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
10#include <linux/acpi_iort.h>
11#include <linux/export.h>
12#include <linux/init.h>
13#include <linux/list.h>
14#include <linux/device.h>
15#include <linux/slab.h>
16#include <linux/rwsem.h>
17#include <linux/acpi.h>
18#include <linux/dma-mapping.h>
19#include <linux/platform_device.h>
20
21#include "internal.h"
22
23#define ACPI_GLUE_DEBUG 0
24#if ACPI_GLUE_DEBUG
25#define DBG(fmt, ...) \
26 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
27#else
28#define DBG(fmt, ...) \
29do { \
30 if (0) \
31 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__); \
32} while (0)
33#endif
34static LIST_HEAD(bus_type_list);
35static DECLARE_RWSEM(bus_type_sem);
36
37#define PHYSICAL_NODE_STRING "physical_node"
38#define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
39
40int register_acpi_bus_type(struct acpi_bus_type *type)
41{
42 if (acpi_disabled)
43 return -ENODEV;
44 if (type && type->match && type->find_companion) {
45 down_write(&bus_type_sem);
46 list_add_tail(&type->list, &bus_type_list);
47 up_write(&bus_type_sem);
48 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
49 return 0;
50 }
51 return -ENODEV;
52}
53EXPORT_SYMBOL_GPL(register_acpi_bus_type);
54
55int unregister_acpi_bus_type(struct acpi_bus_type *type)
56{
57 if (acpi_disabled)
58 return 0;
59 if (type) {
60 down_write(&bus_type_sem);
61 list_del_init(&type->list);
62 up_write(&bus_type_sem);
63 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
64 type->name);
65 return 0;
66 }
67 return -ENODEV;
68}
69EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
70
71static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
72{
73 struct acpi_bus_type *tmp, *ret = NULL;
74
75 down_read(&bus_type_sem);
76 list_for_each_entry(tmp, &bus_type_list, list) {
77 if (tmp->match(dev)) {
78 ret = tmp;
79 break;
80 }
81 }
82 up_read(&bus_type_sem);
83 return ret;
84}
85
86#define FIND_CHILD_MIN_SCORE 1
87#define FIND_CHILD_MAX_SCORE 2
88
89static int find_child_checks(struct acpi_device *adev, bool check_children)
90{
91 bool sta_present = true;
92 unsigned long long sta;
93 acpi_status status;
94
95 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
96 if (status == AE_NOT_FOUND)
97 sta_present = false;
98 else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
99 return -ENODEV;
100
101 if (check_children && list_empty(&adev->children))
102 return -ENODEV;
103
104 /*
105 * If the device has a _HID returning a valid ACPI/PNP device ID, it is
106 * better to make it look less attractive here, so that the other device
107 * with the same _ADR value (that may not have a valid device ID) can be
108 * matched going forward. [This means a second spec violation in a row,
109 * so whatever we do here is best effort anyway.]
110 */
111 return sta_present && !adev->pnp.type.platform_id ?
112 FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
113}
114
115struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
116 u64 address, bool check_children)
117{
118 struct acpi_device *adev, *ret = NULL;
119 int ret_score = 0;
120
121 if (!parent)
122 return NULL;
123
124 list_for_each_entry(adev, &parent->children, node) {
125 unsigned long long addr;
126 acpi_status status;
127 int score;
128
129 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
130 NULL, &addr);
131 if (ACPI_FAILURE(status) || addr != address)
132 continue;
133
134 if (!ret) {
135 /* This is the first matching object. Save it. */
136 ret = adev;
137 continue;
138 }
139 /*
140 * There is more than one matching device object with the same
141 * _ADR value. That really is unexpected, so we are kind of
142 * beyond the scope of the spec here. We have to choose which
143 * one to return, though.
144 *
145 * First, check if the previously found object is good enough
146 * and return it if so. Second, do the same for the object that
147 * we've just found.
148 */
149 if (!ret_score) {
150 ret_score = find_child_checks(ret, check_children);
151 if (ret_score == FIND_CHILD_MAX_SCORE)
152 return ret;
153 }
154 score = find_child_checks(adev, check_children);
155 if (score == FIND_CHILD_MAX_SCORE) {
156 return adev;
157 } else if (score > ret_score) {
158 ret = adev;
159 ret_score = score;
160 }
161 }
162 return ret;
163}
164EXPORT_SYMBOL_GPL(acpi_find_child_device);
165
166static void acpi_physnode_link_name(char *buf, unsigned int node_id)
167{
168 if (node_id > 0)
169 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
170 PHYSICAL_NODE_STRING "%u", node_id);
171 else
172 strcpy(buf, PHYSICAL_NODE_STRING);
173}
174
175int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
176{
177 struct acpi_device_physical_node *physical_node, *pn;
178 char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
179 struct list_head *physnode_list;
180 unsigned int node_id;
181 int retval = -EINVAL;
182
183 if (has_acpi_companion(dev)) {
184 if (acpi_dev) {
185 dev_warn(dev, "ACPI companion already set\n");
186 return -EINVAL;
187 } else {
188 acpi_dev = ACPI_COMPANION(dev);
189 }
190 }
191 if (!acpi_dev)
192 return -EINVAL;
193
194 get_device(&acpi_dev->dev);
195 get_device(dev);
196 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
197 if (!physical_node) {
198 retval = -ENOMEM;
199 goto err;
200 }
201
202 mutex_lock(&acpi_dev->physical_node_lock);
203
204 /*
205 * Keep the list sorted by node_id so that the IDs of removed nodes can
206 * be recycled easily.
