drivers/leds/flash/leds-mt6370-flash.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2023 Richtek Technology Corp.
   4  *
   5  * Authors:
   6  *   Alice Chen <alice_chen@richtek.com>
   7  *   ChiYuan Huang <cy_huang@richtek.com>
   8  */
   9
  10 #include <linux/bitops.h>
  11 #include <linux/delay.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/led-class-flash.h>
  16 #include <linux/module.h>
  17 #include <linux/mutex.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/property.h>
  20 #include <linux/regmap.h>
  21
  22 #include <media/v4l2-flash-led-class.h>
  23
  24 enum {
  25         MT6370_LED_FLASH1 = 0,
  26         MT6370_LED_FLASH2,
  27         MT6370_MAX_LEDS
  28 };
  29
  30 /* Virtual definition for multicolor */
  31
  32 #define MT6370_REG_FLEDEN               0x17E
  33 #define MT6370_REG_STRBTO               0x173
  34 #define MT6370_REG_CHGSTAT2             0x1D1
  35 #define MT6370_REG_FLEDSTAT1            0x1D9
  36 #define MT6370_REG_FLEDISTRB(_id)       (0x174 + 4 * (_id))
  37 #define MT6370_REG_FLEDITOR(_id)        (0x175 + 4 * (_id))
  38 #define MT6370_ITORCH_MASK              GENMASK(4, 0)
  39 #define MT6370_ISTROBE_MASK             GENMASK(6, 0)
  40 #define MT6370_STRBTO_MASK              GENMASK(6, 0)
  41 #define MT6370_TORCHEN_MASK             BIT(3)
  42 #define MT6370_STROBEN_MASK             BIT(2)
  43 #define MT6370_FLCSEN_MASK(_id)         BIT(MT6370_LED_FLASH2 - (_id))
  44 #define MT6370_FLCSEN_MASK_ALL          GENMASK(1, 0)
  45 #define MT6370_FLEDCHGVINOVP_MASK       BIT(3)
  46 #define MT6370_FLED1STRBTO_MASK         BIT(11)
  47 #define MT6370_FLED2STRBTO_MASK         BIT(10)
  48 #define MT6370_FLED1STRB_MASK           BIT(9)
  49 #define MT6370_FLED2STRB_MASK           BIT(8)
  50 #define MT6370_FLED1SHORT_MASK          BIT(7)
  51 #define MT6370_FLED2SHORT_MASK          BIT(6)
  52 #define MT6370_FLEDLVF_MASK             BIT(3)
  53
  54 #define MT6370_LED_JOINT                2
  55 #define MT6370_RANGE_FLED_REG           4
  56 #define MT6370_ITORCH_MIN_uA            25000
  57 #define MT6370_ITORCH_STEP_uA           12500
  58 #define MT6370_ITORCH_MAX_uA            400000
  59 #define MT6370_ITORCH_DOUBLE_MAX_uA     800000
  60 #define MT6370_ISTRB_MIN_uA             50000
  61 #define MT6370_ISTRB_STEP_uA            12500
  62 #define MT6370_ISTRB_MAX_uA             1500000
  63 #define MT6370_ISTRB_DOUBLE_MAX_uA      3000000
  64 #define MT6370_STRBTO_MIN_US            64000
  65 #define MT6370_STRBTO_STEP_US           32000
  66 #define MT6370_STRBTO_MAX_US            2432000
  67
  68 #define to_mt6370_led(ptr, member) container_of(ptr, struct mt6370_led, member)
  69
  70 struct mt6370_led {
  71         struct led_classdev_flash flash;
  72         struct v4l2_flash *v4l2_flash;
  73         struct mt6370_priv *priv;
  74         u8 led_no;
  75 };
  76
  77 struct mt6370_priv {
  78         struct regmap *regmap;
  79         struct mutex lock;
  80         unsigned int fled_strobe_used;
  81         unsigned int fled_torch_used;
  82         unsigned int leds_active;
  83         unsigned int leds_count;
  84         struct mt6370_led leds[] __counted_by(leds_count);
  85 };
  86
  87 static int mt6370_torch_brightness_set(struct led_classdev *lcdev, enum led_brightness level)
  88 {
  89         struct mt6370_led *led = to_mt6370_led(lcdev, flash.led_cdev);
  90         struct mt6370_priv *priv = led->priv;
  91         u32 led_enable_mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
  92                               MT6370_FLCSEN_MASK(led->led_no);
  93         u32 enable_mask = MT6370_TORCHEN_MASK | led_enable_mask;
  94         u32 val = level ? led_enable_mask : 0;
  95         u32 curr;
  96         int ret, i;
  97
  98         mutex_lock(&priv->lock);
  99
 100         /*
 101          * There is only one set of flash control logic, and this flag is used to check if 'strobe'
 102          * is currently being used.
