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", type->bus->name);
  33                 return 0;
  34         }
  35         return -ENODEV;
  36 }
  37
  38 EXPORT_SYMBOL(register_acpi_bus_type);
  39
  40 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  41 {
  42         if (acpi_disabled)
  43                 return 0;
  44         if (type) {
  45                 down_write(&bus_type_sem);
  46                 list_del_init(&type->list);
  47                 up_write(&bus_type_sem);
  48                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n", type->bus->name);
  49                 return 0;
  50         }
  51         return -ENODEV;
  52 }
  53
  54 EXPORT_SYMBOL(unregister_acpi_bus_type);
  55
  56 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  57 {
  58         struct acpi_bus_type *tmp, *ret = NULL;
  59
  60         down_read(&bus_type_sem);
  61         list_for_each_entry(tmp, &bus_type_list, list) {
  62                 if (tmp->bus == type) {
  63                         ret = tmp;
  64                         break;
  65                 }
  66         }
  67         up_read(&bus_type_sem);
  68         return ret;
  69 }
  70
  71 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  72 {
  73         struct acpi_bus_type *tmp;
  74         int ret = -ENODEV;
  75
  76         down_read(&bus_type_sem);
  77         list_for_each_entry(tmp, &bus_type_list, list) {
  78                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  79                         ret = 0;
  80                         break;
  81                 }
  82         }
  83         up_read(&bus_type_sem);
  84         return ret;
  85 }
  86
  87 /* Get PCI root bridge's handle from its segment and bus number */
  88 struct acpi_find_pci_root {
  89         unsigned int seg;
  90         unsigned int bus;
  91         acpi_handle handle;
  92 };
  93
  94 static acpi_status
  95 do_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
  96 {
  97         int *busnr = (int *)data;
  98         struct acpi_resource_address64 address;
  99
 100         if (resource->id != ACPI_RSTYPE_ADDRESS16 &&
 101             resource->id != ACPI_RSTYPE_ADDRESS32 &&
 102             resource->id != ACPI_RSTYPE_ADDRESS64)
 103                 return AE_OK;
 104
 105         acpi_resource_to_address64(resource, &address);
 106         if ((address.address_length > 0) &&
 107             (address.resource_type == ACPI_BUS_NUMBER_RANGE))
 108                 *busnr = address.min_address_range;
 109
 110         return AE_OK;
 111 }
 112
 113 static int get_root_bridge_busnr(acpi_handle handle)
 114 {
 115         acpi_status status;
 116         int bus, bbn;
 117         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 118
 119         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 120
 121         status = acpi_evaluate_integer(handle, METHOD_NAME__BBN, NULL,
 122                                        (unsigned long *)&bbn);
 123         if (status == AE_NOT_FOUND) {
 124                 /* Assume bus = 0 */
 125                 printk(KERN_INFO PREFIX
 126                        "Assume root bridge [%s] bus is 0\n",
 127                        (char *)buffer.pointer);
 128                 status = AE_OK;
 129                 bbn = 0;
 130         }
 131         if (ACPI_FAILURE(status)) {
 132                 bbn = -ENODEV;
 133                 goto exit;
 134         }
 135         if (bbn > 0)
 136                 goto exit;
 137
 138         /* _BBN in some systems return 0 for all root bridges */
 139         bus = -1;
 140         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 141                                      do_root_bridge_busnr_callback, &bus);
 142         /* If _CRS failed, we just use _BBN */
 143         if (ACPI_FAILURE(status) || (bus == -1))
 144                 goto exit;
 145         /* We select _CRS */
 146         if (bbn != bus) {
 147                 printk(KERN_INFO PREFIX
 148                        "_BBN and _CRS returns different value for %s. Select _CRS\n",
 149                        (char *)buffer.pointer);
 150                 bbn = bus;
 151         }
 152       exit:
 153         acpi_os_free(buffer.pointer);
 154         return bbn;
 155 }
 156
 157 static acpi_status
 158 find_pci_rootbridge(acpi_handle handle, u32 lvl, void *context, void **rv)
 159 {
 160         struct acpi_find_pci_root *find = (struct acpi_find_pci_root *)context;
 161         unsigned long seg, bus;
 162         acpi_status status;
 163         int tmp;
 164         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 165
 166         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 167
 168         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL, &seg);
 169         if (status == AE_NOT_FOUND) {
 170                 /* Assume seg = 0 */
 171                 printk(KERN_INFO PREFIX
 172                        "Assume root bridge [%s] segment is 0\n",
 173                        (char *)buffer.pointer);
 174                 status = AE_OK;
 175                 seg = 0;
 176         }
 177         if (ACPI_FAILURE(status)) {
 178                 status = AE_CTRL_DEPTH;
 179                 goto exit;
 180         }
 181
 182         tmp = get_root_bridge_busnr(handle);
 183         if (tmp < 0) {
 184                 printk(KERN_ERR PREFIX
 185                        "Find root bridge failed for %s\n",
 186                        (char *)buffer.pointer);
 187                 status = AE_CTRL_DEPTH;
 188                 goto exit;