207 */
208 physnode_list = &acpi_dev->physical_node_list;
209 node_id = 0;
210 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
211 /* Sanity check. */
212 if (pn->dev == dev) {
213 mutex_unlock(&acpi_dev->physical_node_lock);
214
215 dev_warn(dev, "Already associated with ACPI node\n");
216 kfree(physical_node);
217 if (ACPI_COMPANION(dev) != acpi_dev)
218 goto err;
219
220 put_device(dev);
221 put_device(&acpi_dev->dev);
222 return 0;
223 }
224 if (pn->node_id == node_id) {
225 physnode_list = &pn->node;
226 node_id++;
227 }
228 }
229
230 physical_node->node_id = node_id;
231 physical_node->dev = dev;
232 list_add(&physical_node->node, physnode_list);
233 acpi_dev->physical_node_count++;
234
235 if (!has_acpi_companion(dev))
236 ACPI_COMPANION_SET(dev, acpi_dev);
237
238 acpi_physnode_link_name(physical_node_name, node_id);
239 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
240 physical_node_name);
241 if (retval)
242 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
243 physical_node_name, retval);
244
245 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
246 "firmware_node");
247 if (retval)
248 dev_err(dev, "Failed to create link firmware_node (%d)\n",
249 retval);
250
251 mutex_unlock(&acpi_dev->physical_node_lock);
252
253 if (acpi_dev->wakeup.flags.valid)
254 device_set_wakeup_capable(dev, true);
255
256 return 0;
257
258 err:
259 ACPI_COMPANION_SET(dev, NULL);
260 put_device(dev);
261 put_device(&acpi_dev->dev);
262 return retval;
263}
264EXPORT_SYMBOL_GPL(acpi_bind_one);
265
266int acpi_unbind_one(struct device *dev)
267{
268 struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
269 struct acpi_device_physical_node *entry;
270
271 if (!acpi_dev)
272 return 0;
273
274 mutex_lock(&acpi_dev->physical_node_lock);
275
276 list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
277 if (entry->dev == dev) {
278 char physnode_name[PHYSICAL_NODE_NAME_SIZE];
279
280 list_del(&entry->node);
281 acpi_dev->physical_node_count--;
282
283 acpi_physnode_link_name(physnode_name, entry->node_id);
284 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
285 sysfs_remove_link(&dev->kobj, "firmware_node");
286 ACPI_COMPANION_SET(dev, NULL);
287 /* Drop references taken by acpi_bind_one(). */
288 put_device(dev);
289 put_device(&acpi_dev->dev);
290 kfree(entry);
291 break;
292 }
293
294 mutex_unlock(&acpi_dev->physical_node_lock);
295 return 0;
296}
297EXPORT_SYMBOL_GPL(acpi_unbind_one);
298
299static int acpi_device_notify(struct device *dev)
300{
301 struct acpi_bus_type *type = acpi_get_bus_type(dev);
302 struct acpi_device *adev;
303 int ret;
304
305 ret = acpi_bind_one(dev, NULL);
306 if (ret && type) {
307 struct acpi_device *adev;
308
309 adev = type->find_companion(dev);
310 if (!adev) {
311 DBG("Unable to get handle for %s\n", dev_name(dev));
312 ret = -ENODEV;
313 goto out;
314 }
315 ret = acpi_bind_one(dev, adev);
316 if (ret)
317 goto out;
318 }
319 adev = ACPI_COMPANION(dev);
320 if (!adev)
321 goto out;
322
323 if (dev_is_platform(dev))
324 acpi_configure_pmsi_domain(dev);
325
326 if (type && type->setup)
327 type->setup(dev);
328 else if (adev->handler && adev->handler->bind)
329 adev->handler->bind(dev);
330
331 out:
332#if ACPI_GLUE_DEBUG
333 if (!ret) {
334 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
335
336 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
337 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
338 kfree(buffer.pointer);
339 } else
340 DBG("Device %s -> No ACPI support\n", dev_name(dev));
341#endif
342
343 return ret;
344}
345
346static int acpi_device_notify_remove(struct device *dev)
347{
348 struct acpi_device *adev = ACPI_COMPANION(dev);
349 struct acpi_bus_type *type;
350
351 if (!adev)
352 return 0;
353
354 type = acpi_get_bus_type(dev);
355 if (type && type->cleanup)
356 type->cleanup(dev);
357 else if (adev->handler && adev->handler->unbind)
358 adev->handler->unbind(dev);
359
360 acpi_unbind_one(dev);
361 return 0;
362}
363
364int acpi_platform_notify(struct device *dev, enum kobject_action action)
365{
366 switch (action) {
367 case KOBJ_ADD:
368 acpi_device_notify(dev);
369 break;
370 case KOBJ_REMOVE:
371 acpi_device_notify_remove(dev);
372 break;
373 default:
374 break;
375 }
376 return 0;
377}
378