drivers/acpi/container.c

   1 /*
   2  * acpi_container.c  - ACPI Generic Container Driver
   3  * ($Revision: )
   4  *
   5  * Copyright (C) 2004 Anil S Keshavamurthy ([email protected])
   6  * Copyright (C) 2004 Keiichiro Tokunaga ([email protected])
   7  * Copyright (C) 2004 Motoyuki Ito ([email protected])
   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
  41 ACPI_MODULE_NAME("container");
  42
  43 static const struct acpi_device_id container_device_ids[] = {
  44         {"ACPI0004", 0},
  45         {"PNP0A05", 0},
  46         {"PNP0A06", 0},
  47         {"", 0},
  48 };
  49
  50 static 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
  60 static struct acpi_scan_handler container_device_handler = {
  61         .ids = container_device_ids,
  62         .attach = container_device_attach,
  63 };
  64
  65 static 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
  83 static 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
 151 static 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
 172 static 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
 183 void __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 }