drivers/leds/leds-lp5521.c

   1 /*
   2  * LP5521 LED chip driver.
   3  *
   4  * Copyright (C) 2010 Nokia Corporation
   5  * Copyright (C) 2012 Texas Instruments
   6  *
   7  * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
   8  *          Milo(Woogyom) Kim <milo.kim@ti.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * version 2 as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  22  * 02110-1301 USA
  23  */
  24
  25 #include <linux/delay.h>
  26 #include <linux/firmware.h>
  27 #include <linux/i2c.h>
  28 #include <linux/init.h>
  29 #include <linux/leds.h>
  30 #include <linux/module.h>
  31 #include <linux/mutex.h>
  32 #include <linux/platform_data/leds-lp55xx.h>
  33 #include <linux/slab.h>
  34 #include <linux/of.h>
  35
  36 #include "leds-lp55xx-common.h"
  37
  38 #define LP5521_PROGRAM_LENGTH           32
  39 #define LP5521_MAX_LEDS                 3
  40 #define LP5521_CMD_DIRECT               0x3F
  41
  42 /* Registers */
  43 #define LP5521_REG_ENABLE               0x00
  44 #define LP5521_REG_OP_MODE              0x01
  45 #define LP5521_REG_R_PWM                0x02
  46 #define LP5521_REG_G_PWM                0x03
  47 #define LP5521_REG_B_PWM                0x04
  48 #define LP5521_REG_R_CURRENT            0x05
  49 #define LP5521_REG_G_CURRENT            0x06
  50 #define LP5521_REG_B_CURRENT            0x07
  51 #define LP5521_REG_CONFIG               0x08
  52 #define LP5521_REG_STATUS               0x0C
  53 #define LP5521_REG_RESET                0x0D
  54 #define LP5521_REG_R_PROG_MEM           0x10
  55 #define LP5521_REG_G_PROG_MEM           0x30
  56 #define LP5521_REG_B_PROG_MEM           0x50
  57
  58 /* Base register to set LED current */
  59 #define LP5521_REG_LED_CURRENT_BASE     LP5521_REG_R_CURRENT
  60 /* Base register to set the brightness */
  61 #define LP5521_REG_LED_PWM_BASE         LP5521_REG_R_PWM
  62
  63 /* Bits in ENABLE register */
  64 #define LP5521_MASTER_ENABLE            0x40    /* Chip master enable */
  65 #define LP5521_LOGARITHMIC_PWM          0x80    /* Logarithmic PWM adjustment */
  66 #define LP5521_EXEC_RUN                 0x2A
  67 #define LP5521_ENABLE_DEFAULT   \
  68         (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
  69 #define LP5521_ENABLE_RUN_PROGRAM       \
  70         (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
  71
  72 /* CONFIG register */
  73 #define LP5521_PWM_HF                   0x40    /* PWM: 0 = 256Hz, 1 = 558Hz */
  74 #define LP5521_PWRSAVE_EN               0x20    /* 1 = Power save mode */
  75 #define LP5521_CP_MODE_OFF              0       /* Charge pump (CP) off */
  76 #define LP5521_CP_MODE_BYPASS           8       /* CP forced to bypass mode */
  77 #define LP5521_CP_MODE_1X5              0x10    /* CP forced to 1.5x mode */
  78 #define LP5521_CP_MODE_AUTO             0x18    /* Automatic mode selection */
  79 #define LP5521_R_TO_BATT                0x04    /* R out: 0 = CP, 1 = Vbat */
  80 #define LP5521_CLK_INT                  0x01    /* Internal clock */
  81 #define LP5521_DEFAULT_CFG              \
  82         (LP5521_PWM_HF | LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO)
  83
  84 /* Status */
  85 #define LP5521_EXT_CLK_USED             0x08
  86
  87 /* default R channel current register value */
  88 #define LP5521_REG_R_CURR_DEFAULT       0xAF
  89
  90 /* Reset register value */
  91 #define LP5521_RESET                    0xFF
  92
  93 /* Program Memory Operations */
  94 #define LP5521_MODE_R_M                 0x30    /* Operation Mode Register */
  95 #define LP5521_MODE_G_M                 0x0C
  96 #define LP5521_MODE_B_M                 0x03
  97 #define LP5521_LOAD_R                   0x10
  98 #define LP5521_LOAD_G                   0x04
  99 #define LP5521_LOAD_B                   0x01
 100
 101 #define LP5521_R_IS_LOADING(mode)       \
 102         ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
 103 #define LP5521_G_IS_LOADING(mode)       \
 104         ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
 105 #define LP5521_B_IS_LOADING(mode)       \
 106         ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
 107
 108 #define LP5521_EXEC_R_M                 0x30    /* Enable Register */
 109 #define LP5521_EXEC_G_M                 0x0C
 110 #define LP5521_EXEC_B_M                 0x03
