[PATCH] Only disallow _setting_ of function key string
[linux-2.6] / drivers / acpi / container.c
1 /*
2  * acpi_container.c  - ACPI Generic Container Driver
3  * ($Revision: )
4  *
5  * Copyright (C) 2004 Anil S Keshavamurthy (anil.s.keshavamurthy@intel.com)
6  * Copyright (C) 2004 Keiichiro Tokunaga (tokunaga.keiich@jp.fujitsu.com)
7  * Copyright (C) 2004 Motoyuki Ito (motoyuki@soft.fujitsu.com)
8  * Copyright (C) 2004 Intel Corp.
9  * Copyright (C) 2004 FUJITSU LIMITED
10  *
11  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License as published by
15  *  the Free Software Foundation; either version 2 of the License, or (at
16  *  your option) any later version.
17  *
18  *  This program is distributed in the hope that it will be useful, but
19  *  WITHOUT ANY WARRANTY; without even the implied warranty of
20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21  *  General Public License for more details.
22  *
23  *  You should have received a copy of the GNU General Public License along
24  *  with this program; if not, write to the Free Software Foundation, Inc.,
25  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26  *
27  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28  */
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/types.h>
33 #include <linux/acpi.h>
34 #include <acpi/acpi_bus.h>
35 #include <acpi/acpi_drivers.h>
36 #include <acpi/container.h>
37
38 #define ACPI_CONTAINER_DRIVER_NAME      "ACPI container driver"
39 #define ACPI_CONTAINER_DEVICE_NAME      "ACPI container device"
40 #define ACPI_CONTAINER_CLASS            "container"
41
42 #define INSTALL_NOTIFY_HANDLER          1
43 #define UNINSTALL_NOTIFY_HANDLER        2
44
45 #define ACPI_CONTAINER_COMPONENT        0x01000000
46 #define _COMPONENT                      ACPI_CONTAINER_COMPONENT
47 ACPI_MODULE_NAME("acpi_container")
48
49     MODULE_AUTHOR("Anil S Keshavamurthy");
50 MODULE_DESCRIPTION(ACPI_CONTAINER_DRIVER_NAME);
51 MODULE_LICENSE("GPL");
52
53 #define ACPI_STA_PRESENT                (0x00000001)
54
55 static int acpi_container_add(struct acpi_device *device);
56 static int acpi_container_remove(struct acpi_device *device, int type);
57
58 static struct acpi_driver acpi_container_driver = {
59         .name = ACPI_CONTAINER_DRIVER_NAME,
60         .class = ACPI_CONTAINER_CLASS,
61         .ids = "ACPI0004,PNP0A05,PNP0A06",
62         .ops = {
63                 .add = acpi_container_add,
64                 .remove = acpi_container_remove,
65                 },
66 };
67
68 /*******************************************************************/
69
70 static int is_device_present(acpi_handle handle)
71 {
72         acpi_handle temp;
73         acpi_status status;
74         unsigned long sta;
75
76         ACPI_FUNCTION_TRACE("is_device_present");
77
78         status = acpi_get_handle(handle, "_STA", &temp);
79         if (ACPI_FAILURE(status))
80                 return_VALUE(1);        /* _STA not found, assmue device present */
81
82         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
83         if (ACPI_FAILURE(status))
84                 return_VALUE(0);        /* Firmware error */
85
86         return_VALUE((sta & ACPI_STA_PRESENT) == ACPI_STA_PRESENT);
87 }
88
89 /*******************************************************************/
90 static int acpi_container_add(struct acpi_device *device)
91 {
92         struct acpi_container *container;
93
94         ACPI_FUNCTION_TRACE("acpi_container_add");
95
96         if (!device) {
97                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "device is NULL\n"));
98                 return_VALUE(-EINVAL);
99         }
100
101         container = kmalloc(sizeof(struct acpi_container), GFP_KERNEL);
102         if (!container)
103                 return_VALUE(-ENOMEM);
104
105         memset(container, 0, sizeof(struct acpi_container));
106         container->handle = device->handle;
107         strcpy(acpi_device_name(device), ACPI_CONTAINER_DEVICE_NAME);
108         strcpy(acpi_device_class(device), ACPI_CONTAINER_CLASS);
109         acpi_driver_data(device) = container;
110
111         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device <%s> bid <%s>\n",
112                           acpi_device_name(device), acpi_device_bid(device)));
113
114         return_VALUE(0);
115 }
116
117 static int acpi_container_remove(struct acpi_device *device, int type)
118 {
119         acpi_status status = AE_OK;
120         struct acpi_container *pc = NULL;
121         pc = (struct acpi_container *)acpi_driver_data(device);
122
123         if (pc)
124                 kfree(pc);
125
126         return status;
127 }
128
129 static int container_device_add(struct acpi_device **device, acpi_handle handle)
130 {
131         acpi_handle phandle;
132         struct acpi_device *pdev;
133         int result;
134
135         ACPI_FUNCTION_TRACE("container_device_add");
136
137         if (acpi_get_parent(handle, &phandle)) {
138                 return_VALUE(-ENODEV);
139         }
140
141         if (acpi_bus_get_device(phandle, &pdev)) {
142                 return_VALUE(-ENODEV);
143         }
144
145         if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_DEVICE)) {
146                 return_VALUE(-ENODEV);
147         }
148
149         result = acpi_bus_start(*device);
150
151         return_VALUE(result);
152 }
153
154 static void container_notify_cb(acpi_handle handle, u32 type, void *context)
155 {
156         struct acpi_device *device = NULL;
157         int result;
158         int present;
159         acpi_status status;
160
161         ACPI_FUNCTION_TRACE("container_notify_cb");
162
163         present = is_device_present(handle);
164
165         switch (type) {
166         case ACPI_NOTIFY_BUS_CHECK:
167                 /* Fall through */
168         case ACPI_NOTIFY_DEVICE_CHECK:
169                 printk("Container driver received %s event\n",
170                        (type == ACPI_NOTIFY_BUS_CHECK) ?
