drivers/leds/leds-blinkm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  leds-blinkm.c
   4  *  (c) Jan-Simon Möller (dl9pf@gmx.de)
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/slab.h>
   9 #include <linux/jiffies.h>
  10 #include <linux/i2c.h>
  11 #include <linux/err.h>
  12 #include <linux/mutex.h>
  13 #include <linux/sysfs.h>
  14 #include <linux/printk.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/leds.h>
  17 #include <linux/delay.h>
  18
  19 /* Addresses to scan - BlinkM is on 0x09 by default*/
  20 static const unsigned short normal_i2c[] = { 0x09, I2C_CLIENT_END };
  21
  22 static int blinkm_transfer_hw(struct i2c_client *client, int cmd);
  23 static int blinkm_test_run(struct i2c_client *client);
  24
  25 struct blinkm_led {
  26         struct i2c_client *i2c_client;
  27         struct led_classdev led_cdev;
  28         int id;
  29 };
  30
  31 #define cdev_to_blmled(c)          container_of(c, struct blinkm_led, led_cdev)
  32
  33 struct blinkm_data {
  34         struct i2c_client *i2c_client;
  35         struct mutex update_lock;
  36         /* used for led class interface */
  37         struct blinkm_led blinkm_leds[3];
  38         /* used for "blinkm" sysfs interface */
  39         u8 red;                 /* color red */
  40         u8 green;               /* color green */
  41         u8 blue;                /* color blue */
  42         /* next values to use for transfer */
  43         u8 next_red;                    /* color red */
  44         u8 next_green;          /* color green */
  45         u8 next_blue;           /* color blue */
  46         /* internal use */
  47         u8 args[7];             /* set of args for transmission */
  48         u8 i2c_addr;            /* i2c addr */
  49         u8 fw_ver;              /* firmware version */
  50         /* used, but not from userspace */
  51         u8 hue;                 /* HSB  hue */
  52         u8 saturation;          /* HSB  saturation */
  53         u8 brightness;          /* HSB  brightness */
  54         u8 next_hue;                    /* HSB  hue */
  55         u8 next_saturation;             /* HSB  saturation */
  56         u8 next_brightness;             /* HSB  brightness */
  57         /* currently unused / todo */
  58         u8 fade_speed;          /* fade speed     1 - 255 */
  59         s8 time_adjust;         /* time adjust -128 - 127 */
  60         u8 fade:1;              /* fade on = 1, off = 0 */
  61         u8 rand:1;              /* rand fade mode on = 1 */
  62         u8 script_id;           /* script ID */
  63         u8 script_repeats;      /* repeats of script */
  64         u8 script_startline;    /* line to start */
  65 };
  66
  67 /* Colors */
  68 #define RED   0
  69 #define GREEN 1
  70 #define BLUE  2
  71
  72 /* mapping command names to cmd chars - see datasheet */
  73 #define BLM_GO_RGB            0
  74 #define BLM_FADE_RGB          1
  75 #define BLM_FADE_HSB          2
  76 #define BLM_FADE_RAND_RGB     3
  77 #define BLM_FADE_RAND_HSB     4
  78 #define BLM_PLAY_SCRIPT       5
  79 #define BLM_STOP_SCRIPT       6
  80 #define BLM_SET_FADE_SPEED    7
  81 #define BLM_SET_TIME_ADJ      8
  82 #define BLM_GET_CUR_RGB       9
  83 #define BLM_WRITE_SCRIPT_LINE 10
  84 #define BLM_READ_SCRIPT_LINE  11
  85 #define BLM_SET_SCRIPT_LR     12        /* Length & Repeats */
  86 #define BLM_SET_ADDR          13
  87 #define BLM_GET_ADDR          14
  88 #define BLM_GET_FW_VER        15
  89 #define BLM_SET_STARTUP_PARAM 16
  90
  91 /* BlinkM Commands
  92  *  as extracted out of the datasheet:
  93  *
  94  *  cmdchar = command (ascii)
  95  *  cmdbyte = command in hex
  96  *  nr_args = number of arguments (to send)
  97  *  nr_ret  = number of return values (to read)
  98  *  dir = direction (0 = read, 1 = write, 2 = both)
