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/init.h>
  10 #include <linux/list.h>
  11 #include <linux/device.h>
  12 #include <linux/rwsem.h>
  13 #include <linux/acpi.h>
  14
  15 #define ACPI_GLUE_DEBUG 0
  16 #if ACPI_GLUE_DEBUG
  17 #define DBG(x...) printk(PREFIX x)
  18 #else
  19 #define DBG(x...) do { } while(0)
  20 #endif
  21 static LIST_HEAD(bus_type_list);
  22 static DECLARE_RWSEM(bus_type_sem);
  23
  24 int register_acpi_bus_type(struct acpi_bus_type *type)
  25 {
  26         if (acpi_disabled)
  27                 return -ENODEV;
  28         if (type && type->bus && type->find_device) {
  29                 down_write(&bus_type_sem);
  30                 list_add_tail(&type->list, &bus_type_list);
  31                 up_write(&bus_type_sem);
  32                 printk(KERN_INFO PREFIX "bus type %s registered\n",
  33                        type->bus->name);
  34                 return 0;
  35         }
  36         return -ENODEV;
  37 }
  38
  39 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  40 {
  41         if (acpi_disabled)
  42                 return 0;
  43         if (type) {
  44                 down_write(&bus_type_sem);
  45                 list_del_init(&type->list);
  46                 up_write(&bus_type_sem);
  47                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  48                        type->bus->name);
  49                 return 0;
  50         }
  51         return -ENODEV;
  52 }
  53
  54 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  55 {
  56         struct acpi_bus_type *tmp, *ret = NULL;
  57
  58         down_read(&bus_type_sem);
  59         list_for_each_entry(tmp, &bus_type_list, list) {
  60                 if (tmp->bus == type) {
  61                         ret = tmp;
  62                         break;
  63                 }
  64         }
  65         up_read(&bus_type_sem);
  66         return ret;
  67 }
  68
  69 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  70 {
  71         struct acpi_bus_type *tmp;
  72         int ret = -ENODEV;
  73
  74         down_read(&bus_type_sem);
  75         list_for_each_entry(tmp, &bus_type_list, list) {
  76                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  77                         ret = 0;
  78                         break;
  79                 }
  80         }
  81         up_read(&bus_type_sem);
  82         return ret;
  83 }
  84
  85 /* Get device's handler per its address under its parent */
  86 struct acpi_find_child {
  87         acpi_handle handle;
  88         acpi_integer address;
  89 };
  90
  91 static acpi_status
  92 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
  93 {
  94         acpi_status status;
  95         struct acpi_device_info *info;
  96         struct acpi_find_child *find = context;
  97
  98         status = acpi_get_object_info(handle, &info);
  99         if (ACPI_SUCCESS(status)) {
 100                 if (info->address == find->address)
 101                         find->handle = handle;
 102                 kfree(info);
 103         }
 104         return AE_OK;
 105 }
 106
 107 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
 108 {
 109         struct acpi_find_child find = { NULL, address };
 110
 111         if (!parent)
 112                 return NULL;
 113         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 114                             1, do_acpi_find_child, &find, NULL);
 115         return find.handle;
 116 }
 117
 118 EXPORT_SYMBOL(acpi_get_child);
 119
 120 /* Link ACPI devices with physical devices */
 121 static void acpi_glue_data_handler(acpi_handle handle,
 122                                    u32 function, void *context)
 123 {
 124         /* we provide an empty handler */
 125 }
 126
 127 /* Note: a success call will increase reference count by one */
 128 struct device *acpi_get_physical_device(acpi_handle handle)
 129 {
 130         acpi_status status;
 131         struct device *dev;
 132
 133         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 134         if (ACPI_SUCCESS(status))
 135                 return get_device(dev);
 136         return NULL;
 137 }
 138
 139 EXPORT_SYMBOL(acpi_get_physical_device);
 140
 141 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 142 {
 143         struct acpi_device *acpi_dev;
 144         acpi_status status;
 145
 146         if (dev->archdata.acpi_handle) {
 147                 dev_warn(dev, "Drivers changed 'acpi_handle'\n");
 148                 return -EINVAL;
 149         }
 150         get_device(dev);
 151         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 152         if (ACPI_FAILURE(status)) {
 153                 put_device(dev);
 154                 return -EINVAL;
 155         }
 156         dev->archdata.acpi_handle = handle;
 157
 158         status = acpi_bus_get_device(handle, &acpi_dev);
 159         if (!ACPI_FAILURE(status)) {
 160                 int ret;
 161
 162                 ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 163                                 "firmware_node");
 164                 ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 165                                 "physical_node");
 166                 if (acpi_dev->wakeup.flags.valid) {
 167                         device_set_wakeup_capable(dev, true);
 168                         device_set_wakeup_enable(dev,
 169                                                 acpi_dev->wakeup.state.enabled);
 170                 }
 171         }
 172
 173         return 0;
 174 }
 175
 176 static int acpi_unbind_one(struct device *dev)
 177 {
 178         if (!dev->archdata.acpi_handle)
 179                 return 0;
 180         if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
 181                 struct acpi_device *acpi_dev;
 182
 183                 /* acpi_get_physical_device increase refcnt by one */
 184                 put_device(dev);
 185
 186                 if (!acpi_bus_get_device(dev->archdata.acpi_handle,
 187                                         &acpi_dev)) {
 188                         sysfs_remove_link(&dev->kobj, "firmware_node");
 189                         sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
 190                 }
 191
 192                 acpi_detach_data(dev->archdata.acpi_handle,
 193                                  acpi_glue_data_handler);
 194                 dev->archdata.acpi_handle = NULL;
 195                 /* acpi_bind_one increase refcnt by one */
 196                 put_device(dev);
 197         } else {
 198                 dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 199         }
 200         return 0;
 201 }
 202
 203 static int acpi_platform_notify(struct device *dev)
 204 {
 205         struct acpi_bus_type *type;
 206         acpi_handle handle;
 207         int ret = -EINVAL;
 208
 209         if (!dev->bus || !dev->parent) {
 210                 /* bridge devices genernally haven't bus or parent */
 211                 ret = acpi_find_bridge_device(dev, &handle);
 212                 goto end;
 213         }
 214         type = acpi_get_bus_type(dev->bus);
 215         if (!type) {
 216                 DBG("No ACPI bus support for %s\n", dev_name(dev));
 217                 ret = -EINVAL;
 218                 goto end;
 219         }
 220         if ((ret = type->find_device(dev, &handle)) != 0)
 221                 DBG("Can't get handler for %s\n", dev_name(dev));
 222       end:
 223         if (!ret)
 224                 acpi_bind_one(dev, handle);
 225
 226 #if ACPI_GLUE_DEBUG
 227         if (!ret) {
 228                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 229
 230                 acpi_get_name(dev->archdata.acpi_handle,
 231                               ACPI_FULL_PATHNAME, &buffer);
 232                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 233                 kfree(buffer.pointer);
 234         } else
 235                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 236 #endif
 237
 238         return ret;
 239 }
 240
 241 static int acpi_platform_notify_remove(struct device *dev)
 242 {
 243         acpi_unbind_one(dev);
 244         return 0;
 245 }
 246
 247 int __init init_acpi_device_notify(void)
 248 {
 249         if (platform_notify || platform_notify_remove) {
 250                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 251                 return 0;
 252         }
 253         platform_notify = acpi_platform_notify;
 254         platform_notify_remove = acpi_platform_notify_remove;
 255         return 0;
 256 }