drivers/staging/quickstart/quickstart.c

   1 /*
   2  *  quickstart.c - ACPI Direct App Launch driver
   3  *
   4  *
   5  *  Copyright (C) 2007-2010 Angelo Arrifano <miknix@gmail.com>
   6  *
   7  *  Information gathered from disassembled dsdt and from here:
   8  *  <http://www.microsoft.com/whdc/system/platform/firmware/DirAppLaunch.mspx>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  */
  25
  26 #define QUICKSTART_VERSION "1.04"
  27
  28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  29
  30 #include <linux/kernel.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/types.h>
  34 #include <linux/acpi.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/input.h>
  37
  38 MODULE_AUTHOR("Angelo Arrifano");
  39 MODULE_DESCRIPTION("ACPI Direct App Launch driver");
  40 MODULE_LICENSE("GPL");
  41
  42 #define QUICKSTART_ACPI_DEVICE_NAME     "quickstart"
  43 #define QUICKSTART_ACPI_CLASS           "quickstart"
  44 #define QUICKSTART_ACPI_HID             "PNP0C32"
  45
  46 #define QUICKSTART_PF_DRIVER_NAME       "quickstart"
  47 #define QUICKSTART_PF_DEVICE_NAME       "quickstart"
  48
  49 /*
  50  * There will be two events:
  51  * 0x02 - A hot button was pressed while device was off/sleeping.
  52  * 0x80 - A hot button was pressed while device was up.
  53  */
  54 #define QUICKSTART_EVENT_WAKE           0x02
  55 #define QUICKSTART_EVENT_RUNTIME        0x80
  56
  57 struct quickstart_button {
  58         char *name;
  59         unsigned int id;
  60         struct list_head list;
  61 };
  62
  63 struct quickstart_acpi {
  64         struct acpi_device *device;
  65         struct quickstart_button *button;
  66 };
  67
  68 static LIST_HEAD(buttons);
  69 static struct quickstart_button *pressed;
  70
  71 static struct input_dev *quickstart_input;
  72
  73 /* Platform driver functions */
  74 static ssize_t buttons_show(struct device *dev, struct device_attribute *attr,
  75                             char *buf)
  76 {
  77         int count = 0;
  78         struct quickstart_button *b;
  79
  80         if (list_empty(&buttons))
  81                 return snprintf(buf, PAGE_SIZE, "none");
  82
  83         list_for_each_entry(b, &buttons, list) {
  84                 count += snprintf(buf + count, PAGE_SIZE - count, "%u\t%s\n",
  85                                                         b->id, b->name);
  86
  87                 if (count >= PAGE_SIZE) {
  88                         count = PAGE_SIZE;
  89                         break;
  90                 }
  91         }
  92
  93         return count;
  94 }
  95
  96 static ssize_t pressed_button_show(struct device *dev,
  97                                    struct device_attribute *attr, char *buf)
  98 {
  99         return scnprintf(buf, PAGE_SIZE, "%s\n",
 100                                         (pressed ? pressed->name : "none"));
 101 }
 102
 103
 104 static ssize_t pressed_button_store(struct device *dev,
 105                                     struct device_attribute *attr,
 106                                     const char *buf, size_t count)
 107 {
 108         if (count < 2)
 109                 return -EINVAL;
 110
 111         if (strncasecmp(buf, "none", 4) != 0)
 112                 return -EINVAL;
 113
 114         pressed = NULL;
 115         return count;
 116 }
 117
 118 /* Helper functions */
 119 static struct quickstart_button *quickstart_buttons_add(void)
 120 {
 121         struct quickstart_button *b;
 122
 123         b = kzalloc(sizeof(*b), GFP_KERNEL);
 124         if (!b)
 125                 return NULL;
 126
 127         list_add_tail(&b->list, &buttons);
 128
 129         return b;
 130 }
 131
 132 static void quickstart_button_del(struct quickstart_button *data)
 133 {
 134         if (!data)
 135                 return;
 136
 137         list_del(&data->list);
 138         kfree(data->name);
 139         kfree(data);
 140 }
 141
 142 static void quickstart_buttons_free(void)
 143 {
 144         struct quickstart_button *b, *n;
 145
 146         list_for_each_entry_safe(b, n, &buttons, list)
 147                 quickstart_button_del(b);
 148 }
 149
 150 /* ACPI Driver functions */
 151 static void quickstart_acpi_notify(acpi_handle handle, u32 event, void *data)
 152 {
 153         struct quickstart_acpi *quickstart = data;
 154
 155         if (!quickstart)
 156                 return;
 157
 158         switch (event) {
 159         case QUICKSTART_EVENT_WAKE:
 160                 pressed = quickstart->button;
 161                 break;
 162         case QUICKSTART_EVENT_RUNTIME:
 163                 input_report_key(quickstart_input, quickstart->button->id, 1);
 164                 input_sync(quickstart_input);
 165                 input_report_key(quickstart_input, quickstart->button->id, 0);
 166                 input_sync(quickstart_input);
 167                 break;
 168         default:
 169                 pr_err("Unexpected ACPI event notify (%u)\n", event);
 170                 break;
 171         }
 172 }
 173
 174 static int quickstart_acpi_ghid(struct quickstart_acpi *quickstart)
 175 {
 176         acpi_status status;
 177         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 178         int ret = 0;
 179
 180         /*
 181          * This returns a buffer telling the button usage ID,
 182          * and triggers pending notify events (The ones before booting).
