drivers/acpi/glue.c

   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...)
  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 EXPORT_SYMBOL(register_acpi_bus_type);
  40
  41 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  42 {
  43         if (acpi_disabled)
  44                 return 0;
  45         if (type) {
  46                 down_write(&bus_type_sem);
  47                 list_del_init(&type->list);
  48                 up_write(&bus_type_sem);
  49                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  50                        type->bus->name);
  51                 return 0;
  52         }
  53         return -ENODEV;
  54 }
  55
  56 EXPORT_SYMBOL(unregister_acpi_bus_type);
  57
  58 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  59 {
  60         struct acpi_bus_type *tmp, *ret = NULL;
  61
  62         down_read(&bus_type_sem);
  63         list_for_each_entry(tmp, &bus_type_list, list) {
  64                 if (tmp->bus == type) {
  65                         ret = tmp;
  66                         break;
  67                 }
  68         }
  69         up_read(&bus_type_sem);
  70         return ret;
  71 }
  72
  73 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  74 {
  75         struct acpi_bus_type *tmp;
  76         int ret = -ENODEV;
  77
  78         down_read(&bus_type_sem);
  79         list_for_each_entry(tmp, &bus_type_list, list) {
  80                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  81                         ret = 0;
  82                         break;
  83                 }
  84         }
  85         up_read(&bus_type_sem);
  86         return ret;
  87 }
  88
  89 /* Get PCI root bridge's handle from its segment and bus number */
  90 struct acpi_find_pci_root {
  91         unsigned int seg;
  92         unsigned int bus;
  93         acpi_handle handle;
  94 };
  95
  96 static acpi_status
  97 do_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
  98 {
  99         unsigned long *busnr = (unsigned long *)data;
 100         struct acpi_resource_address64 address;
 101
 102         if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 103             resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 104             resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 105                 return AE_OK;
 106
 107         acpi_resource_to_address64(resource, &address);
 108         if ((address.address_length > 0) &&
 109             (address.resource_type == ACPI_BUS_NUMBER_RANGE))
 110                 *busnr = address.minimum;
 111
 112         return AE_OK;
 113 }
 114
 115 static int get_root_bridge_busnr(acpi_handle handle)
 116 {
 117         acpi_status status;
 118         unsigned long bus, bbn;
 119         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 120
 121         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 122
 123         status = acpi_evaluate_integer(handle, METHOD_NAME__BBN, NULL,
 124                                        &bbn);
 125         if (status == AE_NOT_FOUND) {
 126                 /* Assume bus = 0 */
 127                 printk(KERN_INFO PREFIX
 128                        "Assume root bridge [%s] bus is 0\n",
 129                        (char *)buffer.pointer);
 130                 status = AE_OK;
 131                 bbn = 0;
 132         }
 133         if (ACPI_FAILURE(status)) {
 134                 bbn = -ENODEV;
 135                 goto exit;
 136         }
 137         if (bbn > 0)
 138                 goto exit;
 139
 140         /* _BBN in some systems return 0 for all root bridges */
 141         bus = -1;
 142         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 143                                      do_root_bridge_busnr_callback, &bus);
 144         /* If _CRS failed, we just use _BBN */
 145         if (ACPI_FAILURE(status) || (bus == -1))
 146                 goto exit;
 147         /* We select _CRS */
 148         if (bbn != bus) {
 149                 printk(KERN_INFO PREFIX
 150                        "_BBN and _CRS returns different value for %s. Select _CRS\n",
 151                        (char *)buffer.pointer);
 152                 bbn = bus;
 153         }
 154       exit:
 155         kfree(buffer.pointer);
 156         return (int)bbn;
 157 }
 158
 159 static acpi_status
 160 find_pci_rootbridge(acpi_handle handle, u32 lvl, void *context, void **rv)
 161 {
 162         struct acpi_find_pci_root *find = (struct acpi_find_pci_root *)context;
 163         unsigned long seg, bus;
 164         acpi_status status;
 165         int tmp;
 166         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 167
 168         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 169
 170         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL, &seg);
 171         if (status == AE_NOT_FOUND) {
 172                 /* Assume seg = 0 */
 173                 status = AE_OK;
 174                 seg = 0;
 175         }
 176         if (ACPI_FAILURE(status)) {
 177                 status = AE_CTRL_DEPTH;
 178                 goto exit;
 179         }
 180
 181         tmp = get_root_bridge_busnr(handle);
 182         if (tmp < 0) {
 183                 printk(KERN_ERR PREFIX
 184                        "Find root bridge failed for %s\n",
 185                        (char *)buffer.pointer);
 186                 status = AE_CTRL_DEPTH;
 187                 goto exit;
 188         }
 189         bus = tmp;
 190
 191         if (seg == find->seg && bus == find->bus)
 192         {
 193                 find->handle = handle;
 194                 status = AE_CTRL_TERMINATE;
 195         }
 196         else
 197                 status = AE_OK;
 198       exit:
 199         kfree(buffer.pointer);
