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 /**
 205  * eject_removable_drive - try to eject this drive
 206  * @dev : the device structure of the drive
 207  *
 208  * If a device is a removable drive that requires an _EJ0 method
 209  * to be executed in order to safely remove from the system, do
 210  * it.  ATM - always returns success
 211  */
 212 int eject_removable_drive(struct device *dev)
 213 {
 214         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 215
 216         if (handle) {
 217                 bay_dprintk(handle, "Got device handle");
 218                 if (is_ejectable_bay(handle))
 219                         eject_device(handle);
 220         } else {
 221                 printk("No acpi handle for device\n");
 222         }
 223
 224         /* should I return an error code? */
 225         return 0;
 226 }
 227 EXPORT_SYMBOL_GPL(eject_removable_drive);
 228
 229 static int acpi_bay_add_fs(struct bay *bay)
 230 {
 231         int ret;
 232         struct device *dev = &bay->pdev->dev;
 233
 234         ret = device_create_file(dev, &dev_attr_present);
 235         if (ret)
 236                 goto add_fs_err;
 237         ret = device_create_file(dev, &dev_attr_eject);
 238         if (ret) {
 239                 device_remove_file(dev, &dev_attr_present);
 240                 goto add_fs_err;
 241         }
 242         return 0;
 243
 244  add_fs_err:
 245         bay_dprintk(bay->handle, "Error adding sysfs files\n");
 246         return ret;
 247 }
 248
 249 static void acpi_bay_remove_fs(struct bay *bay)
 250 {
 251         struct device *dev = &bay->pdev->dev;
 252
 253         /* cleanup sysfs */
 254         device_remove_file(dev, &dev_attr_present);
 255         device_remove_file(dev, &dev_attr_eject);
 256 }
 257
 258 static int bay_is_dock_device(acpi_handle handle)
 259 {
 260         acpi_handle parent;
 261
 262         acpi_get_parent(handle, &parent);
 263
 264         /* if the device or it's parent is dependent on the
 265          * dock, then we are a dock device
 266          */
 267         return (is_dock_device(handle) || is_dock_device(parent));
 268 }
 269
 270 static int bay_add(acpi_handle handle, int id)
 271 {
 272         acpi_status status;
 273         struct bay *new_bay;
 274         struct platform_device *pdev;
 275         struct acpi_buffer nbuffer = {ACPI_ALLOCATE_BUFFER, NULL};
 276         acpi_get_name(handle, ACPI_FULL_PATHNAME, &nbuffer);
 277
 278         bay_dprintk(handle, "Adding notify handler");
 279
 280         /*
 281          * Initialize bay device structure
 282          */
 283         new_bay = kzalloc(sizeof(*new_bay), GFP_ATOMIC);
 284         INIT_LIST_HEAD(&new_bay->list);
 285         new_bay->handle = handle;
 286         new_bay->name = (char *)nbuffer.pointer;
 287
 288         /* initialize platform device stuff */
 289         pdev = platform_device_register_simple(ACPI_BAY_CLASS, id, NULL, 0);
 290         if (IS_ERR(pdev)) {
 291                 printk(KERN_ERR PREFIX "Error registering bay device\n");
 292                 goto bay_add_err;
 293         }
 294         new_bay->pdev = pdev;
 295         platform_set_drvdata(pdev, new_bay);
 296
 297         /*
 298          * we want the bay driver to be able to send uevents
 299          */
 300         pdev->dev.uevent_suppress = 0;
 301
 302         if (acpi_bay_add_fs(new_bay)) {
 303                 platform_device_unregister(new_bay->pdev);
 304                 goto bay_add_err;
 305         }
 306
 307         /* register for events on this device */
 308         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 309                         bay_notify, new_bay);
 310         if (ACPI_FAILURE(status)) {
 311                 printk(KERN_ERR PREFIX "Error installing bay notify handler\n");
 312         }
 313
 314         /* if we are on a dock station, we should register for dock
 315          * notifications.
 316          */
 317         if (bay_is_dock_device(handle)) {
 318                 bay_dprintk(handle, "Is dependent on dock\n");
 319                 register_hotplug_dock_device(handle, bay_notify, new_bay);
 320         }
 321         list_add(&new_bay->list, &drive_bays);
 322         printk(KERN_INFO PREFIX "Bay [%s] Added\n", new_bay->name);
 323         return 0;
 324
 325 bay_add_err:
 326         kfree(new_bay->name);
 327         kfree(new_bay);
 328         return -ENODEV;
 329 }
 330
 331 /**
 332  * bay_notify - act upon an acpi bay notification
 333  * @handle: the bay handle
 334  * @event: the acpi event
 335  * @data: our driver data struct
 336  *
 337  */
 338 static void bay_notify(acpi_handle handle, u32 event, void *data)
 339 {
 340         struct bay *bay_dev = (struct bay *)data;
 341         struct device *dev = &bay_dev->pdev->dev;
 342         char event_string[12];
 343         char *envp[] = { event_string, NULL };
 344
 345         bay_dprintk(handle, "Bay event");
 346         sprintf(event_string, "BAY_EVENT=%d", event);
 347         kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 348 }
 349
 350 static acpi_status
 351 find_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 352 {
 353         int *count = (int *)context;
 354
 355         /*
 356          * there could be more than one ejectable bay.
 357          * so, just return AE_OK always so that every object
 358          * will be checked.
 359          */
 360         if (is_ejectable_bay(handle)) {
 361                 bay_dprintk(handle, "found ejectable bay");
 362                 if (!bay_add(handle, *count))
 363                         (*count)++;
 364         }
 365         return AE_OK;
 366 }
 367
 368 static int __init bay_init(void)
 369 {
 370         int bays = 0;
 371
 372         INIT_LIST_HEAD(&drive_bays);
 373
 374         /* look for dockable drive bays */
 375         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 376                 ACPI_UINT32_MAX, find_bay, &bays, NULL);
 377
 378         if (!bays)
 379                 return -ENODEV;
 380
 381         return 0;
 382 }
 383
 384 static void __exit bay_exit(void)
 385 {
 386         struct bay *bay, *tmp;
 387
 388         list_for_each_entry_safe(bay, tmp, &drive_bays, list) {
 389                 if (is_dock_device(bay->handle))
 390                         unregister_hotplug_dock_device(bay->handle);
 391                 acpi_bay_remove_fs(bay);
 392                 acpi_remove_notify_handler(bay->handle, ACPI_SYSTEM_NOTIFY,
 393                         bay_notify);
 394                 platform_device_unregister(bay->pdev);
 395                 kfree(bay->name);
 396                 kfree(bay);
 397         }
 398 }
 399
 400 postcore_initcall(bay_init);
 401 module_exit(bay_exit);
 402