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
  35 int register_acpi_bus_type(struct acpi_bus_type *type)
  36 {
  37         if (acpi_disabled)
  38                 return -ENODEV;
  39         if (type && type->bus && type->find_device) {
  40                 down_write(&bus_type_sem);
  41                 list_add_tail(&type->list, &bus_type_list);
  42                 up_write(&bus_type_sem);
  43                 printk(KERN_INFO PREFIX "bus type %s registered\n",
  44                        type->bus->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 "ACPI bus type %s unregistered\n",
  60                        type->bus->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 bus_type *type)
  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->bus == type) {
  74                         ret = tmp;
  75                         break;
  76                 }
  77         }
  78         up_read(&bus_type_sem);
  79         return ret;
  80 }
  81
  82 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  83 {
  84         struct acpi_bus_type *tmp;
  85         int ret = -ENODEV;
  86
  87         down_read(&bus_type_sem);
  88         list_for_each_entry(tmp, &bus_type_list, list) {
  89                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  90                         ret = 0;
  91                         break;
  92                 }
  93         }
  94         up_read(&bus_type_sem);
  95         return ret;
  96 }
  97
  98 /* Get device's handler per its address under its parent */
  99 struct acpi_find_child {
 100         acpi_handle handle;
 101         u64 address;
 102 };
 103
 104 static acpi_status
 105 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
 106 {
 107         acpi_status status;
 108         struct acpi_device_info *info;
 109         struct acpi_find_child *find = context;
 110
 111         status = acpi_get_object_info(handle, &info);
 112         if (ACPI_SUCCESS(status)) {
 113                 if ((info->address == find->address)
 114                         && (info->valid & ACPI_VALID_ADR))
 115                         find->handle = handle;
 116                 kfree(info);
 117         }
 118         return AE_OK;
 119 }
 120
 121 acpi_handle acpi_get_child(acpi_handle parent, u64 address)
 122 {
 123         struct acpi_find_child find = { NULL, address };
 124
 125         if (!parent)
 126                 return NULL;
 127         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 128                             1, do_acpi_find_child, NULL, &find, NULL);
 129         return find.handle;
 130 }
 131
 132 EXPORT_SYMBOL(acpi_get_child);
 133
 134 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 135 {
 136         struct acpi_device *acpi_dev;
 137         acpi_status status;
 138         struct acpi_device_physical_node *physical_node, *pn;
 139         char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
 140         int retval = -EINVAL;
 141
 142         if (ACPI_HANDLE(dev)) {
 143                 if (handle) {
 144                         dev_warn(dev, "ACPI handle is already set\n");
 145                         return -EINVAL;
 146                 } else {
 147                         handle = ACPI_HANDLE(dev);
 148                 }
 149         }
 150         if (!handle)
 151                 return -EINVAL;
 152
 153         get_device(dev);
 154         status = acpi_bus_get_device(handle, &acpi_dev);
 155         if (ACPI_FAILURE(status))
 156                 goto err;
 157
 158         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 159         if (!physical_node) {
 160                 retval = -ENOMEM;
 161                 goto err;
 162         }
 163
 164         mutex_lock(&acpi_dev->physical_node_lock);
 165
 166         /* Sanity check. */
 167         list_for_each_entry(pn, &acpi_dev->physical_node_list, node)
 168                 if (pn->dev == dev) {
 169                         dev_warn(dev, "Already associated with ACPI node\n");
 170                         goto err_free;
 171                 }
 172
 173         /* allocate physical node id according to physical_node_id_bitmap */
 174         physical_node->node_id =
 175                 find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
 176                 ACPI_MAX_PHYSICAL_NODE);
 177         if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
 178                 retval = -ENOSPC;
 179                 goto err_free;
 180         }
 181
 182         set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
 183         physical_node->dev = dev;
 184         list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
 185         acpi_dev->physical_node_count++;
 186
 187         mutex_unlock(&acpi_dev->physical_node_lock);
 188
 189         if (!ACPI_HANDLE(dev))
