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 #include <linux/dma-mapping.h>
  17
  18 #include "internal.h"
  19
  20 #define ACPI_GLUE_DEBUG 0
  21 #if ACPI_GLUE_DEBUG
  22 #define DBG(fmt, ...)                                           \
  23         printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
  24 #else
  25 #define DBG(fmt, ...)                                           \
  26 do {                                                            \
  27         if (0)                                                  \
  28                 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);   \
  29 } while (0)
  30 #endif
  31 static LIST_HEAD(bus_type_list);
  32 static DECLARE_RWSEM(bus_type_sem);
  33
  34 #define PHYSICAL_NODE_STRING "physical_node"
  35 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
  36
  37 int register_acpi_bus_type(struct acpi_bus_type *type)
  38 {
  39         if (acpi_disabled)
  40                 return -ENODEV;
  41         if (type && type->match && type->find_companion) {
  42                 down_write(&bus_type_sem);
  43                 list_add_tail(&type->list, &bus_type_list);
  44                 up_write(&bus_type_sem);
  45                 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
  46                 return 0;
  47         }
  48         return -ENODEV;
  49 }
  50 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  51
  52 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  53 {
  54         if (acpi_disabled)
  55                 return 0;
  56         if (type) {
  57                 down_write(&bus_type_sem);
  58                 list_del_init(&type->list);
  59                 up_write(&bus_type_sem);
  60                 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
  61                        type->name);
  62                 return 0;
  63         }
  64         return -ENODEV;
  65 }
  66 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  67
  68 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
  69 {
  70         struct acpi_bus_type *tmp, *ret = NULL;
  71
  72         down_read(&bus_type_sem);
  73         list_for_each_entry(tmp, &bus_type_list, list) {
  74                 if (tmp->match(dev)) {
  75                         ret = tmp;
  76                         break;
  77                 }
  78         }
  79         up_read(&bus_type_sem);
  80         return ret;
  81 }
  82
  83 #define FIND_CHILD_MIN_SCORE    1
  84 #define FIND_CHILD_MAX_SCORE    2
  85
  86 static int find_child_checks(struct acpi_device *adev, bool check_children)
  87 {
  88         bool sta_present = true;
  89         unsigned long long sta;
  90         acpi_status status;
  91
  92         status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
  93         if (status == AE_NOT_FOUND)
  94                 sta_present = false;
  95         else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
  96                 return -ENODEV;
  97
  98         if (check_children && list_empty(&adev->children))
  99                 return -ENODEV;
 100
 101         /*
 102          * If the device has a _HID returning a valid ACPI/PNP device ID, it is
 103          * better to make it look less attractive here, so that the other device
 104          * with the same _ADR value (that may not have a valid device ID) can be
 105          * matched going forward.  [This means a second spec violation in a row,
 106          * so whatever we do here is best effort anyway.]
 107          */
 108         return sta_present && !adev->pnp.type.platform_id ?
 109                         FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 110 }
 111
 112 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
 113                                            u64 address, bool check_children)
 114 {
 115         struct acpi_device *adev, *ret = NULL;
 116         int ret_score = 0;
 117
 118         if (!parent)
 119                 return NULL;
 120
 121         list_for_each_entry(adev, &parent->children, node) {
 122                 unsigned long long addr;
 123                 acpi_status status;
 124                 int score;
 125
 126                 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
 127                                                NULL, &addr);
 128                 if (ACPI_FAILURE(status) || addr != address)
 129                         continue;
 130
 131                 if (!ret) {
 132                         /* This is the first matching object.  Save it. */
 133                         ret = adev;
 134                         continue;
 135                 }
 136                 /*
 137                  * There is more than one matching device object with the same
 138                  * _ADR value.  That really is unexpected, so we are kind of
 139                  * beyond the scope of the spec here.  We have to choose which
 140                  * one to return, though.
 141                  *
 142                  * First, check if the previously found object is good enough
 143                  * and return it if so.  Second, do the same for the object that
 144                  * we've just found.
 145                  */
 146                 if (!ret_score) {
 147                         ret_score = find_child_checks(ret, check_children);
 148                         if (ret_score == FIND_CHILD_MAX_SCORE)
 149                                 return ret;
 150                 }
 151                 score = find_child_checks(adev, check_children);
 152                 if (score == FIND_CHILD_MAX_SCORE) {
 153                         return adev;
 154                 } else if (score > ret_score) {
 155                         ret = adev;
 156                         ret_score = score;
 157                 }
 158         }
 159         return ret;
 160 }
 161 EXPORT_SYMBOL_GPL(acpi_find_child_device);
 162
 163 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 164 {
 165         if (node_id > 0)
 166                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 167                          PHYSICAL_NODE_STRING "%u", node_id);
 168         else
 169                 strcpy(buf, PHYSICAL_NODE_STRING);
 170 }
 171
 172 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 173 {
 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 (has_acpi_companion(dev)) {
 181                 if (acpi_dev) {
 182                         dev_warn(dev, "ACPI companion already set\n");
 183                         return -EINVAL;
 184                 } else {
 185                         acpi_dev = ACPI_COMPANION(dev);
 186                 }
 187         }
 188         if (!acpi_dev)
 189                 return -EINVAL;
 190
 191         get_device(&acpi_dev->dev);
 192         get_device(dev);
 193         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 194         if (!physical_node) {
 195                 retval = -ENOMEM;
 196                 goto err;
 197         }
 198
 199         mutex_lock(&acpi_dev->physical_node_lock);
 200
 201         /*
 202          * Keep the list sorted by node_id so that the IDs of removed nodes can
 203          * be recycled easily.
