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 ACPI_MODULE_NAME("bay");
  36 MODULE_AUTHOR("Kristen Carlson Accardi");
  37 MODULE_DESCRIPTION("ACPI Removable Drive Bay Driver");
  38 MODULE_LICENSE("GPL");
  39 #define ACPI_BAY_CLASS "bay"
  40 #define ACPI_BAY_COMPONENT      0x10000000
  41 #define _COMPONENT ACPI_BAY_COMPONENT
  42 #define bay_dprintk(h,s) {\
  43         char prefix[80] = {'\0'};\
  44         struct acpi_buffer buffer = {sizeof(prefix), prefix};\
  45         acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);\
  46         printk(KERN_DEBUG PREFIX "%s: %s\n", prefix, s); }
  47 static void bay_notify(acpi_handle handle, u32 event, void *data);
  48
  49 static const struct acpi_device_id bay_device_ids[] = {
  50         {"LNXIOBAY", 0},
  51         {"", 0},
  52 };
  53 MODULE_DEVICE_TABLE(acpi, bay_device_ids);
  54
  55 struct bay {
  56         acpi_handle handle;
  57         char *name;
  58         struct list_head list;
  59         struct platform_device *pdev;
  60 };
  61
  62 static LIST_HEAD(drive_bays);
  63
  64
  65 /*****************************************************************************
  66  *                         Drive Bay functions                               *
  67  *****************************************************************************/
  68 /**
  69  * is_ejectable - see if a device is ejectable
  70  * @handle: acpi handle of the device
  71  *
  72  * If an acpi object has a _EJ0 method, then it is ejectable
  73  */
  74 static int is_ejectable(acpi_handle handle)
  75 {
  76         acpi_status status;
  77         acpi_handle tmp;
  78
  79         status = acpi_get_handle(handle, "_EJ0", &tmp);
  80         if (ACPI_FAILURE(status))
  81                 return 0;
  82         return 1;
  83 }
  84
  85 /**
  86  * bay_present - see if the bay device is present
  87  * @bay: the drive bay
  88  *
  89  * execute the _STA method.
  90  */
  91 static int bay_present(struct bay *bay)
  92 {
  93         unsigned long sta;
  94         acpi_status status;
  95
  96         if (bay) {
  97                 status = acpi_evaluate_integer(bay->handle, "_STA", NULL, &sta);
  98                 if (ACPI_SUCCESS(status) && sta)
  99                         return 1;
 100         }
 101         return 0;
 102 }
 103
 104 /**
 105  * eject_device - respond to an eject request
 106  * @handle - the device to eject
 107  *
 108  * Call this devices _EJ0 method.
 109  */
 110 static void eject_device(acpi_handle handle)
 111 {
 112         struct acpi_object_list arg_list;
 113         union acpi_object arg;
 114
 115         bay_dprintk(handle, "Ejecting device");
 116
 117         arg_list.count = 1;
 118         arg_list.pointer = &arg;
 119         arg.type = ACPI_TYPE_INTEGER;
 120         arg.integer.value = 1;
 121
 122         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
 123                                               &arg_list, NULL)))
 124                 pr_debug("Failed to evaluate _EJ0!\n");
 125 }
 126
 127 /*
 128  * show_present - read method for "present" file in sysfs
 129  */
 130 static ssize_t show_present(struct device *dev,
 131                            struct device_attribute *attr, char *buf)
 132 {
 133         struct bay *bay = dev_get_drvdata(dev);
 134         return snprintf(buf, PAGE_SIZE, "%d\n", bay_present(bay));
 135
 136 }
 137 static DEVICE_ATTR(present, S_IRUGO, show_present, NULL);
 138
 139 /*
 140  * write_eject - write method for "eject" file in sysfs
 141  */
 142 static ssize_t write_eject(struct device *dev, struct device_attribute *attr,
 143                            const char *buf, size_t count)
 144 {
 145         struct bay *bay = dev_get_drvdata(dev);
 146
 147         if (!count)
 148                 return -EINVAL;
 149
 150         eject_device(bay->handle);
 151         return count;
 152 }
 153 static DEVICE_ATTR(eject, S_IWUSR, NULL, write_eject);
 154
 155 /**
 156  * is_ata - see if a device is an ata device
 157  * @handle: acpi handle of the device
