET(dev, acpi_dev);
 236
 237         acpi_physnode_link_name(physical_node_name, node_id);
 238         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 239                                    physical_node_name);
 240         if (retval)
 241                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 242                         physical_node_name, retval);
 243
 244         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 245                                    "firmware_node");
 246         if (retval)
 247                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 248                         retval);
 249
 250         mutex_unlock(&acpi_dev->physical_node_lock);
 251
 252         if (acpi_dev->wakeup.flags.valid)
 253                 device_set_wakeup_capable(dev, true);
 254
 255         return 0;
 256
 257  err:
 258         ACPI_COMPANION_SET(dev, NULL);
 259         put_device(dev);
 260         put_device(&acpi_dev->dev);
 261         return retval;
 262 }
 263 EXPORT_SYMBOL_GPL(acpi_bind_one);
 264
 265 int acpi_unbind_one(struct device *dev)
 266 {
 267         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 268         struct acpi_device_physical_node *entry;
 269
 270         if (!acpi_dev)
 271                 return 0;
 272
 273         mutex_lock(&acpi_dev->physical_node_lock);
 274
 275         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 276                 if (entry->dev == dev) {
 277                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 278
 279                         list_del(&entry->node);
 280                         acpi_dev->physical_node_count--;
 281
 282                         acpi_physnode_link_name(physnode_name, entry->node_id);
 283                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 284                         sysfs_remove_link(&dev->kobj, "firmware_node");
 285                         ACPI_COMPANION_SET(dev, NULL);
 286                         /* Drop references taken by acpi_bind_one(). */
 287                         put_device(dev);
 288                         put_device(&acpi_dev->dev);
 289                         kfree(entry);
 290                         break;
 291                 }
 292
 293         mutex_unlock(&acpi_dev->physical_node_lock);
 294         return 0;
 295 }
 296 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 297
 298 void acpi_preset_companion(struct device *dev, acpi_handle parent, u64 addr)
 299 {
 300         struct acpi_device *adev;
 301
 302         if (!acpi_bus_get_device(acpi_get_child(parent, addr), &adev))
 303                 ACPI_COMPANION_SET(dev, adev);
 304 }
 305 EXPORT_SYMBOL_GPL(acpi_preset_companion);
 306
 307 static int acpi_platform_notify(struct device *dev)
 308 {
 309         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 310         acpi_handle handle;
 311         int ret;
 312
 313         ret = acpi_bind_one(dev, NULL);
 314         if (ret && type) {
 315                 ret = type->find_device(dev, &handle);
 316                 if (ret) {
 317                         DBG("Unable to get handle for %s\n", dev_name(dev));
 318                         goto out;
 319                 }
 320                 ret = acpi_bind_one(dev, handle);
 321                 if (ret)
 322                         goto out;
 323         }
 324
 325         if (type && type->setup)
 326                 type->setup(dev);
 327
 328  out:
 329 #if ACPI_GLUE_DEBUG
 330         if (!ret) {
 331                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 332
 333                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 334                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 335                 kfree(buffer.pointer);
 336         } else
 337                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 338 #endif
 339
 340         return ret;
 341 }
 342
 343 static int acpi_platform_notify_remove(struct device *dev)
 344 {
 345         struct acpi_bus_type *type;
 346
 347         type = acpi_get_bus_type(dev);
 348         if (type && type->cleanup)
 349                 type->cleanup(dev);
 350
 351         acpi_unbind_one(dev);
 352         return 0;
 353 }
 354
 355 int __init init_acpi_device_notify(void)
 356 {
 357         if (platform_notify || platform_notify_remove) {
 358                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 359                 return 0;
 360         }
 361         platform_notify = acpi_platform_notify;
 362         platform_notify_remove = acpi_platform_notify_remove;
 363         return 0;
 364 }