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/slab.h>
  13 #include <linux/rwsem.h>
  14 #include <linux/acpi.h>
  15
  16 #include "internal.h"
  17
  18 #define ACPI_GLUE_DEBUG 0
  19 #if ACPI_GLUE_DEBUG
  20 #define DBG(x...) printk(PREFIX x)
  21 #else
  22 #define DBG(x...) do { } while(0)
  23 #endif
  24 static LIST_HEAD(bus_type_list);
  25 static DECLARE_RWSEM(bus_type_sem);
  26
  27 int register_acpi_bus_type(struct acpi_bus_type *type)
  28 {
  29         if (acpi_disabled)
  30                 return -ENODEV;
  31         if (type && type->bus && type->find_device) {
  32                 down_write(&bus_type_sem);
  33                 list_add_tail(&type->list, &bus_type_list);
  34                 up_write(&bus_type_sem);
  35                 printk(KERN_INFO PREFIX "bus type %s registered\n",
  36                        type->bus->name);
  37                 return 0;
  38         }
  39         return -ENODEV;
  40 }
  41
  42 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  43 {
  44         if (acpi_disabled)
  45                 return 0;
  46         if (type) {
  47                 down_write(&bus_type_sem);
  48                 list_del_init(&type->list);
  49                 up_write(&bus_type_sem);
  50                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  51                        type->bus->name);
  52                 return 0;
  53         }
  54         return -ENODEV;
  55 }
  56
  57 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  58 {
  59         struct acpi_bus_type *tmp, *ret = NULL;
  60
  61         down_read(&bus_type_sem);
  62         list_for_each_entry(tmp, &bus_type_list, list) {
  63                 if (tmp->bus == type) {
  64                         ret = tmp;
  65                         break;
  66                 }
  67         }
  68         up_read(&bus_type_sem);
  69         return ret;
  70 }
  71
  72 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  73 {
  74         struct acpi_bus_type *tmp;
  75         int ret = -ENODEV;
  76
  77         down_read(&bus_type_sem);
  78         list_for_each_entry(tmp, &bus_type_list, list) {
  79                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  80                         ret = 0;
  81                         break;
  82                 }
  83         }
  84         up_read(&bus_type_sem);
  85         return ret;
  86 }
  87
  88 /* Get device's handler per its address under its parent */
  89 struct acpi_find_child {
  90         acpi_handle handle;
  91         u64 address;
  92 };
  93
  94 static acpi_status
  95 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
  96 {
  97         acpi_status status;
  98         struct acpi_device_info *info;
  99         struct acpi_find_child *find = context;
 100
 101         status = acpi_get_object_info(handle, &info);
 102         if (ACPI_SUCCESS(status)) {
 103                 if ((info->address == find->address)
 104                         && (info->valid & ACPI_VALID_ADR))
 105                         find->handle = handle;
 106                 kfree(info);
 107         }
 108         return AE_OK;
 109 }
 110
 111 acpi_handle acpi_get_child(acpi_handle parent, u64 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, NULL, &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                                    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         }
 173
 174         return 0;
 175 }
 176
 177 static int acpi_unbind_one(struct device *dev)
 178 {
 179         if (!dev->archdata.acpi_handle)
 180                 return 0;
 181         if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
 182                 struct acpi_device *acpi_dev;
 183
 184                 /* acpi_get_physical_device increase refcnt by one */
 185                 put_device(dev);
 186
 187                 if (!acpi_bus_get_device(dev->archdata.acpi_handle,
 188                                         &acpi_dev)) {
 189                         sysfs_remove_link(&dev->kobj, "firmware_node");
 190                         sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
 191                 }
 192
 193                 acpi_detach_data(dev->archdata.acpi_handle,
 194                                  acpi_glue_data_handler);
 195                 dev->archdata.acpi_handle = NULL;
 196                 /* acpi_bind_one increase refcnt by one */
 197                 put_device(dev);
 198         } else {
 199                 dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 200         }
 201         return 0;
 202 }
 203
 204 static int acpi_platform_notify(struct device *dev)
 205 {
 206         struct acpi_bus_type *type;
 207         acpi_handle handle;
 208         int ret = -EINVAL;
 209
 210         if (!dev->bus || !dev->parent) {
 211                 /* bridge devices genernally haven't bus or parent */
 212                 ret = acpi_find_bridge_device(dev, &handle);
 213                 goto end;
 214         }
 215         type = acpi_get_bus_type(dev->bus);
 216         if (!type) {
 217                 DBG("No ACPI bus support for %s\n", dev_name(dev));
 218                 ret = -EINVAL;
 219                 goto end;
 220         }
 221         if ((ret = type->find_device(dev, &handle)) != 0)
 222                 DBG("Can't get handler for %s\n", dev_name(dev));
 223       end:
 224         if (!ret)
 225                 acpi_bind_one(dev, handle);
 226
 227 #if ACPI_GLUE_DEBUG
 228         if (!ret) {
 229                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 230
 231                 acpi_get_name(dev->archdata.acpi_handle,
 232                               ACPI_FULL_PATHNAME, &buffer);
 233                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 234                 kfree(buffer.pointer);
 235         } else
 236                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 237 #endif
 238
 239         return ret;
 240 }
 241
 242 static int acpi_platform_notify_remove(struct device *dev)
 243 {
 244         acpi_unbind_one(dev);
 245         return 0;
 246 }
 247
 248 int __init init_acpi_device_notify(void)
 249 {
 250         if (platform_notify || platform_notify_remove) {
 251                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 252                 return 0;
 253         }
 254         platform_notify = acpi_platform_notify;
 255         platform_notify_remove = acpi_platform_notify_remove;
 256         return 0;
 257 }