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#include <acpi/container.h>
  38
  39#define PREFIX "ACPI: "
  40
  41#define ACPI_CONTAINER_DEVICE_NAME      "ACPI container device"
  42#define ACPI_CONTAINER_CLASS            "container"
  43
  44#define INSTALL_NOTIFY_HANDLER          1
  45#define UNINSTALL_NOTIFY_HANDLER        2
  46
  47#define _COMPONENT                      ACPI_CONTAINER_COMPONENT
  48ACPI_MODULE_NAME("container");
  49
  50MODULE_AUTHOR("Anil S Keshavamurthy");
  51MODULE_DESCRIPTION("ACPI container driver");
  52MODULE_LICENSE("GPL");
  53
  54static int acpi_container_add(struct acpi_device *device);
  55static int acpi_container_remove(struct acpi_device *device, int type);
  56
  57static const struct acpi_device_id container_device_ids[] = {
  58        {"ACPI0004", 0},
  59        {"PNP0A05", 0},
  60        {"PNP0A06", 0},
  61        {"", 0},
  62};
  63MODULE_DEVICE_TABLE(acpi, container_device_ids);
  64
  65static struct acpi_driver acpi_container_driver = {
  66        .name = "container",
  67        .class = ACPI_CONTAINER_CLASS,
  68        .ids = container_device_ids,
  69        .ops = {
  70                .add = acpi_container_add,
  71                .remove = acpi_container_remove,
  72                },
  73};
  74
  75/*******************************************************************/
  76
  77static int is_device_present(acpi_handle handle)
  78{
  79        acpi_handle temp;
  80        acpi_status status;
  81        unsigned long long sta;
  82
  83
  84        status = acpi_get_handle(handle, "_STA", &temp);
  85        if (ACPI_FAILURE(status))
  86                return 1;       /* _STA not found, assume device present */
  87
  88        status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  89        if (ACPI_FAILURE(status))
  90                return 0;       /* Firmware error */
  91
  92        return ((sta & ACPI_STA_DEVICE_PRESENT) == ACPI_STA_DEVICE_PRESENT);
  93}
  94
  95static bool is_container_device(const char *hid)
  96{
  97        const struct acpi_device_id *container_id;
  98
  99        for (container_id = container_device_ids;
 100             container_id->id[0]; container_id++) {
 101                if (!strcmp((char *)container_id->id, hid))
 102                        return true;
 103        }
 104
 105        return false;
 106}
 107
 108/*******************************************************************/
 109static int acpi_container_add(struct acpi_device *device)
 110{
 111        struct acpi_container *container;
 112
 113        container = kzalloc(sizeof(struct acpi_container), GFP_KERNEL);
 114        if (!container)
 115                return -ENOMEM;
 116
 117        container->handle = device->handle;
 118        strcpy(acpi_device_name(device), ACPI_CONTAINER_DEVICE_NAME);
 119        strcpy(acpi_device_class(device), ACPI_CONTAINER_CLASS);
 120        device->driver_data = container;
 121
 122        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device <%s> bid <%s>\n",
 123                          acpi_device_name(device), acpi_device_bid(device)));
 124
 125        return 0;
 126}
 127
 128static int acpi_container_remove(struct acpi_device *device, int type)
 129{
 130        acpi_status status = AE_OK;
 131        struct acpi_container *pc = NULL;
 132
 133        pc = acpi_driver_data(device);
 134        kfree(pc);
 135        return status;
 136}
 137
 138static int container_device_add(struct acpi_device **device, acpi_handle handle)
 139{
 140        acpi_handle phandle;
 141        struct acpi_device *pdev;
 142        int result;
 143
 144
 145        if (acpi_get_parent(handle, &phandle)) {
 146                return -ENODEV;
 147        }
 148
 149        if (acpi_bus_get_device(phandle, &pdev)) {
 150                return -ENODEV;
 151        }
 152
 153        if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_DEVICE)) {
 154                return -ENODEV;
 155        }
 156
 157        result = acpi_bus_start(*device);
 158
 159        return result;
 160}
 161
 162static void container_notify_cb(acpi_handle handle, u32 type, void *context)
 163{
 164        struct acpi_device *device = NULL;
 165        int result;
 166        int present;
 167        acpi_status status;
 168        u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 169
 170        switch (type) {
 171        case ACPI_NOTIFY_BUS_CHECK:
 172                /* Fall through */
 173        case ACPI_NOTIFY_DEVICE_CHECK:
 174                pr_debug("Container driver received %s event\n",
 175                       (type == ACPI_NOTIFY_BUS_CHECK) ?
