xref: /openbmc/linux/drivers/acpi/glue.c (revision 9d749629)
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, ...)						\
25 do {								\
26 	if (0)							\
27 		printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);	\
28 } while (0)
29 #endif
30 static LIST_HEAD(bus_type_list);
31 static DECLARE_RWSEM(bus_type_sem);
32 
33 #define PHYSICAL_NODE_STRING "physical_node"
34 
35 int register_acpi_bus_type(struct acpi_bus_type *type)
36 {
37 	if (acpi_disabled)
38 		return -ENODEV;
39 	if (type && type->bus && type->find_device) {
40 		down_write(&bus_type_sem);
41 		list_add_tail(&type->list, &bus_type_list);
42 		up_write(&bus_type_sem);
43 		printk(KERN_INFO PREFIX "bus type %s registered\n",
44 		       type->bus->name);
45 		return 0;
46 	}
47 	return -ENODEV;
48 }
49 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
50 
51 int 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 "ACPI bus type %s unregistered\n",
60 		       type->bus->name);
61 		return 0;
62 	}
63 	return -ENODEV;
64 }
65 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
66 
67 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
68 {
69 	struct acpi_bus_type *tmp, *ret = NULL;
70 
71 	if (!type)
72 		return NULL;
73 
74 	down_read(&bus_type_sem);
75 	list_for_each_entry(tmp, &bus_type_list, list) {
76 		if (tmp->bus == type) {
77 			ret = tmp;
78 			break;
79 		}
80 	}
81 	up_read(&bus_type_sem);
82 	return ret;
83 }
84 
85 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
86 {
87 	struct acpi_bus_type *tmp;
88 	int ret = -ENODEV;
89 
90 	down_read(&bus_type_sem);
91 	list_for_each_entry(tmp, &bus_type_list, list) {
92 		if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
93 			ret = 0;
94 			break;
95 		}
96 	}
97 	up_read(&bus_type_sem);
98 	return ret;
99 }
100 
101 static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used,
102 				      void *addr_p, void **ret_p)
103 {
104 	unsigned long long addr;
105 	acpi_status status;
106 
107 	status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
108 	if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) {
109 		*ret_p = handle;
110 		return AE_CTRL_TERMINATE;
111 	}
112 	return AE_OK;
113 }
114 
115 acpi_handle acpi_get_child(acpi_handle parent, u64 address)
116 {
117 	void *ret = NULL;
118 
119 	if (!parent)
120 		return NULL;
121 
122 	acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL,
123 			    do_acpi_find_child, &address, &ret);
124 	return (acpi_handle)ret;
125 }
126 EXPORT_SYMBOL(acpi_get_child);
127 
128 static int acpi_bind_one(struct device *dev, acpi_handle handle)
129 {
130 	struct acpi_device *acpi_dev;
131 	acpi_status status;
132 	struct acpi_device_physical_node *physical_node, *pn;
133 	char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
134 	int retval = -EINVAL;
135 
136 	if (ACPI_HANDLE(dev)) {
137 		if (handle) {
138 			dev_warn(dev, "ACPI handle is already set\n");
139 			return -EINVAL;
140 		} else {
141 			handle = ACPI_HANDLE(dev);
142 		}
143 	}
144 	if (!handle)
145 		return -EINVAL;
146 
147 	get_device(dev);
148 	status = acpi_bus_get_device(handle, &acpi_dev);
149 	if (ACPI_FAILURE(status))
150 		goto err;
151 
152 	physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
153 	if (!physical_node) {
154 		retval = -ENOMEM;
155 		goto err;
156 	}
157 
158 	mutex_lock(&acpi_dev->physical_node_lock);
159 
160 	/* Sanity check. */
161 	list_for_each_entry(pn, &acpi_dev->physical_node_list, node)
162 		if (pn->dev == dev) {
163 			dev_warn(dev, "Already associated with ACPI node\n");
164 			goto err_free;
165 		}
166 
167 	/* allocate physical node id according to physical_node_id_bitmap */
168 	physical_node->node_id =
169 		find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
170 		ACPI_MAX_PHYSICAL_NODE);
171 	if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
172 		retval = -ENOSPC;
173 		goto err_free;
174 	}
175 
176 	set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
177 	physical_node->dev = dev;
178 	list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
179 	acpi_dev->physical_node_count++;
180 