 200         return status;
 201 }
 202
 203 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 204 {
 205         struct acpi_find_pci_root find = { seg, bus, NULL };
 206
 207         acpi_get_devices(PCI_ROOT_HID_STRING, find_pci_rootbridge, &find, NULL);
 208         return find.handle;
 209 }
 210 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
 211
 212 /* Get device's handler per its address under its parent */
 213 struct acpi_find_child {
 214         acpi_handle handle;
 215         acpi_integer address;
 216 };
 217
 218 static acpi_status
 219 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
 220 {
 221         acpi_status status;
 222         struct acpi_device_info *info;
 223         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 224         struct acpi_find_child *find = (struct acpi_find_child *)context;
 225
 226         status = acpi_get_object_info(handle, &buffer);
 227         if (ACPI_SUCCESS(status)) {
 228                 info = buffer.pointer;
 229                 if (info->address == find->address)
 230                         find->handle = handle;
 231                 kfree(buffer.pointer);
 232         }
 233         return AE_OK;
 234 }
 235
 236 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
 237 {
 238         struct acpi_find_child find = { NULL, address };
 239
 240         if (!parent)
 241                 return NULL;
 242         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 243                             1, do_acpi_find_child, &find, NULL);
 244         return find.handle;
 245 }
 246
 247 EXPORT_SYMBOL(acpi_get_child);
 248
 249 /* Link ACPI devices with physical devices */
 250 static void acpi_glue_data_handler(acpi_handle handle,
 251                                    u32 function, void *context)
 252 {
 253         /* we provide an empty handler */
 254 }
 255
 256 /* Note: a success call will increase reference count by one */
 257 struct device *acpi_get_physical_device(acpi_handle handle)
 258 {
 259         acpi_status status;
 260         struct device *dev;
 261
 262         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 263         if (ACPI_SUCCESS(status))
 264                 return get_device(dev);
 265         return NULL;
 266 }
 267
 268 EXPORT_SYMBOL(acpi_get_physical_device);
 269
 270 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 271 {
 272         acpi_status status;
 273
 274         if (dev->archdata.acpi_handle) {
 275                 printk(KERN_WARNING PREFIX
 276                        "Drivers changed 'acpi_handle' for %s\n", dev->bus_id);
 277                 return -EINVAL;
 278         }
 279         get_device(dev);
 280         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 281         if (ACPI_FAILURE(status)) {
 282                 put_device(dev);
 283                 return -EINVAL;
 284         }
 285         dev->archdata.acpi_handle = handle;
 286
 287         return 0;
 288 }
 289
 290 static int acpi_unbind_one(struct device *dev)
 291 {
 292         if (!dev->archdata.acpi_handle)
 293                 return 0;
 294         if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
 295                 /* acpi_get_physical_device increase refcnt by one */
 296                 put_device(dev);
 297                 acpi_detach_data(dev->archdata.acpi_handle,
 298                                  acpi_glue_data_handler);
 299                 dev->archdata.acpi_handle = NULL;
 300                 /* acpi_bind_one increase refcnt by one */
 301                 put_device(dev);
 302         } else {
 303                 printk(KERN_ERR PREFIX
 304                        "Oops, 'acpi_handle' corrupt for %s\n", dev->bus_id);
 305         }
 306         return 0;
 307 }
 308
 309 static int acpi_platform_notify(struct device *dev)
 310 {
 311         struct acpi_bus_type *type;
 312         acpi_handle handle;
 313         int ret = -EINVAL;
 314
 315         if (!dev->bus || !dev->parent) {
 316                 /* bridge devices genernally haven't bus or parent */
 317                 ret = acpi_find_bridge_device(dev, &handle);
 318                 goto end;
 319         }
 320         type = acpi_get_bus_type(dev->bus);
 321         if (!type) {
 322                 DBG("No ACPI bus support for %s\n", dev->bus_id);
 323                 ret = -EINVAL;
 324                 goto end;
 325         }
 326         if ((ret = type->find_device(dev, &handle)) != 0)
 327                 DBG("Can't get handler for %s\n", dev->bus_id);
 328       end:
 329         if (!ret)
 330                 acpi_bind_one(dev, handle);
 331
 332 #if ACPI_GLUE_DEBUG
 333         if (!ret) {
 334                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 335
 336                 acpi_get_name(dev->archdata.acpi_handle,
 337                               ACPI_FULL_PATHNAME, &buffer);
 338                 DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
 339                 kfree(buffer.pointer);
 340         } else
 341                 DBG("Device %s -> No ACPI support\n", dev->bus_id);
 342 #endif
 343
 344         return ret;
 345 }
 346
 347 static int acpi_platform_notify_remove(struct device *dev)
 348 {
 349         acpi_unbind_one(dev);
 350         return 0;
 351 }
 352
 353 static int __init init_acpi_device_notify(void)
 354 {
 355         if (acpi_disabled)
 356                 return 0;
 357         if (platform_notify || platform_notify_remove) {
 358                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 359                 return 0;
 360         }
 361         platform_notify = acpi_platform_notify;
 362         platform_notify_remove = acpi_platform_notify_remove;
 363         return 0;
 364 }
 365
 366 arch_initcall(init_acpi_device_notify);