 158  *
 159  * If an acpi object has one of 4 ATA ACPI methods defined,
 160  * then it is an ATA device
 161  */
 162 static int is_ata(acpi_handle handle)
 163 {
 164         acpi_handle tmp;
 165
 166         if ((ACPI_SUCCESS(acpi_get_handle(handle, "_GTF", &tmp))) ||
 167            (ACPI_SUCCESS(acpi_get_handle(handle, "_GTM", &tmp))) ||
 168            (ACPI_SUCCESS(acpi_get_handle(handle, "_STM", &tmp))) ||
 169            (ACPI_SUCCESS(acpi_get_handle(handle, "_SDD", &tmp))))
 170                 return 1;
 171
 172         return 0;
 173 }
 174
 175 /**
 176  * parent_is_ata(acpi_handle handle)
 177  *
 178  */
 179 static int parent_is_ata(acpi_handle handle)
 180 {
 181         acpi_handle phandle;
 182
 183         if (acpi_get_parent(handle, &phandle))
 184                 return 0;
 185
 186         return is_ata(phandle);
 187 }
 188
 189 /**
 190  * is_ejectable_bay - see if a device is an ejectable drive bay
 191  * @handle: acpi handle of the device
 192  *
 193  * If an acpi object is ejectable and has one of the ACPI ATA
 194  * methods defined, then we can safely call it an ejectable
 195  * drive bay
 196  */
 197 static int is_ejectable_bay(acpi_handle handle)
 198 {
 199         if ((is_ata(handle) || parent_is_ata(handle)) && is_ejectable(handle))
 200                 return 1;
 201         return 0;
 202 }
 203
 204 #if 0
 205 /**
 206  * eject_removable_drive - try to eject this drive
 207  * @dev : the device structure of the drive
 208  *
 209  * If a device is a removable drive that requires an _EJ0 method
 210  * to be executed in order to safely remove from the system, do
 211  * it.  ATM - always returns success
 212  */
 213 int eject_removable_drive(struct device *dev)
 214 {
 215         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 216
 217         if (handle) {
 218                 bay_dprintk(handle, "Got device handle");
 219                 if (is_ejectable_bay(handle))
 220                         eject_device(handle);
 221         } else {
 222                 printk("No acpi handle for device\n");
 223         }
 224
 225         /* should I return an error code? */
 226         return 0;
 227 }
 228 EXPORT_SYMBOL_GPL(eject_removable_drive);
 229 #endif  /*  0  */
 230
 231 static int acpi_bay_add_fs(struct bay *bay)
 232 {
 233         int ret;
 234         struct device *dev = &bay->pdev->dev;
 235
 236         ret = device_create_file(dev, &dev_attr_present);
 237         if (ret)
 238                 goto add_fs_err;
 239         ret = device_create_file(dev, &dev_attr_eject);
 240         if (ret) {
 241                 device_remove_file(dev, &dev_attr_present);
 242                 goto add_fs_err;
 243         }
 244         return 0;
 245
 246  add_fs_err:
 247         bay_dprintk(bay->handle, "Error adding sysfs files\n");
 248         return ret;
 249 }
 250
 251 static void acpi_bay_remove_fs(struct bay *bay)
 252 {
 253         struct device *dev = &bay->pdev->dev;
 254
 255         /* cleanup sysfs */
 256         device_remove_file(dev, &dev_attr_present);
 257         device_remove_file(dev, &dev_attr_eject);
 258 }
 259
 260 static int bay_is_dock_device(acpi_handle handle)
 261 {
 262         acpi_handle parent;
 263
 264         acpi_get_parent(handle, &parent);
 265
 266         /* if the device or it's parent is dependent on the
 267          * dock, then we are a dock device
 268          */
 269         return (is_dock_device(handle) || is_dock_device(parent));
 270 }
 271
 272 static int bay_add(acpi_handle handle, int id)
 273 {
 274         acpi_status status;
 275         struct bay *new_bay;
 276         struct platform_device *pdev;
 277         struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
 278         acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
 279
 280         bay_dprintk(handle, "Adding notify handler");
 281
 282         /*
 283          * Initialize bay device structure
 284          */
 285         new_bay = kzalloc(sizeof(*new_bay), GFP_ATOMIC);