 176                       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
 177
 178                present = is_device_present(handle);
 179                status = acpi_bus_get_device(handle, &device);
 180                if (!present) {
 181                        if (ACPI_SUCCESS(status)) {
 182                                /* device exist and this is a remove request */
 183                                device->flags.eject_pending = 1;
 184                                kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 185                                return;
 186                        }
 187                        break;
 188                }
 189
 190                if (!ACPI_FAILURE(status) || device)
 191                        break;
 192
 193                result = container_device_add(&device, handle);
 194                if (result) {
 195                        acpi_handle_warn(handle, "Failed to add container\n");
 196                        break;
 197                }
 198
 199                kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
 200                ost_code = ACPI_OST_SC_SUCCESS;
 201                break;
 202
 203        case ACPI_NOTIFY_EJECT_REQUEST:
 204                if (!acpi_bus_get_device(handle, &device) && device) {
 205                        device->flags.eject_pending = 1;
 206                        kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
 207                        return;
 208                }
 209                break;
 210
 211        default:
 212                /* non-hotplug event; possibly handled by other handler */
 213                return;
 214        }
 215
 216        /* Inform firmware that the hotplug operation has completed */
 217        (void) acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 218        return;
 219}
 220
 221static acpi_status
 222container_walk_namespace_cb(acpi_handle handle,
 223                            u32 lvl, void *context, void **rv)
 224{
 225        char *hid = NULL;
 226        struct acpi_device_info *info;
 227        acpi_status status;
 228        int *action = context;
 229
 230        status = acpi_get_object_info(handle, &info);
 231        if (ACPI_FAILURE(status)) {
 232                return AE_OK;
 233        }
 234
 235        if (info->valid & ACPI_VALID_HID)
 236                hid = info->hardware_id.string;
 237
 238        if (hid == NULL) {
 239                goto end;
 240        }
 241
 242        if (!is_container_device(hid))
 243                goto end;
 244
 245        switch (*action) {
 246        case INSTALL_NOTIFY_HANDLER:
 247                acpi_install_notify_handler(handle,
 248                                            ACPI_SYSTEM_NOTIFY,
 249                                            container_notify_cb, NULL);
 250                break;
 251        case UNINSTALL_NOTIFY_HANDLER:
 252                acpi_remove_notify_handler(handle,
 253                                           ACPI_SYSTEM_NOTIFY,
 254                                           container_notify_cb);
 255                break;
 256        default:
 257                break;
 258        }
 259
 260      end:
 261        kfree(info);
 262
 263        return AE_OK;
 264}
 265
 266static int __init acpi_container_init(void)
 267{
 268        int result = 0;
 269        int action = INSTALL_NOTIFY_HANDLER;
 270
 271        result = acpi_bus_register_driver(&acpi_container_driver);
 272        if (result < 0) {
 273                return (result);
 274        }
 275
 276        /* register notify handler to every container device */
 277        acpi_walk_namespace(ACPI_TYPE_DEVICE,
 278                            ACPI_ROOT_OBJECT,
 279                            ACPI_UINT32_MAX,
 280                            container_walk_namespace_cb, NULL, &action, NULL);
 281
 282        return (0);
 283}
 284
 285static void __exit acpi_container_exit(void)
 286{
 287        int action = UNINSTALL_NOTIFY_HANDLER;
 288
 289
 290        acpi_walk_namespace(ACPI_TYPE_DEVICE,
 291                            ACPI_ROOT_OBJECT,
 292                            ACPI_UINT32_MAX,
 293                            container_walk_namespace_cb, NULL, &action, NULL);
 294
 295        acpi_bus_unregister_driver(&acpi_container_driver);
 296
 297        return;
 298}
 299
 300module_init(acpi_container_init);
 301module_exit(acpi_container_exit);
 302
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