 111 #define LP5521_EXEC_M                   0x3F
 112 #define LP5521_RUN_R                    0x20
 113 #define LP5521_RUN_G                    0x08
 114 #define LP5521_RUN_B                    0x02
 115
 116 static inline void lp5521_wait_opmode_done(void)
 117 {
 118         /* operation mode change needs to be longer than 153 us */
 119         usleep_range(200, 300);
 120 }
 121
 122 static inline void lp5521_wait_enable_done(void)
 123 {
 124         /* it takes more 488 us to update ENABLE register */
 125         usleep_range(500, 600);
 126 }
 127
 128 static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
 129 {
 130         led->led_current = led_current;
 131         lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
 132                 led_current);
 133 }
 134
 135 static void lp5521_load_engine(struct lp55xx_chip *chip)
 136 {
 137         enum lp55xx_engine_index idx = chip->engine_idx;
 138         u8 mask[] = {
 139                 [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
 140                 [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
 141                 [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
 142         };
 143
 144         u8 val[] = {
 145                 [LP55XX_ENGINE_1] = LP5521_LOAD_R,
 146                 [LP55XX_ENGINE_2] = LP5521_LOAD_G,
 147                 [LP55XX_ENGINE_3] = LP5521_LOAD_B,
 148         };
 149
 150         lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]);
 151
 152         lp5521_wait_opmode_done();
 153 }
 154
 155 static void lp5521_stop_engine(struct lp55xx_chip *chip)
 156 {
 157         lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
 158         lp5521_wait_opmode_done();
 159 }
 160
 161 static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
 162 {
 163         int ret;
 164         u8 mode;
 165         u8 exec;
 166
 167         /* stop engine */
 168         if (!start) {
 169                 lp5521_stop_engine(chip);
 170                 lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 171                 lp5521_wait_opmode_done();
 172                 return;
 173         }
 174
 175         /*
 176          * To run the engine,
 177          * operation mode and enable register should updated at the same time
 178          */
 179
 180         ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode);
 181         if (ret)
 182                 return;
 183
 184         ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec);
 185         if (ret)
 186                 return;
 187
 188         /* change operation mode to RUN only when each engine is loading */
 189         if (LP5521_R_IS_LOADING(mode)) {
 190                 mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
 191                 exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
 192         }
 193
 194         if (LP5521_G_IS_LOADING(mode)) {
 195                 mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
 196                 exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
 197         }
 198
 199         if (LP5521_B_IS_LOADING(mode)) {
 200                 mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
 201                 exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
 202         }
 203
 204         lp55xx_write(chip, LP5521_REG_OP_MODE, mode);
 205         lp5521_wait_opmode_done();
 206
 207         lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
 208         lp5521_wait_enable_done();
 209 }
 210
 211 static int lp5521_update_program_memory(struct lp55xx_chip *chip,
 212                                         const u8 *data, size_t size)
 213 {
 214         enum lp55xx_engine_index idx = chip->engine_idx;
 215         u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
 216         u8 addr[] = {
 217                 [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
 218                 [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
 219                 [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
 220         };
 221         unsigned cmd;
 222         char c[3];
 223         int nrchars;
 224         int ret;
 225         int offset = 0;
 226         int i = 0;
 227
 228         while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
 229                 /* separate sscanfs because length is working only for %s */
