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(x...) printk(PREFIX x)
  22 #else
  23 #define DBG(x...) do { } while(0)
  24 #endif
  25 static LIST_HEAD(bus_type_list);
  26 static DECLARE_RWSEM(bus_type_sem);
  27
  28 #define PHYSICAL_NODE_STRING "physical_node"
  29
  30 int register_acpi_bus_type(struct acpi_bus_type *type)
  31 {
  32         if (acpi_disabled)
  33                 return -ENODEV;
  34         if (type && type->bus && type->find_device) {
  35                 down_write(&bus_type_sem);
  36                 list_add_tail(&type->list, &bus_type_list);
  37                 up_write(&bus_type_sem);
  38                 printk(KERN_INFO PREFIX "bus type %s registered\n",
  39                        type->bus->name);
  40                 return 0;
  41         }
  42         return -ENODEV;
  43 }
  44 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  45
  46 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  47 {
  48         if (acpi_disabled)
  49                 return 0;
  50         if (type) {
  51                 down_write(&bus_type_sem);
  52                 list_del_init(&type->list);
  53                 up_write(&bus_type_sem);
  54                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  55                        type->bus->name);
  56                 return 0;
  57         }
  58         return -ENODEV;
  59 }
  60 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  61
  62 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  63 {
  64         struct acpi_bus_type *tmp, *ret = NULL;
  65
  66         down_read(&bus_type_sem);
  67         list_for_each_entry(tmp, &bus_type_list, list) {
  68                 if (tmp->bus == type) {
  69                         ret = tmp;
  70                         break;
  71                 }
  72         }
  73         up_read(&bus_type_sem);
  74         return ret;
  75 }
  76
  77 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  78 {
  79         struct acpi_bus_type *tmp;
  80         int ret = -ENODEV;
  81
  82         down_read(&bus_type_sem);
  83         list_for_each_entry(tmp, &bus_type_list, list) {
  84                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  85                         ret = 0;
  86                         break;
  87                 }
  88         }
  89         up_read(&bus_type_sem);
  90         return ret;
  91 }
  92
  93 /* Get device's handler per its address under its parent */
  94 struct acpi_find_child {
  95         acpi_handle handle;
  96         u64 address;
  97 };
  98
  99 static acpi_status
 100 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
 101 {
 102         acpi_status status;
 103         struct acpi_device_info *info;
 104         struct acpi_find_child *find = context;
 105
 106         status = acpi_get_object_info(handle, &info);
 107         if (ACPI_SUCCESS(status)) {
 108                 if ((info->address == find->address)
 109                         && (info->valid & ACPI_VALID_ADR))
 110                         find->handle = handle;
 111                 kfree(info);
 112         }
 113         return AE_OK;
 114 }
 115
 116 acpi_handle acpi_get_child(acpi_handle parent, u64 address)
 117 {
 118         struct acpi_find_child find = { NULL, address };
 119
 120         if (!parent)
 121                 return NULL;
 122         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 123                             1, do_acpi_find_child, NULL, &find, NULL);
 124         return find.handle;
 125 }
 126
 127 EXPORT_SYMBOL(acpi_get_child);
 128
 129 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 130 {
 131         struct acpi_device *acpi_dev;
 132         acpi_status status;
 133         struct acpi_device_physical_node *physical_node, *pn;
 134         char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
 135         int retval = -EINVAL;
 136
 137         if (ACPI_HANDLE(dev)) {
 138                 if (handle) {
 139                         dev_warn(dev, "ACPI handle is already set\n");
 140                         return -EINVAL;
 141                 } else {
 142                         handle = ACPI_HANDLE(dev);
 143                 }
 144         }
 145         if (!handle)
 146                 return -EINVAL;
 147
 148         get_device(dev);
 149         status = acpi_bus_get_device(handle, &acpi_dev);
 150         if (ACPI_FAILURE(status))
 151                 goto err;
 152
 153         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 154         if (!physical_node) {
 155                 retval = -ENOMEM;
 156                 goto err;
 157         }
 158
 159         mutex_lock(&acpi_dev->physical_node_lock);
 160
 161         /* Sanity check. */
 162         list_for_each_entry(pn, &acpi_dev->physical_node_list, node)
 163                 if (pn->dev == dev) {
 164                         dev_warn(dev, "Already associated with ACPI node\n");
 165                         goto err_free;
 166                 }
 167
 168         /* allocate physical node id according to physical_node_id_bitmap */
 169         physical_node->node_id =
 170                 find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
 171                 ACPI_MAX_PHYSICAL_NODE);
