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         enum dev_dma_attr attr;
 180
 181         if (has_acpi_companion(dev)) {
 182                 if (acpi_dev) {
 183                         dev_warn(dev, "ACPI companion already set\n");
 184                         return -EINVAL;
 185                 } else {
 186                         acpi_dev = ACPI_COMPANION(dev);
 187                 }
 188         }
 189         if (!acpi_dev)
 190                 return -EINVAL;
 191
 192         get_device(&acpi_dev->dev);
 193         get_device(dev);
 194         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 195         if (!physical_node) {
 196                 retval = -ENOMEM;
 197                 goto err;
 198         }
 199
 200         mutex_lock(&acpi_dev->physical_node_lock);
 201
 202         /*
 203          * Keep the list sorted by node_id so that the IDs of removed nodes can
 204          * be recycled easily.
 205          */
 206         physnode_list = &acpi_dev->physical_node_list;
 207         node_id = 0;
 208         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 209                 /* Sanity check. */
 210                 if (pn->dev == dev) {
 211                         mutex_unlock(&acpi_dev->physical_node_lock);
 212
 213                         dev_warn(dev, "Already associated with ACPI node\n");
 214                         kfree(physical_node);
 215                         if (ACPI_COMPANION(dev) != acpi_dev)
 216                                 goto err;
 217
 218                         put_device(dev);
 219                         put_device(&acpi_dev->dev);
 220                         return 0;
 221                 }
 222                 if (pn->node_id == node_id) {
 223                         physnode_list = &pn->node;
 224                         node_id++;
 225                 }
 226         }
 227
 228         physical_node->node_id = node_id;
 229         physical_node->dev = dev;
 230         list_add(&physical_node->node, physnode_list);
 231         acpi_dev->physical_node_count++;
 232
 233         if (!has_acpi_companion(dev))
 234                 ACPI_COMPANION_SET(dev, acpi_dev);
 235
 236         attr = acpi_get_dma_attr(acpi_dev);
 237         if (attr != DEV_DMA_NOT_SUPPORTED)
 238                 acpi_dma_configure(dev, attr);
 239
 240         acpi_physnode_link_name(physical_node_name, node_id);
 241         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 242                                    physical_node_name);
 243         if (retval)
 244                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 245                         physical_node_name, retval);
 246
 247         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 248                                    "firmware_node");
 249         if (retval)
 250                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 251                         retval);
 252
 253         mutex_unlock(&acpi_dev->physical_node_lock);
 254
 255         if (acpi_dev->wakeup.flags.valid)
 256                 device_set_wakeup_capable(dev, true);
 257
 258         return 0;
 259
 260  err:
 261         ACPI_COMPANION_SET(dev, NULL);
 262         put_device(dev);
 263         put_device(&acpi_dev->dev);
 264         return retval;
 265 }
 266 EXPORT_SYMBOL_GPL(acpi_bind_one);
 267
 268 int acpi_unbind_one(struct device *dev)
 269 {
 270         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 271         struct acpi_device_physical_node *entry;
 272
 273         if (!acpi_dev)
 274                 return 0;
 275
 276         mutex_lock(&acpi_dev->physical_node_lock);
 277
 278         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 279                 if (entry->dev == dev) {
 280                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 281
 282                         list_del(&entry->node);
 283                         acpi_dev->physical_node_count--;
 284
 285                         acpi_physnode_link_name(physnode_name, entry->node_id);
 286                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 287                         sysfs_remove_link(&dev->kobj, "firmware_node");
 288                         ACPI_COMPANION_SET(dev, NULL);
 289                         /* Drop references taken by acpi_bind_one(). */
 290                         put_device(dev);
 291                         put_device(&acpi_dev->dev);
 292                         kfree(entry);
 293                         break;
 294                 }
 295
 296         mutex_unlock(&acpi_dev->physical_node_lock);
 297         return 0;
 298 }
 299 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 300
 301 static int acpi_platform_notify(struct device *dev)
 302 {
 303         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 304         struct acpi_device *adev;
 305         int ret;
 306
 307         ret = acpi_bind_one(dev, NULL);
 308         if (ret && type) {
 309                 struct acpi_device *adev;
 310
 311                 adev = type->find_companion(dev);
 312                 if (!adev) {
 313                         DBG("Unable to get handle for %s\n", dev_name(dev));
 314                         ret = -ENODEV;
 315                         goto out;
 316                 }
 317                 ret = acpi_bind_one(dev, adev);
 318                 if (ret)
 319                         goto out;
 320         }
 321         adev = ACPI_COMPANION(dev);
 322         if (!adev)
 323                 goto out;
 324
 325         if (type && type->setup)
 326                 type->setup(dev);
 327         else if (adev->handler && adev->handler->bind)
 328                 adev->handler->bind(dev);
 329
 330  out:
 331 #if ACPI_GLUE_DEBUG
 332         if (!ret) {
 333                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 334
 335                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 336                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 337                 kfree(buffer.pointer);
 338         } else
 339                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 340 #endif
 341
 342         return ret;
 343 }
 344
 345 static int acpi_platform_notify_remove(struct device *dev)
 346 {
 347         struct acpi_device *adev = ACPI_COMPANION(dev);
 348         struct acpi_bus_type *type;
 349
 350         if (!adev)
 351                 return 0;
 352
 353         type = acpi_get_bus_type(dev);
 354         if (type && type->cleanup)
 355                 type->cleanup(dev);
 356         else if (adev->handler && adev->handler->unbind)
 357                 adev->handler->unbind(dev);
 358
 359         acpi_unbind_one(dev);
 360         return 0;
 361 }
 362
 363 void __init init_acpi_device_notify(void)
 364 {
 365         if (platform_notify || platform_notify_remove) {
 366                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 367                 return;
 368         }
 369         platform_notify = acpi_platform_notify;
 370         platform_notify_remove = acpi_platform_notify_remove;
 371 }