 204          */
 205         physnode_list = &acpi_dev->physical_node_list;
 206         node_id = 0;
 207         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 208                 /* Sanity check. */
 209                 if (pn->dev == dev) {
 210                         mutex_unlock(&acpi_dev->physical_node_lock);
 211
 212                         dev_warn(dev, "Already associated with ACPI node\n");
 213                         kfree(physical_node);
 214                         if (ACPI_COMPANION(dev) != acpi_dev)
 215                                 goto err;
 216
 217                         put_device(dev);
 218                         put_device(&acpi_dev->dev);
 219                         return 0;
 220                 }
 221                 if (pn->node_id == node_id) {
 222                         physnode_list = &pn->node;
 223                         node_id++;
 224                 }
 225         }
 226
 227         physical_node->node_id = node_id;
 228         physical_node->dev = dev;
 229         list_add(&physical_node->node, physnode_list);
 230         acpi_dev->physical_node_count++;
 231
 232         if (!has_acpi_companion(dev))
 233                 ACPI_COMPANION_SET(dev, acpi_dev);
 234
 235         acpi_physnode_link_name(physical_node_name, node_id);
 236         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 237                                    physical_node_name);
 238         if (retval)
 239                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 240                         physical_node_name, retval);
 241
 242         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 243                                    "firmware_node");
 244         if (retval)
 245                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 246                         retval);
 247
 248         mutex_unlock(&acpi_dev->physical_node_lock);
 249
 250         if (acpi_dev->wakeup.flags.valid)
 251                 device_set_wakeup_capable(dev, true);
 252
 253         return 0;
 254
 255  err:
 256         ACPI_COMPANION_SET(dev, NULL);
 257         put_device(dev);
 258         put_device(&acpi_dev->dev);
 259         return retval;
 260 }
 261 EXPORT_SYMBOL_GPL(acpi_bind_one);
 262
 263 int acpi_unbind_one(struct device *dev)
 264 {
 265         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 266         struct acpi_device_physical_node *entry;
 267
 268         if (!acpi_dev)
 269                 return 0;
 270
 271         mutex_lock(&acpi_dev->physical_node_lock);
 272
 273         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 274                 if (entry->dev == dev) {
 275                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 276
 277                         list_del(&entry->node);
 278                         acpi_dev->physical_node_count--;
 279
 280                         acpi_physnode_link_name(physnode_name, entry->node_id);
 281                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 282                         sysfs_remove_link(&dev->kobj, "firmware_node");
 283                         ACPI_COMPANION_SET(dev, NULL);
 284                         /* Drop references taken by acpi_bind_one(). */
 285                         put_device(dev);
 286                         put_device(&acpi_dev->dev);
 287                         kfree(entry);
 288                         break;
 289                 }
 290
 291         mutex_unlock(&acpi_dev->physical_node_lock);
 292         return 0;
 293 }
 294 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 295
 296 static int acpi_platform_notify(struct device *dev)
 297 {
 298         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 299         struct acpi_device *adev;
 300         int ret;
 301
 302         ret = acpi_bind_one(dev, NULL);
 303         if (ret && type) {
 304                 struct acpi_device *adev;
 305
 306                 adev = type->find_companion(dev);
 307                 if (!adev) {
 308                         DBG("Unable to get handle for %s\n", dev_name(dev));
 309                         ret = -ENODEV;
 310                         goto out;
 311                 }
 312                 ret = acpi_bind_one(dev, adev);
 313                 if (ret)
 314                         goto out;
 315         }
 316         adev = ACPI_COMPANION(dev);
 317         if (!adev)
 318                 goto out;
 319
 320         if (type && type->setup)
 321                 type->setup(dev);
 322         else if (adev->handler && adev->handler->bind)
 323                 adev->handler->bind(dev);
 324
 325  out:
 326 #if ACPI_GLUE_DEBUG
 327         if (!ret) {
 328                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 329
 330                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 331                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 332                 kfree(buffer.pointer);
 333         } else
 334                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 335 #endif
 336
 337         return ret;
 338 }
 339
 340 static int acpi_platform_notify_remove(struct device *dev)
 341 {
 342         struct acpi_device *adev = ACPI_COMPANION(dev);
 343         struct acpi_bus_type *type;
 344
 345         if (!adev)
 346                 return 0;
 347
 348         type = acpi_get_bus_type(dev);
 349         if (type && type->cleanup)
 350                 type->cleanup(dev);
 351         else if (adev->handler && adev->handler->unbind)
 352                 adev->handler->unbind(dev);
 353
 354         acpi_unbind_one(dev);
 355         return 0;
 356 }
 357
 358 void __init init_acpi_device_notify(void)
 359 {
 360         if (platform_notify || platform_notify_remove) {
 361                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 362                 return;
 363         }
 364         platform_notify = acpi_platform_notify;
 365         platform_notify_remove = acpi_platform_notify_remove;
 366 }