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 acpi_status acpi_dev_present(acpi_handle handle, u32 lvl_not_used,
  86                                   void *not_used, void **ret_p)
  87 {
  88         struct acpi_device *adev = NULL;
  89
  90         acpi_bus_get_device(handle, &adev);
  91         if (adev) {
  92                 *ret_p = handle;
  93                 return AE_CTRL_TERMINATE;
  94         }
  95         return AE_OK;
  96 }
  97
  98 static int do_find_child_checks(acpi_handle handle, bool is_bridge)
  99 {
 100         bool sta_present = true;
 101         unsigned long long sta;
 102         acpi_status status;
 103
 104         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 105         if (status == AE_NOT_FOUND)
 106                 sta_present = false;
 107         else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
 108                 return -ENODEV;
 109
 110         if (is_bridge) {
 111                 void *test = NULL;
 112
 113                 /* Check if this object has at least one child device. */
 114                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 115                                     acpi_dev_present, NULL, NULL, &test);
 116                 if (!test)
 117                         return -ENODEV;
 118         }
 119         return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 120 }
 121
 122 struct find_child_context {
 123         u64 addr;
 124         bool is_bridge;
 125         acpi_handle ret;
 126         int ret_score;
 127 };
 128
 129 static acpi_status do_find_child(acpi_handle handle, u32 lvl_not_used,
 130                                  void *data, void **not_used)
 131 {
 132         struct find_child_context *context = data;
 133         unsigned long long addr;
 134         acpi_status status;
 135         int score;
 136
 137         status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
 138         if (ACPI_FAILURE(status) || addr != context->addr)
 139                 return AE_OK;
 140
 141         if (!context->ret) {
 142                 /* This is the first matching object.  Save its handle. */
 143                 context->ret = handle;
 144                 return AE_OK;
 145         }
 146         /*
 147          * There is more than one matching object with the same _ADR value.
 148          * That really is unexpected, so we are kind of beyond the scope of the
 149          * spec here.  We have to choose which one to return, though.
 150          *
 151          * First, check if the previously found object is good enough and return
 152          * its handle if so.  Second, check the same for the object that we've
 153          * just found.
 154          */
 155         if (!context->ret_score) {
 156                 score = do_find_child_checks(context->ret, context->is_bridge);
 157                 if (score == FIND_CHILD_MAX_SCORE)
 158                         return AE_CTRL_TERMINATE;
 159                 else
 160                         context->ret_score = score;
 161         }
 162         score = do_find_child_checks(handle, context->is_bridge);
 163         if (score == FIND_CHILD_MAX_SCORE) {
 164                 context->ret = handle;
 165                 return AE_CTRL_TERMINATE;
 166         } else if (score > context->ret_score) {
 167                 context->ret = handle;
 168                 context->ret_score = score;
 169         }
 170         return AE_OK;
 171 }
 172
 173 acpi_handle acpi_find_child(acpi_handle parent, u64 addr, bool is_bridge)
 174 {
 175         if (parent) {
 176                 struct find_child_context context = {
 177                         .addr = addr,
 178                         .is_bridge = is_bridge,
 179                 };
 180
 181                 acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, do_find_child,
 182                                     NULL, &context, NULL);
 183                 return context.ret;
 184         }
 185         return NULL;
 186 }
 187 EXPORT_SYMBOL_GPL(acpi_find_child);
 188
 189 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 190 {
 191         if (node_id > 0)
 192                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 193                          PHYSICAL_NODE_STRING "%u", node_id);
 194         else
 195                 strcpy(buf, PHYSICAL_NODE_STRING);
 196 }
 197
 198 int acpi_bind_one(struct device *dev, acpi_handle handle)
 199 {
 200         struct acpi_device *acpi_dev = NULL;
 201         struct acpi_device_physical_node *physical_node, *pn;
 202         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 203         struct list_head *physnode_list;
 204         unsigned int node_id;
 205         int retval = -EINVAL;
 206
 207         if (ACPI_COMPANION(dev)) {
 208                 if (handle) {
 209                         dev_warn(dev, "ACPI companion already set\n");
 210                         return -EINVAL;
 211                 } else {
 212                         acpi_dev = ACPI_COMPANION(dev);
 213                 }
 214         } else {
 215                 acpi_bus_get_device(handle, &acpi_dev);
 216         }
 217         if (!acpi_dev)
 218                 return -EINVAL;
 219
 220         get_device(&acpi_dev->dev);
 221         get_device(dev);
 222         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 223         if (!physical_node) {
 224                 retval = -ENOMEM;
 225                 goto err;
 226         }
 227
 228         mutex_lock(&acpi_dev->physical_node_lock);
 229
 230         /*
 231          * Keep the list sorted by node_id so that the IDs of removed nodes can
 232          * be recycled easily.