  99  *
 100  */
 101 static const struct {
 102         char cmdchar;
 103         u8 cmdbyte;
 104         u8 nr_args;
 105         u8 nr_ret;
 106         u8 dir:2;
 107 } blinkm_cmds[17] = {
 108   /* cmdchar, cmdbyte, nr_args, nr_ret,  dir */
 109         { 'n', 0x6e, 3, 0, 1},
 110         { 'c', 0x63, 3, 0, 1},
 111         { 'h', 0x68, 3, 0, 1},
 112         { 'C', 0x43, 3, 0, 1},
 113         { 'H', 0x48, 3, 0, 1},
 114         { 'p', 0x70, 3, 0, 1},
 115         { 'o', 0x6f, 0, 0, 1},
 116         { 'f', 0x66, 1, 0, 1},
 117         { 't', 0x74, 1, 0, 1},
 118         { 'g', 0x67, 0, 3, 0},
 119         { 'W', 0x57, 7, 0, 1},
 120         { 'R', 0x52, 2, 5, 2},
 121         { 'L', 0x4c, 3, 0, 1},
 122         { 'A', 0x41, 4, 0, 1},
 123         { 'a', 0x61, 0, 1, 0},
 124         { 'Z', 0x5a, 0, 1, 0},
 125         { 'B', 0x42, 5, 0, 1},
 126 };
 127
 128 static ssize_t show_color_common(struct device *dev, char *buf, int color)
 129 {
 130         struct i2c_client *client;
 131         struct blinkm_data *data;
 132         int ret;
 133
 134         client = to_i2c_client(dev);
 135         data = i2c_get_clientdata(client);
 136
 137         ret = blinkm_transfer_hw(client, BLM_GET_CUR_RGB);
 138         if (ret < 0)
 139                 return ret;
 140         switch (color) {
 141         case RED:
 142                 return sysfs_emit(buf, "%02X\n", data->red);
 143         case GREEN:
 144                 return sysfs_emit(buf, "%02X\n", data->green);
 145         case BLUE:
 146                 return sysfs_emit(buf, "%02X\n", data->blue);
 147         default:
 148                 return -EINVAL;
 149         }
 150         return -EINVAL;
 151 }
 152
 153 static int store_color_common(struct device *dev, const char *buf, int color)
 154 {
 155         struct i2c_client *client;
 156         struct blinkm_data *data;
 157         int ret;
 158         u8 value;
 159
 160         client = to_i2c_client(dev);
 161         data = i2c_get_clientdata(client);
 162
 163         ret = kstrtou8(buf, 10, &value);
 164         if (ret < 0) {
 165                 dev_err(dev, "BlinkM: value too large!\n");
 166                 return ret;
 167         }
 168
 169         switch (color) {
 170         case RED:
 171                 data->next_red = value;
 172                 break;
 173         case GREEN:
 174                 data->next_green = value;
 175                 break;
 176         case BLUE:
 177                 data->next_blue = value;
 178                 break;
 179         default:
 180                 return -EINVAL;
 181         }
 182
 183         dev_dbg(dev, "next_red = %d, next_green = %d, next_blue = %d\n",
 184                         data->next_red, data->next_green, data->next_blue);
 185
 186         /* if mode ... */
 187         ret = blinkm_transfer_hw(client, BLM_GO_RGB);
 188         if (ret < 0) {
 189                 dev_err(dev, "BlinkM: can't set RGB\n");
 190                 return ret;
 191         }
 192         return 0;
 193 }
 194
 195 static ssize_t red_show(struct device *dev, struct device_attribute *attr,
 196                         char *buf)
 197 {
 198         return show_color_common(dev, buf, RED);
 199 }
 200
 201 static ssize_t red_store(struct device *dev, struct device_attribute *attr,
 202                          const char *buf, size_t count)
 203 {
 204         int ret;
 205
 206         ret = store_color_common(dev, buf, RED);
 207         if (ret < 0)
 208                 return ret;
 209         return count;
 210 }
 211
 212 static DEVICE_ATTR_RW(red);
 213
 214 static ssize_t green_show(struct device *dev, struct device_attribute *attr,
 215                           char *buf)
 216 {
 217         return show_color_common(dev, buf, GREEN);
 218 }
 219
 220 static ssize_t green_store(struct device *dev, struct device_attribute *attr,
