glue.c

Go to the documentation of this file.

/*
 * Link physical devices with ACPI devices support
 *
 * Copyright (c) 2005 David Shaohua Li <[email protected]>
 * Copyright (c) 2005 Intel Corp.
 *
 * This file is released under the GPLv2.
 */
#include <linux/export.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/acpi.h>

#include "internal.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);

#define PHYSICAL_NODE_STRING "physical_node"

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_GPL(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_GPL(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;
    u64 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_find_child *find = context;

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

acpi_handle acpi_get_child(acpi_handle parent, u64 address)
{
    struct acpi_find_child find = { NULL, address };

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

EXPORT_SYMBOL(acpi_get_child);

static int acpi_bind_one(struct device *dev, acpi_handle handle)
{
    struct acpi_device *acpi_dev;
    acpi_status status;
    struct acpi_device_physical_node *physical_node;
    char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];
    int retval = -EINVAL;

    if (dev->archdata.acpi_handle) {
        dev_warn(dev, "Drivers changed 'acpi_handle'\n");
        return -EINVAL;
    }

    get_device(dev);
    status = acpi_bus_get_device(handle, &acpi_dev);
    if (ACPI_FAILURE(status))
        goto err;

    physical_node = kzalloc(sizeof(struct acpi_device_physical_node),
        GFP_KERNEL);
    if (!physical_node) {
        retval = -ENOMEM;
        goto err;
    }

    mutex_lock(&acpi_dev->physical_node_lock);
    /* allocate physical node id according to physical_node_id_bitmap */
    physical_node->node_id =
        find_first_zero_bit(acpi_dev->physical_node_id_bitmap,
        ACPI_MAX_PHYSICAL_NODE);
    if (physical_node->node_id >= ACPI_MAX_PHYSICAL_NODE) {
        retval = -ENOSPC;
        mutex_unlock(&acpi_dev->physical_node_lock);
        kfree(physical_node);
        goto err;
    }

    set_bit(physical_node->node_id, acpi_dev->physical_node_id_bitmap);
    physical_node->dev = dev;
    list_add_tail(&physical_node->node, &acpi_dev->physical_node_list);
    acpi_dev->physical_node_count++;
    mutex_unlock(&acpi_dev->physical_node_lock);

    dev->archdata.acpi_handle = handle;

    if (!physical_node->node_id)
        strcpy(physical_node_name, PHYSICAL_NODE_STRING);
    else
        sprintf(physical_node_name,
            "physical_node%d", physical_node->node_id);
    retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
            physical_node_name);
    retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
        "firmware_node");

    if (acpi_dev->wakeup.flags.valid)
        device_set_wakeup_capable(dev, true);

    return 0;

 err:
    put_device(dev);
    return retval;
}

static int acpi_unbind_one(struct device *dev)
{
    struct acpi_device_physical_node *entry;
    struct acpi_device *acpi_dev;
    acpi_status status;
    struct list_head *node, *next;

    if (!dev->archdata.acpi_handle)
        return 0;

    status = acpi_bus_get_device(dev->archdata.acpi_handle,
        &acpi_dev);
    if (ACPI_FAILURE(status))
        goto err;

    mutex_lock(&acpi_dev->physical_node_lock);
    list_for_each_safe(node, next, &acpi_dev->physical_node_list) {
        char physical_node_name[sizeof(PHYSICAL_NODE_STRING) + 2];

        entry = list_entry(node, struct acpi_device_physical_node,
            node);
        if (entry->dev != dev)
            continue;

        list_del(node);
        clear_bit(entry->node_id, acpi_dev->physical_node_id_bitmap);

        acpi_dev->physical_node_count--;

        if (!entry->node_id)
            strcpy(physical_node_name, PHYSICAL_NODE_STRING);
        else
            sprintf(physical_node_name,
                "physical_node%d", entry->node_id);

        sysfs_remove_link(&acpi_dev->dev.kobj, physical_node_name);
        sysfs_remove_link(&dev->kobj, "firmware_node");
        dev->archdata.acpi_handle = NULL;
        /* acpi_bind_one increase refcnt by one */
        put_device(dev);
        kfree(entry);
    }
    mutex_unlock(&acpi_dev->physical_node_lock);

    return 0;

err:
    dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
    return -EINVAL;
}

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_name(dev));
        ret = -EINVAL;
        goto end;
    }
    if ((ret = type->find_device(dev, &handle)) != 0)
        DBG("Can't get handler for %s\n", dev_name(dev));
      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_name(dev), (char *)buffer.pointer);
        kfree(buffer.pointer);
    } else
        DBG("Device %s -> No ACPI support\n", dev_name(dev));
#endif

    return ret;
}

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

int __init init_acpi_device_notify(void)
{
    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;
}