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         return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 102 }
 103
 104 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
 105                                            u64 address, bool check_children)
 106 {
 107         struct acpi_device *adev, *ret = NULL;
 108         int ret_score = 0;
 109
 110         if (!parent)
 111                 return NULL;
 112
 113         list_for_each_entry(adev, &parent->children, node) {
 114                 unsigned long long addr;
 115                 acpi_status status;
 116                 int score;
 117
 118                 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
 119                                                NULL, &addr);
 120                 if (ACPI_FAILURE(status) || addr != address)
 121                         continue;
 122
 123                 if (!ret) {
 124                         /* This is the first matching object.  Save it. */
 125                         ret = adev;
 126                         continue;
 127                 }
 128                 /*
 129                  * There is more than one matching device object with the same
 130                  * _ADR value.  That really is unexpected, so we are kind of
 131                  * beyond the scope of the spec here.  We have to choose which
 132                  * one to return, though.
 133                  *
 134                  * First, check if the previously found object is good enough
 135                  * and return it if so.  Second, do the same for the object that
 136                  * we've just found.
 137                  */
 138                 if (!ret_score) {
 139                         ret_score = find_child_checks(ret, check_children);
 140                         if (ret_score == FIND_CHILD_MAX_SCORE)
 141                                 return ret;
 142                 }
 143                 score = find_child_checks(adev, check_children);
 144                 if (score == FIND_CHILD_MAX_SCORE) {
 145                         return adev;
 146                 } else if (score > ret_score) {
 147                         ret = adev;
 148                         ret_score = score;
 149                 }
 150         }
 151         return ret;
 152 }
 153 EXPORT_SYMBOL_GPL(acpi_find_child_device);
 154
 155 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 156 {
 157         if (node_id > 0)
 158                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 159                          PHYSICAL_NODE_STRING "%u", node_id);
 160         else
 161                 strcpy(buf, PHYSICAL_NODE_STRING);
 162 }
 163
 164 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 165 {
 166         struct acpi_device_physical_node *physical_node, *pn;
 167         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 168         struct list_head *physnode_list;
 169         unsigned int node_id;
 170         int retval = -EINVAL;
 171         enum dev_dma_attr attr;
 172
 173         if (has_acpi_companion(dev)) {
 174                 if (acpi_dev) {
 175                         dev_warn(dev, "ACPI companion already set\n");
 176                         return -EINVAL;
 177                 } else {
 178                         acpi_dev = ACPI_COMPANION(dev);
 179                 }
 180         }
 181         if (!acpi_dev)
 182                 return -EINVAL;
 183
 184         get_device(&acpi_dev->dev);
 185         get_device(dev);
 186         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 187         if (!physical_node) {
 188                 retval = -ENOMEM;
 189                 goto err;
 190         }
 191
 192         mutex_lock(&acpi_dev->physical_node_lock);
 193
 194         /*
 195          * Keep the list sorted by node_id so that the IDs of removed nodes can
 196          * be recycled easily.
 197          */
 198         physnode_list = &acpi_dev->physical_node_list;
 199         node_id = 0;
 200         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 201                 /* Sanity check. */
 202                 if (pn->dev == dev) {
 203                         mutex_unlock(&acpi_dev->physical_node_lock);
 204
 205                         dev_warn(dev, "Already associated with ACPI node\n");
 206                         kfree(physical_node);
 207                         if (ACPI_COMPANION(dev) != acpi_dev)
 208                                 goto err;
 209
 210                         put_device(dev);
 211                         put_device(&acpi_dev->dev);
 212                         return 0;
 213                 }
 214                 if (pn->node_id == node_id) {
 215                         physnode_list = &pn->node;
 216                         node_id++;
 217                 }
 218         }
 219
 220         physical_node->node_id = node_id;
 221         physical_node->dev = dev;
 222         list_add(&physical_node->node, physnode_list);
 223         acpi_dev->physical_node_count++;
 224
 225         if (!has_acpi_companion(dev))
 226                 ACPI_COMPANION_SET(dev, acpi_dev);
 227
 228         attr = acpi_get_dma_attr(acpi_dev);
 229         if (attr != DEV_DMA_NOT_SUPPORTED)
 230                 acpi_dma_configure(dev, attr);
 231
 232         acpi_physnode_link_name(physical_node_name, node_id);
 233         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 234                                    physical_node_name);
 235         if (retval)
 236                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 237                         physical_node_name, retval);
 238
 239         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 240                                    "firmware_node");
 241         if (retval)
 242                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 243                         retval);
 244
 245         mutex_unlock(&acpi_dev->physical_node_lock);
 246
 247         if (acpi_dev->wakeup.flags.valid)
 248                 device_set_wakeup_capable(dev, true);
 249
 250         return 0;
 251
 252  err:
 253         ACPI_COMPANION_SET(dev, NULL);
 254         put_device(dev);
 255         put_device(&acpi_dev->dev);
 256         return retval;
 257 }
 258 EXPORT_SYMBOL_GPL(acpi_bind_one);
 259
 260 int acpi_unbind_one(struct device *dev)
 261 {
 262         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 263         struct acpi_device_physical_node *entry;
 264
 265         if (!acpi_dev)
 266                 return 0;
 267
 268         mutex_lock(&acpi_dev->physical_node_lock);
 269
 270         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 271                 if (entry->dev == dev) {
 272                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 273
 274                         list_del(&entry->node);
 275                         acpi_dev->physical_node_count--;
 276
 277                         acpi_physnode_link_name(physnode_name, entry->node_id);
 278                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 279                         sysfs_remove_link(&dev->kobj, "firmware_node");
 280                         ACPI_COMPANION_SET(dev, NULL);
 281                         /* Drop references taken by acpi_bind_one(). */
 282                         put_device(dev);
 283                         put_device(&acpi_dev->dev);
 284                         kfree(entry);
 285                         break;
 286                 }
 287
 288         mutex_unlock(&acpi_dev->physical_node_lock);
 289         return 0;
 290 }
 291 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 292
 293 static int acpi_platform_notify(struct device *dev)
 294 {
 295         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 296         struct acpi_device *adev;
 297         int ret;
 298
 299         ret = acpi_bind_one(dev, NULL);
 300         if (ret && type) {
 301                 struct acpi_device *adev;
 302
 303                 adev = type->find_companion(dev);
 304                 if (!adev) {
 305                         DBG("Unable to get handle for %s\n", dev_name(dev));
 306                         ret = -ENODEV;
 307                         goto out;
 308                 }
 309                 ret = acpi_bind_one(dev, adev);
 310                 if (ret)
 311                         goto out;
 312         }
 313         adev = ACPI_COMPANION(dev);
 314         if (!adev)
 315                 goto out;
 316
 317         if (type && type->setup)
 318                 type->setup(dev);
 319         else if (adev->handler && adev->handler->bind)
 320                 adev->handler->bind(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_device *adev = ACPI_COMPANION(dev);
 340         struct acpi_bus_type *type;
 341
 342         if (!adev)
 343                 return 0;
 344
 345         type = acpi_get_bus_type(dev);
 346         if (type && type->cleanup)
 347                 type->cleanup(dev);
 348         else if (adev->handler && adev->handler->unbind)
 349                 adev->handler->unbind(dev);
 350
 351         acpi_unbind_one(dev);
 352         return 0;
 353 }
 354
 355 void __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;
 360         }
 361         platform_notify = acpi_platform_notify;
 362         platform_notify_remove = acpi_platform_notify_remove;
 363 }