Revert "ACPI: don't walk tables if ACPI was disabled"
[linux-2.6.git] / 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 #define ACPI_GLUE_DEBUG 0
16 #if ACPI_GLUE_DEBUG
17 #define DBG(x...) printk(PREFIX x)
18 #else
19 #define DBG(x...) do { } while(0)
20 #endif
21 static LIST_HEAD(bus_type_list);
22 static DECLARE_RWSEM(bus_type_sem);
23
24 int register_acpi_bus_type(struct acpi_bus_type *type)
25 {
26         if (acpi_disabled)
27                 return -ENODEV;
28         if (type && type->bus && type->find_device) {
29                 down_write(&bus_type_sem);
30                 list_add_tail(&type->list, &bus_type_list);
31                 up_write(&bus_type_sem);
32                 printk(KERN_INFO PREFIX "bus type %s registered\n",
33                        type->bus->name);
34                 return 0;
35         }
36         return -ENODEV;
37 }
38
39 int unregister_acpi_bus_type(struct acpi_bus_type *type)
40 {
41         if (acpi_disabled)
42                 return 0;
43         if (type) {
44                 down_write(&bus_type_sem);
45                 list_del_init(&type->list);
46                 up_write(&bus_type_sem);
47                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
48                        type->bus->name);
49                 return 0;
50         }
51         return -ENODEV;
52 }
53
54 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
55 {
56         struct acpi_bus_type *tmp, *ret = NULL;
57
58         down_read(&bus_type_sem);
59         list_for_each_entry(tmp, &bus_type_list, list) {
60                 if (tmp->bus == type) {
61                         ret = tmp;
62                         break;
63                 }
64         }
65         up_read(&bus_type_sem);
66         return ret;
67 }
68
69 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
70 {
71         struct acpi_bus_type *tmp;
72         int ret = -ENODEV;
73
74         down_read(&bus_type_sem);
75         list_for_each_entry(tmp, &bus_type_list, list) {
76                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
77                         ret = 0;
78                         break;
79                 }
80         }
81         up_read(&bus_type_sem);
82         return ret;
83 }
84
85 /* Get device's handler per its address under its parent */
86 struct acpi_find_child {
87         acpi_handle handle;
88         acpi_integer address;
89 };
90
91 static acpi_status
92 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
93 {
94         acpi_status status;
95         struct acpi_device_info *info;
96         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
97         struct acpi_find_child *find = context;
98
99         status = acpi_get_object_info(handle, &buffer);
100         if (ACPI_SUCCESS(status)) {
101                 info = buffer.pointer;
102                 if (info->address == find->address)
103                         find->handle = handle;
104                 kfree(buffer.pointer);
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, &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                                    u32 function, 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                 printk(KERN_WARNING PREFIX
150                        "Drivers changed 'acpi_handle' for %s\n", dev->bus_id);
151                 return -EINVAL;
152         }
153         get_device(dev);
154         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
155         if (ACPI_FAILURE(status)) {
156                 put_device(dev);
157                 return -EINVAL;
158         }
159         dev->archdata.acpi_handle = handle;
160
161         status = acpi_bus_get_device(handle, &acpi_dev);
162         if (!ACPI_FAILURE(status)) {
163                 int ret;
164
165                 ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
166                                 "firmware_node");
167                 ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
168                                 "physical_node");
169                 if (acpi_dev->wakeup.flags.valid)
170                         device_set_wakeup_capable(dev, true);
171         }
172
173         return 0;
174 }
175
176 static int acpi_unbind_one(struct device *dev)
177 {
178         if (!dev->archdata.acpi_handle)
179                 return 0;
180         if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
181                 struct acpi_device *acpi_dev;
182
183                 /* acpi_get_physical_device increase refcnt by one */
184                 put_device(dev);
185
186                 if (!acpi_bus_get_device(dev->archdata.acpi_handle,
187                                         &acpi_dev)) {
188                         sysfs_remove_link(&dev->kobj, "firmware_node");
189                         sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node");
190                 }
191
192                 acpi_detach_data(dev->archdata.acpi_handle,
193                                  acpi_glue_data_handler);
194                 dev->archdata.acpi_handle = NULL;
195                 /* acpi_bind_one increase refcnt by one */
196                 put_device(dev);
197         } else {
198                 printk(KERN_ERR PREFIX
199                        "Oops, 'acpi_handle' corrupt for %s\n", dev->bus_id);
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->bus_id);
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->bus_id);
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->bus_id, (char *)buffer.pointer);
234                 kfree(buffer.pointer);
235         } else
236                 DBG("Device %s -> No ACPI support\n", dev->bus_id);
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 static int __init init_acpi_device_notify(void)
249 {
250         if (acpi_disabled)
251                 return 0;
252         if (platform_notify || platform_notify_remove) {
253                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
254                 return 0;
255         }
256         platform_notify = acpi_platform_notify;
257         platform_notify_remove = acpi_platform_notify_remove;
258         return 0;
259 }
260
261 arch_initcall(init_acpi_device_notify);
262
263
264 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
265
266 #ifdef CONFIG_PM
267 static u32 rtc_handler(void *context)
268 {
269         acpi_clear_event(ACPI_EVENT_RTC);
270         acpi_disable_event(ACPI_EVENT_RTC, 0);
271         return ACPI_INTERRUPT_HANDLED;
272 }
273
274 static inline void rtc_wake_setup(void)
275 {
276         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
277         /*
278          * After the RTC handler is installed, the Fixed_RTC event should
279          * be disabled. Only when the RTC alarm is set will it be enabled.