 190                 ACPI_HANDLE_SET(dev, acpi_dev->handle);
 191
 192         if (!physical_node->node_id)
 193                 strcpy(physical_node_name, PHYSICAL_NODE_STRING);
 194         else
 195                 sprintf(physical_node_name,
 196                         "physical_node%d", physical_node->node_id);
 197         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 198                         physical_node_name);
 199         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 200                 "firmware_node");
 201
 202         if (acpi_dev->wakeup.flags.valid)
 203                 device_set_wakeup_capable(dev, true);
 204
 205         return 0;
 206
 207  err:
 208         ACPI_HANDLE_SET(dev, NULL);
 209         put_device(dev);
 210         return retval;
 211
 212  err_free:
 213         mutex_unlock(&acpi_dev->physical_node_lock);
 214         kfree(physical_node);
 215         goto err;
 216 }
 217
 218 static int acpi_unbind_one(struct device *dev)
 219 {
 220         struct acpi_device_physical_node *entry;
 221         struct acpi_device *acpi_dev;
 222         acpi_status status;
 223         struct list_head *node, *next;
 224
 225         if (!ACPI_HANDLE(dev))
 226                 return 0;
 227
 228         status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
 229         if (ACPI_FAILURE(status))
 230                 goto err;
 231
 232         mutex_lock(&acpi_dev->physical_node_lock);
 233         list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
 234                 char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
 235
 236                 entry = list_entry(node, struct acpi_device_physical_node,
 237                         node);
 238                 if (entry->dev != dev)
 239                         continue;
 240
 241                 list_del(node);
 242                 clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);
 243
 244                 acpi_dev->physical_node_count--;
 245
 246                 if (!entry->node_id)
 247                         strcpy(physical_node_name, PHYSICAL_NODE_STRING);
 248                 else
 249                         sprintf(physical_node_name,
 250                                 "physical_node%d", entry->node_id);
 251
 252                 sysfs_remove_link(&acpi_dev->dev.kobj, physical_node_name);
 253                 sysfs_remove_link(&dev->kobj, "firmware_node");
 254                 ACPI_HANDLE_SET(dev, NULL);
 255                 /* acpi_bind_one increase refcnt by one */
 256                 put_device(dev);
 257                 kfree(entry);
 258         }
 259         mutex_unlock(&acpi_dev->physical_node_lock);
 260
 261         return 0;
 262
 263 err:
 264         dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 265         return -EINVAL;
 266 }
 267
 268 static int acpi_platform_notify(struct device *dev)
 269 {
 270         struct acpi_bus_type *type;
 271         acpi_handle handle;
 272         int ret = -EINVAL;
 273
 274         ret = acpi_bind_one(dev, NULL);
 275         if (!ret)
 276                 goto out;
 277
 278         if (!dev->bus || !dev->parent) {
 279                 /* bridge devices genernally haven't bus or parent */
 280                 ret = acpi_find_bridge_device(dev, &handle);
 281                 goto end;
 282         }
 283         type = acpi_get_bus_type(dev->bus);
 284         if (!type) {
 285                 DBG("No ACPI bus support for %s\n", dev_name(dev));
 286                 ret = -EINVAL;
 287                 goto end;
 288         }
 289         if ((ret = type->find_device(dev, &handle)) != 0)
 290                 DBG("Can't get handler for %s\n", dev_name(dev));
 291  end:
 292         if (!ret)
 293                 acpi_bind_one(dev, handle);
 294
 295  out:
 296 #if ACPI_GLUE_DEBUG
 297         if (!ret) {
 298                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 299
 300                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 301                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 302                 kfree(buffer.pointer);
 303         } else
 304                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 305 #endif
 306
 307         return ret;
 308 }
 309
 310 static int acpi_platform_notify_remove(struct device *dev)
 311 {
 312         acpi_unbind_one(dev);
 313         return 0;
 314 }
 315
 316 int __init init_acpi_device_notify(void)
 317 {
 318         if (platform_notify || platform_notify_remove) {
 319                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 320                 return 0;
 321         }
 322         platform_notify = acpi_platform_notify;
 323         platform_notify_remove = acpi_platform_notify_remove;
 324         return 0;
 325 }