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 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         struct platform_device *pdev;
  70 };
  71
  72 static LIST_HEAD(drive_bays);
  73
  74
  75 /*****************************************************************************
  76  *                         Drive Bay functions                               *
  77  *****************************************************************************/
  78 /**
  79  * is_ejectable - see if a device is ejectable
  80  * @handle: acpi handle of the device
  81  *
  82  * If an acpi object has a _EJ0 method, then it is ejectable
  83  */
  84 static int is_ejectable(acpi_handle handle)
  85 {
  86         acpi_status status;
  87         acpi_handle tmp;
  88
  89         status = acpi_get_handle(handle, "_EJ0", &tmp);
  90         if (ACPI_FAILURE(status))
  91                 return 0;
  92         return 1;
  93 }
  94
  95 /**
  96  * bay_present - see if the bay device is present
  97  * @bay: the drive bay
  98  *
  99  * execute the _STA method.
 100  */
 101 static int bay_present(struct bay *bay)
 102 {
 103         unsigned long sta;
 104         acpi_status status;
 105
 106         if (bay) {
 107                 status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
 108                 if (ACPI_SUCCESS(status) && sta)
 109                         return 1;
 110         }
 111         return 0;
 112 }
 113
 114 /**
 115  * eject_device - respond to an eject request
 116  * @handle - the device to eject
 117  *
 118  * Call this devices _EJ0 method.
 119  */
 120 static void eject_device(acpi_handle handle)
 121 {
 122         struct acpi_object_list arg_list;
 123         union acpi_object arg;
 124
 125         bay_dprintk(handle, "Ejecting device");
 126
 127         arg_list.count = 1;
 128         arg_list.pointer = &arg;
 129         arg.type = ACPI_TYPE_INTEGER;
 130         arg.integer.value = 1;
 131
 132         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
 133                                               &arg_list, NULL)))
 134                 pr_debug("Failed to evaluate _EJ0!\n");
 135 }
 136
 137 /*
 138  * show_present - read method for "present" file in sysfs
 139  */
 140 static ssize_t show_present(struct device *dev,
 141                            struct device_attribute *attr, char *buf)
 142 {
 143         struct bay *bay = dev_get_drvdata(dev);
 144         return snprintf(buf, PAGE_SIZE, "%d\n", bay_present(bay));
 145
 146 }
 147 DEVICE_ATTR(present, S_IRUGO, show_present, NULL);
 148
 149 /*
 150  * write_eject - write method for "eject" file in sysfs
 151  */
 152 static ssize_t write_eject(struct device *dev, struct device_attribute *attr,
 153                            const char *buf, size_t count)
 154 {
 155         struct bay *bay = dev_get_drvdata(dev);
 156
 157         if (!count)
 158                 return -EINVAL;
 159
 160         eject_device(bay->handle);
 161         return count;
 162 }
 163 DEVICE_ATTR(eject, S_IWUSR, NULL, write_eject);
 164
 165 /**
 166  * is_ata - see if a device is an ata device
 167  * @handle: acpi handle of the device
 168  *
 169  * If an acpi object has one of 4 ATA ACPI methods defined,
 170  * then it is an ATA device
 171  */
 172 static int is_ata(acpi_handle handle)
 173 {
 174         acpi_handle tmp;
 175
 176         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 177            (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 178            (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 179            (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 180                 return 1;
 181
 182         return 0;
 183 }
 184
 185 /**
 186  * parent_is_ata(acpi_handle handle)
 187  *
 188  */
 189 static int parent_is_ata(acpi_handle handle)
 190 {
 191         acpi_handle phandle;
 192
 193         if (acpi_get_parent(handle, &phandle))
 194                 return 0;
 195
 196         return is_ata(phandle);
 197 }
 198
 199 /**
 200  * is_ejectable_bay - see if a device is an ejectable drive bay
 201  * @handle: acpi handle of the device
 202  *
 203  * If an acpi object is ejectable and has one of the ACPI ATA
 204  * methods defined, then we can safely call it an ejectable
 205  * drive bay
 206  */
 207 static int is_ejectable_bay(acpi_handle handle)
 208 {
 209         if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
 210                 return 1;
 211         return 0;
 212 }
 213
 214 /**
 215  * eject_removable_drive - try to eject this drive
 216  * @dev : the device structure of the drive
 217  *
 218  * If a device is a removable drive that requires an _EJ0 method
 219  * to be executed in order to safely remove from the system, do
 220  * it.  ATM - always returns success
 221  */
 222 int eject_removable_drive(struct device *dev)
 223 {
 224         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 225
 226         if (handle) {