280          */
281         acpi_clear_event(ACPI_EVENT_RTC);
282         acpi_disable_event(ACPI_EVENT_RTC, 0);
283 }
284
285 static void rtc_wake_on(struct device *dev)
286 {
287         acpi_clear_event(ACPI_EVENT_RTC);
288         acpi_enable_event(ACPI_EVENT_RTC, 0);
289 }
290
291 static void rtc_wake_off(struct device *dev)
292 {
293         acpi_disable_event(ACPI_EVENT_RTC, 0);
294 }
295 #else
296 #define rtc_wake_setup()        do{}while(0)
297 #define rtc_wake_on             NULL
298 #define rtc_wake_off            NULL
299 #endif
300
301 /* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
302  * its device node and pass extra config data.  This helps its driver use
303  * capabilities that the now-obsolete mc146818 didn't have, and informs it
304  * that this board's RTC is wakeup-capable (per ACPI spec).
305  */
306 #include <linux/mc146818rtc.h>
307
308 static struct cmos_rtc_board_info rtc_info;
309
310
311 /* PNP devices are registered in a subsys_initcall();
312  * ACPI specifies the PNP IDs to use.
313  */
314 #include <linux/pnp.h>
315
316 static int __init pnp_match(struct device *dev, void *data)
317 {
318         static const char *ids[] = { "PNP0b00", "PNP0b01", "PNP0b02", };
319         struct pnp_dev *pnp = to_pnp_dev(dev);
320         int i;
321
322         for (i = 0; i < ARRAY_SIZE(ids); i++) {
323                 if (compare_pnp_id(pnp->id, ids[i]) != 0)
324                         return 1;
325         }
326         return 0;
327 }
328
329 static struct device *__init get_rtc_dev(void)
330 {
331         return bus_find_device(&pnp_bus_type, NULL, NULL, pnp_match);
332 }
333
334 static int __init acpi_rtc_init(void)
335 {
336         struct device *dev = get_rtc_dev();
337
338         if (acpi_disabled)
339                 return 0;
340
341         if (dev) {
342                 rtc_wake_setup();
343                 rtc_info.wake_on = rtc_wake_on;
344                 rtc_info.wake_off = rtc_wake_off;
345
346                 /* workaround bug in some ACPI tables */
347                 if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
348                         DBG("bogus FADT month_alarm\n");
349                         acpi_gbl_FADT.month_alarm = 0;
350                 }
351
352                 rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
353                 rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
354                 rtc_info.rtc_century = acpi_gbl_FADT.century;
355
356                 /* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
357                 if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
358                         printk(PREFIX "RTC can wake from S4\n");
359
360
361                 dev->platform_data = &rtc_info;
362
363                 /* RTC always wakes from S1/S2/S3, and often S4/STD */
364                 device_init_wakeup(dev, 1);
365
366                 put_device(dev);
367         } else
368                 DBG("RTC unavailable?\n");
369         return 0;
370 }
371 /* do this between RTC subsys_initcall() and rtc_cmos driver_initcall() */
372 fs_initcall(acpi_rtc_init);
373
374 #endif