 189         }
 190         bus = tmp;
 191
 192         if (seg == find->seg && bus == find->bus)
 193                 find->handle = handle;
 194         status = AE_OK;
 195       exit:
 196         acpi_os_free(buffer.pointer);
 197         return status;
 198 }
 199
 200 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 201 {
 202         struct acpi_find_pci_root find = { seg, bus, NULL };
 203
 204         acpi_get_devices(PCI_ROOT_HID_STRING, find_pci_rootbridge, &find, NULL);
 205         return find.handle;
 206 }
 207
 208 /* Get device's handler per its address under its parent */
 209 struct acpi_find_child {
 210         acpi_handle handle;
 211         acpi_integer address;
 212 };
 213
 214 static acpi_status
 215 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
 216 {
 217         acpi_status status;
 218         struct acpi_device_info *info;
 219         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 220         struct acpi_find_child *find = (struct acpi_find_child *)context;
 221
 222         status = acpi_get_object_info(handle, &buffer);
 223         if (ACPI_SUCCESS(status)) {
 224                 info = buffer.pointer;
 225                 if (info->address == find->address)
 226                         find->handle = handle;
 227                 acpi_os_free(buffer.pointer);
 228         }
 229         return AE_OK;
 230 }
 231
 232 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
 233 {
 234         struct acpi_find_child find = { NULL, address };
 235
 236         if (!parent)
 237                 return NULL;
 238         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 239                             1, do_acpi_find_child, &find, NULL);
 240         return find.handle;
 241 }
 242
 243 EXPORT_SYMBOL(acpi_get_child);
 244
 245 /* Link ACPI devices with physical devices */
 246 static void acpi_glue_data_handler(acpi_handle handle,
 247                                    u32 function, void *context)
 248 {
 249         /* we provide an empty handler */
 250 }
 251
 252 /* Note: a success call will increase reference count by one */
 253 struct device *acpi_get_physical_device(acpi_handle handle)
 254 {
 255         acpi_status status;
 256         struct device *dev;
 257
 258         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 259         if (ACPI_SUCCESS(status))
 260                 return get_device(dev);
 261         return NULL;
 262 }
 263
 264 EXPORT_SYMBOL(acpi_get_physical_device);
 265
 266 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 267 {
 268         acpi_status status;
 269
 270         if (dev->firmware_data) {
 271                 printk(KERN_WARNING PREFIX
 272                        "Drivers changed 'firmware_data' for %s\n", dev->bus_id);
 273                 return -EINVAL;
 274         }
 275         get_device(dev);
 276         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 277         if (ACPI_FAILURE(status)) {
 278                 put_device(dev);
 279                 return -EINVAL;
 280         }
 281         dev->firmware_data = handle;
 282
 283         return 0;
 284 }
 285
 286 static int acpi_unbind_one(struct device *dev)
 287 {
 288         if (!dev->firmware_data)
 289                 return 0;
 290         if (dev == acpi_get_physical_device(dev->firmware_data)) {
 291                 /* acpi_get_physical_device increase refcnt by one */
 292                 put_device(dev);
 293                 acpi_detach_data(dev->firmware_data, acpi_glue_data_handler);
 294                 dev->firmware_data = NULL;
 295                 /* acpi_bind_one increase refcnt by one */
 296                 put_device(dev);
 297         } else {
 298                 printk(KERN_ERR PREFIX
 299                        "Oops, 'firmware_data' corrupt for %s\n", dev->bus_id);
 300         }
 301         return 0;
 302 }
 303
 304 static int acpi_platform_notify(struct device *dev)
 305 {
 306         struct acpi_bus_type *type;
 307         acpi_handle handle;
 308         int ret = -EINVAL;
 309
 310         if (!dev->bus || !dev->parent) {
 311                 /* bridge devices genernally haven't bus or parent */
 312                 ret = acpi_find_bridge_device(dev, &handle);
 313                 goto end;
 314         }
 315         type = acpi_get_bus_type(dev->bus);
 316         if (!type) {
 317                 DBG("No ACPI bus support for %s\n", dev->bus_id);
 318                 ret = -EINVAL;
 319                 goto end;
 320         }
 321         if ((ret = type->find_device(dev, &handle)) != 0)
 322                 DBG("Can't get handler for %s\n", dev->bus_id);
 323       end:
 324         if (!ret)
 325                 acpi_bind_one(dev, handle);
 326
 327 #if ACPI_GLUE_DEBUG
 328         if (!ret) {
 329                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 330
 331                 acpi_get_name(dev->firmware_data, ACPI_FULL_PATHNAME, &buffer);
 332                 DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
 333                 acpi_os_free(buffer.pointer);
 334         } else
 335                 DBG("Device %s -> No ACPI support\n", dev->bus_id);
 336 #endif
 337
 338         return ret;
 339 }
 340
 341 static int acpi_platform_notify_remove(struct device *dev)
 342 {
 343         acpi_unbind_one(dev);
 344         return 0;
 345 }
 346
 347 static int __init init_acpi_device_notify(void)
 348 {
 349         if (acpi_disabled)
 350                 return 0;
 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
 360 arch_initcall(init_acpi_device_notify);