 103          */
 104         if (priv->fled_strobe_used) {
 105                 dev_warn(lcdev->dev, "Please disable strobe first [%d]\n", priv->fled_strobe_used);
 106                 ret = -EBUSY;
 107                 goto unlock;
 108         }
 109
 110         if (level)
 111                 curr = priv->fled_torch_used | BIT(led->led_no);
 112         else
 113                 curr = priv->fled_torch_used & ~BIT(led->led_no);
 114
 115         if (curr)
 116                 val |= MT6370_TORCHEN_MASK;
 117
 118         if (level) {
 119                 level -= 1;
 120                 if (led->led_no == MT6370_LED_JOINT) {
 121                         u32 flevel[MT6370_MAX_LEDS];
 122
 123                         /*
 124                          * There're two flash channels in MT6370. If joint flash output is used,
 125                          * torch current will be averaged output from both channels.
 126                          */
 127                         flevel[0] = level / 2;
 128                         flevel[1] = level - flevel[0];
 129                         for (i = 0; i < MT6370_MAX_LEDS; i++) {
 130                                 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDITOR(i),
 131                                                          MT6370_ITORCH_MASK, flevel[i]);
 132                                 if (ret)
 133                                         goto unlock;
 134                         }
 135                 } else {
 136                         ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDITOR(led->led_no),
 137                                                  MT6370_ITORCH_MASK, level);
 138                         if (ret)
 139                                 goto unlock;
 140                 }
 141         }
 142
 143         ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask, val);
 144         if (ret)
 145                 goto unlock;
 146
 147         priv->fled_torch_used = curr;
 148
 149 unlock:
 150         mutex_unlock(&priv->lock);
 151         return ret;
 152 }
 153
 154 static int mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
 155 {
 156         /*
 157          * Because of the current spikes when turning on the flash, the brightness should be kept
 158          * by the LED framework. This empty function is used to prevent checking failure when
 159          * led_classdev_flash registers ops.
 160          */
 161         return 0;
 162 }
 163
 164 static int _mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
 165 {
 166         struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
 167         struct mt6370_priv *priv = led->priv;
 168         struct led_flash_setting *setting = &fl_cdev->brightness;
 169         u32 val = (brightness - setting->min) / setting->step;
 170         int ret, i;
 171
 172         if (led->led_no == MT6370_LED_JOINT) {
 173                 u32 flevel[MT6370_MAX_LEDS];
 174
 175                 /*
 176                  * There're two flash channels in MT6370. If joint flash output is used, storbe
 177                  * current will be averaged output from both channels.