 230                 ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 231                 if (ret != 1)
 232                         goto err;
 233
 234                 ret = sscanf(c, "%2x", &cmd);
 235                 if (ret != 1)
 236                         goto err;
 237
 238                 pattern[i] = (u8)cmd;
 239                 offset += nrchars;
 240                 i++;
 241         }
 242
 243         /* Each instruction is 16bit long. Check that length is even */
 244         if (i % 2)
 245                 goto err;
 246
 247         for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) {
 248                 ret = lp55xx_write(chip, addr[idx] + i, pattern[i]);
 249                 if (ret)
 250                         return -EINVAL;
 251         }
 252
 253         return size;
 254
 255 err:
 256         dev_err(&chip->cl->dev, "wrong pattern format\n");
 257         return -EINVAL;
 258 }
 259
 260 static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
 261 {
 262         const struct firmware *fw = chip->fw;
 263
 264         if (fw->size > LP5521_PROGRAM_LENGTH) {
 265                 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 266                         fw->size);
 267                 return;
 268         }
 269
 270         /*
 271          * Program momery sequence
 272          *  1) set engine mode to "LOAD"
 273          *  2) write firmware data into program memory
 274          */
 275
 276         lp5521_load_engine(chip);
 277         lp5521_update_program_memory(chip, fw->data, fw->size);
 278 }
 279
 280 static int lp5521_post_init_device(struct lp55xx_chip *chip)
 281 {
 282         int ret;
 283         u8 val;
 284
 285         /*
 286          * Make sure that the chip is reset by reading back the r channel
 287          * current reg. This is dummy read is required on some platforms -
 288          * otherwise further access to the R G B channels in the
 289          * LP5521_REG_ENABLE register will not have any effect - strange!
 290          */
 291         ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
 292         if (ret) {
 293                 dev_err(&chip->cl->dev, "error in resetting chip\n");
 294                 return ret;
 295         }
 296         if (val != LP5521_REG_R_CURR_DEFAULT) {
 297                 dev_err(&chip->cl->dev,
 298                         "unexpected data in register (expected 0x%x got 0x%x)\n",
 299                         LP5521_REG_R_CURR_DEFAULT, val);
 300                 ret = -EINVAL;
 301                 return ret;
 302         }
 303         usleep_range(10000, 20000);
 304
 305         /* Set all PWMs to direct control mode */
 306         ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
 307
 308         /* Update configuration for the clock setting */
 309         val = LP5521_DEFAULT_CFG;
 310         if (!lp55xx_is_extclk_used(chip))
 311                 val |= LP5521_CLK_INT;
 312
 313         ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
 314         if (ret)
 315                 return ret;
 316
 317         /* Initialize all channels PWM to zero -> leds off */
 318         lp55xx_write(chip, LP5521_REG_R_PWM, 0);
 319         lp55xx_write(chip, LP5521_REG_G_PWM, 0);
 320         lp55xx_write(chip, LP5521_REG_B_PWM, 0);
 321
 322         /* Set engines are set to run state when OP_MODE enables engines */
 323         ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
 324         if (ret)
 325                 return ret;
 326
 327         lp5521_wait_enable_done();
 328
 329         return 0;
 330 }
 331
 332 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
 333 {
 334         struct lp55xx_platform_data *pdata = chip->pdata;
 335         int ret;
 336         u8 status;
 337
 338         ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
 339         if (ret < 0)
 340                 return ret;
 341
 342         if (pdata->clock_mode != LP55XX_CLOCK_EXT)
 343                 return 0;
 344
 345         /* Check that ext clock is really in use if requested */
 346         if  ((status & LP5521_EXT_CLK_USED) == 0)
 347                 return -EIO;
 348
 349         return 0;
 350 }
 351
 352 static void lp5521_led_brightness_work(struct work_struct *work)
 353 {
 354         struct lp55xx_led *led = container_of(work, struct lp55xx_led,
