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 int register_acpi_bus_type(struct acpi_bus_type *type)
  29 {
  30         if (acpi_disabled)
  31                 return -ENODEV;
  32         if (type && type->bus && type->find_device) {
  33                 down_write(&bus_type_sem);
  34                 list_add_tail(&type->list, &bus_type_list);
  35                 up_write(&bus_type_sem);
  36                 printk(KERN_INFO PREFIX "bus type %s registered\n",
  37                        type->bus->name);
  38                 return 0;
  39         }
  40         return -ENODEV;
  41 }
  42 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  43
  44 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  45 {
  46         if (acpi_disabled)
  47                 return 0;
  48         if (type) {
  49                 down_write(&bus_type_sem);
  50                 list_del_init(&type->list);
  51                 up_write(&bus_type_sem);
  52                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  53                        type->bus->name);
  54                 return 0;
  55         }
  56         return -ENODEV;
  57 }
  58 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  59
  60 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  61 {
  62         struct acpi_bus_type *tmp, *ret = NULL;
  63
  64         down_read(&bus_type_sem);
  65         list_for_each_entry(tmp, &bus_type_list, list) {
  66                 if (tmp->bus == type) {
  67                         ret = tmp;
  68                         break;
  69                 }
  70         }
  71         up_read(&bus_type_sem);
  72         return ret;
  73 }
  74
  75 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  76 {
  77         struct acpi_bus_type *tmp;
  78         int ret = -ENODEV;
  79
  80         down_read(&bus_type_sem);
  81         list_for_each_entry(tmp, &bus_type_list, list) {
  82                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  83                         ret = 0;
  84                         break;
  85                 }
  86         }
  87         up_read(&bus_type_sem);
  88         return ret;
  89 }
  90
  91 /* Get device's handler per its address under its parent */
  92 struct acpi_find_child {
  93         acpi_handle handle;
  94         u64 address;
  95 };
  96
  97 static acpi_status
  98 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
  99 {
 100         acpi_status status;
 101         struct acpi_device_info *info;
 102         struct acpi_find_child *find = context;
 103
 104         status = acpi_get_object_info(handle, &info);
 105         if (ACPI_SUCCESS(status)) {
 106                 if ((info->address == find->address)
 107                         && (info->valid & ACPI_VALID_ADR))
 108                         find->handle = handle;
 109                 kfree(info);
 110         }
 111         return AE_OK;
 112 }
 113
 114 acpi_handle acpi_get_child(acpi_handle parent, u64 address)
 115 {
 116         struct acpi_find_child find = { NULL, address };
 117
 118         if (!parent)
 119                 return NULL;
 120         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 121                             1, do_acpi_find_child, NULL, &find, NULL);
 122         return find.handle;
 123 }
 124
 125 EXPORT_SYMBOL(acpi_get_child);
 126
 127 /* Link ACPI devices with physical devices */
 128 static void acpi_glue_data_handler(acpi_handle handle,
 129                                    void *context)
 130 {
 131         /* we provide an empty handler */
 132 }
 133
 134 /* Note: a success call will increase reference count by one */
 135 struct device *acpi_get_physical_device(acpi_handle handle)
 136 {
 137         acpi_status status;
 138         struct device *dev;
 139
 140         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 141         if (ACPI_SUCCESS(status))
 142                 return get_device(dev);
 143         return NULL;
 144 }
 145
 146 EXPORT_SYMBOL(acpi_get_physical_device);
 147
 148 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 149 {
 150         struct acpi_device *acpi_dev;
 151         acpi_status status;
 152
 153         if (dev->archdata.acpi_handle) {
 154                 dev_warn(dev, "Drivers changed 'acpi_handle'\n");
 155                 return -EINVAL;
 156         }
 157         get_device(dev);
 158         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 159         if (ACPI_FAILURE(status)) {
 160                 put_device(dev);
 161                 return -EINVAL;
 162         }
 163         dev->archdata.acpi_handle = handle;
 164
 165         status = acpi_bus_get_device(handle, &acpi_dev);
 166         if (!ACPI_FAILURE(status)) {
 167                 int ret;
 168
 169                 ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 170                                 "firmware_node");
 171                 ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 172                                 "physical_node");
 173                 if (acpi_dev->wakeup.flags.valid)
 174                         device_set_wakeup_capable(dev, true);
 175         }
 176
 177         return 0;
 178 }
 179
 180 static int acpi_unbind_one(struct device *dev)
 181 {
 182         if (!dev->archdata.acpi_handle)
 183                 return 0;
 184         if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
 185                 struct acpi_device *acpi_dev;
 186
 187                 /* acpi_get_physical_device increase refcnt by one */
 188                 put_device(dev);
 189
 190                 if (!acpi_bus_get_device(dev->archdata.acpi_handle,
 191                                         &acpi_dev)) {
 192                         sysfs_remove_link(&dev->kobj, "firmware_node");
 193                         sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
 194                 }
 195
 196                 acpi_detach_data(dev->archdata.acpi_handle,
 197                                  acpi_glue_data_handler);
 198                 dev->archdata.acpi_handle = NULL;
 199                 /* acpi_bind_one increase refcnt by one */
 200                 put_device(dev);
 201         } else {
 202                 dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 203         }
 204         return 0;
 205 }
 206
 207 static int acpi_platform_notify(struct device *dev)
 208 {
 209         struct acpi_bus_type *type;
 210         acpi_handle handle;
 211         int ret = -EINVAL;
 212
 213         if (!dev->bus || !dev->parent) {
 214                 /* bridge devices genernally haven't bus or parent */
 215                 ret = acpi_find_bridge_device(dev, &handle);
 216                 goto end;
 217         }
 218         type = acpi_get_bus_type(dev->bus);
 219         if (!type) {
 220                 DBG("No ACPI bus support for %s\n", dev_name(dev));
 221                 ret = -EINVAL;
 222                 goto end;
 223         }
 224         if ((ret = type->find_device(dev, &handle)) != 0)
 225                 DBG("Can't get handler for %s\n", dev_name(dev));
 226       end:
 227         if (!ret)
 228                 acpi_bind_one(dev, handle);
 229
 230 #if ACPI_GLUE_DEBUG
 231         if (!ret) {
 232                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 233
 234                 acpi_get_name(dev->archdata.acpi_handle,
 235                               ACPI_FULL_PATHNAME, &buffer);
 236                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 237                 kfree(buffer.pointer);
 238         } else
 239                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 240 #endif
 241
 242         return ret;
 243 }
 244
 245 static int acpi_platform_notify_remove(struct device *dev)
 246 {
 247         acpi_unbind_one(dev);
 248         return 0;
 249 }
 250
 251 int __init init_acpi_device_notify(void)
 252 {
 253         if (platform_notify || platform_notify_remove) {
 254                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 255                 return 0;
 256         }
 257         platform_notify = acpi_platform_notify;
 258         platform_notify_remove = acpi_platform_notify_remove;
 259         return 0;
 260 }