 178                  */
 179                 flevel[0] = val / 2;
 180                 flevel[1] = val - flevel[0];
 181                 for (i = 0; i < MT6370_MAX_LEDS; i++) {
 182                         ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDISTRB(i),
 183                                                  MT6370_ISTROBE_MASK, flevel[i]);
 184                         if (ret)
 185                                 break;
 186                 }
 187         } else {
 188                 ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDISTRB(led->led_no),
 189                                          MT6370_ISTROBE_MASK, val);
 190         }
 191
 192         return ret;
 193 }
 194
 195 static int mt6370_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
 196 {
 197         struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
 198         struct mt6370_priv *priv = led->priv;
 199         struct led_classdev *lcdev = &fl_cdev->led_cdev;
 200         struct led_flash_setting *s = &fl_cdev->brightness;
 201         u32 led_enable_mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
 202                               MT6370_FLCSEN_MASK(led->led_no);
 203         u32 enable_mask = MT6370_STROBEN_MASK | led_enable_mask;
 204         u32 val = state ? led_enable_mask : 0;
 205         u32 curr;
 206         int ret;
 207
 208         mutex_lock(&priv->lock);
 209
 210         /*
 211          * There is only one set of flash control logic, and this flag is used to check if 'torch'
 212          * is currently being used.
 213          */
 214         if (priv->fled_torch_used) {
 215                 dev_warn(lcdev->dev, "Please disable torch first [0x%x]\n", priv->fled_torch_used);
 216                 ret = -EBUSY;
 217                 goto unlock;
 218         }
 219
 220         if (state)
 221                 curr = priv->fled_strobe_used | BIT(led->led_no);
 222         else
 223                 curr = priv->fled_strobe_used & ~BIT(led->led_no);
 224
 225         if (curr)
 226                 val |= MT6370_STROBEN_MASK;
 227
 228         ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask, val);
 229         if (ret) {
 230                 dev_err(lcdev->dev, "[%d] control current source %d fail\n", led->led_no, state);
 231                 goto unlock;
 232         }
 233
 234         /*
 235          * If the flash needs to turn on, configure the flash current to ramp up to the setting
 236          * value. Otherwise, always revert to the minimum one.
 237          */
 238         ret = _mt6370_flash_brightness_set(fl_cdev, state ? s->val : s->min);
 239         if (ret) {
 240                 dev_err(lcdev->dev, "[%d] Failed to set brightness\n", led->led_no);
 241                 goto unlock;
 242         }
 243
 244         /*
 245          * For the flash to turn on/off, we must wait for HW ramping up/down time 5ms/500us to
 246          * prevent the unexpected problem.
 247          */
 248         if (!priv->fled_strobe_used && curr)
 249                 usleep_range(5000, 6000);
 250         else if (priv->fled_strobe_used && !curr)
 251                 usleep_range(500, 600);
 252
 253         priv->fled_strobe_used = curr;
 254
 255 unlock:
 256         mutex_unlock(&priv->lock);
 257         return ret;
 258 }
 259
 260 static int mt6370_strobe_get(struct led_classdev_flash *fl_cdev, bool *state)
 261 {
 262         struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
 263         struct mt6370_priv *priv = led->priv;
 264
 265         mutex_lock(&priv->lock);
 266         *state = !!(priv->fled_strobe_used & BIT(led->led_no));
 267         mutex_unlock(&priv->lock);
 268
 269         return 0;
 270 }
 271
 272 static int mt6370_timeout_set(struct led_classdev_flash *fl_cdev, u32 timeout)
 273 {
 274         struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