 221                            const char *buf, size_t count)
 222 {
 223
 224         int ret;
 225
 226         ret = store_color_common(dev, buf, GREEN);
 227         if (ret < 0)
 228                 return ret;
 229         return count;
 230 }
 231
 232 static DEVICE_ATTR_RW(green);
 233
 234 static ssize_t blue_show(struct device *dev, struct device_attribute *attr,
 235                          char *buf)
 236 {
 237         return show_color_common(dev, buf, BLUE);
 238 }
 239
 240 static ssize_t blue_store(struct device *dev, struct device_attribute *attr,
 241                           const char *buf, size_t count)
 242 {
 243         int ret;
 244
 245         ret = store_color_common(dev, buf, BLUE);
 246         if (ret < 0)
 247                 return ret;
 248         return count;
 249 }
 250
 251 static DEVICE_ATTR_RW(blue);
 252
 253 static ssize_t test_show(struct device *dev, struct device_attribute *attr,
 254                          char *buf)
 255 {
 256         return sysfs_emit(buf,
 257                          "#Write into test to start test sequence!#\n");
 258 }
 259
 260 static ssize_t test_store(struct device *dev, struct device_attribute *attr,
 261                           const char *buf, size_t count)
 262 {
 263
 264         struct i2c_client *client;
 265         int ret;
 266         client = to_i2c_client(dev);
 267
 268         /*test */
 269         ret = blinkm_test_run(client);
 270         if (ret < 0)
 271                 return ret;
 272
 273         return count;
 274 }
 275
 276 static DEVICE_ATTR_RW(test);
 277
 278 /* TODO: HSB, fade, timeadj, script ... */
 279
 280 static struct attribute *blinkm_attrs[] = {
 281         &dev_attr_red.attr,
 282         &dev_attr_green.attr,
 283         &dev_attr_blue.attr,
 284         &dev_attr_test.attr,
 285         NULL,
 286 };
 287
 288 static const struct attribute_group blinkm_group = {
 289         .name = "blinkm",
 290         .attrs = blinkm_attrs,
 291 };
 292
 293 static int blinkm_write(struct i2c_client *client, int cmd, u8 *arg)
 294 {
 295         int result;
 296         int i;
 297         int arglen = blinkm_cmds[cmd].nr_args;
 298         /* write out cmd to blinkm - always / default step */
 299         result = i2c_smbus_write_byte(client, blinkm_cmds[cmd].cmdbyte);
 300         if (result < 0)
 301                 return result;
 302         /* no args to write out */
 303         if (arglen == 0)
 304                 return 0;
 305
 306         for (i = 0; i < arglen; i++) {
 307                 /* repeat for arglen */
 308                 result = i2c_smbus_write_byte(client, arg[i]);
 309                 if (result < 0)
 310                         return result;
 311         }
 312         return 0;
 313 }
 314
 315 static int blinkm_read(struct i2c_client *client, int cmd, u8 *arg)
 316 {
 317         int result;
 318         int i;
 319         int retlen = blinkm_cmds[cmd].nr_ret;
 320         for (i = 0; i < retlen; i++) {
 321                 /* repeat for retlen */
 322                 result = i2c_smbus_read_byte(client);
 323                 if (result < 0)
 324                         return result;
 325                 arg[i] = result;
 326         }
 327
 328         return 0;
 329 }
 330
 331 static int blinkm_transfer_hw(struct i2c_client *client, int cmd)
 332 {
 333         /* the protocol is simple but non-standard:
 334          * e.g.  cmd 'g' (= 0x67) for "get device address"
 335          * - which defaults to 0x09 - would be the sequence:
 336          *   a) write 0x67 to the device (byte write)
 337          *   b) read the value (0x09) back right after (byte read)
 338          *
 339          * Watch out for "unfinished" sequences (i.e. not enough reads
 340          * or writes after a command. It will make the blinkM misbehave.
