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 #include "internal.h"
  16
  17 #define ACPI_GLUE_DEBUG 0
  18 #if ACPI_GLUE_DEBUG
  19 #define DBG(x...) printk(PREFIX x)
  20 #else
  21 #define DBG(x...) do { } while(0)
  22 #endif
  23 static LIST_HEAD(bus_type_list);
  24 static DECLARE_RWSEM(bus_type_sem);
  25
  26 int register_acpi_bus_type(struct acpi_bus_type *type)
  27 {
  28         if (acpi_disabled)
  29                 return -ENODEV;
  30         if (type && type->bus && type->find_device) {
  31                 down_write(&bus_type_sem);
  32                 list_add_tail(&type->list, &bus_type_list);
  33                 up_write(&bus_type_sem);
  34                 printk(KERN_INFO PREFIX "bus type %s registered\n",
  35                        type->bus->name);
  36                 return 0;
  37         }
  38         return -ENODEV;
  39 }
  40
  41 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  42 {
  43         if (acpi_disabled)
  44                 return 0;
  45         if (type) {
  46                 down_write(&bus_type_sem);
  47                 list_del_init(&type->list);
  48                 up_write(&bus_type_sem);
  49                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  50                        type->bus->name);
  51                 return 0;
  52         }
  53         return -ENODEV;
  54 }
  55
  56 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  57 {
  58         struct acpi_bus_type *tmp, *ret = NULL;
  59
  60         down_read(&bus_type_sem);
  61         list_for_each_entry(tmp, &bus_type_list, list) {
  62                 if (tmp->bus == type) {
  63                         ret = tmp;
  64                         break;
  65                 }
  66         }
  67         up_read(&bus_type_sem);
  68         return ret;
  69 }
  70
  71 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  72 {
  73         struct acpi_bus_type *tmp;
  74         int ret = -ENODEV;
  75
  76         down_read(&bus_type_sem);
  77         list_for_each_entry(tmp, &bus_type_list, list) {
  78                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  79                         ret = 0;
  80                         break;
  81                 }
  82         }
  83         up_read(&bus_type_sem);
  84         return ret;
  85 }
  86
  87 /* Get device's handler per its address under its parent */
  88 struct acpi_find_child {
  89         acpi_handle handle;
  90         acpi_integer address;
  91 };
  92
  93 static acpi_status
  94 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
  95 {
  96         acpi_status status;
  97         struct acpi_device_info *info;
  98         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  99         struct acpi_find_child *find = context;
 100
 101         status = acpi_get_object_info(handle, &buffer);
 102         if (ACPI_SUCCESS(status)) {
 103                 info = buffer.pointer;
 104                 if (info->address == find->address)
 105                         find->handle = handle;
 106                 kfree(buffer.pointer);
 107         }
 108         return AE_OK;
 109 }
 110
 111 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
 112 {
 113         struct acpi_find_child find = { NULL, address };
 114
 115         if (!parent)
 116                 return NULL;
 117         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 118                             1, do_acpi_find_child, &find, NULL);
 119         return find.handle;
 120 }
 121
 122 EXPORT_SYMBOL(acpi_get_child);
 123
 124 /* Link ACPI devices with physical devices */
 125 static void acpi_glue_data_handler(acpi_handle handle,
 126                                    u32 function, void *context)
 127 {
 128         /* we provide an empty handler */
 129 }
 130
 131 /* Note: a success call will increase reference count by one */
 132 struct device *acpi_get_physical_device(acpi_handle handle)
 133 {
 134         acpi_status status;
 135         struct device *dev;
 136
 137         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 138         if (ACPI_SUCCESS(status))
 139                 return get_device(dev);
 140         return NULL;
 141 }
 142
 143 EXPORT_SYMBOL(acpi_get_physical_device);
 144
 145 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 146 {
 147         struct acpi_device *acpi_dev;
 148         acpi_status status;
 149
 150         if (dev->archdata.acpi_handle) {
 151                 dev_warn(dev, "Drivers changed 'acpi_handle'\n");
 152                 return -EINVAL;
 153         }
 154         get_device(dev);
 155         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 156         if (ACPI_FAILURE(status)) {
 157                 put_device(dev);
 158                 return -EINVAL;
 159         }
 160         dev->archdata.acpi_handle = handle;
 161
 162         status = acpi_bus_get_device(handle, &acpi_dev);
 163         if (!ACPI_FAILURE(status)) {
 164                 int ret;
 165
 166                 ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 167                                 "firmware_node");
 168                 ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 169                                 "physical_node");
 170                 if (acpi_dev->wakeup.flags.valid) {
 171                         device_set_wakeup_capable(dev, true);
 172                         device_set_wakeup_enable(dev,
 173                                                 acpi_dev->wakeup.state.enabled);
 174                 }
 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 }