 183          */
 184         status = acpi_evaluate_object(quickstart->device->handle, "GHID", NULL,
 185                                                                 &buffer);
 186         if (ACPI_FAILURE(status)) {
 187                 pr_err("%s GHID method failed\n", quickstart->button->name);
 188                 return -EINVAL;
 189         }
 190
 191         /*
 192          * <<The GHID method can return a BYTE, WORD, or DWORD.
 193          * The value must be encoded in little-endian byte
 194          * order (least significant byte first).>>
 195          */
 196         switch (buffer.length) {
 197         case 1:
 198                 quickstart->button->id = *(uint8_t *)buffer.pointer;
 199                 break;
 200         case 2:
 201                 quickstart->button->id = *(uint16_t *)buffer.pointer;
 202                 break;
 203         case 4:
 204                 quickstart->button->id = *(uint32_t *)buffer.pointer;
 205                 break;
 206         case 8:
 207                 quickstart->button->id = *(uint64_t *)buffer.pointer;
 208                 break;
 209         default:
 210                 pr_err("%s GHID method returned buffer of unexpected length %lu\n",
 211                                 quickstart->button->name,
 212                                 (unsigned long)buffer.length);
 213                 ret = -EINVAL;
 214                 break;
 215         }
 216
 217         kfree(buffer.pointer);
 218
 219         return ret;
 220 }
 221
 222 static int quickstart_acpi_config(struct quickstart_acpi *quickstart)
 223 {
 224         char *bid = acpi_device_bid(quickstart->device);
 225         char *name;
 226
 227         name = kmalloc(strlen(bid) + 1, GFP_KERNEL);
 228         if (!name)
 229                 return -ENOMEM;
 230
 231         /* Add new button to list */
 232         quickstart->button = quickstart_buttons_add();
 233         if (!quickstart->button) {
 234                 kfree(name);
 235                 return -ENOMEM;
 236         }
 237
 238         quickstart->button->name = name;
 239         strcpy(quickstart->button->name, bid);
 240
 241         return 0;
 242 }
 243
 244 static int quickstart_acpi_add(struct acpi_device *device)
 245 {
 246         int ret;
 247         acpi_status status;
 248         struct quickstart_acpi *quickstart;
 249
 250         if (!device)
 251                 return -EINVAL;
 252
 253         quickstart = kzalloc(sizeof(*quickstart), GFP_KERNEL);
 254         if (!quickstart)
 255                 return -ENOMEM;
 256
 257         quickstart->device = device;
 258
 259         strcpy(acpi_device_name(device), QUICKSTART_ACPI_DEVICE_NAME);
 260         strcpy(acpi_device_class(device), QUICKSTART_ACPI_CLASS);
 261         device->driver_data = quickstart;
 262
 263         /* Add button to list and initialize some stuff */
 264         ret = quickstart_acpi_config(quickstart);
 265         if (ret < 0)
 266                 goto fail_config;
 267
 268         status = acpi_install_notify_handler(device->handle, ACPI_ALL_NOTIFY,
 269                                                 quickstart_acpi_notify,
 270                                                 quickstart);
 271         if (ACPI_FAILURE(status)) {
 272                 pr_err("Notify handler install error\n");
 273                 ret = -ENODEV;
 274                 goto fail_installnotify;
 275         }
 276
 277         ret = quickstart_acpi_ghid(quickstart);
 278         if (ret < 0)
 279                 goto fail_ghid;
 280
 281         return 0;
 282
 283 fail_ghid:
 284         acpi_remove_notify_handler(device->handle, ACPI_ALL_NOTIFY,
 285                                                 quickstart_acpi_notify);
 286
 287 fail_installnotify:
 288         quickstart_button_del(quickstart->button);
 289
 290 fail_config:
 291
 292         kfree(quickstart);
 293
 294         return ret;
 295 }
 296
 297 static int quickstart_acpi_remove(struct acpi_device *device)
 298 {
 299         acpi_status status;
 300         struct quickstart_acpi *quickstart;
 301
 302         if (!device)
 303                 return -EINVAL;
 304
 305         quickstart = acpi_driver_data(device);
 306         if (!quickstart)
 307                 return -EINVAL;
 308
 309         status = acpi_remove_notify_handler(device->handle, ACPI_ALL_NOTIFY,
 310                                                 quickstart_acpi_notify);
 311         if (ACPI_FAILURE(status))
