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;
 134         char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
 135         int retval = -EINVAL;
 136
 137         if (dev->archdata.acpi_handle) {
 138                 dev_warn(dev, "Drivers changed 'acpi_handle'\n");
 139                 return -EINVAL;
 140         }
 141
 142         get_device(dev);
 143         status = acpi_bus_get_device(handle, &acpi_dev);
 144         if (ACPI_FAILURE(status))
 145                 goto err;
 146
 147         physical_node = kzalloc(sizeof(struct acpi_device_physical_node),
 148                 GFP_KERNEL);
 149         if (!physical_node) {
 150                 retval = -ENOMEM;
 151                 goto err;
 152         }
 153
 154         mutex_lock(&acpi_dev->physical_node_lock);
 155         /* allocate physical node id according to physical_node_id_bitmap */
 156         physical_node->node_id =
 157                 find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
 158                 ACPI_MAX_PHYSICAL_NODE);
 159         if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
 160                 retval = -ENOSPC;
 161                 mutex_unlock(&acpi_dev->physical_node_lock);
 162                 goto err;
 163         }
 164
 165         set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
 166         physical_node->dev = dev;
 167         list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
 168         acpi_dev->physical_node_count++;
 169         mutex_unlock(&acpi_dev->physical_node_lock);
 170
 171         dev->archdata.acpi_handle = handle;
 172
 173         if (!physical_node->node_id)
 174                 strcpy(physical_node_name, PHYSICAL_NODE_STRING);
 175         else
 176                 sprintf(physical_node_name,
 177                         "physical_node%d", physical_node->node_id);
 178         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 179                         physical_node_name);
 180         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 181                 "firmware_node");
 182
 183         if (acpi_dev->wakeup.flags.valid)
 184                 device_set_wakeup_capable(dev, true);
 185
 186         return 0;
 187
 188  err:
 189         put_device(dev);
 190         return retval;
 191 }
 192
 193 static int acpi_unbind_one(struct device *dev)
 194 {
 195         struct acpi_device_physical_node *entry;
 196         struct acpi_device *acpi_dev;
 197         acpi_status status;
 198         struct list_head *node, *next;
 199
 200         if (!dev->archdata.acpi_handle)
 201                 return 0;
 202
 203         status = acpi_bus_get_device(dev->archdata.acpi_handle,
 204                 &acpi_dev);
 205         if (ACPI_FAILURE(status))
 206                 goto err;
 207
 208         mutex_lock(&acpi_dev->physical_node_lock);
 209         list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
 210                 char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
 211
 212                 entry = list_entry(node, struct acpi_device_physical_node,
 213                         node);
 214                 if (entry->dev != dev)
 215                         continue;
 216
 217                 list_del(node);
 218                 clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);
 219
 220                 acpi_dev->physical_node_count--;
 221
 222                 if (!entry->node_id)
 223                         strcpy(physical_node_name, PHYSICAL_NODE_STRING);
 224                 else
 225                         sprintf(physical_node_name,
 226                                 "physical_node%d", entry->node_id);
 227
 228                 sysfs_remove_link(&acpi_dev->dev.kobj, physical_node_name);
 229                 sysfs_remove_link(&dev->kobj, "firmware_node");
 230                 dev->archdata.acpi_handle = NULL;
 231                 /* acpi_bind_one increase refcnt by one */
 232                 put_device(dev);
 233                 kfree(entry);
 234         }
 235         mutex_unlock(&acpi_dev->physical_node_lock);
 236
 237         return 0;
 238
 239 err:
 240         dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 241         return -EINVAL;
 242 }
 243
 244 static int acpi_platform_notify(struct device *dev)
 245 {
 246         struct acpi_bus_type *type;
 247         acpi_handle handle;
 248         int ret = -EINVAL;
 249
 250         if (!dev->bus || !dev->parent) {
 251                 /* bridge devices genernally haven't bus or parent */
 252                 ret = acpi_find_bridge_device(dev, &handle);
 253                 goto end;
 254         }
 255         type = acpi_get_bus_type(dev->bus);
 256         if (!type) {
 257                 DBG("No ACPI bus support for %s\n", dev_name(dev));
 258                 ret = -EINVAL;
 259                 goto end;
 260         }
 261         if ((ret = type->find_device(dev, &handle)) != 0)
 262                 DBG("Can't get handler for %s\n", dev_name(dev));
 263       end:
 264         if (!ret)
 265                 acpi_bind_one(dev, handle);
 266
 267 #if ACPI_GLUE_DEBUG
 268         if (!ret) {
 269                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 270
 271                 acpi_get_name(dev->archdata.acpi_handle,
 272                               ACPI_FULL_PATHNAME, &buffer);
 273                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 274                 kfree(buffer.pointer);
 275         } else
 276                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 277 #endif
 278
 279         return ret;
 280 }
 281
 282 static int acpi_platform_notify_remove(struct device *dev)
 283 {
 284         acpi_unbind_one(dev);
 285         return 0;
 286 }
 287
 288 int __init init_acpi_device_notify(void)
 289 {
 290         if (platform_notify || platform_notify_remove) {
 291                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 292                 return 0;
 293         }
 294         platform_notify = acpi_platform_notify;
 295         platform_notify_remove = acpi_platform_notify_remove;
 296         return 0;
 297 }