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 #include <linux/platform_device.h>
  34
  35 #define ACPI_BAY_DRIVER_NAME "ACPI Removable Drive Bay Driver"
  36
  37 ACPI_MODULE_NAME("bay")
  38 MODULE_AUTHOR("Kristen Carlson Accardi");
  39 MODULE_DESCRIPTION(ACPI_BAY_DRIVER_NAME);
  40 MODULE_LICENSE("GPL");
  41 #define ACPI_BAY_CLASS "bay"
  42 #define ACPI_BAY_COMPONENT      0x10000000
  43 #define _COMPONENT ACPI_BAY_COMPONENT
  44 #define bay_dprintk(h,s) {\
  45         char prefix[80] = {'\0'};\
  46         struct acpi_buffer buffer = {sizeof(prefix), prefix};\
  47         acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);\
  48         printk(KERN_DEBUG PREFIX "%s: %s\n", prefix, s); }
  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
  53 static struct acpi_driver acpi_bay_driver = {
  54         .name = ACPI_BAY_DRIVER_NAME,
  55         .class = ACPI_BAY_CLASS,
  56         .ids = ACPI_BAY_HID,
  57         .ops = {
  58                 .add = acpi_bay_add,
  59                 .remove = acpi_bay_remove,
  60                 },
  61 };
  62
  63 struct bay {
  64         acpi_handle handle;
  65         char *name;
  66         struct list_head list;
  67         struct platform_device *pdev;
  68 };
  69
  70 static LIST_HEAD(drive_bays);
  71
  72
  73 /*****************************************************************************
  74  *                         Drive Bay functions                               *
  75  *****************************************************************************/
  76 /**
  77  * is_ejectable - see if a device is ejectable
  78  * @handle: acpi handle of the device
  79  *
  80  * If an acpi object has a _EJ0 method, then it is ejectable
  81  */
  82 static int is_ejectable(acpi_handle handle)
  83 {
  84         acpi_status status;
  85         acpi_handle tmp;
  86
  87         status = acpi_get_handle(handle, "_EJ0", &tmp);
  88         if (ACPI_FAILURE(status))
  89                 return 0;
  90         return 1;
  91 }
  92
  93 /**
  94  * bay_present - see if the bay device is present
  95  * @bay: the drive bay
  96  *
  97  * execute the _STA method.
  98  */
  99 static int bay_present(struct bay *bay)
 100 {
 101         unsigned long sta;
 102         acpi_status status;
 103
 104         if (bay) {
 105                 status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
 106                 if (ACPI_SUCCESS(status) && sta)
 107                         return 1;
 108         }
 109         return 0;
 110 }
 111
 112 /**
 113  * eject_device - respond to an eject request
 114  * @handle - the device to eject
 115  *
 116  * Call this devices _EJ0 method.
 117  */
 118 static void eject_device(acpi_handle handle)
 119 {
 120         struct acpi_object_list arg_list;
 121         union acpi_object arg;
 122
 123         bay_dprintk(handle, "Ejecting device");
 124
 125         arg_list.count = 1;
 126         arg_list.pointer = &arg;
 127         arg.type = ACPI_TYPE_INTEGER;
 128         arg.integer.value = 1;
 129
 130         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
 131                                               &arg_list, NULL)))
 132                 pr_debug("Failed to evaluate _EJ0!\n");
 133 }
 134
 135 /*
 136  * show_present - read method for "present" file in sysfs
 137  */
 138 static ssize_t show_present(struct device *dev,
 139                            struct device_attribute *attr, char *buf)
 140 {
 141         struct bay *bay = dev_get_drvdata(dev);
 142         return snprintf(buf, PAGE_SIZE, "%d\n", bay_present(bay));
 143
 144 }
 145 DEVICE_ATTR(present, S_IRUGO, show_present, NULL);
 146
 147 /*
 148  * write_eject - write method for "eject" file in sysfs
 149  */
 150 static ssize_t write_eject(struct device *dev, struct device_attribute *attr,
 151                            const char *buf, size_t count)
 152 {
 153         struct bay *bay = dev_get_drvdata(dev);
 154
 155         if (!count)
 156                 return -EINVAL;
 157
 158         eject_device(bay->handle);
 159         return count;
 160 }
 161 DEVICE_ATTR(eject, S_IWUSR, NULL, write_eject);
 162
 163 /**
 164  * is_ata - see if a device is an ata device
 165  * @handle: acpi handle of the device
 166  *
 167  * If an acpi object has one of 4 ATA ACPI methods defined,
 168  * then it is an ATA device
 169  */
 170 static int is_ata(acpi_handle handle)
 171 {
 172         acpi_handle tmp;
 173
 174         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 175            (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 176            (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 177            (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 178                 return 1;
 179
 180         return 0;
 181 }
