drivers/acpi/bay.c

   1 /*
   2  *  bay.c - ACPI removable drive bay driver
   3  *
   4  *  Copyright (C) 2006 Kristen Carlson Accardi <kristen.c.accardi@intel.com>
   5  *
   6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or (at
  11  *  your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful, but
  14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with this program; if not, write to the Free Software Foundation, Inc.,
  20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21  *
  22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  */
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/notifier.h>
  29 #include <acpi/acpi_bus.h>
  30 #include <acpi/acpi_drivers.h>
  31 #include <linux/seq_file.h>
  32 #include <asm/uaccess.h>
  33
  34 #define ACPI_BAY_DRIVER_NAME "ACPI Removable Drive Bay Driver"
  35
  36 ACPI_MODULE_NAME("bay")
  37 MODULE_AUTHOR("Kristen Carlson Accardi");
  38 MODULE_DESCRIPTION(ACPI_BAY_DRIVER_NAME);
  39 MODULE_LICENSE("GPL");
  40 #define ACPI_BAY_CLASS "bay"
  41 #define ACPI_BAY_COMPONENT      0x10000000
  42 #define _COMPONENT ACPI_BAY_COMPONENT
  43 #define bay_dprintk(h,s) {\
  44         char prefix[80] = {'\0'};\
  45         struct acpi_buffer buffer = {sizeof(prefix), prefix};\
  46         acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);\
  47         printk(KERN_DEBUG PREFIX "%s: %s\n", prefix, s); }
  48
  49 static void bay_notify(acpi_handle handle, u32 event, void *data);
  50 static int acpi_bay_add(struct acpi_device *device);
  51 static int acpi_bay_remove(struct acpi_device *device, int type);
  52 static int acpi_bay_match(struct acpi_device *device,
  53                                 struct acpi_driver *driver);
  54
  55 static struct acpi_driver acpi_bay_driver = {
  56         .name = ACPI_BAY_DRIVER_NAME,
  57         .class = ACPI_BAY_CLASS,
  58         .ops = {
  59                 .add = acpi_bay_add,
  60                 .remove = acpi_bay_remove,
  61                 .match = acpi_bay_match,
  62                 },
  63 };
  64
  65 struct bay {
  66         acpi_handle handle;
  67         char *name;
  68         struct list_head list;
  69 };
  70
  71 LIST_HEAD(drive_bays);
  72
  73
  74 /*****************************************************************************
  75  *                         Drive Bay functions                               *
  76  *****************************************************************************/
  77 /**
  78  * is_ejectable - see if a device is ejectable
  79  * @handle: acpi handle of the device
  80  *
  81  * If an acpi object has a _EJ0 method, then it is ejectable
  82  */
  83 static int is_ejectable(acpi_handle handle)
  84 {
  85         acpi_status status;
  86         acpi_handle tmp;
  87
  88         status = acpi_get_handle(handle, "_EJ0", &tmp);
  89         if (ACPI_FAILURE(status))
  90                 return 0;
  91         return 1;
  92 }
  93
  94 /**
  95  * bay_present - see if the bay device is present
  96  * @bay: the drive bay
  97  *
  98  * execute the _STA method.
  99  */
 100 static int bay_present(struct bay *bay)
 101 {
 102         unsigned long sta;
 103         acpi_status status;
 104
 105         if (bay) {
 106                 status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
 107                 if (ACPI_SUCCESS(status) && sta)
 108                         return 1;
 109         }
 110         return 0;
 111 }
 112
 113 /**
 114  * eject_device - respond to an eject request
 115  * @handle - the device to eject
 116  *
 117  * Call this devices _EJ0 method.
