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 <acpi/acpi_drivers.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 quickstart_buttons_show(struct device *dev,
  75                                         struct device_attribute *attr,
  76                                         char *buf)
  77 {
  78         int count = 0;
  79         struct quickstart_button *b;
  80
  81         if (list_empty(&buttons))
  82                 return snprintf(buf, PAGE_SIZE, "none");
  83
  84         list_for_each_entry(b, &buttons, list) {
  85                 count += snprintf(buf + count, PAGE_SIZE - count, "%u\t%s\n",
  86                                                         b->id, b->name);
  87
  88                 if (count >= PAGE_SIZE) {
  89                         count = PAGE_SIZE;
  90                         break;
  91                 }
  92         }
  93
  94         return count;
  95 }
  96
  97 static ssize_t quickstart_pressed_button_show(struct device *dev,
  98                                                 struct device_attribute *attr,
  99                                                 char *buf)
 100 {
 101         return scnprintf(buf, PAGE_SIZE, "%s\n",
 102                                         (pressed ? pressed->name : "none"));
 103 }
 104
 105
 106 static ssize_t quickstart_pressed_button_store(struct device *dev,
 107                                                 struct device_attribute *attr,
 108                                                 const char *buf, size_t count)
 109 {
 110         if (count < 2)
 111                 return -EINVAL;
 112
 113         if (strncasecmp(buf, "none", 4) != 0)
 114                 return -EINVAL;
 115
 116         pressed = NULL;
 117         return count;
 118 }
 119
 120 /* Helper functions */
 121 static struct quickstart_button *quickstart_buttons_add(void)
 122 {
 123         struct quickstart_button *b;
 124
 125         b = kzalloc(sizeof(*b), GFP_KERNEL);
 126         if (!b)
 127                 return NULL;
 128
 129         list_add_tail(&b->list, &buttons);
 130
 131         return b;
 132 }
 133
 134 static void quickstart_button_del(struct quickstart_button *data)
 135 {
 136         if (!data)
 137                 return;
 138
 139         list_del(&data->list);
 140         kfree(data->name);
 141         kfree(data);
 142 }
 143
 144 static void quickstart_buttons_free(void)
 145 {
 146         struct quickstart_button *b, *n;
 147
 148         list_for_each_entry_safe(b, n, &buttons, list)
 149                 quickstart_button_del(b);
 150 }
 151
 152 /* ACPI Driver functions */
 153 static void quickstart_acpi_notify(acpi_handle handle, u32 event, void *data)
 154 {
 155         struct quickstart_acpi *quickstart = data;
 156
 157         if (!quickstart)
 158                 return;
 159
 160         switch (event) {
 161         case QUICKSTART_EVENT_WAKE:
 162                 pressed = quickstart->button;
 163                 break;
 164         case QUICKSTART_EVENT_RUNTIME:
 165                 input_report_key(quickstart_input, quickstart->button->id, 1);
 166                 input_sync(quickstart_input);
 167                 input_report_key(quickstart_input, quickstart->button->id, 0);
 168                 input_sync(quickstart_input);
 169                 break;
 170         default:
 171                 pr_err("Unexpected ACPI event notify (%u)\n", event);
 172                 break;
 173         }
 174 }
 175
 176 static int quickstart_acpi_ghid(struct quickstart_acpi *quickstart)
 177 {
 178         acpi_status status;
 179         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 180         int ret = 0;
 181
 182         /*
 183          * This returns a buffer telling the button usage ID,
 184          * and triggers pending notify events (The ones before booting).
 185          */
 186         status = acpi_evaluate_object(quickstart->device->handle, "GHID", NULL,
 187                                                                 &buffer);
 188         if (ACPI_FAILURE(status)) {
 189                 pr_err("%s GHID method failed\n", quickstart->button->name);
 190                 return -EINVAL;
 191         }
 192
 193         /*
 194          * <<The GHID method can return a BYTE, WORD, or DWORD.