 182
 183 /**
 184  * parent_is_ata(acpi_handle handle)
 185  *
 186  */
 187 static int parent_is_ata(acpi_handle handle)
 188 {
 189         acpi_handle phandle;
 190
 191         if (acpi_get_parent(handle, &phandle))
 192                 return 0;
 193
 194         return is_ata(phandle);
 195 }
 196
 197 /**
 198  * is_ejectable_bay - see if a device is an ejectable drive bay
 199  * @handle: acpi handle of the device
 200  *
 201  * If an acpi object is ejectable and has one of the ACPI ATA
 202  * methods defined, then we can safely call it an ejectable
 203  * drive bay
 204  */
 205 static int is_ejectable_bay(acpi_handle handle)
 206 {
 207         if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
 208                 return 1;
 209         return 0;
 210 }
 211
 212 /**
 213  * eject_removable_drive - try to eject this drive
 214  * @dev : the device structure of the drive
 215  *
 216  * If a device is a removable drive that requires an _EJ0 method
 217  * to be executed in order to safely remove from the system, do
 218  * it.  ATM - always returns success
 219  */
 220 int eject_removable_drive(struct device *dev)
 221 {
 222         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 223
 224         if (handle) {
 225                 bay_dprintk(handle, "Got device handle");
 226                 if (is_ejectable_bay(handle))
 227                         eject_device(handle);
 228         } else {
 229                 printk("No acpi handle for device\n");
 230         }
 231
 232         /* should I return an error code? */
 233         return 0;
 234 }
 235 EXPORT_SYMBOL_GPL(eject_removable_drive);
 236
 237 static int acpi_bay_add(struct acpi_device *device)
 238 {
 239         bay_dprintk(device->handle, "adding bay device");
 240         strcpy(acpi_device_name(device), "Dockable Bay");
 241         strcpy(acpi_device_class(device), "bay");
 242         return 0;
 243 }
 244
 245 static int acpi_bay_add_fs(struct bay *bay)
 246 {
 247         int ret;
 248         struct device *dev = &bay->pdev->dev;
 249
 250         ret = device_create_file(dev, &dev_attr_present);
 251         if (ret)
 252                 goto add_fs_err;
 253         ret = device_create_file(dev, &dev_attr_eject);
 254         if (ret) {
 255                 device_remove_file(dev, &dev_attr_present);
 256                 goto add_fs_err;
 257         }
 258         return 0;
 259
 260  add_fs_err:
 261         bay_dprintk(bay->handle, "Error adding sysfs files\n");
 262         return ret;
 263 }
 264
 265 static void acpi_bay_remove_fs(struct bay *bay)
 266 {
 267         struct device *dev = &bay->pdev->dev;
 268
 269         /* cleanup sysfs */
 270         device_remove_file(dev, &dev_attr_present);
 271         device_remove_file(dev, &dev_attr_eject);
 272 }
 273
 274 static int bay_is_dock_device(acpi_handle handle)
 275 {
 276         acpi_handle parent;
 277
 278         acpi_get_parent(handle, &parent);
 279
 280         /* if the device or it's parent is dependent on the
 281          * dock, then we are a dock device
 282          */
 283         return (is_dock_device(handle) || is_dock_device(parent));
 284 }
 285
 286 static int bay_add(acpi_handle handle, int id)
 287 {
 288         acpi_status status;
 289         struct bay *new_bay;
 290         struct platform_device *pdev;
 291         struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
 292         acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
 293
 294         bay_dprintk(handle, "Adding notify handler");
 295
 296         /*
 297          * Initialize bay device structure
 298          */
 299         new_bay = kzalloc(GFP_ATOMIC, sizeof(*new_bay));
 300         INIT_LIST_HEAD(&new_bay->list);
 301         new_bay->handle = handle;
 302         new_bay->name = (char *)nbuffer.pointer;
 303
 304         /* initialize platform device stuff */
 305         pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
 306         if (pdev == NULL) {
 307                 printk(KERN_ERR PREFIX "Error registering bay device\n");
 308                 goto bay_add_err;
 309         }
 310         new_bay->pdev = pdev;
 311         platform_set_drvdata(pdev, new_bay);
 312
 313         if (acpi_bay_add_fs(new_bay)) {
 314                 platform_device_unregister(new_bay->pdev);
 315                 goto bay_add_err;
 316         }
 317
 318         /* register for events on this device */
 319         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 320                         bay_notify, new_bay);
 321         if (ACPI_FAILURE(status)) {
 322                 printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
 323         }
 324
 325         /* if we are on a dock station, we should register for dock
 326          * notifications.