171                        "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
172                 status = acpi_bus_get_device(handle, &device);
173                 if (present) {
174                         if (ACPI_FAILURE(status) || !device) {
175                                 result = container_device_add(&device, handle);
176                                 if (!result)
177                                         kobject_hotplug(&device->kobj,
178                                                         KOBJ_ONLINE);
179                                 else
180                                         printk("Failed to add container\n");
181                         }
182                 } else {
183                         if (ACPI_SUCCESS(status)) {
184                                 /* device exist and this is a remove request */
185                                 kobject_hotplug(&device->kobj, KOBJ_OFFLINE);
186                         }
187                 }
188                 break;
189         case ACPI_NOTIFY_EJECT_REQUEST:
190                 if (!acpi_bus_get_device(handle, &device) && device) {
191                         kobject_hotplug(&device->kobj, KOBJ_OFFLINE);
192                 }
193                 break;
194         default:
195                 break;
196         }
197         return_VOID;
198 }
199
200 static acpi_status
201 container_walk_namespace_cb(acpi_handle handle,
202                             u32 lvl, void *context, void **rv)
203 {
204         char *hid = NULL;
205         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
206         struct acpi_device_info *info;
207         acpi_status status;
208         int *action = context;
209
210         ACPI_FUNCTION_TRACE("container_walk_namespace_cb");
211
212         status = acpi_get_object_info(handle, &buffer);
213         if (ACPI_FAILURE(status) || !buffer.pointer) {
214                 return_ACPI_STATUS(AE_OK);
215         }
216
217         info = buffer.pointer;
218         if (info->valid & ACPI_VALID_HID)
219                 hid = info->hardware_id.value;
220
221         if (hid == NULL) {
222                 goto end;
223         }
224
225         if (strcmp(hid, "ACPI0004") && strcmp(hid, "PNP0A05") &&
226             strcmp(hid, "PNP0A06")) {
227                 goto end;
228         }
229
230         switch (*action) {
231         case INSTALL_NOTIFY_HANDLER:
232                 acpi_install_notify_handler(handle,
233                                             ACPI_SYSTEM_NOTIFY,
234                                             container_notify_cb, NULL);
235                 break;
236         case UNINSTALL_NOTIFY_HANDLER:
237                 acpi_remove_notify_handler(handle,
238                                            ACPI_SYSTEM_NOTIFY,
239                                            container_notify_cb);
240                 break;
241         default:
242                 break;
243         }
244
245       end:
246         acpi_os_free(buffer.pointer);
247
248         return_ACPI_STATUS(AE_OK);
249 }
250
251 static int __init acpi_container_init(void)
252 {
253         int result = 0;
254         int action = INSTALL_NOTIFY_HANDLER;
255
256         result = acpi_bus_register_driver(&acpi_container_driver);
257         if (result < 0) {
258                 return (result);
259         }
260
261         /* register notify handler to every container device */
262         acpi_walk_namespace(ACPI_TYPE_DEVICE,
263                             ACPI_ROOT_OBJECT,
264                             ACPI_UINT32_MAX,
265                             container_walk_namespace_cb, &action, NULL);
266
267         return (0);
268 }
269
270 static void __exit acpi_container_exit(void)
271 {
272         int action = UNINSTALL_NOTIFY_HANDLER;
273
274         ACPI_FUNCTION_TRACE("acpi_container_exit");
275
276         acpi_walk_namespace(ACPI_TYPE_DEVICE,
277                             ACPI_ROOT_OBJECT,
278                             ACPI_UINT32_MAX,
279                             container_walk_namespace_cb, &action, NULL);
280
281         acpi_bus_unregister_driver(&acpi_container_driver);
282
283         return_VOID;
284 }
285
286 module_init(acpi_container_init);
287 module_exit(acpi_container_exit);