 275         struct mt6370_priv *priv = led->priv;
 276         struct led_flash_setting *s = &fl_cdev->timeout;
 277         u32 val = (timeout - s->min) / s->step;
 278
 279         return regmap_update_bits(priv->regmap, MT6370_REG_STRBTO, MT6370_STRBTO_MASK, val);
 280 }
 281
 282 static int mt6370_fault_get(struct led_classdev_flash *fl_cdev, u32 *fault)
 283 {
 284         struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
 285         struct mt6370_priv *priv = led->priv;
 286         u16 fled_stat;
 287         unsigned int chg_stat, strobe_timeout_mask, fled_short_mask;
 288         u32 rfault = 0;
 289         int ret;
 290
 291         ret = regmap_read(priv->regmap, MT6370_REG_CHGSTAT2, &chg_stat);
 292         if (ret)
 293                 return ret;
 294
 295         ret = regmap_raw_read(priv->regmap, MT6370_REG_FLEDSTAT1, &fled_stat, sizeof(fled_stat));
 296         if (ret)
 297                 return ret;
 298
 299         switch (led->led_no) {
 300         case MT6370_LED_FLASH1:
 301                 strobe_timeout_mask = MT6370_FLED1STRBTO_MASK;
 302                 fled_short_mask = MT6370_FLED1SHORT_MASK;
 303                 break;
 304
 305         case MT6370_LED_FLASH2:
 306                 strobe_timeout_mask = MT6370_FLED2STRBTO_MASK;
 307                 fled_short_mask = MT6370_FLED2SHORT_MASK;
 308                 break;
 309
 310         case MT6370_LED_JOINT:
 311                 strobe_timeout_mask = MT6370_FLED1STRBTO_MASK | MT6370_FLED2STRBTO_MASK;
 312                 fled_short_mask = MT6370_FLED1SHORT_MASK | MT6370_FLED2SHORT_MASK;
 313                 break;
 314         default:
 315                 return -EINVAL;
 316         }
 317
 318         if (chg_stat & MT6370_FLEDCHGVINOVP_MASK)
 319                 rfault |= LED_FAULT_INPUT_VOLTAGE;
 320
 321         if (fled_stat & strobe_timeout_mask)
 322                 rfault |= LED_FAULT_TIMEOUT;
 323
 324         if (fled_stat & fled_short_mask)
 325                 rfault |= LED_FAULT_SHORT_CIRCUIT;
 326
 327         if (fled_stat & MT6370_FLEDLVF_MASK)
 328                 rfault |= LED_FAULT_UNDER_VOLTAGE;
 329
 330         *fault = rfault;
 331         return ret;
 332 }
 333
 334 static const struct led_flash_ops mt6370_flash_ops = {
 335         .flash_brightness_set = mt6370_flash_brightness_set,
 336         .strobe_set = mt6370_strobe_set,
 337         .strobe_get = mt6370_strobe_get,
 338         .timeout_set = mt6370_timeout_set,
 339         .fault_get = mt6370_fault_get,
 340 };
 341
 342 #if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
 343 static int mt6370_flash_external_strobe_set(struct v4l2_flash *v4l2_flash,
 344                                             bool enable)
 345 {
 346         struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
 347         struct mt6370_led *led = to_mt6370_led(flash, flash);
 348         struct mt6370_priv *priv = led->priv;
 349         u32 mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
 350                    MT6370_FLCSEN_MASK(led->led_no);
 351         u32 val = enable ? mask : 0;
 352         int ret;
 353
 354         mutex_lock(&priv->lock);
 355
 356         ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, mask, val);
 357         if (ret)
 358                 goto unlock;
 359
 360         if (enable)
 361                 priv->fled_strobe_used |= BIT(led->led_no);
 362         else
 363                 priv->fled_strobe_used &= ~BIT(led->led_no);
 364
 365 unlock:
 366         mutex_unlock(&priv->lock);
 367         return ret;
 368 }
 369
 370 static const struct v4l2_flash_ops v4l2_flash_ops = {
 371         .external_strobe_set = mt6370_flash_external_strobe_set,
 372 };
 373
 374 static void mt6370_init_v4l2_flash_config(struct mt6370_led *led, struct v4l2_flash_config *cfg)
 375 {
 376         struct led_classdev *lcdev;