 195          * The value must be encoded in little-endian byte
 196          * order (least significant byte first).>>
 197          */
 198         switch (buffer.length) {
 199         case 1:
 200                 quickstart->button->id = *(uint8_t *)buffer.pointer;
 201                 break;
 202         case 2:
 203                 quickstart->button->id = *(uint16_t *)buffer.pointer;
 204                 break;
 205         case 4:
 206                 quickstart->button->id = *(uint32_t *)buffer.pointer;
 207                 break;
 208         case 8:
 209                 quickstart->button->id = *(uint64_t *)buffer.pointer;
 210                 break;
 211         default:
 212                 pr_err("%s GHID method returned buffer of unexpected length %lu\n",
 213                                 quickstart->button->name,
 214                                 (unsigned long)buffer.length);
 215                 ret = -EINVAL;
 216                 break;
 217         }
 218
 219         kfree(buffer.pointer);
 220
 221         return ret;
 222 }
 223
 224 static int quickstart_acpi_config(struct quickstart_acpi *quickstart)
 225 {
 226         char *bid = acpi_device_bid(quickstart->device);
 227         char *name;
 228
 229         name = kmalloc(strlen(bid) + 1, GFP_KERNEL);
 230         if (!name)
 231                 return -ENOMEM;
 232
 233         /* Add new button to list */
 234         quickstart->button = quickstart_buttons_add();
 235         if (!quickstart->button) {
 236                 kfree(name);
 237                 return -ENOMEM;
 238         }
 239
 240         quickstart->button->name = name;
 241         strcpy(quickstart->button->name, bid);
 242
 243         return 0;
 244 }
 245
 246 static int quickstart_acpi_add(struct acpi_device *device)
 247 {
 248         int ret;
 249         acpi_status status;
 250         struct quickstart_acpi *quickstart;
 251
 252         if (!device)
 253                 return -EINVAL;
 254
 255         quickstart = kzalloc(sizeof(*quickstart), GFP_KERNEL);
 256         if (!quickstart)
 257                 return -ENOMEM;
 258
 259         quickstart->device = device;
 260
 261         strcpy(acpi_device_name(device), QUICKSTART_ACPI_DEVICE_NAME);
 262         strcpy(acpi_device_class(device), QUICKSTART_ACPI_CLASS);
 263         device->driver_data = quickstart;
 264
 265         /* Add button to list and initialize some stuff */
 266         ret = quickstart_acpi_config(quickstart);
 267         if (ret < 0)
 268                 goto fail_config;
 269
 270         status = acpi_install_notify_handler(device->handle, ACPI_ALL_NOTIFY,
 271                                                 quickstart_acpi_notify,
 272                                                 quickstart);
 273         if (ACPI_FAILURE(status)) {
 274                 pr_err("Notify handler install error\n");
 275                 ret = -ENODEV;
 276                 goto fail_installnotify;
 277         }
 278
 279         ret = quickstart_acpi_ghid(quickstart);
 280         if (ret < 0)
 281                 goto fail_ghid;
 282
 283         return 0;
 284
 285 fail_ghid:
 286         acpi_remove_notify_handler(device->handle, ACPI_ALL_NOTIFY,
 287                                                 quickstart_acpi_notify);
 288
 289 fail_installnotify:
 290         quickstart_button_del(quickstart->button);
 291
 292 fail_config:
 293
 294         kfree(quickstart);
 295
 296         return ret;
 297 }
 298
 299 static int quickstart_acpi_remove(struct acpi_device *device, int type)
 300 {
 301         acpi_status status;
 302         struct quickstart_acpi *quickstart;
 303
 304         if (!device)
 305                 return -EINVAL;
 306
 307         quickstart = acpi_driver_data(device);
 308         if (!quickstart)
 309                 return -EINVAL;
 310
 311         status = acpi_remove_notify_handler(device->handle, ACPI_ALL_NOTIFY,
 312                                                 quickstart_acpi_notify);
 313         if (ACPI_FAILURE(status))
 314                 pr_err("Error removing notify handler\n");
 315
 316         kfree(quickstart);
 317
 318         return 0;
 319 }
 320
 321 /* Platform driver structs */
 322 static DEVICE_ATTR(pressed_button, 0666, quickstart_pressed_button_show,
 323                                          quickstart_pressed_button_store);