 227                 bay_dprintk(handle, "Got device handle");
 228                 if (is_ejectable_bay(handle))
 229                         eject_device(handle);
 230         } else {
 231                 printk("No acpi handle for device\n");
 232         }
 233
 234         /* should I return an error code? */
 235         return 0;
 236 }
 237 EXPORT_SYMBOL_GPL(eject_removable_drive);
 238
 239 static int acpi_bay_add(struct acpi_device *device)
 240 {
 241         bay_dprintk(device->handle, "adding bay device");
 242         strcpy(acpi_device_name(device), "Dockable Bay");
 243         strcpy(acpi_device_class(device), "bay");
 244         return 0;
 245 }
 246
 247 static int acpi_bay_add_fs(struct bay *bay)
 248 {
 249         int ret;
 250         struct device *dev = &bay->pdev->dev;
 251
 252         ret = device_create_file(dev, &dev_attr_present);
 253         if (ret)
 254                 goto add_fs_err;
 255         ret = device_create_file(dev, &dev_attr_eject);
 256         if (ret) {
 257                 device_remove_file(dev, &dev_attr_present);
 258                 goto add_fs_err;
 259         }
 260         return 0;
 261
 262  add_fs_err:
 263         bay_dprintk(bay->handle, "Error adding sysfs files\n");
 264         return ret;
 265 }
 266
 267 static void acpi_bay_remove_fs(struct bay *bay)
 268 {
 269         struct device *dev = &bay->pdev->dev;
 270
 271         /* cleanup sysfs */
 272         device_remove_file(dev, &dev_attr_present);
 273         device_remove_file(dev, &dev_attr_eject);
 274 }
 275
 276 static int bay_is_dock_device(acpi_handle handle)
 277 {
 278         acpi_handle parent;
 279
 280         acpi_get_parent(handle, &parent);
 281
 282         /* if the device or it's parent is dependent on the
 283          * dock, then we are a dock device
 284          */
 285         return (is_dock_device(handle) || is_dock_device(parent));
 286 }
 287
 288 static int bay_add(acpi_handle handle, int id)
 289 {
 290         acpi_status status;
 291         struct bay *new_bay;
 292         struct platform_device *pdev;
 293         struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
 294         acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
 295
 296         bay_dprintk(handle, "Adding notify handler");
 297
 298         /*
 299          * Initialize bay device structure
 300          */
 301         new_bay = kzalloc(GFP_ATOMIC, sizeof(*new_bay));
 302         INIT_LIST_HEAD(&new_bay->list);
 303         new_bay->handle = handle;
 304         new_bay->name = (char *)nbuffer.pointer;
 305
 306         /* initialize platform device stuff */
 307         pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
 308         if (pdev == NULL) {
 309                 printk(KERN_ERR PREFIX "Error registering bay device\n");
 310                 goto bay_add_err;
 311         }
 312         new_bay->pdev = pdev;
 313         platform_set_drvdata(pdev, new_bay);
 314
 315         if (acpi_bay_add_fs(new_bay)) {
 316                 platform_device_unregister(new_bay->pdev);
 317                 goto bay_add_err;
 318         }
 319
 320         /* register for events on this device */
 321         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 322                         bay_notify, new_bay);
 323         if (ACPI_FAILURE(status)) {
 324                 printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
 325         }
 326
 327         /* if we are on a dock station, we should register for dock
 328          * notifications.
 329          */
 330         if (bay_is_dock_device(handle)) {
 331                 bay_dprintk(handle, "Is dependent on dock\n");
 332                 register_hotplug_dock_device(handle, bay_notify, new_bay);
 333         }
 334         list_add(&new_bay->list, &drive_bays);
 335         printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
 336         return 0;
 337
 338 bay_add_err:
 339         kfree(new_bay->name);
 340         kfree(new_bay);
 341         return -ENODEV;
 342 }
 343
 344 static int acpi_bay_remove(struct acpi_device *device, int type)
 345 {
 346         /*** FIXME: do something here */
 347         return 0;
 348 }
 349
 350 static int acpi_bay_match(struct acpi_device *device,
 351                                 struct acpi_driver *driver)
 352 {
 353         if (!device || !driver)
 354                 return -EINVAL;
 355
 356         if (is_ejectable_bay(device->handle)) {
 357                 bay_dprintk(device->handle, "matching bay device");
 358                 return 0;
 359         }
 360
 361         return -ENODEV;
 362 }
 363
 364 /**
 365  * bay_create_acpi_device - add new devices to acpi
 366  * @handle - handle of the device to add
 367  *
 368  *  This function will create a new acpi_device for the given
 369  *  handle if one does not exist already.  This should cause
 370  *  acpi to scan for drivers for the given devices, and call
 371  *  matching driver's add routine.