 341          * Sequence is key here.
 342          */
 343
 344         /* args / return are in private data struct */
 345         struct blinkm_data *data = i2c_get_clientdata(client);
 346
 347         /* We start hardware transfers which are not to be
 348          * mixed with other commands. Aquire a lock now. */
 349         if (mutex_lock_interruptible(&data->update_lock) < 0)
 350                 return -EAGAIN;
 351
 352         /* switch cmd - usually write before reads */
 353         switch (cmd) {
 354         case BLM_FADE_RAND_RGB:
 355         case BLM_GO_RGB:
 356         case BLM_FADE_RGB:
 357                 data->args[0] = data->next_red;
 358                 data->args[1] = data->next_green;
 359                 data->args[2] = data->next_blue;
 360                 blinkm_write(client, cmd, data->args);
 361                 data->red = data->args[0];
 362                 data->green = data->args[1];
 363                 data->blue = data->args[2];
 364                 break;
 365         case BLM_FADE_HSB:
 366         case BLM_FADE_RAND_HSB:
 367                 data->args[0] = data->next_hue;
 368                 data->args[1] = data->next_saturation;
 369                 data->args[2] = data->next_brightness;
 370                 blinkm_write(client, cmd, data->args);
 371                 data->hue = data->next_hue;
 372                 data->saturation = data->next_saturation;
 373                 data->brightness = data->next_brightness;
 374                 break;
 375         case BLM_PLAY_SCRIPT:
 376                 data->args[0] = data->script_id;
 377                 data->args[1] = data->script_repeats;
 378                 data->args[2] = data->script_startline;
 379                 blinkm_write(client, cmd, data->args);
 380                 break;
 381         case BLM_STOP_SCRIPT:
 382                 blinkm_write(client, cmd, NULL);
 383                 break;
 384         case BLM_GET_CUR_RGB:
 385                 data->args[0] = data->red;
 386                 data->args[1] = data->green;
 387                 data->args[2] = data->blue;
 388                 blinkm_write(client, cmd, NULL);
 389                 blinkm_read(client, cmd, data->args);
 390                 data->red = data->args[0];
 391                 data->green = data->args[1];
 392                 data->blue = data->args[2];
 393                 break;
 394         case BLM_GET_ADDR:
 395                 data->args[0] = data->i2c_addr;
 396                 blinkm_write(client, cmd, NULL);
 397                 blinkm_read(client, cmd, data->args);
 398                 data->i2c_addr = data->args[0];
 399                 break;
 400         case BLM_SET_TIME_ADJ:
 401         case BLM_SET_FADE_SPEED:
 402         case BLM_READ_SCRIPT_LINE:
 403         case BLM_WRITE_SCRIPT_LINE:
 404         case BLM_SET_SCRIPT_LR:
 405         case BLM_SET_ADDR:
 406         case BLM_GET_FW_VER:
 407         case BLM_SET_STARTUP_PARAM:
 408                 dev_err(&client->dev,
 409                                 "BlinkM: cmd %d not implemented yet.\n", cmd);
 410                 break;
 411         default:
 412                 dev_err(&client->dev, "BlinkM: unknown command %d\n", cmd);
 413                 mutex_unlock(&data->update_lock);
 414                 return -EINVAL;
 415         }                       /* end switch(cmd) */
 416
 417         /* transfers done, unlock */
 418         mutex_unlock(&data->update_lock);
 419         return 0;
 420 }
 421
 422 static int blinkm_led_common_set(struct led_classdev *led_cdev,
 423                                  enum led_brightness value, int color)
 424 {
 425         /* led_brightness is 0, 127 or 255 - we just use it here as-is */
 426         struct blinkm_led *led = cdev_to_blmled(led_cdev);
 427         struct blinkm_data *data = i2c_get_clientdata(led->i2c_client);
 428
 429         switch (color) {
 430         case RED:
 431                 /* bail out if there's no change */
 432                 if (data->next_red == (u8) value)
 433                         return 0;
 434                 data->next_red = (u8) value;
