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...) do { } while(0)
  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 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  40 {
  41         if (acpi_disabled)
  42                 return 0;
  43         if (type) {
  44                 down_write(&bus_type_sem);
  45                 list_del_init(&type->list);
  46                 up_write(&bus_type_sem);
  47                 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
  48                        type->bus->name);
  49                 return 0;
  50         }
  51         return -ENODEV;
  52 }
  53
  54 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
  55 {
  56         struct acpi_bus_type *tmp, *ret = NULL;
  57
  58         down_read(&bus_type_sem);
  59         list_for_each_entry(tmp, &bus_type_list, list) {
  60                 if (tmp->bus == type) {
  61                         ret = tmp;
  62                         break;
  63                 }
  64         }
  65         up_read(&bus_type_sem);
  66         return ret;
  67 }
  68
  69 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
  70 {
  71         struct acpi_bus_type *tmp;
  72         int ret = -ENODEV;
  73
  74         down_read(&bus_type_sem);
  75         list_for_each_entry(tmp, &bus_type_list, list) {
  76                 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
  77                         ret = 0;
  78                         break;
  79                 }
  80         }
  81         up_read(&bus_type_sem);
  82         return ret;
  83 }
  84
  85 /* Get device's handler per its address under its parent */
  86 struct acpi_find_child {
  87         acpi_handle handle;
  88         acpi_integer address;
  89 };
  90
  91 static acpi_status
  92 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
  93 {
  94         acpi_status status;
  95         struct acpi_device_info *info;
  96         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  97         struct acpi_find_child *find = context;
  98
  99         status = acpi_get_object_info(handle, &buffer);
 100         if (ACPI_SUCCESS(status)) {
 101                 info = buffer.pointer;
 102                 if (info->address == find->address)
 103                         find->handle = handle;
 104                 kfree(buffer.pointer);
 105         }
 106         return AE_OK;
 107 }
 108
 109 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
 110 {
 111         struct acpi_find_child find = { NULL, address };
 112
 113         if (!parent)
 114                 return NULL;
 115         acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
 116                             1, do_acpi_find_child, &find, NULL);
 117         return find.handle;
 118 }
 119
 120 EXPORT_SYMBOL(acpi_get_child);
 121
 122 /* Link ACPI devices with physical devices */
 123 static void acpi_glue_data_handler(acpi_handle handle,
 124                                    u32 function, void *context)
 125 {
 126         /* we provide an empty handler */
 127 }
 128
 129 /* Note: a success call will increase reference count by one */
 130 struct device *acpi_get_physical_device(acpi_handle handle)
 131 {
 132         acpi_status status;
 133         struct device *dev;
 134
 135         status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
 136         if (ACPI_SUCCESS(status))
 137                 return get_device(dev);
 138         return NULL;
 139 }
 140
 141 EXPORT_SYMBOL(acpi_get_physical_device);
 142
 143 static int acpi_bind_one(struct device *dev, acpi_handle handle)
 144 {
 145         acpi_status status;
 146
 147         if (dev->archdata.acpi_handle) {
 148                 printk(KERN_WARNING PREFIX
 149                        "Drivers changed 'acpi_handle' for %s\n", dev->bus_id);
 150                 return -EINVAL;
 151         }
 152         get_device(dev);
 153         status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
 154         if (ACPI_FAILURE(status)) {
 155                 put_device(dev);
 156                 return -EINVAL;
 157         }
 158         dev->archdata.acpi_handle = handle;
 159
 160         return 0;
 161 }
 162
 163 static int acpi_unbind_one(struct device *dev)
 164 {
 165         if (!dev->archdata.acpi_handle)
 166                 return 0;
 167         if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
 168                 /* acpi_get_physical_device increase refcnt by one */
 169                 put_device(dev);
 170                 acpi_detach_data(dev->archdata.acpi_handle,
 171                                  acpi_glue_data_handler);
 172                 dev->archdata.acpi_handle = NULL;
 173                 /* acpi_bind_one increase refcnt by one */
 174                 put_device(dev);
 175         } else {
 176                 printk(KERN_ERR PREFIX
 177                        "Oops, 'acpi_handle' corrupt for %s\n", dev->bus_id);
 178         }
 179         return 0;
 180 }
 181
 182 static int acpi_platform_notify(struct device *dev)
 183 {
 184         struct acpi_bus_type *type;
 185         acpi_handle handle;
 186         int ret = -EINVAL;
 187
 188         if (!dev->bus || !dev->parent) {
