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_find_child *find = context;
  99
 100         status = acpi_get_object_info(handle, &info);
 101         if (ACPI_SUCCESS(status)) {
 102                 if (info->address == find->address)
 103                         find->handle = handle;
 104                 kfree(info);
 105         }
 106         return AE_OK;
 107 }
 108
 109 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
 110 {
 111         struct acpi_find_child find = { NULL, address };
 112
 113         if (!parent)
 114                 return NULL;
 115         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 116                             1, do_acpi_find_child, NULL, &find, NULL);
 117         return find.handle;
 118 }
 119
 120 EXPORT_SYMBOL(acpi_get_child);
 121
 122 /* Link ACPI devices with physical devices */
 123 static void acpi_glue_data_handler(acpi_handle handle,
 124                                    void *context)
 125 {
 126         /* we provide an empty handler */
 127 }
 128
 129 /* Note: a success call will increase reference count by one */
 130 struct device *acpi_get_physical_device(acpi_handle handle)
 131 {
 132         acpi_status status;
 133         struct device *dev;
 134
 135         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 136         if (ACPI_SUCCESS(status))
 137                 return get_device(dev);
 138         return NULL;
 139 }
 140
 141 EXPORT_SYMBOL(acpi_get_physical_device);
 142
 143 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 144 {
 145         struct acpi_device *acpi_dev;
 146         acpi_status status;
 147
 148         if (dev->archdata.acpi_handle) {
 149                 dev_warn(dev, "Drivers changed 'acpi_handle'\n");
 150                 return -EINVAL;
 151         }
 152         get_device(dev);
 153         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 154         if (ACPI_FAILURE(status)) {
 155                 put_device(dev);
 156                 return -EINVAL;
 157         }
 158         dev->archdata.acpi_handle = handle;
 159
 160         status = acpi_bus_get_device(handle, &acpi_dev);
 161         if (!ACPI_FAILURE(status)) {
 162                 int ret;
 163
 164                 ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 165                                 "firmware_node");
 166                 ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 167                                 "physical_node");
 168                 if (acpi_dev->wakeup.flags.valid) {
 169                         device_set_wakeup_capable(dev, true);
 170                         device_set_wakeup_enable(dev,
 171                                                 acpi_dev->wakeup.state.enabled);
 172                 }
 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 }