 435                 break;
 436         case GREEN:
 437                 /* bail out if there's no change */
 438                 if (data->next_green == (u8) value)
 439                         return 0;
 440                 data->next_green = (u8) value;
 441                 break;
 442         case BLUE:
 443                 /* bail out if there's no change */
 444                 if (data->next_blue == (u8) value)
 445                         return 0;
 446                 data->next_blue = (u8) value;
 447                 break;
 448
 449         default:
 450                 dev_err(&led->i2c_client->dev, "BlinkM: unknown color.\n");
 451                 return -EINVAL;
 452         }
 453
 454         blinkm_transfer_hw(led->i2c_client, BLM_GO_RGB);
 455         dev_dbg(&led->i2c_client->dev,
 456                         "# DONE # next_red = %d, next_green = %d,"
 457                         " next_blue = %d\n",
 458                         data->next_red, data->next_green,
 459                         data->next_blue);
 460         return 0;
 461 }
 462
 463 static int blinkm_led_red_set(struct led_classdev *led_cdev,
 464                                enum led_brightness value)
 465 {
 466         return blinkm_led_common_set(led_cdev, value, RED);
 467 }
 468
 469 static int blinkm_led_green_set(struct led_classdev *led_cdev,
 470                                  enum led_brightness value)
 471 {
 472         return blinkm_led_common_set(led_cdev, value, GREEN);
 473 }
 474
 475 static int blinkm_led_blue_set(struct led_classdev *led_cdev,
 476                                 enum led_brightness value)
 477 {
 478         return blinkm_led_common_set(led_cdev, value, BLUE);
 479 }
 480
 481 static void blinkm_init_hw(struct i2c_client *client)
 482 {
 483         blinkm_transfer_hw(client, BLM_STOP_SCRIPT);
 484         blinkm_transfer_hw(client, BLM_GO_RGB);
 485 }
 486
 487 static int blinkm_test_run(struct i2c_client *client)
 488 {
 489         int ret;
 490         struct blinkm_data *data = i2c_get_clientdata(client);
 491
 492         data->next_red = 0x01;
 493         data->next_green = 0x05;
 494         data->next_blue = 0x10;
 495         ret = blinkm_transfer_hw(client, BLM_GO_RGB);
 496         if (ret < 0)
 497                 return ret;
 498         msleep(2000);
 499
 500         data->next_red = 0x25;
 501         data->next_green = 0x10;
 502         data->next_blue = 0x31;
 503         ret = blinkm_transfer_hw(client, BLM_FADE_RGB);
 504         if (ret < 0)
 505                 return ret;
 506         msleep(2000);
 507
 508         data->next_hue = 0x50;
 509         data->next_saturation = 0x10;
 510         data->next_brightness = 0x20;
 511         ret = blinkm_transfer_hw(client, BLM_FADE_HSB);
 512         if (ret < 0)
 513                 return ret;
 514         msleep(2000);
 515
 516         return 0;
 517 }
 518
 519 /* Return 0 if detection is successful, -ENODEV otherwise */
 520 static int blinkm_detect(struct i2c_client *client, struct i2c_board_info *info)
 521 {
 522         struct i2c_adapter *adapter = client->adapter;
 523         int ret;
 524         int count = 99;
 525         u8 tmpargs[7];
 526
 527         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 528                                      | I2C_FUNC_SMBUS_WORD_DATA
 529                                      | I2C_FUNC_SMBUS_WRITE_BYTE))
 530                 return -ENODEV;
 531
 532         /* Now, we do the remaining detection. Simple for now. */
 533         /* We might need more guards to protect other i2c slaves */
 534
 535         /* make sure the blinkM is balanced (read/writes) */
 536         while (count > 0) {
 537                 ret = blinkm_write(client, BLM_GET_ADDR, NULL);
 538                 if (ret)
 539                         return ret;
 540                 usleep_range(5000, 10000);
 541                 ret = blinkm_read(client, BLM_GET_ADDR, tmpargs);
 542                 if (ret)
 543                         return ret;
 544                 usleep_range(5000, 10000);
 545                 if (tmpargs[0] == 0x09)
