[go: nahoru, domu]
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(fmt, ...)						\
22	printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
23#else
24#define DBG(fmt, ...)						\
25do {								\
26	if (0)							\
27		printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);	\
28} while (0)
29#endif
30static LIST_HEAD(bus_type_list);
31static DECLARE_RWSEM(bus_type_sem);
32
33#define PHYSICAL_NODE_STRING "physical_node"
34#define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
35
36int register_acpi_bus_type(struct acpi_bus_type *type)
37{
38	if (acpi_disabled)
39		return -ENODEV;
40	if (type && type->match && type->find_companion) {
41		down_write(&bus_type_sem);
42		list_add_tail(&type->list, &bus_type_list);
43		up_write(&bus_type_sem);
44		printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
45		return 0;
46	}
47	return -ENODEV;
48}
49EXPORT_SYMBOL_GPL(register_acpi_bus_type);
50
51int unregister_acpi_bus_type(struct acpi_bus_type *type)
52{
53	if (acpi_disabled)
54		return 0;
55	if (type) {
56		down_write(&bus_type_sem);
57		list_del_init(&type->list);
58		up_write(&bus_type_sem);
59		printk(KERN_INFO PREFIX "bus type %s unregistered\n",
60		       type->name);
61		return 0;
62	}
63	return -ENODEV;
64}
65EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
66
67static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
68{
69	struct acpi_bus_type *tmp, *ret = NULL;
70
71	down_read(&bus_type_sem);
72	list_for_each_entry(tmp, &bus_type_list, list) {
73		if (tmp->match(dev)) {
74			ret = tmp;
75			break;
76		}
77	}
78	up_read(&bus_type_sem);
79	return ret;
80}
81
82#define FIND_CHILD_MIN_SCORE	1
83#define FIND_CHILD_MAX_SCORE	2
84
85static int find_child_checks(struct acpi_device *adev, bool check_children)
86{
87	bool sta_present = true;
88	unsigned long long sta;
89	acpi_status status;
90
91	status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
92	if (status == AE_NOT_FOUND)
93		sta_present = false;
94	else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
95		return -ENODEV;
96
97	if (check_children && list_empty(&adev->children))
98		return -ENODEV;
99
100	return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
101}
102
103struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
104					   u64 address, bool check_children)
105{
106	struct acpi_device *adev, *ret = NULL;
107	int ret_score = 0;
108
109	if (!parent)
110		return NULL;
111
112	list_for_each_entry(adev, &parent->children, node) {
113		unsigned long long addr;
114		acpi_status status;
115		int score;
116
117		status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
118					       NULL, &addr);
119		if (ACPI_FAILURE(status) || addr != address)
120			continue;
121
122		if (!ret) {
123			/* This is the first matching object.  Save it. */
124			ret = adev;
125			continue;
126		}
127		/*
128		 * There is more than one matching device object with the same
129		 * _ADR value.  That really is unexpected, so we are kind of
130		 * beyond the scope of the spec here.  We have to choose which
131		 * one to return, though.
132		 *
133		 * First, check if the previously found object is good enough
134		 * and return it if so.  Second, do the same for the object that
135		 * we've just found.
136		 */
137		if (!ret_score) {
138			ret_score = find_child_checks(ret, check_children);
139			if (ret_score == FIND_CHILD_MAX_SCORE)
140				return ret;
141		}
142		score = find_child_checks(adev, check_children);
143		if (score == FIND_CHILD_MAX_SCORE) {
144			return adev;
145		} else if (score > ret_score) {
146			ret = adev;
147			ret_score = score;
148		}
149	}
150	return ret;
151}
152EXPORT_SYMBOL_GPL(acpi_find_child_device);
153
154static void acpi_physnode_link_name(char *buf, unsigned int node_id)
155{
156	if (node_id > 0)
157		snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
158			 PHYSICAL_NODE_STRING "%u", node_id);
159	else
160		strcpy(buf, PHYSICAL_NODE_STRING);
161}
162
163int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
164{
165	struct acpi_device_physical_node *physical_node, *pn;
166	char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
167	struct list_head *physnode_list;
168	unsigned int node_id;
169	int retval = -EINVAL;
170
171	if (ACPI_COMPANION(dev)) {
172		if (acpi_dev) {
173			dev_warn(dev, "ACPI companion already set\n");
174			return -EINVAL;
175		} else {
176			acpi_dev = ACPI_COMPANION(dev);
177		}
178	}
179	if (!acpi_dev)
180		return -EINVAL;
181
182	get_device(&acpi_dev->dev);
183	get_device(dev);
184	physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
185	if (!physical_node) {
186		retval = -ENOMEM;
187		goto err;
188	}
189
190	mutex_lock(&acpi_dev->physical_node_lock);
191
192	/*
193	 * Keep the list sorted by node_id so that the IDs of removed nodes can
194	 * be recycled easily.