 377         struct led_flash_setting *s = &cfg->intensity;
 378
 379         lcdev = &led->flash.led_cdev;
 380
 381         s->min = MT6370_ITORCH_MIN_uA;
 382         s->step = MT6370_ITORCH_STEP_uA;
 383         s->val = s->max = s->min + (lcdev->max_brightness - 1) * s->step;
 384
 385         cfg->has_external_strobe = 1;
 386         strscpy(cfg->dev_name, dev_name(lcdev->dev), sizeof(cfg->dev_name));
 387
 388         cfg->flash_faults = LED_FAULT_SHORT_CIRCUIT | LED_FAULT_TIMEOUT |
 389                             LED_FAULT_INPUT_VOLTAGE | LED_FAULT_UNDER_VOLTAGE;
 390 }
 391 #else
 392 static const struct v4l2_flash_ops v4l2_flash_ops;
 393 static void mt6370_init_v4l2_flash_config(struct mt6370_led *led, struct v4l2_flash_config *cfg)
 394 {
 395 }
 396 #endif
 397
 398 static void mt6370_v4l2_flash_release(void *v4l2_flash)
 399 {
 400         v4l2_flash_release(v4l2_flash);
 401 }
 402
 403 static int mt6370_led_register(struct device *parent, struct mt6370_led *led,
 404                                struct fwnode_handle *fwnode)
 405 {
 406         struct led_init_data init_data = { .fwnode = fwnode };
 407         struct v4l2_flash_config v4l2_config = {};
 408         int ret;
 409
 410         ret = devm_led_classdev_flash_register_ext(parent, &led->flash, &init_data);
 411         if (ret)
 412                 return dev_err_probe(parent, ret, "Couldn't register flash %d\n", led->led_no);
 413
 414         mt6370_init_v4l2_flash_config(led, &v4l2_config);
 415         led->v4l2_flash = v4l2_flash_init(parent, fwnode, &led->flash, &v4l2_flash_ops,
 416                                           &v4l2_config);
 417         if (IS_ERR(led->v4l2_flash))
 418                 return dev_err_probe(parent, PTR_ERR(led->v4l2_flash),
 419                                      "Failed to register %d v4l2 sd\n", led->led_no);
 420
 421         return devm_add_action_or_reset(parent, mt6370_v4l2_flash_release, led->v4l2_flash);
 422 }
 423
 424 static u32 mt6370_clamp(u32 val, u32 min, u32 max, u32 step)
 425 {
 426         u32 retval;
 427
 428         retval = clamp_val(val, min, max);
 429         if (step > 1)
 430                 retval = rounddown(retval - min, step) + min;
 431
 432         return retval;
 433 }
 434
 435 static int mt6370_init_flash_properties(struct device *dev, struct mt6370_led *led,
 436                                         struct fwnode_handle *fwnode)
 437 {
 438         struct led_classdev_flash *flash = &led->flash;
 439         struct led_classdev *lcdev = &flash->led_cdev;
 440         struct mt6370_priv *priv = led->priv;
 441         struct led_flash_setting *s;
 442         u32 sources[MT6370_MAX_LEDS];
 443         u32 max_ua, val;
 444         int i, ret, num;
 445
 446         num = fwnode_property_count_u32(fwnode, "led-sources");
 447         if (num < 1)
 448                 return dev_err_probe(dev, -EINVAL,
 449                                      "Not specified or wrong number of led-sources\n");
 450
 451         ret = fwnode_property_read_u32_array(fwnode, "led-sources", sources, num);
 452         if (ret)
 453                 return ret;
 454
 455         for (i = 0; i < num; i++) {
 456                 if (sources[i] >= MT6370_MAX_LEDS)
 457                         return -EINVAL;
 458                 if (priv->leds_active & BIT(sources[i]))
 459                         return -EINVAL;
 460                 priv->leds_active |= BIT(sources[i]);
 461         }
 462
 463         /* If both channels are specified in 'led-sources', joint flash output mode is used */
 464         led->led_no = num == 2 ? MT6370_LED_JOINT : sources[0];
 465
 466         max_ua = num == 2 ? MT6370_ITORCH_DOUBLE_MAX_uA : MT6370_ITORCH_MAX_uA;
 467         val = MT6370_ITORCH_MIN_uA;
 468         ret = fwnode_property_read_u32(fwnode, "led-max-microamp", &val);
 469         if (!ret)