181 	mutex_unlock(&acpi_dev->physical_node_lock);
182 
183 	if (!ACPI_HANDLE(dev))
184 		ACPI_HANDLE_SET(dev, acpi_dev->handle);
185 
186 	if (!physical_node->node_id)
187 		strcpy(physical_node_name, PHYSICAL_NODE_STRING);
188 	else
189 		sprintf(physical_node_name,
190 			"physical_node%d", physical_node->node_id);
191 	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
192 			physical_node_name);
193 	retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
194 		"firmware_node");
195 
196 	if (acpi_dev->wakeup.flags.valid)
197 		device_set_wakeup_capable(dev, true);
198 
199 	return 0;
200 
201  err:
202 	ACPI_HANDLE_SET(dev, NULL);
203 	put_device(dev);
204 	return retval;
205 
206  err_free:
207 	mutex_unlock(&acpi_dev->physical_node_lock);
208 	kfree(physical_node);
209 	goto err;
210 }
211 
212 static int acpi_unbind_one(struct device *dev)
213 {
214 	struct acpi_device_physical_node *entry;
215 	struct acpi_device *acpi_dev;
216 	acpi_status status;
217 	struct list_head *node, *next;
218 
219 	if (!ACPI_HANDLE(dev))
220 		return 0;
221 
222 	status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
223 	if (ACPI_FAILURE(status))
224 		goto err;
225 
226 	mutex_lock(&acpi_dev->physical_node_lock);
227 	list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
228 		char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
229 
230 		entry = list_entry(node, struct acpi_device_physical_node,
231 			node);
232 		if (entry->dev != dev)
233 			continue;
234 
235 		list_del(node);
236 		clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);
237 
238 		acpi_dev->physical_node_count--;
239 
240 		if (!entry->node_id)
241 			strcpy(physical_node_name, PHYSICAL_NODE_STRING);
242 		else
243 			sprintf(physical_node_name,
244 				"physical_node%d", entry->node_id);
245 
246 		sysfs_remove_link(&acpi_dev->dev.kobj, physical_node_name);
247 		sysfs_remove_link(&dev->kobj, "firmware_node");
248 		ACPI_HANDLE_SET(dev, NULL);
249 		/* acpi_bind_one increase refcnt by one */
250 		put_device(dev);
251 		kfree(entry);
252 	}
253 	mutex_unlock(&acpi_dev->physical_node_lock);
254 
255 	return 0;
256 
257 err:
258 	dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
259 	return -EINVAL;
260 }
261 
262 static int acpi_platform_notify(struct device *dev)
263 {
264 	struct acpi_bus_type *type;
265 	acpi_handle handle;
266 	int ret;
267 
268 	ret = acpi_bind_one(dev, NULL);
269 	if (ret && (!dev->bus || !dev->parent)) {
270 		/* bridge devices genernally haven't bus or parent */
271 		ret = acpi_find_bridge_device(dev, &handle);
272 		if (!ret) {
273 			ret = acpi_bind_one(dev, handle);
274 			if (ret)
275 				goto out;
276 		}
277 	}
278 
279 	type = acpi_get_bus_type(dev->bus);
280 	if (ret) {
281 		if (!type || !type->find_device) {
282 			DBG("No ACPI bus support for %s\n", dev_name(dev));
283 			ret = -EINVAL;
284 			goto out;
285 		}
286 
287 		ret = type->find_device(dev, &handle);
288 		if (ret) {
289 			DBG("Unable to get handle for %s\n", dev_name(dev));
290 			goto out;
291 		}
292 		ret = acpi_bind_one(dev, handle);
293 		if (ret)
294 			goto out;
295 	}
296 
297 	if (type && type->setup)
298 		type->setup(dev);
299 
300  out:
301 #if ACPI_GLUE_DEBUG
302 	if (!ret) {
303 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
304 
305 		acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
306 		DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
307 		kfree(buffer.pointer);
308 	} else
309 		DBG("Device %s -> No ACPI support\n", dev_name(dev));
310 #endif
311 
312 	return ret;
313 }
314 
315 static int acpi_platform_notify_remove(struct device *dev)
316 {
317 	struct acpi_bus_type *type;
318 
319 	type = acpi_get_bus_type(dev->bus);
320 	if (type && type->cleanup)
321 		type->cleanup(dev);
322 
323 	acpi_unbind_one(dev);
324 	return 0;
325 }
326 
327 int __init init_acpi_device_notify(void)
328 {
329 	if (platform_notify || platform_notify_remove) {
330 		printk(KERN_ERR PREFIX "Can't use platform_notify\n");
331 		return 0;
332 	}
333 	platform_notify = acpi_platform_notify;
334 	platform_notify_remove = acpi_platform_notify_remove;
335 	return 0;
336 }
337