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