195	 */
196	physnode_list = &acpi_dev->physical_node_list;
197	node_id = 0;
198	list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
199		/* Sanity check. */
200		if (pn->dev == dev) {
201			mutex_unlock(&acpi_dev->physical_node_lock);
202
203			dev_warn(dev, "Already associated with ACPI node\n");
204			kfree(physical_node);
205			if (ACPI_COMPANION(dev) != acpi_dev)
206				goto err;
207
208			put_device(dev);
209			put_device(&acpi_dev->dev);
210			return 0;
211		}
212		if (pn->node_id == node_id) {
213			physnode_list = &pn->node;
214			node_id++;
215		}
216	}
217
218	physical_node->node_id = node_id;
219	physical_node->dev = dev;
220	list_add(&physical_node->node, physnode_list);
221	acpi_dev->physical_node_count++;
222
223	if (!ACPI_COMPANION(dev))
224		ACPI_COMPANION_SET(dev, acpi_dev);
225
226	acpi_physnode_link_name(physical_node_name, node_id);
227	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
228				   physical_node_name);
229	if (retval)
230		dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
231			physical_node_name, retval);
232
233	retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
234				   "firmware_node");
235	if (retval)
236		dev_err(dev, "Failed to create link firmware_node (%d)\n",
237			retval);
238
239	mutex_unlock(&acpi_dev->physical_node_lock);
240
241	if (acpi_dev->wakeup.flags.valid)
242		device_set_wakeup_capable(dev, true);
243
244	return 0;
245
246 err:
247	ACPI_COMPANION_SET(dev, NULL);
248	put_device(dev);
249	put_device(&acpi_dev->dev);
250	return retval;
251}
252EXPORT_SYMBOL_GPL(acpi_bind_one);
253
254int acpi_unbind_one(struct device *dev)
255{
256	struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
257	struct acpi_device_physical_node *entry;
258
259	if (!acpi_dev)
260		return 0;
261
262	mutex_lock(&acpi_dev->physical_node_lock);
263
264	list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
265		if (entry->dev == dev) {
266			char physnode_name[PHYSICAL_NODE_NAME_SIZE];
267
268			list_del(&entry->node);
269			acpi_dev->physical_node_count--;
270
271			acpi_physnode_link_name(physnode_name, entry->node_id);
272			sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
273			sysfs_remove_link(&dev->kobj, "firmware_node");
274			ACPI_COMPANION_SET(dev, NULL);
275			/* Drop references taken by acpi_bind_one(). */
276			put_device(dev);
277			put_device(&acpi_dev->dev);
278			kfree(entry);
279			break;
280		}
281
282	mutex_unlock(&acpi_dev->physical_node_lock);
283	return 0;
284}
285EXPORT_SYMBOL_GPL(acpi_unbind_one);
286
287static int acpi_platform_notify(struct device *dev)
288{
289	struct acpi_bus_type *type = acpi_get_bus_type(dev);
290	struct acpi_device *adev;
291	int ret;
292
293	ret = acpi_bind_one(dev, NULL);
294	if (ret && type) {
295		struct acpi_device *adev;
296
297		adev = type->find_companion(dev);
298		if (!adev) {
299			DBG("Unable to get handle for %s\n", dev_name(dev));
300			ret = -ENODEV;
301			goto out;
302		}
303		ret = acpi_bind_one(dev, adev);
304		if (ret)
305			goto out;
306	}
307	adev = ACPI_COMPANION(dev);
308	if (!adev)
309		goto out;
310
311	if (type && type->setup)
312		type->setup(dev);
313	else if (adev->handler && adev->handler->bind)
314		adev->handler->bind(dev);
315
316 out:
317#if ACPI_GLUE_DEBUG
318	if (!ret) {
319		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
320
321		acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
322		DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
323		kfree(buffer.pointer);
324	} else
325		DBG("Device %s -> No ACPI support\n", dev_name(dev));
326#endif
327
328	return ret;
329}
330
331static int acpi_platform_notify_remove(struct device *dev)
332{
333	struct acpi_device *adev = ACPI_COMPANION(dev);
334	struct acpi_bus_type *type;
335
336	if (!adev)
337		return 0;
338
339	type = acpi_get_bus_type(dev);
340	if (type && type->cleanup)
341		type->cleanup(dev);
342	else if (adev->handler && adev->handler->unbind)
343		adev->handler->unbind(dev);
344
345	acpi_unbind_one(dev);
346	return 0;
347}
348
349int __init init_acpi_device_notify(void)
350{
351	if (platform_notify || platform_notify_remove) {
352		printk(KERN_ERR PREFIX "Can't use platform_notify\n");
353		return 0;
354	}
355	platform_notify = acpi_platform_notify;
356	platform_notify_remove = acpi_platform_notify_remove;
357	return 0;
358}
359