 372  *
 373  *  Returns a pointer to the acpi_device corresponding to the handle.
 374  */
 375 static struct acpi_device * bay_create_acpi_device(acpi_handle handle)
 376 {
 377         struct acpi_device *device = NULL;
 378         struct acpi_device *parent_device;
 379         acpi_handle parent;
 380         int ret;
 381
 382         bay_dprintk(handle, "Trying to get device");
 383         if (acpi_bus_get_device(handle, &device)) {
 384                 /*
 385                  * no device created for this object,
 386                  * so we should create one.
 387                  */
 388                 bay_dprintk(handle, "No device for handle");
 389                 acpi_get_parent(handle, &parent);
 390                 if (acpi_bus_get_device(parent, &parent_device))
 391                         parent_device = NULL;
 392
 393                 ret = acpi_bus_add(&device, parent_device, handle,
 394                         ACPI_BUS_TYPE_DEVICE);
 395                 if (ret) {
 396                         pr_debug("error adding bus, %x\n",
 397                                 -ret);
 398                         return NULL;
 399                 }
 400         }
 401         return device;
 402 }
 403
 404 /**
 405  * bay_notify - act upon an acpi bay notification
 406  * @handle: the bay handle
 407  * @event: the acpi event
 408  * @data: our driver data struct
 409  *
 410  */
 411 static void bay_notify(acpi_handle handle, u32 event, void *data)
 412 {
 413         struct acpi_device *dev;
 414
 415         bay_dprintk(handle, "Bay event");
 416
 417         switch(event) {
 418         case ACPI_NOTIFY_BUS_CHECK:
 419                 printk("Bus Check\n");
 420         case ACPI_NOTIFY_DEVICE_CHECK:
 421                 printk("Device Check\n");
 422                 dev = bay_create_acpi_device(handle);
 423                 if (dev)
 424                         acpi_bus_generate_event(dev, event, 0);
 425                 else
 426                         printk("No device for generating event\n");
 427                 /* wouldn't it be a good idea to just rescan SATA
 428                  * right here?
 429                  */
 430                 break;
 431         case ACPI_NOTIFY_EJECT_REQUEST:
 432                 printk("Eject request\n");
 433                 dev = bay_create_acpi_device(handle);
 434                 if (dev)
 435                         acpi_bus_generate_event(dev, event, 0);
 436                 else
 437                         printk("No device for generating eventn");
 438
 439                 /* wouldn't it be a good idea to just call the
 440                  * eject_device here if we were a SATA device?
 441                  */
 442                 break;
 443         default:
 444                 printk("unknown event %d\n", event);
 445         }
 446 }
 447
 448 static acpi_status
 449 find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 450 {
 451         int *count = (int *)context;
 452
 453         /*
 454          * there could be more than one ejectable bay.
 455          * so, just return AE_OK always so that every object
 456          * will be checked.
 457          */
 458         if (is_ejectable_bay(handle)) {
 459                 bay_dprintk(handle, "found ejectable bay");
 460                 if (!bay_add(handle, *count))
 461                         (*count)++;
 462         }
 463         return AE_OK;
 464 }
 465
 466 static int __init bay_init(void)
 467 {
 468         int bays = 0;
 469
 470         INIT_LIST_HEAD(&drive_bays);
 471
 472         /* look for dockable drive bays */
 473         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 474                 ACPI_UINT32_MAX, find_bay, &bays, NULL);
 475
 476         if (bays)
 477                 if ((acpi_bus_register_driver(&acpi_bay_driver) < 0))
 478                         printk(KERN_ERR "Unable to register bay driver\n");
 479
 480         if (!bays)
 481                 return -ENODEV;
 482
 483         return 0;
 484 }
 485
 486 static void __exit bay_exit(void)
 487 {
 488         struct bay *bay, *tmp;
 489
 490         list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
 491                 if (is_dock_device(bay->handle))
 492                         unregister_hotplug_dock_device(bay->handle);
 493                 acpi_bay_remove_fs(bay);
 494                 acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
 495                         bay_notify);
 496                 platform_device_unregister(bay->pdev);
 497                 kfree(bay->name);
 498                 kfree(bay);
 499         }
 500
 501         acpi_bus_unregister_driver(&acpi_bay_driver);
 502 }
 503
 504 postcore_initcall(bay_init);
 505 module_exit(bay_exit);
 506