Root/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/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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