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glue.c

/*
 * Link physical devices with ACPI devices support
 *
 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
 * Copyright (c) 2005 Intel Corp.
 *
 * This file is released under the GPLv2.
 */
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>

#define ACPI_GLUE_DEBUG 0
#if ACPI_GLUE_DEBUG
#define DBG(x...) printk(PREFIX x)
#else
#define DBG(x...) do { } while(0)
#endif
static LIST_HEAD(bus_type_list);
static DECLARE_RWSEM(bus_type_sem);

int register_acpi_bus_type(struct acpi_bus_type *type)
{
      if (acpi_disabled)
            return -ENODEV;
      if (type && type->bus && type->find_device) {
            down_write(&bus_type_sem);
            list_add_tail(&type->list, &bus_type_list);
            up_write(&bus_type_sem);
            printk(KERN_INFO PREFIX "bus type %s registered\n",
                   type->bus->name);
            return 0;
      }
      return -ENODEV;
}

EXPORT_SYMBOL(register_acpi_bus_type);

int unregister_acpi_bus_type(struct acpi_bus_type *type)
{
      if (acpi_disabled)
            return 0;
      if (type) {
            down_write(&bus_type_sem);
            list_del_init(&type->list);
            up_write(&bus_type_sem);
            printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n",
                   type->bus->name);
            return 0;
      }
      return -ENODEV;
}

EXPORT_SYMBOL(unregister_acpi_bus_type);

static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type)
{
      struct acpi_bus_type *tmp, *ret = NULL;

      down_read(&bus_type_sem);
      list_for_each_entry(tmp, &bus_type_list, list) {
            if (tmp->bus == type) {
                  ret = tmp;
                  break;
            }
      }
      up_read(&bus_type_sem);
      return ret;
}

static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle)
{
      struct acpi_bus_type *tmp;
      int ret = -ENODEV;

      down_read(&bus_type_sem);
      list_for_each_entry(tmp, &bus_type_list, list) {
            if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) {
                  ret = 0;
                  break;
            }
      }
      up_read(&bus_type_sem);
      return ret;
}

/* Get device's handler per its address under its parent */
struct acpi_find_child {
      acpi_handle handle;
      acpi_integer address;
};

static acpi_status
do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv)
{
      acpi_status status;
      struct acpi_device_info *info;
      struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
      struct acpi_find_child *find = context;

      status = acpi_get_object_info(handle, &buffer);
      if (ACPI_SUCCESS(status)) {
            info = buffer.pointer;
            if (info->address == find->address)
                  find->handle = handle;
            kfree(buffer.pointer);
      }
      return AE_OK;
}

acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address)
{
      struct acpi_find_child find = { NULL, address };

      if (!parent)
            return NULL;
      acpi_walk_namespace(ACPI_TYPE_DEVICE, parent,
                      1, do_acpi_find_child, &find, NULL);
      return find.handle;
}

EXPORT_SYMBOL(acpi_get_child);

/* Link ACPI devices with physical devices */
static void acpi_glue_data_handler(acpi_handle handle,
                           u32 function, void *context)
{
      /* we provide an empty handler */
}

/* Note: a success call will increase reference count by one */
struct device *acpi_get_physical_device(acpi_handle handle)
{
      acpi_status status;
      struct device *dev;

      status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev);
      if (ACPI_SUCCESS(status))
            return get_device(dev);
      return NULL;
}

EXPORT_SYMBOL(acpi_get_physical_device);

static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
      acpi_status status;

      if (dev->archdata.acpi_handle) {
            printk(KERN_WARNING PREFIX
                   "Drivers changed 'acpi_handle' for %s\n", dev->bus_id);
            return -EINVAL;
      }
      get_device(dev);
      status = acpi_attach_data(handle, acpi_glue_data_handler, dev);
      if (ACPI_FAILURE(status)) {
            put_device(dev);
            return -EINVAL;
      }
      dev->archdata.acpi_handle = handle;

      return 0;
}

static int acpi_unbind_one(struct device *dev)
{
      if (!dev->archdata.acpi_handle)
            return 0;
      if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) {
            /* acpi_get_physical_device increase refcnt by one */
            put_device(dev);
            acpi_detach_data(dev->archdata.acpi_handle,
                         acpi_glue_data_handler);
            dev->archdata.acpi_handle = NULL;
            /* acpi_bind_one increase refcnt by one */
            put_device(dev);
      } else {
            printk(KERN_ERR PREFIX
                   "Oops, 'acpi_handle' corrupt for %s\n", dev->bus_id);
      }
      return 0;
}

