linux/drivers/acpi/glue.c
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   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
  25static LIST_HEAD(bus_type_list);
  26static DECLARE_RWSEM(bus_type_sem);
  27
  28int 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}
  42EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  43
  44int unregister_acpi_bus_type(struct acpi_bus_type *type)
  45{
  46        if (acpi_disabled)
  47                return 0;
  48        if (type) {
  49                down_write(&bus_type_sem);
  50                list_del_init(&type->list);
  51                up_write(&bus_type_sem);
  52                printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  53                       type->bus->name);
  54                return 0;
  55        }
  56        return -ENODEV;
  57}
  58EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  59
  60static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  61{
  62        struct acpi_bus_type *tmp, *ret = NULL;
  63
  64        down_read(&bus_type_sem);
  65        list_for_each_entry(tmp, &bus_type_list, list) {
  66                if (tmp->bus == type) {
  67                        ret = tmp;
  68                        break;
  69                }
  70        }
  71        up_read(&bus_type_sem);
  72        return ret;
  73}
  74
  75static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  76{
  77        struct acpi_bus_type *tmp;
  78        int ret = -ENODEV;
  79
  80        down_read(&bus_type_sem);
  81        list_for_each_entry(tmp, &bus_type_list, list) {
  82                if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  83                        ret = 0;
  84                        break;
  85                }
  86        }
  87        up_read(&bus_type_sem);
  88        return ret;
  89}
  90
  91/* Get device's handler per its address under its parent */
  92struct acpi_find_child {
  93        acpi_handle handle;
  94        u64 address;
  95};
  96
  97static acpi_status
  98do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
  99{
 100        acpi_status status;
 101        struct acpi_device_info *info;
 102        struct acpi_find_child *find = context;
 103
 104        status = acpi_get_object_info(handle, &info);
 105        if (ACPI_SUCCESS(status)) {
 106                if ((info->address == find->address)
 107                        && (info->valid & ACPI_VALID_ADR))
 108                        find->handle = handle;
 109                kfree(info);
 110        }
 111        return AE_OK;
 112}
 113
 114acpi_handle acpi_get_child(acpi_handle parent, u64 address)
 115{
 116        struct acpi_find_child find = { NULL, address };
 117
 118        if (!parent)
 119                return NULL;
 120        acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 121                            1, do_acpi_find_child, NULL, &find, NULL);
 122        return find.handle;
 123}
 124
 125EXPORT_SYMBOL(acpi_get_child);
 126
 127/* Link ACPI devices with physical devices */
 128static void acpi_glue_data_handler(acpi_handle handle,
 129                                   void *context)
 130{
 131        /* we provide an empty handler */
 132}
 133
 134/* Note: a success call will increase reference count by one */
 135struct device *acpi_get_physical_device(acpi_handle handle)
 136{
 137        acpi_status status;
 138        struct device *dev;
 139
 140        status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 141        if (ACPI_SUCCESS(status))
 142                return get_device(dev);
 143        return NULL;
 144}
 145
 146EXPORT_SYMBOL(acpi_get_physical_device);
 147
 148static int acpi_bind_one(struct device *dev, acpi_handle handle)
 149{
 150        struct acpi_device *acpi_dev;
 151        acpi_status status;
 152
 153        if (dev->archdata.acpi_handle) {
 154                dev_warn(dev, "Drivers changed 'acpi_handle'\n");
 155                return -EINVAL;
 156        }
 157        get_device(dev);
 158        status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 159        if (ACPI_FAILURE(status)) {
 160                put_device(dev);
 161                return -EINVAL;
 162        }
 163        dev->archdata.acpi_handle = handle;
 164
 165        status = acpi_bus_get_device(handle, &acpi_dev);
 166        if (!ACPI_FAILURE(status)) {
 167                int ret;
 168
 169                ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 170                                "firmware_node");
 171                ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 172                                "physical_node");
 173                if (acpi_dev->wakeup.flags.valid)
 174                        device_set_wakeup_capable(dev, true);
 175        }
 176
 177        return 0;
 178}
 179
 180static 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
 207static 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
 245static int acpi_platform_notify_remove(struct device *dev)
 246{
 247        acpi_unbind_one(dev);
 248        return 0;
 249}
 250
 251int __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}
 261
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