 286         INIT_LIST_HEAD(&new_bay->list);
 287         new_bay->handle = handle;
 288         new_bay->name = (char *)nbuffer.pointer;
 289
 290         /* initialize platform device stuff */
 291         pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
 292         if (IS_ERR(pdev)) {
 293                 printk(KERN_ERR PREFIX "Error registering bay device\n");
 294                 goto bay_add_err;
 295         }
 296         new_bay->pdev = pdev;
 297         platform_set_drvdata(pdev, new_bay);
 298
 299         /*
 300          * we want the bay driver to be able to send uevents
 301          */
 302         pdev->dev.uevent_suppress = 0;
 303
 304         if (acpi_bay_add_fs(new_bay)) {
 305                 platform_device_unregister(new_bay->pdev);
 306                 goto bay_add_err;
 307         }
 308
 309         /* register for events on this device */
 310         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 311                         bay_notify, new_bay);
 312         if (ACPI_FAILURE(status)) {
 313                 printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
 314         }
 315
 316         /* if we are on a dock station, we should register for dock
 317          * notifications.
 318          */
 319         if (bay_is_dock_device(handle)) {
 320                 bay_dprintk(handle, "Is dependent on dock\n");
 321                 register_hotplug_dock_device(handle, bay_notify, new_bay);
 322         }
 323         list_add(&new_bay->list, &drive_bays);
 324         printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
 325         return 0;
 326
 327 bay_add_err:
 328         kfree(new_bay->name);
 329         kfree(new_bay);
 330         return -ENODEV;
 331 }
 332
 333 /**
 334  * bay_notify - act upon an acpi bay notification
 335  * @handle: the bay handle
 336  * @event: the acpi event
 337  * @data: our driver data struct
 338  *
 339  */
 340 static void bay_notify(acpi_handle handle, u32 event, void *data)
 341 {
 342         struct bay *bay_dev = (struct bay *)data;
 343         struct device *dev = &bay_dev->pdev->dev;
 344         char event_string[12];
 345         char *envp[] = { event_string, NULL };
 346
 347         bay_dprintk(handle, "Bay event");
 348         sprintf(event_string, "BAY_EVENT=%d", event);
 349         kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 350 }
 351
 352 static acpi_status
 353 find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 354 {
 355         int *count = (int *)context;
 356
 357         /*
 358          * there could be more than one ejectable bay.
 359          * so, just return AE_OK always so that every object
 360          * will be checked.
 361          */
 362         if (is_ejectable_bay(handle)) {
 363                 bay_dprintk(handle, "found ejectable bay");
 364                 if (!bay_add(handle, *count))
 365                         (*count)++;
 366         }
 367         return AE_OK;
 368 }
 369
 370 static int __init bay_init(void)
 371 {
 372         int bays = 0;
 373
 374         INIT_LIST_HEAD(&drive_bays);
 375
 376         /* look for dockable drive bays */
 377         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 378                 ACPI_UINT32_MAX, find_bay, &bays, NULL);
 379
 380         if (!bays)
 381                 return -ENODEV;
 382
 383         return 0;
 384 }
 385
 386 static void __exit bay_exit(void)
 387 {
 388         struct bay *bay, *tmp;
 389
 390         list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
 391                 if (is_dock_device(bay->handle))
 392                         unregister_hotplug_dock_device(bay->handle);
 393                 acpi_bay_remove_fs(bay);
 394                 acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
 395                         bay_notify);
 396                 platform_device_unregister(bay->pdev);
 397                 kfree(bay->name);
 398                 kfree(bay);
 399         }
 400 }
 401
 402 postcore_initcall(bay_init);
 403 module_exit(bay_exit);
 404