 324 static DEVICE_ATTR(buttons, 0444, quickstart_buttons_show, NULL);
 325 static struct platform_device *pf_device;
 326 static struct platform_driver pf_driver = {
 327         .driver = {
 328                 .name = QUICKSTART_PF_DRIVER_NAME,
 329                 .owner = THIS_MODULE,
 330         }
 331 };
 332
 333 static const struct acpi_device_id quickstart_device_ids[] = {
 334         {QUICKSTART_ACPI_HID, 0},
 335         {"", 0},
 336 };
 337
 338 static struct acpi_driver quickstart_acpi_driver = {
 339         .name = "quickstart",
 340         .class = QUICKSTART_ACPI_CLASS,
 341         .ids = quickstart_device_ids,
 342         .ops = {
 343                         .add = quickstart_acpi_add,
 344                         .remove = quickstart_acpi_remove,
 345                 },
 346 };
 347
 348 /* Module functions */
 349 static void quickstart_exit(void)
 350 {
 351         input_unregister_device(quickstart_input);
 352
 353         device_remove_file(&pf_device->dev, &dev_attr_pressed_button);
 354         device_remove_file(&pf_device->dev, &dev_attr_buttons);
 355
 356         platform_device_unregister(pf_device);
 357
 358         platform_driver_unregister(&pf_driver);
 359
 360         acpi_bus_unregister_driver(&quickstart_acpi_driver);
 361
 362         quickstart_buttons_free();
 363 }
 364
 365 static int __init quickstart_init_input(void)
 366 {
 367         struct quickstart_button *b;
 368         int ret;
 369
 370         quickstart_input = input_allocate_device();
 371
 372         if (!quickstart_input)
 373                 return -ENOMEM;
 374
 375         quickstart_input->name = "Quickstart ACPI Buttons";
 376         quickstart_input->id.bustype = BUS_HOST;
 377
 378         list_for_each_entry(b, &buttons, list) {
 379                 set_bit(EV_KEY, quickstart_input->evbit);
 380                 set_bit(b->id, quickstart_input->keybit);
 381         }
 382
 383         ret = input_register_device(quickstart_input);
 384         if (ret) {
 385                 input_free_device(quickstart_input);
 386                 return ret;
 387         }
 388
 389         return 0;
 390 }
 391
 392 static int __init quickstart_init(void)
 393 {
 394         int ret;
 395
 396         /* ACPI Check */
 397         if (acpi_disabled)
 398                 return -ENODEV;
 399
 400         /* ACPI driver register */
 401         ret = acpi_bus_register_driver(&quickstart_acpi_driver);
 402         if (ret)
 403                 return ret;
 404
 405         /* If existing bus with no devices */
 406         if (list_empty(&buttons)) {
 407                 ret = -ENODEV;
 408                 goto fail_pfdrv_reg;
 409         }
 410
 411         /* Platform driver register */
 412         ret = platform_driver_register(&pf_driver);
 413         if (ret)
 414                 goto fail_pfdrv_reg;
 415
 416         /* Platform device register */
 417         pf_device = platform_device_alloc(QUICKSTART_PF_DEVICE_NAME, -1);
 418         if (!pf_device) {
 419                 ret = -ENOMEM;
 420                 goto fail_pfdev_alloc;
 421         }
 422         ret = platform_device_add(pf_device);
 423         if (ret)
 424                 goto fail_pfdev_add;
 425
 426         /* Create device sysfs file */
 427         ret = device_create_file(&pf_device->dev, &dev_attr_pressed_button);
 428         if (ret)
 429                 goto fail_dev_file;
 430
 431         ret = device_create_file(&pf_device->dev, &dev_attr_buttons);
 432         if (ret)
 433                 goto fail_dev_file2;
 434
 435         /* Input device */
 436         ret = quickstart_init_input();
 437         if (ret)
 438                 goto fail_input;
 439
 440         pr_info("ACPI Direct App Launch ver %s\n", QUICKSTART_VERSION);
 441
 442         return 0;
 443 fail_input:
 444         device_remove_file(&pf_device->dev, &dev_attr_buttons);
 445
 446 fail_dev_file2:
 447         device_remove_file(&pf_device->dev, &dev_attr_pressed_button);
 448
 449 fail_dev_file:
 450         platform_device_del(pf_device);
 451
 452 fail_pfdev_add:
 453         platform_device_put(pf_device);
 454
 455 fail_pfdev_alloc:
 456         platform_driver_unregister(&pf_driver);
 457
 458 fail_pfdrv_reg:
 459         acpi_bus_unregister_driver(&quickstart_acpi_driver);
 460
 461         return ret;
 462 }
 463
 464 module_init(quickstart_init);
 465 module_exit(quickstart_exit);