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