 172         if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
 173                 retval = -ENOSPC;
 174                 goto err_free;
 175         }
 176
 177         set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
 178         physical_node->dev = dev;
 179         list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
 180         acpi_dev->physical_node_count++;
 181
 182         mutex_unlock(&acpi_dev->physical_node_lock);
 183
 184         if (!ACPI_HANDLE(dev))
 185                 ACPI_HANDLE_SET(dev, acpi_dev->handle);
 186
 187         if (!physical_node->node_id)
 188                 strcpy(physical_node_name, PHYSICAL_NODE_STRING);
 189         else
 190                 sprintf(physical_node_name,
 191                         "physical_node%d", physical_node->node_id);
 192         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 193                         physical_node_name);
 194         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 195                 "firmware_node");
 196
 197         if (acpi_dev->wakeup.flags.valid)
 198                 device_set_wakeup_capable(dev, true);
 199
 200         return 0;
 201
 202  err:
 203         ACPI_HANDLE_SET(dev, NULL);
 204         put_device(dev);
 205         return retval;
 206
 207  err_free:
 208         mutex_unlock(&acpi_dev->physical_node_lock);
 209         kfree(physical_node);
 210         goto err;
 211 }
 212
 213 static int acpi_unbind_one(struct device *dev)
 214 {
 215         struct acpi_device_physical_node *entry;
 216         struct acpi_device *acpi_dev;
 217         acpi_status status;
 218         struct list_head *node, *next;
 219
 220         if (!ACPI_HANDLE(dev))
 221                 return 0;
 222
 223         status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
 224         if (ACPI_FAILURE(status))
 225                 goto err;
 226
 227         mutex_lock(&acpi_dev->physical_node_lock);
 228         list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
 229                 char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
 230
 231                 entry = list_entry(node, struct acpi_device_physical_node,
 232                         node);
 233                 if (entry->dev != dev)
 234                         continue;
 235
 236                 list_del(node);
 237                 clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);
 238
 239                 acpi_dev->physical_node_count--;
 240
 241                 if (!entry->node_id)
 242                         strcpy(physical_node_name, PHYSICAL_NODE_STRING);
 243                 else
 244                         sprintf(physical_node_name,
 245                                 "physical_node%d", entry->node_id);
 246
 247                 sysfs_remove_link(&acpi_dev->dev.kobj, physical_node_name);
 248                 sysfs_remove_link(&dev->kobj, "firmware_node");
 249                 ACPI_HANDLE_SET(dev, NULL);
 250                 /* acpi_bind_one increase refcnt by one */
 251                 put_device(dev);
 252                 kfree(entry);
 253         }
 254         mutex_unlock(&acpi_dev->physical_node_lock);
 255
 256         return 0;
 257
 258 err:
 259         dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 260         return -EINVAL;
 261 }
 262
 263 static int acpi_platform_notify(struct device *dev)
 264 {
 265         struct acpi_bus_type *type;
 266         acpi_handle handle;
 267         int ret = -EINVAL;
 268
 269         ret = acpi_bind_one(dev, NULL);
 270         if (!ret)
 271                 goto out;
 272
 273         if (!dev->bus || !dev->parent) {
 274                 /* bridge devices genernally haven't bus or parent */
 275                 ret = acpi_find_bridge_device(dev, &handle);
 276                 goto end;
 277         }
 278         type = acpi_get_bus_type(dev->bus);
 279         if (!type) {
 280                 DBG("No ACPI bus support for %s\n", dev_name(dev));
 281                 ret = -EINVAL;
 282                 goto end;
 283         }
 284         if ((ret = type->find_device(dev, &handle)) != 0)
 285                 DBG("Can't get handler for %s\n", dev_name(dev));
 286  end:
 287         if (!ret)
 288                 acpi_bind_one(dev, handle);
 289
 290  out:
 291 #if ACPI_GLUE_DEBUG
 292         if (!ret) {
 293                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 294
 295                 acpi_get_name(dev->acpi_handle, ACPI_FULL_PATHNAME, &buffer);
 296                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 297                 kfree(buffer.pointer);
 298         } else
 299                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 300 #endif
 301
 302         return ret;
 303 }
 304
 305 static int acpi_platform_notify_remove(struct device *dev)
 306 {
 307         acpi_unbind_one(dev);
 308         return 0;
 309 }
 310
 311 int __init init_acpi_device_notify(void)
 312 {
 313         if (platform_notify || platform_notify_remove) {
 314                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 315                 return 0;
 316         }
 317         platform_notify = acpi_platform_notify;
 318         platform_notify_remove = acpi_platform_notify_remove;
 319         return 0;
 320 }