linux/drivers/acpi/container.c
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   1/*
   2 * acpi_container.c  - ACPI Generic Container Driver
   3 * ($Revision: )
   4 *
   5 * Copyright (C) 2004 Anil S Keshavamurthy (anil.s.keshavamurthy@intel.com)
   6 * Copyright (C) 2004 Keiichiro Tokunaga (tokunaga.keiich@jp.fujitsu.com)
   7 * Copyright (C) 2004 Motoyuki Ito (motoyuki@soft.fujitsu.com)
   8 * Copyright (C) 2004 Intel Corp.
   9 * Copyright (C) 2004 FUJITSU LIMITED
  10 *
  11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  12 *
  13 *  This program is free software; you can redistribute it and/or modify
  14 *  it under the terms of the GNU General Public License as published by
  15 *  the Free Software Foundation; either version 2 of the License, or (at
  16 *  your option) any later version.
  17 *
  18 *  This program is distributed in the hope that it will be useful, but
  19 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  20 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21 *  General Public License for more details.
  22 *
  23 *  You should have received a copy of the GNU General Public License along
  24 *  with this program; if not, write to the Free Software Foundation, Inc.,
  25 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  26 *
  27 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  28 */
  29#include <linux/kernel.h>
  30#include <linux/module.h>
  31#include <linux/init.h>
  32#include <linux/slab.h>
  33#include <linux/types.h>
  34#include <linux/acpi.h>
  35#include <acpi/acpi_bus.h>
  36#include <acpi/acpi_drivers.h>
  37
  38#define PREFIX "ACPI: "
  39
  40#define _COMPONENT                      ACPI_CONTAINER_COMPONENT
  41ACPI_MODULE_NAME("container");
  42
  43static const struct acpi_device_id container_device_ids[] = {
  44        {"ACPI0004", 0},
  45        {"PNP0A05", 0},
  46        {"PNP0A06", 0},
  47        {"", 0},
  48};
  49
  50static int container_device_attach(struct acpi_device *device,
  51                                   const struct acpi_device_id *not_used)
  52{
  53        /*
  54         * FIXME: This is necessary, so that acpi_eject_store() doesn't return
  55         * -ENODEV for containers.
  56         */
  57        return 1;
  58}
  59
  60static struct acpi_scan_handler container_device_handler = {
  61        .ids = container_device_ids,
  62        .attach = container_device_attach,
  63};
  64
  65static int is_device_present(acpi_handle handle)
  66{
  67        acpi_handle temp;
  68        acpi_status status;
  69        unsigned long long sta;
  70
  71
  72        status = acpi_get_handle(handle, "_STA", &temp);
  73        if (ACPI_FAILURE(status))
  74                return 1;       /* _STA not found, assume device present */
  75
  76        status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  77        if (ACPI_FAILURE(status))
  78                return 0;       /* Firmware error */
  79
  80        return ((sta & ACPI_STA_DEVICE_PRESENT) == ACPI_STA_DEVICE_PRESENT);
  81}
  82
  83static void container_notify_cb(acpi_handle handle, u32 type, void *context)
  84{
  85        struct acpi_device *device = NULL;
  86        int result;
  87        int present;
  88        acpi_status status;
  89        u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
  90
  91        acpi_scan_lock_acquire();
  92
  93        switch (type) {
  94        case ACPI_NOTIFY_BUS_CHECK:
  95                /* Fall through */
  96        case ACPI_NOTIFY_DEVICE_CHECK:
  97                pr_debug("Container driver received %s event\n",
  98                       (type == ACPI_NOTIFY_BUS_CHECK) ?
  99                       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
 100
 101                present = is_device_present(handle);
 102                status = acpi_bus_get_device(handle, &device);
 103                if (!present) {
 104                        if (ACPI_SUCCESS(status)) {
 105                                /* device exist and this is a remove request */
 106                                device->flags.eject_pending = 1;
 107                                kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 108                                goto out;
 109                        }
 110                        break;
 111                }
 112
 113                if (!ACPI_FAILURE(status) || device)
 114                        break;
 115
 116                result = acpi_bus_scan(handle);
 117                if (result) {
 118                        acpi_handle_warn(handle, "Failed to add container\n");
 119                        break;
 120                }
 121                result = acpi_bus_get_device(handle, &device);
 122                if (result) {
 123                        acpi_handle_warn(handle, "Missing device object\n");
 124                        break;
 125                }
 126
 127                kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
 128                ost_code = ACPI_OST_SC_SUCCESS;
 129                break;
 130
 131        case ACPI_NOTIFY_EJECT_REQUEST:
 132                if (!acpi_bus_get_device(handle, &device) && device) {
 133                        device->flags.eject_pending = 1;
 134                        kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 135                        goto out;
 136                }
 137                break;
 138
 139        default:
 140                /* non-hotplug event; possibly handled by other handler */
 141                goto out;
 142        }
 143
 144        /* Inform firmware that the hotplug operation has completed */
 145        (void) acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 146
 147 out:
 148        acpi_scan_lock_release();
 149}
 150
 151static bool is_container(acpi_handle handle)
 152{
 153        struct acpi_device_info *info;
 154        bool ret = false;
 155
 156        if (ACPI_FAILURE(acpi_get_object_info(handle, &info)))
 157                return false;
 158
 159        if (info->valid & ACPI_VALID_HID) {
 160                const struct acpi_device_id *id;
 161
 162                for (id = container_device_ids; id->id[0]; id++) {
 163                        ret = !strcmp((char *)id->id, info->hardware_id.string);
 164                        if (ret)
 165                                break;
 166                }
 167        }
 168        kfree(info);
 169        return ret;
 170}
 171
 172static acpi_status acpi_container_register_notify_handler(acpi_handle handle,
 173                                                          u32 lvl, void *ctxt,
 174                                                          void **retv)
 175{
 176        if (is_container(handle))
 177                acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 178                                            container_notify_cb, NULL);
 179
 180        return AE_OK;
 181}
 182
 183void __init acpi_container_init(void)
 184{
 185        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
 186                            acpi_container_register_notify_handler, NULL,
 187                            NULL, NULL);
 188
 189        acpi_scan_add_handler(&container_device_handler);
 190}
 191
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