 118  */
 119 static void eject_device(acpi_handle handle)
 120 {
 121         struct acpi_object_list arg_list;
 122         union acpi_object arg;
 123
 124         bay_dprintk(handle, "Ejecting device");
 125
 126         arg_list.count = 1;
 127         arg_list.pointer = &arg;
 128         arg.type = ACPI_TYPE_INTEGER;
 129         arg.integer.value = 1;
 130
 131         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
 132                                               &arg_list, NULL)))
 133                 pr_debug("Failed to evaluate _EJ0!\n");
 134 }
 135
 136
 137 /**
 138  * is_ata - see if a device is an ata device
 139  * @handle: acpi handle of the device
 140  *
 141  * If an acpi object has one of 4 ATA ACPI methods defined,
 142  * then it is an ATA device
 143  */
 144 static int is_ata(acpi_handle handle)
 145 {
 146         acpi_handle tmp;
 147
 148         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 149            (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 150            (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 151            (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 152                 return 1;
 153
 154         return 0;
 155 }
 156
 157 /**
 158  * parent_is_ata(acpi_handle handle)
 159  *
 160  */
 161 static int parent_is_ata(acpi_handle handle)
 162 {
 163         acpi_handle phandle;
 164
 165         if (acpi_get_parent(handle, &phandle))
 166                 return 0;
 167
 168         return is_ata(phandle);
 169 }
 170
 171 /**
 172  * is_ejectable_bay - see if a device is an ejectable drive bay
 173  * @handle: acpi handle of the device
 174  *
 175  * If an acpi object is ejectable and has one of the ACPI ATA
 176  * methods defined, then we can safely call it an ejectable
 177  * drive bay
 178  */
 179 static int is_ejectable_bay(acpi_handle handle)
 180 {
 181         if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
 182                 return 1;
 183         return 0;
 184 }
 185
 186 /**
 187  * eject_removable_drive - try to eject this drive
 188  * @dev : the device structure of the drive
 189  *
 190  * If a device is a removable drive that requires an _EJ0 method
 191  * to be executed in order to safely remove from the system, do
 192  * it.  ATM - always returns success
 193  */
 194 int eject_removable_drive(struct device *dev)
 195 {
 196         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 197
 198         if (handle) {
 199                 bay_dprintk(handle, "Got device handle");
 200                 if (is_ejectable_bay(handle))
 201                         eject_device(handle);
 202         } else {
 203                 printk("No acpi handle for device\n");
 204         }
 205
 206         /* should I return an error code? */
 207         return 0;
 208 }
 209 EXPORT_SYMBOL_GPL(eject_removable_drive);
 210
 211 static int acpi_bay_add(struct acpi_device *device)
 212 {
 213         bay_dprintk(device->handle, "adding bay device");
 214         strcpy(acpi_device_name(device), "Dockable Bay");
 215         strcpy(acpi_device_class(device), "bay");
 216         return 0;
 217 }
 218
 219 static int acpi_bay_add_fs(struct bay *bay)
 220 {
 221         if (!bay)
 222                 return -EINVAL;
 223 }
 224
 225 static void acpi_bay_remove_fs(struct bay *bay)
 226 {
 227         if (!bay)
 228                 return;
 229 }
 230
 231 static int bay_is_dock_device(acpi_handle handle)
 232 {
 233         acpi_handle parent;
 234
 235         acpi_get_parent(handle, &parent);
 236
 237         /* if the device or it's parent is dependent on the
 238          * dock, then we are a dock device
 239          */
 240         return (is_dock_device(handle) || is_dock_device(parent));
 241 }
 242
 243 static int bay_add(acpi_handle handle)
 244 {
 245         acpi_status status;
 246         struct bay *new_bay;
 247         struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
 248         acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
 249
 250         bay_dprintk(handle, "Adding notify handler");
 251
 252         /*
 253          * Initialize bay device structure
 254          */
 255         new_bay = kmalloc(GFP_ATOMIC, sizeof(*new_bay));
 256         INIT_LIST_HEAD(&new_bay->list);
 257         new_bay->handle = handle;
 258         new_bay->name = (char *)nbuffer.pointer;
 259         list_add(&new_bay->list, &drive_bays);
 260         acpi_bay_add_fs(new_bay);
 261
 262         /* register for events on this device */
 263         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 264                         bay_notify, new_bay);
 265         if (ACPI_FAILURE(status)) {
 266                 printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
 267         }
 268
 269         /* if we are on a dock station, we should register for dock
 270          * notifications.
 271          */
 272         if (bay_is_dock_device(handle)) {
 273                 bay_dprintk(handle, "Is dependent on dock\n");
 274                 register_hotplug_dock_device(handle, bay_notify, new_bay);
 275         }
 276         printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
 277         return 0;
 278 }
 279
 280 static int acpi_bay_remove(struct acpi_device *device, int type)
 281 {
 282         /*** FIXME: do something here */
 283         return 0;
 284 }
 285
 286 static int acpi_bay_match(struct acpi_device *device,
 287                                 struct acpi_driver *driver)
 288 {
 289         if (!device || !driver)
 290                 return -EINVAL;
 291
 292         if (is_ejectable_bay(device->handle)) {
 293                 bay_dprintk(device->handle, "matching bay device");
 294                 return 0;
 295         }
 296
 297         return -ENODEV;
 298 }
 299
 300 /**
 301  * bay_create_acpi_device - add new devices to acpi
 302  * @handle - handle of the device to add
 303  *
 304  *  This function will create a new acpi_device for the given
 305  *  handle if one does not exist already.  This should cause
 306  *  acpi to scan for drivers for the given devices, and call
 307  *  matching driver's add routine.