 546                         count = 0;
 547                 count--;
 548         }
 549
 550         /* Step 1: Read BlinkM address back  -  cmd_char 'a' */
 551         ret = blinkm_write(client, BLM_GET_ADDR, NULL);
 552         if (ret < 0)
 553                 return ret;
 554         usleep_range(20000, 30000);     /* allow a small delay */
 555         ret = blinkm_read(client, BLM_GET_ADDR, tmpargs);
 556         if (ret < 0)
 557                 return ret;
 558
 559         if (tmpargs[0] != 0x09) {
 560                 dev_err(&client->dev, "enodev DEV ADDR = 0x%02X\n", tmpargs[0]);
 561                 return -ENODEV;
 562         }
 563
 564         strscpy(info->type, "blinkm", I2C_NAME_SIZE);
 565         return 0;
 566 }
 567
 568 static int blinkm_probe(struct i2c_client *client)
 569 {
 570         struct blinkm_data *data;
 571         struct blinkm_led *led[3];
 572         int err, i;
 573         char blinkm_led_name[28];
 574
 575         data = devm_kzalloc(&client->dev,
 576                         sizeof(struct blinkm_data), GFP_KERNEL);
 577         if (!data) {
 578                 err = -ENOMEM;
 579                 goto exit;
 580         }
 581
 582         data->i2c_addr = 0x08;
 583         /* i2c addr  - use fake addr of 0x08 initially (real is 0x09) */
 584         data->fw_ver = 0xfe;
 585         /* firmware version - use fake until we read real value
 586          * (currently broken - BlinkM confused!) */
 587         data->script_id = 0x01;
 588         data->i2c_client = client;
 589
 590         i2c_set_clientdata(client, data);
 591         mutex_init(&data->update_lock);
 592
 593         /* Register sysfs hooks */
 594         err = sysfs_create_group(&client->dev.kobj, &blinkm_group);
 595         if (err < 0) {
 596                 dev_err(&client->dev, "couldn't register sysfs group\n");
 597                 goto exit;
 598         }
 599
 600         for (i = 0; i < 3; i++) {
 601                 /* RED = 0, GREEN = 1, BLUE = 2 */
 602                 led[i] = &data->blinkm_leds[i];
 603                 led[i]->i2c_client = client;
 604                 led[i]->id = i;
 605                 led[i]->led_cdev.max_brightness = 255;
 606                 led[i]->led_cdev.flags = LED_CORE_SUSPENDRESUME;
 607                 switch (i) {
 608                 case RED:
 609                         snprintf(blinkm_led_name, sizeof(blinkm_led_name),
 610                                          "blinkm-%d-%d-red",
 611                                          client->adapter->nr,
 612                                          client->addr);
 613                         led[i]->led_cdev.name = blinkm_led_name;
 614                         led[i]->led_cdev.brightness_set_blocking =
 615                                                         blinkm_led_red_set;
 616                         err = led_classdev_register(&client->dev,
 617                                                     &led[i]->led_cdev);
 618                         if (err < 0) {
 619                                 dev_err(&client->dev,
 620                                         "couldn't register LED %s\n",
 621                                         led[i]->led_cdev.name);
 622                                 goto failred;
 623                         }
 624                         break;
 625                 case GREEN:
 626                         snprintf(blinkm_led_name, sizeof(blinkm_led_name),
 627                                          "blinkm-%d-%d-green",
 628                                          client->adapter->nr,
 629                                          client->addr);
 630                         led[i]->led_cdev.name = blinkm_led_name;
 631                         led[i]->led_cdev.brightness_set_blocking =
 632                                                         blinkm_led_green_set;
 633                         err = led_classdev_register(&client->dev,
 634                                                     &led[i]->led_cdev);
 635                         if (err < 0) {
 636                                 dev_err(&client->dev,