 355                                               brightness_work);
 356         struct lp55xx_chip *chip = led->chip;
 357
 358         mutex_lock(&chip->lock);
 359         lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
 360                 led->brightness);
 361         mutex_unlock(&chip->lock);
 362 }
 363
 364 static ssize_t show_engine_mode(struct device *dev,
 365                                 struct device_attribute *attr,
 366                                 char *buf, int nr)
 367 {
 368         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 369         struct lp55xx_chip *chip = led->chip;
 370         enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
 371
 372         switch (mode) {
 373         case LP55XX_ENGINE_RUN:
 374                 return sprintf(buf, "run\n");
 375         case LP55XX_ENGINE_LOAD:
 376                 return sprintf(buf, "load\n");
 377         case LP55XX_ENGINE_DISABLED:
 378         default:
 379                 return sprintf(buf, "disabled\n");
 380         }
 381 }
 382 show_mode(1)
 383 show_mode(2)
 384 show_mode(3)
 385
 386 static ssize_t store_engine_mode(struct device *dev,
 387                                  struct device_attribute *attr,
 388                                  const char *buf, size_t len, int nr)
 389 {
 390         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 391         struct lp55xx_chip *chip = led->chip;
 392         struct lp55xx_engine *engine = &chip->engines[nr - 1];
 393
 394         mutex_lock(&chip->lock);
 395
 396         chip->engine_idx = nr;
 397
 398         if (!strncmp(buf, "run", 3)) {
 399                 lp5521_run_engine(chip, true);
 400                 engine->mode = LP55XX_ENGINE_RUN;
 401         } else if (!strncmp(buf, "load", 4)) {
 402                 lp5521_stop_engine(chip);
 403                 lp5521_load_engine(chip);
 404                 engine->mode = LP55XX_ENGINE_LOAD;
 405         } else if (!strncmp(buf, "disabled", 8)) {
 406                 lp5521_stop_engine(chip);
 407                 engine->mode = LP55XX_ENGINE_DISABLED;
 408         }
 409
 410         mutex_unlock(&chip->lock);
 411
 412         return len;
 413 }
 414 store_mode(1)
 415 store_mode(2)
 416 store_mode(3)
 417
 418 static ssize_t store_engine_load(struct device *dev,
 419                              struct device_attribute *attr,
 420                              const char *buf, size_t len, int nr)
 421 {
 422         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 423         struct lp55xx_chip *chip = led->chip;
 424         int ret;
 425
 426         mutex_lock(&chip->lock);
 427
 428         chip->engine_idx = nr;
 429         lp5521_load_engine(chip);
 430         ret = lp5521_update_program_memory(chip, buf, len);
 431
 432         mutex_unlock(&chip->lock);
 433
 434         return ret;
 435 }
 436 store_load(1)
 437 store_load(2)
 438 store_load(3)
 439
 440 static ssize_t lp5521_selftest(struct device *dev,
 441                                struct device_attribute *attr,
 442                                char *buf)
 443 {
 444         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
 445         struct lp55xx_chip *chip = led->chip;
 446         int ret;
 447
 448         mutex_lock(&chip->lock);
 449         ret = lp5521_run_selftest(chip, buf);
 450         mutex_unlock(&chip->lock);
 451
 452         return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK");
 453 }
 454
 455 /* device attributes */
 456 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
 457 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
 458 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
 459 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
 460 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
 461 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
 462 static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
 463
 464 static struct attribute *lp5521_attributes[] = {
 465         &dev_attr_engine1_mode.attr,
 466         &dev_attr_engine2_mode.attr,
 467         &dev_attr_engine3_mode.attr,
 468         &dev_attr_engine1_load.attr,
 469         &dev_attr_engine2_load.attr,
 470         &dev_attr_engine3_load.attr,
 471         &dev_attr_selftest.attr,
 472         NULL
 473 };
 474
 475 static const struct attribute_group lp5521_group = {