 189                 /* bridge devices genernally haven't bus or parent */
 190                 ret = acpi_find_bridge_device(dev, &handle);
 191                 goto end;
 192         }
 193         type = acpi_get_bus_type(dev->bus);
 194         if (!type) {
 195                 DBG("No ACPI bus support for %s\n", dev->bus_id);
 196                 ret = -EINVAL;
 197                 goto end;
 198         }
 199         if ((ret = type->find_device(dev, &handle)) != 0)
 200                 DBG("Can't get handler for %s\n", dev->bus_id);
 201       end:
 202         if (!ret)
 203                 acpi_bind_one(dev, handle);
 204
 205 #if ACPI_GLUE_DEBUG
 206         if (!ret) {
 207                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 208
 209                 acpi_get_name(dev->archdata.acpi_handle,
 210                               ACPI_FULL_PATHNAME, &buffer);
 211                 DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
 212                 kfree(buffer.pointer);
 213         } else
 214                 DBG("Device %s -> No ACPI support\n", dev->bus_id);
 215 #endif
 216
 217         return ret;
 218 }
 219
 220 static int acpi_platform_notify_remove(struct device *dev)
 221 {
 222         acpi_unbind_one(dev);
 223         return 0;
 224 }
 225
 226 static int __init init_acpi_device_notify(void)
 227 {
 228         if (acpi_disabled)
 229                 return 0;
 230         if (platform_notify || platform_notify_remove) {
 231                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 232                 return 0;
 233         }
 234         platform_notify = acpi_platform_notify;
 235         platform_notify_remove = acpi_platform_notify_remove;
 236         return 0;
 237 }
 238
 239 arch_initcall(init_acpi_device_notify);
 240
 241
 242 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
 243
 244 #ifdef CONFIG_PM
 245 static u32 rtc_handler(void *context)
 246 {
 247         acpi_clear_event(ACPI_EVENT_RTC);
 248         acpi_disable_event(ACPI_EVENT_RTC, 0);
 249         return ACPI_INTERRUPT_HANDLED;
 250 }
 251
 252 static inline void rtc_wake_setup(void)
 253 {
 254         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
 255 }
 256
 257 static void rtc_wake_on(struct device *dev)
 258 {
 259         acpi_clear_event(ACPI_EVENT_RTC);
 260         acpi_enable_event(ACPI_EVENT_RTC, 0);
 261 }
 262
 263 static void rtc_wake_off(struct device *dev)
 264 {
 265         acpi_disable_event(ACPI_EVENT_RTC, 0);
 266 }
 267 #else
 268 #define rtc_wake_setup()        do{}while(0)
 269 #define rtc_wake_on             NULL
 270 #define rtc_wake_off            NULL
 271 #endif
 272
 273 /* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
 274  * its device node and pass extra config data.  This helps its driver use
 275  * capabilities that the now-obsolete mc146818 didn't have, and informs it
 276  * that this board's RTC is wakeup-capable (per ACPI spec).
 277  */
 278 #include <linux/mc146818rtc.h>
 279
 280 static struct cmos_rtc_board_info rtc_info;
 281
 282
 283 /* PNP devices are registered in a subsys_initcall();
 284  * ACPI specifies the PNP IDs to use.
 285  */
 286 #include <linux/pnp.h>
 287
 288 static int __init pnp_match(struct device *dev, void *data)
 289 {
 290         static const char *ids[] = { "PNP0b00", "PNP0b01", "PNP0b02", };
 291         struct pnp_dev *pnp = to_pnp_dev(dev);
 292         int i;
 293
 294         for (i = 0; i < ARRAY_SIZE(ids); i++) {
 295                 if (compare_pnp_id(pnp->id, ids[i]) != 0)
 296                         return 1;
 297         }
 298         return 0;
 299 }
 300
 301 static struct device *__init get_rtc_dev(void)
 302 {
 303         return bus_find_device(&pnp_bus_type, NULL, NULL, pnp_match);
 304 }
 305
 306 static int __init acpi_rtc_init(void)
 307 {
 308         struct device *dev = get_rtc_dev();
 309
 310         if (dev) {
 311                 rtc_wake_setup();
 312                 rtc_info.wake_on = rtc_wake_on;
 313                 rtc_info.wake_off = rtc_wake_off;
 314
 315                 /* workaround bug in some ACPI tables */
 316                 if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
 317                         DBG("bogus FADT month_alarm\n");
 318                         acpi_gbl_FADT.month_alarm = 0;
 319                 }
 320
 321                 rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
 322                 rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
 323                 rtc_info.rtc_century = acpi_gbl_FADT.century;
 324
 325                 /* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
 326                 if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
 327                         printk(PREFIX "RTC can wake from S4\n");
 328
 329
 330                 dev->platform_data = &rtc_info;
 331
 332                 /* RTC always wakes from S1/S2/S3, and often S4/STD */
 333                 device_init_wakeup(dev, 1);
 334
 335                 put_device(dev);
 336         } else
 337                 DBG("RTC unavailable?\n");
 338         return 0;
 339 }
 340 /* do this between RTC subsys_initcall() and rtc_cmos driver_initcall() */
 341 fs_initcall(acpi_rtc_init);
 342
 343 #endif