 327          */
 328         if (bay_is_dock_device(handle)) {
 329                 bay_dprintk(handle, "Is dependent on dock\n");
 330                 register_hotplug_dock_device(handle, bay_notify, new_bay);
 331         }
 332         list_add(&new_bay->list, &drive_bays);
 333         printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
 334         return 0;
 335
 336 bay_add_err:
 337         kfree(new_bay->name);
 338         kfree(new_bay);
 339         return -ENODEV;
 340 }
 341
 342 static int acpi_bay_remove(struct acpi_device *device, int type)
 343 {
 344         /*** FIXME: do something here */
 345         return 0;
 346 }
 347
 348 /**
 349  * bay_create_acpi_device - add new devices to acpi
 350  * @handle - handle of the device to add
 351  *
 352  *  This function will create a new acpi_device for the given
 353  *  handle if one does not exist already.  This should cause
 354  *  acpi to scan for drivers for the given devices, and call
 355  *  matching driver's add routine.
 356  *
 357  *  Returns a pointer to the acpi_device corresponding to the handle.
 358  */
 359 static struct acpi_device * bay_create_acpi_device(acpi_handle handle)
 360 {
 361         struct acpi_device *device = NULL;
 362         struct acpi_device *parent_device;
 363         acpi_handle parent;
 364         int ret;
 365
 366         bay_dprintk(handle, "Trying to get device");
 367         if (acpi_bus_get_device(handle, &device)) {
 368                 /*
 369                  * no device created for this object,
 370                  * so we should create one.
 371                  */
 372                 bay_dprintk(handle, "No device for handle");
 373                 acpi_get_parent(handle, &parent);
 374                 if (acpi_bus_get_device(parent, &parent_device))
 375                         parent_device = NULL;
 376
 377                 ret = acpi_bus_add(&device, parent_device, handle,
 378                         ACPI_BUS_TYPE_DEVICE);
 379                 if (ret) {
 380                         pr_debug("error adding bus, %x\n",
 381                                 -ret);
 382                         return NULL;
 383                 }
 384         }
 385         return device;
 386 }
 387
 388 /**
 389  * bay_notify - act upon an acpi bay notification
 390  * @handle: the bay handle
 391  * @event: the acpi event
 392  * @data: our driver data struct
 393  *
 394  */
 395 static void bay_notify(acpi_handle handle, u32 event, void *data)
 396 {
 397         struct acpi_device *dev;
 398
 399         bay_dprintk(handle, "Bay event");
 400
 401         switch(event) {
 402         case ACPI_NOTIFY_BUS_CHECK:
 403                 printk("Bus Check\n");
 404         case ACPI_NOTIFY_DEVICE_CHECK:
 405                 printk("Device Check\n");
 406                 dev = bay_create_acpi_device(handle);
 407                 if (dev)
 408                         acpi_bus_generate_event(dev, event, 0);
 409                 else
 410                         printk("No device for generating event\n");
 411                 /* wouldn't it be a good idea to just rescan SATA
 412                  * right here?
 413                  */
 414                 break;
 415         case ACPI_NOTIFY_EJECT_REQUEST:
 416                 printk("Eject request\n");
 417                 dev = bay_create_acpi_device(handle);
 418                 if (dev)
 419                         acpi_bus_generate_event(dev, event, 0);
 420                 else
 421                         printk("No device for generating eventn");
 422
 423                 /* wouldn't it be a good idea to just call the
 424                  * eject_device here if we were a SATA device?
 425                  */
 426                 break;
 427         default:
 428                 printk("unknown event %d\n", event);
 429         }
 430 }
 431
 432 static acpi_status
 433 find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 434 {
 435         int *count = (int *)context;
 436
 437         /*
 438          * there could be more than one ejectable bay.
 439          * so, just return AE_OK always so that every object
 440          * will be checked.
 441          */
 442         if (is_ejectable_bay(handle)) {
 443                 bay_dprintk(handle, "found ejectable bay");
 444                 if (!bay_add(handle, *count))
 445                         (*count)++;
 446         }
 447         return AE_OK;
 448 }
 449
 450 static int __init bay_init(void)
 451 {
 452         int bays = 0;
 453
 454         INIT_LIST_HEAD(&drive_bays);
 455
 456         /* look for dockable drive bays */
 457         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 458                 ACPI_UINT32_MAX, find_bay, &bays, NULL);
 459
 460         if (bays)
 461                 if ((acpi_bus_register_driver(&acpi_bay_driver) < 0))
 462                         printk(KERN_ERR "Unable to register bay driver\n");
 463
 464         if (!bays)
 465                 return -ENODEV;
 466
 467         return 0;
 468 }
 469
 470 static void __exit bay_exit(void)
 471 {
 472         struct bay *bay, *tmp;
 473
 474         list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
 475                 if (is_dock_device(bay->handle))
 476                         unregister_hotplug_dock_device(bay->handle);
 477                 acpi_bay_remove_fs(bay);
 478                 acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
 479                         bay_notify);
 480                 platform_device_unregister(bay->pdev);
 481                 kfree(bay->name);
 482                 kfree(bay);
 483         }
 484
 485         acpi_bus_unregister_driver(&acpi_bay_driver);
 486 }
 487
 488 postcore_initcall(bay_init);
 489 module_exit(bay_exit);
 490