 470                 val = mt6370_clamp(val, MT6370_ITORCH_MIN_uA, max_ua, MT6370_ITORCH_STEP_uA);
 471
 472         lcdev->max_brightness = (val - MT6370_ITORCH_MIN_uA) / MT6370_ITORCH_STEP_uA + 1;
 473         lcdev->brightness_set_blocking = mt6370_torch_brightness_set;
 474         lcdev->flags |= LED_DEV_CAP_FLASH;
 475
 476         max_ua = num == 2 ? MT6370_ISTRB_DOUBLE_MAX_uA : MT6370_ISTRB_MAX_uA;
 477         val = MT6370_ISTRB_MIN_uA;
 478         ret = fwnode_property_read_u32(fwnode, "flash-max-microamp", &val);
 479         if (!ret)
 480                 val = mt6370_clamp(val, MT6370_ISTRB_MIN_uA, max_ua, MT6370_ISTRB_STEP_uA);
 481
 482         s = &flash->brightness;
 483         s->min = MT6370_ISTRB_MIN_uA;
 484         s->step = MT6370_ISTRB_STEP_uA;
 485         s->val = s->max = val;
 486
 487         /* Always configure to the minimum level when off to prevent flash current spikes. */
 488         ret = _mt6370_flash_brightness_set(flash, s->min);
 489         if (ret)
 490                 return ret;
 491
 492         val = MT6370_STRBTO_MIN_US;
 493         ret = fwnode_property_read_u32(fwnode, "flash-max-timeout-us", &val);
 494         if (!ret)
 495                 val = mt6370_clamp(val, MT6370_STRBTO_MIN_US, MT6370_STRBTO_MAX_US,
 496                                    MT6370_STRBTO_STEP_US);
 497
 498         s = &flash->timeout;
 499         s->min = MT6370_STRBTO_MIN_US;
 500         s->step = MT6370_STRBTO_STEP_US;
 501         s->val = s->max = val;
 502
 503         flash->ops = &mt6370_flash_ops;
 504
 505         return 0;
 506 }
 507
 508 static int mt6370_led_probe(struct platform_device *pdev)
 509 {
 510         struct device *dev = &pdev->dev;
 511         struct mt6370_priv *priv;
 512         struct fwnode_handle *child;
 513         size_t count;
 514         int i = 0, ret;
 515
 516         count = device_get_child_node_count(dev);
 517         if (!count || count > MT6370_MAX_LEDS)
 518                 return dev_err_probe(dev, -EINVAL,
 519                        "No child node or node count over max led number %zu\n", count);
 520
 521         priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
 522         if (!priv)
 523                 return -ENOMEM;
 524
 525         priv->leds_count = count;
 526         mutex_init(&priv->lock);
 527
 528         priv->regmap = dev_get_regmap(dev->parent, NULL);
 529         if (!priv->regmap)
 530                 return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
 531
 532         device_for_each_child_node(dev, child) {
 533                 struct mt6370_led *led = priv->leds + i;
 534
 535                 led->priv = priv;
 536
 537                 ret = mt6370_init_flash_properties(dev, led, child);
 538                 if (ret) {
 539                         fwnode_handle_put(child);
 540                         return ret;
 541                 }
 542
 543                 ret = mt6370_led_register(dev, led, child);
 544                 if (ret) {
 545                         fwnode_handle_put(child);
 546                         return ret;
 547                 }
 548
 549                 i++;
 550         }
 551
 552         return 0;
 553 }
 554
 555 static const struct of_device_id mt6370_led_of_id[] = {
 556         { .compatible = "mediatek,mt6370-flashlight" },
 557         {}
 558 };
 559 MODULE_DEVICE_TABLE(of, mt6370_led_of_id);
 560
 561 static struct platform_driver mt6370_led_driver = {
 562         .driver = {
 563                 .name = "mt6370-flashlight",
 564                 .of_match_table = mt6370_led_of_id,
 565         },
 566         .probe = mt6370_led_probe,
 567 };
 568 module_platform_driver(mt6370_led_driver);
 569
 570 MODULE_AUTHOR("Alice Chen <alice_chen@richtek.com>");
 571 MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
 572 MODULE_DESCRIPTION("MT6370 FLASH LED Driver");
 573 MODULE_LICENSE("GPL");