 476         .attrs = lp5521_attributes,
 477 };
 478
 479 /* Chip specific configurations */
 480 static struct lp55xx_device_config lp5521_cfg = {
 481         .reset = {
 482                 .addr = LP5521_REG_RESET,
 483                 .val  = LP5521_RESET,
 484         },
 485         .enable = {
 486                 .addr = LP5521_REG_ENABLE,
 487                 .val  = LP5521_ENABLE_DEFAULT,
 488         },
 489         .max_channel  = LP5521_MAX_LEDS,
 490         .post_init_device   = lp5521_post_init_device,
 491         .brightness_work_fn = lp5521_led_brightness_work,
 492         .set_led_current    = lp5521_set_led_current,
 493         .firmware_cb        = lp5521_firmware_loaded,
 494         .run_engine         = lp5521_run_engine,
 495         .dev_attr_group     = &lp5521_group,
 496 };
 497
 498 static int lp5521_probe(struct i2c_client *client,
 499                         const struct i2c_device_id *id)
 500 {
 501         int ret;
 502         struct lp55xx_chip *chip;
 503         struct lp55xx_led *led;
 504         struct lp55xx_platform_data *pdata;
 505         struct device_node *np = client->dev.of_node;
 506
 507         if (!dev_get_platdata(&client->dev)) {
 508                 if (np) {
 509                         ret = lp55xx_of_populate_pdata(&client->dev, np);
 510                         if (ret < 0)
 511                                 return ret;
 512                 } else {
 513                         dev_err(&client->dev, "no platform data\n");
 514                         return -EINVAL;
 515                 }
 516         }
 517         pdata = dev_get_platdata(&client->dev);
 518
 519         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 520         if (!chip)
 521                 return -ENOMEM;
 522
 523         led = devm_kzalloc(&client->dev,
 524                         sizeof(*led) * pdata->num_channels, GFP_KERNEL);
 525         if (!led)
 526                 return -ENOMEM;
 527
 528         chip->cl = client;
 529         chip->pdata = pdata;
 530         chip->cfg = &lp5521_cfg;
 531
 532         mutex_init(&chip->lock);
 533
 534         i2c_set_clientdata(client, led);
 535
 536         ret = lp55xx_init_device(chip);
 537         if (ret)
 538                 goto err_init;
 539
 540         dev_info(&client->dev, "%s programmable led chip found\n", id->name);
 541
 542         ret = lp55xx_register_leds(led, chip);
 543         if (ret)
 544                 goto err_register_leds;
 545
 546         ret = lp55xx_register_sysfs(chip);
 547         if (ret) {
 548                 dev_err(&client->dev, "registering sysfs failed\n");
 549                 goto err_register_sysfs;
 550         }
 551
 552         return 0;
 553
 554 err_register_sysfs:
 555         lp55xx_unregister_leds(led, chip);
 556 err_register_leds:
 557         lp55xx_deinit_device(chip);
 558 err_init:
 559         return ret;
 560 }
 561
 562 static int lp5521_remove(struct i2c_client *client)
 563 {
 564         struct lp55xx_led *led = i2c_get_clientdata(client);
 565         struct lp55xx_chip *chip = led->chip;
 566
 567         lp5521_stop_engine(chip);
 568         lp55xx_unregister_sysfs(chip);
 569         lp55xx_unregister_leds(led, chip);
 570         lp55xx_deinit_device(chip);
 571
 572         return 0;
 573 }
 574
 575 static const struct i2c_device_id lp5521_id[] = {
 576         { "lp5521", 0 }, /* Three channel chip */
 577         { }
 578 };
 579 MODULE_DEVICE_TABLE(i2c, lp5521_id);
 580
 581 #ifdef CONFIG_OF
 582 static const struct of_device_id of_lp5521_leds_match[] = {
 583         { .compatible = "national,lp5521", },
 584         {},
 585 };
 586
 587 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
 588 #endif
 589 static struct i2c_driver lp5521_driver = {
 590         .driver = {
 591                 .name   = "lp5521",
 592                 .of_match_table = of_match_ptr(of_lp5521_leds_match),
 593         },
 594         .probe          = lp5521_probe,
 595         .remove         = lp5521_remove,
 596         .id_table       = lp5521_id,
 597 };
 598
 599 module_i2c_driver(lp5521_driver);
 600
 601 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
 602 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 603 MODULE_DESCRIPTION("LP5521 LED engine");
 604 MODULE_LICENSE("GPL v2");