 312                 pr_err("Error removing notify handler\n");
 313
 314         kfree(quickstart);
 315
 316         return 0;
 317 }
 318
 319 /* Platform driver structs */
 320 static DEVICE_ATTR_RW(pressed_button);
 321 static DEVICE_ATTR_RO(buttons);
 322 static struct platform_device *pf_device;
 323 static struct platform_driver pf_driver = {
 324         .driver = {
 325                 .name = QUICKSTART_PF_DRIVER_NAME,
 326                 .owner = THIS_MODULE,
 327         }
 328 };
 329
 330 static const struct acpi_device_id quickstart_device_ids[] = {
 331         {QUICKSTART_ACPI_HID, 0},
 332         {"", 0},
 333 };
 334
 335 static struct acpi_driver quickstart_acpi_driver = {
 336         .name = "quickstart",
 337         .class = QUICKSTART_ACPI_CLASS,
 338         .ids = quickstart_device_ids,
 339         .ops = {
 340                         .add = quickstart_acpi_add,
 341                         .remove = quickstart_acpi_remove,
 342                 },
 343 };
 344
 345 /* Module functions */
 346 static void quickstart_exit(void)
 347 {
 348         input_unregister_device(quickstart_input);
 349
 350         device_remove_file(&pf_device->dev, &dev_attr_pressed_button);
 351         device_remove_file(&pf_device->dev, &dev_attr_buttons);
 352
 353         platform_device_unregister(pf_device);
 354
 355         platform_driver_unregister(&pf_driver);
 356
 357         acpi_bus_unregister_driver(&quickstart_acpi_driver);
 358
 359         quickstart_buttons_free();
 360 }
 361
 362 static int __init quickstart_init_input(void)
 363 {
 364         struct quickstart_button *b;
 365         int ret;
 366
 367         quickstart_input = input_allocate_device();
 368
 369         if (!quickstart_input)
 370                 return -ENOMEM;
 371
 372         quickstart_input->name = "Quickstart ACPI Buttons";
 373         quickstart_input->id.bustype = BUS_HOST;
 374
 375         list_for_each_entry(b, &buttons, list) {
 376                 set_bit(EV_KEY, quickstart_input->evbit);
 377                 set_bit(b->id, quickstart_input->keybit);
 378         }
 379
 380         ret = input_register_device(quickstart_input);
 381         if (ret) {
 382                 input_free_device(quickstart_input);
 383                 return ret;
 384         }
 385
 386         return 0;
 387 }
 388
 389 static int __init quickstart_init(void)
 390 {
 391         int ret;
 392
 393         /* ACPI driver register */
 394         ret = acpi_bus_register_driver(&quickstart_acpi_driver);
 395         if (ret)
 396                 return ret;
 397
 398         /* If existing bus with no devices */
 399         if (list_empty(&buttons)) {
 400                 ret = -ENODEV;
 401                 goto fail_pfdrv_reg;
 402         }
 403
 404         /* Platform driver register */
 405         ret = platform_driver_register(&pf_driver);
 406         if (ret)
 407                 goto fail_pfdrv_reg;
 408
 409         /* Platform device register */
 410         pf_device = platform_device_alloc(QUICKSTART_PF_DEVICE_NAME, -1);
 411         if (!pf_device) {
 412                 ret = -ENOMEM;
 413                 goto fail_pfdev_alloc;
 414         }
 415         ret = platform_device_add(pf_device);
 416         if (ret)
 417                 goto fail_pfdev_add;
 418
 419         /* Create device sysfs file */
 420         ret = device_create_file(&pf_device->dev, &dev_attr_pressed_button);
 421         if (ret)
 422                 goto fail_dev_file;
 423
 424         ret = device_create_file(&pf_device->dev, &dev_attr_buttons);
 425         if (ret)
 426                 goto fail_dev_file2;
 427
 428         /* Input device */
 429         ret = quickstart_init_input();
 430         if (ret)
 431                 goto fail_input;
 432
 433         pr_info("ACPI Direct App Launch ver %s\n", QUICKSTART_VERSION);
 434
 435         return 0;
 436 fail_input:
 437         device_remove_file(&pf_device->dev, &dev_attr_buttons);
 438
 439 fail_dev_file2:
 440         device_remove_file(&pf_device->dev, &dev_attr_pressed_button);
 441
 442 fail_dev_file:
 443         platform_device_del(pf_device);
 444
 445 fail_pfdev_add:
 446         platform_device_put(pf_device);
 447
 448 fail_pfdev_alloc:
 449         platform_driver_unregister(&pf_driver);
 450
 451 fail_pfdrv_reg:
 452         acpi_bus_unregister_driver(&quickstart_acpi_driver);
 453
 454         return ret;
 455 }
 456
 457 module_init(quickstart_init);
 458 module_exit(quickstart_exit);