 233          */
 234         physnode_list = &acpi_dev->physical_node_list;
 235         node_id = 0;
 236         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 237                 /* Sanity check. */
 238                 if (pn->dev == dev) {
 239                         mutex_unlock(&acpi_dev->physical_node_lock);
 240
 241                         dev_warn(dev, "Already associated with ACPI node\n");
 242                         kfree(physical_node);
 243                         if (ACPI_COMPANION(dev) != acpi_dev)
 244                                 goto err;
 245
 246                         put_device(dev);
 247                         put_device(&acpi_dev->dev);
 248                         return 0;
 249                 }
 250                 if (pn->node_id == node_id) {
 251                         physnode_list = &pn->node;
 252                         node_id++;
 253                 }
 254         }
 255
 256         physical_node->node_id = node_id;
 257         physical_node->dev = dev;
 258         list_add(&physical_node->node, physnode_list);
 259         acpi_dev->physical_node_count++;
 260
 261         if (!ACPI_COMPANION(dev))
 262                 ACPI_COMPANION_SET(dev, acpi_dev);
 263
 264         acpi_physnode_link_name(physical_node_name, node_id);
 265         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 266                                    physical_node_name);
 267         if (retval)
 268                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 269                         physical_node_name, retval);
 270
 271         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 272                                    "firmware_node");
 273         if (retval)
 274                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 275                         retval);
 276
 277         mutex_unlock(&acpi_dev->physical_node_lock);
 278
 279         if (acpi_dev->wakeup.flags.valid)
 280                 device_set_wakeup_capable(dev, true);
 281
 282         return 0;
 283
 284  err:
 285         ACPI_COMPANION_SET(dev, NULL);
 286         put_device(dev);
 287         put_device(&acpi_dev->dev);
 288         return retval;
 289 }
 290 EXPORT_SYMBOL_GPL(acpi_bind_one);
 291
 292 int acpi_unbind_one(struct device *dev)
 293 {
 294         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 295         struct acpi_device_physical_node *entry;
 296
 297         if (!acpi_dev)
 298                 return 0;
 299
 300         mutex_lock(&acpi_dev->physical_node_lock);
 301
 302         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 303                 if (entry->dev == dev) {
 304                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 305
 306                         list_del(&entry->node);
 307                         acpi_dev->physical_node_count--;
 308
 309                         acpi_physnode_link_name(physnode_name, entry->node_id);
 310                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 311                         sysfs_remove_link(&dev->kobj, "firmware_node");
 312                         ACPI_COMPANION_SET(dev, NULL);
 313                         /* Drop references taken by acpi_bind_one(). */
 314                         put_device(dev);
 315                         put_device(&acpi_dev->dev);
 316                         kfree(entry);
 317                         break;
 318                 }
 319
 320         mutex_unlock(&acpi_dev->physical_node_lock);
 321         return 0;
 322 }
 323 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 324
 325 void acpi_preset_companion(struct device *dev, acpi_handle parent, u64 addr)
 326 {
 327         struct acpi_device *adev;
 328
 329         if (!acpi_bus_get_device(acpi_get_child(parent, addr), &adev))
 330                 ACPI_COMPANION_SET(dev, adev);
 331 }
 332 EXPORT_SYMBOL_GPL(acpi_preset_companion);
 333
 334 static int acpi_platform_notify(struct device *dev)
 335 {
 336         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 337         acpi_handle handle;
 338         int ret;
 339
 340         ret = acpi_bind_one(dev, NULL);
 341         if (ret && type) {
 342                 ret = type->find_device(dev, &handle);
 343                 if (ret) {
 344                         DBG("Unable to get handle for %s\n", dev_name(dev));
 345                         goto out;
 346                 }
 347                 ret = acpi_bind_one(dev, handle);
 348                 if (ret)
 349                         goto out;
 350         }
 351
 352         if (type && type->setup)
 353                 type->setup(dev);
 354
 355  out:
 356 #if ACPI_GLUE_DEBUG
 357         if (!ret) {
 358                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 359
 360                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 361                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 362                 kfree(buffer.pointer);
 363         } else
 364                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 365 #endif
 366
 367         return ret;
 368 }
 369
 370 static int acpi_platform_notify_remove(struct device *dev)
 371 {
 372         struct acpi_bus_type *type;
 373
 374         type = acpi_get_bus_type(dev);
 375         if (type && type->cleanup)
 376                 type->cleanup(dev);
 377
 378         acpi_unbind_one(dev);
 379         return 0;
 380 }
 381
 382 int __init init_acpi_device_notify(void)
 383 {
 384         if (platform_notify || platform_notify_remove) {
 385                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 386                 return 0;
 387         }
 388         platform_notify = acpi_platform_notify;
 389         platform_notify_remove = acpi_platform_notify_remove;
 390         return 0;
 391 }