 308  *
 309  *  Returns a pointer to the acpi_device corresponding to the handle.
 310  */
 311 static struct acpi_device * bay_create_acpi_device(acpi_handle handle)
 312 {
 313         struct acpi_device *device = NULL;
 314         struct acpi_device *parent_device;
 315         acpi_handle parent;
 316         int ret;
 317
 318         bay_dprintk(handle, "Trying to get device");
 319         if (acpi_bus_get_device(handle, &device)) {
 320                 /*
 321                  * no device created for this object,
 322                  * so we should create one.
 323                  */
 324                 bay_dprintk(handle, "No device for handle");
 325                 acpi_get_parent(handle, &parent);
 326                 if (acpi_bus_get_device(parent, &parent_device))
 327                         parent_device = NULL;
 328
 329                 ret = acpi_bus_add(&device, parent_device, handle,
 330                         ACPI_BUS_TYPE_DEVICE);
 331                 if (ret) {
 332                         pr_debug("error adding bus, %x\n",
 333                                 -ret);
 334                         return NULL;
 335                 }
 336         }
 337         return device;
 338 }
 339
 340 /**
 341  * bay_notify - act upon an acpi bay notification
 342  * @handle: the bay handle
 343  * @event: the acpi event
 344  * @data: our driver data struct
 345  *
 346  */
 347 static void bay_notify(acpi_handle handle, u32 event, void *data)
 348 {
 349         struct acpi_device *dev;
 350
 351         bay_dprintk(handle, "Bay event");
 352
 353         switch(event) {
 354         case ACPI_NOTIFY_BUS_CHECK:
 355                 printk("Bus Check\n");
 356         case ACPI_NOTIFY_DEVICE_CHECK:
 357                 printk("Device Check\n");
 358                 dev = bay_create_acpi_device(handle);
 359                 if (dev)
 360                         acpi_bus_generate_event(dev, event, 0);
 361                 else
 362                         printk("No device for generating event\n");
 363                 /* wouldn't it be a good idea to just rescan SATA
 364                  * right here?
 365                  */
 366                 break;
 367         case ACPI_NOTIFY_EJECT_REQUEST:
 368                 printk("Eject request\n");
 369                 dev = bay_create_acpi_device(handle);
 370                 if (dev)
 371                         acpi_bus_generate_event(dev, event, 0);
 372                 else
 373                         printk("No device for generating eventn");
 374
 375                 /* wouldn't it be a good idea to just call the
 376                  * eject_device here if we were a SATA device?
 377                  */
 378                 break;
 379         default:
 380                 printk("unknown event %d\n", event);
 381         }
 382 }
 383
 384 static acpi_status
 385 find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 386 {
 387         int *count = (int *)context;
 388
 389         /*
 390          * there could be more than one ejectable bay.
 391          * so, just return AE_OK always so that every object
 392          * will be checked.
 393          */
 394         if (is_ejectable_bay(handle)) {
 395                 bay_dprintk(handle, "found ejectable bay");
 396                 bay_add(handle);
 397                 (*count)++;
 398         }
 399         return AE_OK;
 400 }
 401
 402 static int __init bay_init(void)
 403 {
 404         int bays = 0;
 405
 406         INIT_LIST_HEAD(&drive_bays);
 407
 408         /* look for dockable drive bays */
 409         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 410                 ACPI_UINT32_MAX, find_bay, &bays, NULL);
 411
 412         if (bays)
 413                 if ((acpi_bus_register_driver(&acpi_bay_driver) < 0))
 414                         printk(KERN_ERR "Unable to register bay driver\n");
 415
 416         if (!bays)
 417                 return -ENODEV;
 418
 419         return 0;
 420 }
 421
 422 static void __exit bay_exit(void)
 423 {
 424         struct bay *bay, *tmp;
 425
 426         list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
 427                 if (is_dock_device(bay->handle))
 428                         unregister_hotplug_dock_device(bay->handle);
 429                 acpi_bay_remove_fs(bay);
 430                 acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
 431                         bay_notify);
 432                 kfree(bay->name);
 433                 kfree(bay);
 434         }
 435
 436         acpi_bus_unregister_driver(&acpi_bay_driver);
 437 }
 438
 439 postcore_initcall(bay_init);
 440 module_exit(bay_exit);
 441