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 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10) 35 36 int 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 } 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 "bus type %s unregistered\n", 60 type->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 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 85 static 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 } 102 103 struct 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 } 152 EXPORT_SYMBOL_GPL(acpi_find_child_device); 153 154 static 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 } 162 163 int 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 } 252 EXPORT_SYMBOL_GPL(acpi_bind_one); 253 254 int 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 } 285 EXPORT_SYMBOL_GPL(acpi_unbind_one); 286 287 static 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 } 330 331 static 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 } 348 349 int __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