xref: /openbmc/linux/drivers/acpi/glue.c (revision f42b3800)
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 	acpi_status status;
146 
147 	if (dev->archdata.acpi_handle) {
148 		printk(KERN_WARNING PREFIX
149 		       "Drivers changed 'acpi_handle' for %s\n", dev->bus_id);
150 		return -EINVAL;
151 	}
152 	get_device(dev);
153 	status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
154 	if (ACPI_FAILURE(status)) {
155 		put_device(dev);
156 		return -EINVAL;
157 	}
158 	dev->archdata.acpi_handle = handle;
159 
160 	return 0;
161 }
162 
163 static int acpi_unbind_one(struct device *dev)
164 {
165 	if (!dev->archdata.acpi_handle)
166 		return 0;
167 	if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
168 		/* acpi_get_physical_device increase refcnt by one */
169 		put_device(dev);
170 		acpi_detach_data(dev->archdata.acpi_handle,
171 				 acpi_glue_data_handler);
172 		dev->archdata.acpi_handle = NULL;
173 		/* acpi_bind_one increase refcnt by one */
174 		put_device(dev);
175 	} else {
176 		printk(KERN_ERR PREFIX
177 		       "Oops, 'acpi_handle' corrupt for %s\n", dev->bus_id);
178 	}
179 	return 0;
180 }
181 
182 static int acpi_platform_notify(struct device *dev)
183 {
184 	struct acpi_bus_type *type;
185 	acpi_handle handle;
186 	int ret = -EINVAL;
187 
188 	if (!dev->bus || !dev->parent) {
189 		/* bridge devices genernally haven't bus or parent */
190 		ret = acpi_find_bridge_device(dev, &handle);
191 		goto end;
192 	}
193 	type = acpi_get_bus_type(dev->bus);
194 	if (!type) {
195 		DBG("No ACPI bus support for %s\n", dev->bus_id);
196 		ret = -EINVAL;
197 		goto end;
198 	}
199 	if ((ret = type->find_device(dev, &handle)) != 0)
200 		DBG("Can't get handler for %s\n", dev->bus_id);
201       end:
202 	if (!ret)
203 		acpi_bind_one(dev, handle);
204 
205 #if ACPI_GLUE_DEBUG
206 	if (!ret) {
207 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
208 
209 		acpi_get_name(dev->archdata.acpi_handle,
210 			      ACPI_FULL_PATHNAME, &buffer);
211 		DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
212 		kfree(buffer.pointer);
213 	} else
214 		DBG("Device %s -> No ACPI support\n", dev->bus_id);
215 #endif
216 
217 	return ret;
218 }
219 
220 static int acpi_platform_notify_remove(struct device *dev)
221 {
222 	acpi_unbind_one(dev);
223 	return 0;
224 }
225 
226 static int __init init_acpi_device_notify(void)
227 {
228 	if (acpi_disabled)
229 		return 0;
230 	if (platform_notify || platform_notify_remove) {
231 		printk(KERN_ERR PREFIX "Can't use platform_notify\n");
232 		return 0;
233 	}
234 	platform_notify = acpi_platform_notify;
235 	platform_notify_remove = acpi_platform_notify_remove;
236 	return 0;
237 }
238 
239 arch_initcall(init_acpi_device_notify);
240 
241 
242 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
243 
244 #ifdef CONFIG_PM
245 static u32 rtc_handler(void *context)
246 {
247 	acpi_clear_event(ACPI_EVENT_RTC);
248 	acpi_disable_event(ACPI_EVENT_RTC, 0);
249 	return ACPI_INTERRUPT_HANDLED;
250 }
251 
252 static inline void rtc_wake_setup(void)
253 {
254 	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
255 }
256 
257 static void rtc_wake_on(struct device *dev)
258 {
259 	acpi_clear_event(ACPI_EVENT_RTC);
260 	acpi_enable_event(ACPI_EVENT_RTC, 0);
261 }
262 
263 static void rtc_wake_off(struct device *dev)
264 {
265 	acpi_disable_event(ACPI_EVENT_RTC, 0);
266 }
267 #else
268 #define rtc_wake_setup()	do{}while(0)
269 #define rtc_wake_on		NULL
270 #define rtc_wake_off		NULL
271 #endif
272 
273 /* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
274  * its device node and pass extra config data.  This helps its driver use
275  * capabilities that the now-obsolete mc146818 didn't have, and informs it
276  * that this board's RTC is wakeup-capable (per ACPI spec).
277  */
278 #include <linux/mc146818rtc.h>
279 
280 static struct cmos_rtc_board_info rtc_info;
281 
282 
283 /* PNP devices are registered in a subsys_initcall();
284  * ACPI specifies the PNP IDs to use.
285  */
286 #include <linux/pnp.h>
287 
288 static int __init pnp_match(struct device *dev, void *data)
289 {
290 	static const char *ids[] = { "PNP0b00", "PNP0b01", "PNP0b02", };
291 	struct pnp_dev *pnp = to_pnp_dev(dev);
292 	int i;
293 
294 	for (i = 0; i < ARRAY_SIZE(ids); i++) {
295 		if (compare_pnp_id(pnp->id, ids[i]) != 0)
296 			return 1;
297 	}
298 	return 0;
299 }
300 
301 static struct device *__init get_rtc_dev(void)
302 {
303 	return bus_find_device(&pnp_bus_type, NULL, NULL, pnp_match);
304 }
305 
306 static int __init acpi_rtc_init(void)
307 {
308 	struct device *dev = get_rtc_dev();
309 
310 	if (dev) {
311 		rtc_wake_setup();
312 		rtc_info.wake_on = rtc_wake_on;
313 		rtc_info.wake_off = rtc_wake_off;
314 
315 		/* workaround bug in some ACPI tables */
316 		if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
317 			DBG("bogus FADT month_alarm\n");
318 			acpi_gbl_FADT.month_alarm = 0;
319 		}
320 
321 		rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
322 		rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
323 		rtc_info.rtc_century = acpi_gbl_FADT.century;
324 
325 		/* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
326 		if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
327 			printk(PREFIX "RTC can wake from S4\n");
328 
329 
330 		dev->platform_data = &rtc_info;
331 
332 		/* RTC always wakes from S1/S2/S3, and often S4/STD */
333 		device_init_wakeup(dev, 1);
334 
335 		put_device(dev);
336 	} else
337 		DBG("RTC unavailable?\n");
338 	return 0;
339 }
340 /* do this between RTC subsys_initcall() and rtc_cmos driver_initcall() */
341 fs_initcall(acpi_rtc_init);
342 
343 #endif
344