static int acpi_platform_notify(struct device *dev)
{
      struct acpi_bus_type *type;
      acpi_handle handle;
      int ret = -EINVAL;

      if (!dev->bus || !dev->parent) {
            /* bridge devices genernally haven't bus or parent */
            ret = acpi_find_bridge_device(dev, &handle);
            goto end;
      }
      type = acpi_get_bus_type(dev->bus);
      if (!type) {
            DBG("No ACPI bus support for %s\n", dev->bus_id);
            ret = -EINVAL;
            goto end;
      }
      if ((ret = type->find_device(dev, &handle)) != 0)
            DBG("Can't get handler for %s\n", dev->bus_id);
      end:
      if (!ret)
            acpi_bind_one(dev, handle);

#if ACPI_GLUE_DEBUG
      if (!ret) {
            struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

            acpi_get_name(dev->archdata.acpi_handle,
                        ACPI_FULL_PATHNAME, &buffer);
            DBG("Device %s -> %s\n", dev->bus_id, (char *)buffer.pointer);
            kfree(buffer.pointer);
      } else
            DBG("Device %s -> No ACPI support\n", dev->bus_id);
#endif

      return ret;
}

static int acpi_platform_notify_remove(struct device *dev)
{
      acpi_unbind_one(dev);
      return 0;
}

static int __init init_acpi_device_notify(void)
{
      if (acpi_disabled)
            return 0;
      if (platform_notify || platform_notify_remove) {
            printk(KERN_ERR PREFIX "Can't use platform_notify\n");
            return 0;
      }
      platform_notify = acpi_platform_notify;
      platform_notify_remove = acpi_platform_notify_remove;
      return 0;
}

arch_initcall(init_acpi_device_notify);


#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)

#ifdef CONFIG_PM
static u32 rtc_handler(void *context)
{
      acpi_clear_event(ACPI_EVENT_RTC);
      acpi_disable_event(ACPI_EVENT_RTC, 0);
      return ACPI_INTERRUPT_HANDLED;
}

static inline void rtc_wake_setup(void)
{
      acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
}

static void rtc_wake_on(struct device *dev)
{
      acpi_clear_event(ACPI_EVENT_RTC);
      acpi_enable_event(ACPI_EVENT_RTC, 0);
}

static void rtc_wake_off(struct device *dev)
{
      acpi_disable_event(ACPI_EVENT_RTC, 0);
}
#else
#define rtc_wake_setup()      do{}while(0)
#define rtc_wake_on           NULL
#define rtc_wake_off          NULL
#endif

/* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
 * its device node and pass extra config data.  This helps its driver use
 * capabilities that the now-obsolete mc146818 didn't have, and informs it
 * that this board's RTC is wakeup-capable (per ACPI spec).
 */
#include <linux/mc146818rtc.h>

static struct cmos_rtc_board_info rtc_info;


/* PNP devices are registered in a subsys_initcall();
 * ACPI specifies the PNP IDs to use.
 */
#include <linux/pnp.h>

static int __init pnp_match(struct device *dev, void *data)
{
      static const char *ids[] = { "PNP0b00", "PNP0b01", "PNP0b02", };
      struct pnp_dev *pnp = to_pnp_dev(dev);
      int i;

      for (i = 0; i < ARRAY_SIZE(ids); i++) {
            if (compare_pnp_id(pnp->id, ids[i]) != 0)
                  return 1;
      }
      return 0;
}

static struct device *__init get_rtc_dev(void)
{
      return bus_find_device(&pnp_bus_type, NULL, NULL, pnp_match);
}

static int __init acpi_rtc_init(void)
{
      struct device *dev = get_rtc_dev();

      if (dev) {
            rtc_wake_setup();
            rtc_info.wake_on = rtc_wake_on;
            rtc_info.wake_off = rtc_wake_off;

            /* workaround bug in some ACPI tables */
            if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
                  DBG("bogus FADT month_alarm\n");
                  acpi_gbl_FADT.month_alarm = 0;
            }

            rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
            rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
            rtc_info.rtc_century = acpi_gbl_FADT.century;

            /* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
            if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
                  printk(PREFIX "RTC can wake from S4\n");


            dev->platform_data = &rtc_info;

            /* RTC always wakes from S1/S2/S3, and often S4/STD */
            device_init_wakeup(dev, 1);

            put_device(dev);
      } else
            DBG("RTC unavailable?\n");
      return 0;
}
/* do this between RTC subsys_initcall() and rtc_cmos driver_initcall() */
fs_initcall(acpi_rtc_init);

#endif

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