 637                                         "couldn't register LED %s\n",
 638                                         led[i]->led_cdev.name);
 639                                 goto failgreen;
 640                         }
 641                         break;
 642                 case BLUE:
 643                         snprintf(blinkm_led_name, sizeof(blinkm_led_name),
 644                                          "blinkm-%d-%d-blue",
 645                                          client->adapter->nr,
 646                                          client->addr);
 647                         led[i]->led_cdev.name = blinkm_led_name;
 648                         led[i]->led_cdev.brightness_set_blocking =
 649                                                         blinkm_led_blue_set;
 650                         err = led_classdev_register(&client->dev,
 651                                                     &led[i]->led_cdev);
 652                         if (err < 0) {
 653                                 dev_err(&client->dev,
 654                                         "couldn't register LED %s\n",
 655                                         led[i]->led_cdev.name);
 656                                 goto failblue;
 657                         }
 658                         break;
 659                 }               /* end switch */
 660         }                       /* end for */
 661
 662         /* Initialize the blinkm */
 663         blinkm_init_hw(client);
 664
 665         return 0;
 666
 667 failblue:
 668         led_classdev_unregister(&led[GREEN]->led_cdev);
 669
 670 failgreen:
 671         led_classdev_unregister(&led[RED]->led_cdev);
 672
 673 failred:
 674         sysfs_remove_group(&client->dev.kobj, &blinkm_group);
 675 exit:
 676         return err;
 677 }
 678
 679 static void blinkm_remove(struct i2c_client *client)
 680 {
 681         struct blinkm_data *data = i2c_get_clientdata(client);
 682         int ret = 0;
 683         int i;
 684
 685         /* make sure no workqueue entries are pending */
 686         for (i = 0; i < 3; i++)
 687                 led_classdev_unregister(&data->blinkm_leds[i].led_cdev);
 688
 689         /* reset rgb */
 690         data->next_red = 0x00;
 691         data->next_green = 0x00;
 692         data->next_blue = 0x00;
 693         ret = blinkm_transfer_hw(client, BLM_FADE_RGB);
 694         if (ret < 0)
 695                 dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
 696
 697         /* reset hsb */
 698         data->next_hue = 0x00;
 699         data->next_saturation = 0x00;
 700         data->next_brightness = 0x00;
 701         ret = blinkm_transfer_hw(client, BLM_FADE_HSB);
 702         if (ret < 0)
 703                 dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
 704
 705         /* red fade to off */
 706         data->next_red = 0xff;
 707         ret = blinkm_transfer_hw(client, BLM_GO_RGB);
 708         if (ret < 0)
 709                 dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
 710
 711         /* off */
 712         data->next_red = 0x00;
 713         ret = blinkm_transfer_hw(client, BLM_FADE_RGB);
 714         if (ret < 0)
 715                 dev_err(&client->dev, "Failure in blinkm_remove ignored. Continuing.\n");
 716
 717         sysfs_remove_group(&client->dev.kobj, &blinkm_group);
 718 }
 719
 720 static const struct i2c_device_id blinkm_id[] = {
 721         {"blinkm", 0},
 722         {}
 723 };
 724
 725 MODULE_DEVICE_TABLE(i2c, blinkm_id);
 726
 727   /* This is the driver that will be inserted */
 728 static struct i2c_driver blinkm_driver = {
 729         .class = I2C_CLASS_HWMON,
 730         .driver = {
 731                    .name = "blinkm",
 732                    },
 733         .probe = blinkm_probe,
 734         .remove = blinkm_remove,
 735         .id_table = blinkm_id,
 736         .detect = blinkm_detect,
 737         .address_list = normal_i2c,
 738 };
 739
 740 module_i2c_driver(blinkm_driver);
 741
 742 MODULE_AUTHOR("Jan-Simon Moeller <dl9pf@gmx.de>");
 743 MODULE_DESCRIPTION("BlinkM RGB LED driver");
 744 MODULE_LICENSE("GPL");
 745