drivers/leds/leds-lm3692x.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // TI LM3692x LED chip family driver
   3 // Copyright (C) 2017-18 Texas Instruments Incorporated - https://www.ti.com/
   4
   5 #include <linux/gpio/consumer.h>
   6 #include <linux/i2c.h>
   7 #include <linux/init.h>
   8 #include <linux/leds.h>
   9 #include <linux/log2.h>
  10 #include <linux/mod_devicetable.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <linux/regmap.h>
  14 #include <linux/regulator/consumer.h>
  15 #include <linux/slab.h>
  16
  17 #define LM36922_MODEL   0
  18 #define LM36923_MODEL   1
  19
  20 #define LM3692X_REV             0x0
  21 #define LM3692X_RESET           0x1
  22 #define LM3692X_EN              0x10
  23 #define LM3692X_BRT_CTRL        0x11
  24 #define LM3692X_PWM_CTRL        0x12
  25 #define LM3692X_BOOST_CTRL      0x13
  26 #define LM3692X_AUTO_FREQ_HI    0x15
  27 #define LM3692X_AUTO_FREQ_LO    0x16
  28 #define LM3692X_BL_ADJ_THRESH   0x17
  29 #define LM3692X_BRT_LSB         0x18
  30 #define LM3692X_BRT_MSB         0x19
  31 #define LM3692X_FAULT_CTRL      0x1e
  32 #define LM3692X_FAULT_FLAGS     0x1f
  33
  34 #define LM3692X_SW_RESET        BIT(0)
  35 #define LM3692X_DEVICE_EN       BIT(0)
  36 #define LM3692X_LED1_EN         BIT(1)
  37 #define LM3692X_LED2_EN         BIT(2)
  38 #define LM36923_LED3_EN         BIT(3)
  39 #define LM3692X_ENABLE_MASK     (LM3692X_DEVICE_EN | LM3692X_LED1_EN | \
  40                                  LM3692X_LED2_EN | LM36923_LED3_EN)
  41
  42 /* Brightness Control Bits */
  43 #define LM3692X_BL_ADJ_POL      BIT(0)
  44 #define LM3692X_RAMP_RATE_125us 0x00
  45 #define LM3692X_RAMP_RATE_250us BIT(1)
  46 #define LM3692X_RAMP_RATE_500us BIT(2)
  47 #define LM3692X_RAMP_RATE_1ms   (BIT(1) | BIT(2))
  48 #define LM3692X_RAMP_RATE_2ms   BIT(3)
  49 #define LM3692X_RAMP_RATE_4ms   (BIT(3) | BIT(1))
  50 #define LM3692X_RAMP_RATE_8ms   (BIT(2) | BIT(3))
  51 #define LM3692X_RAMP_RATE_16ms  (BIT(1) | BIT(2) | BIT(3))
  52 #define LM3692X_RAMP_EN         BIT(4)
  53 #define LM3692X_BRHT_MODE_REG   0x00
  54 #define LM3692X_BRHT_MODE_PWM   BIT(5)
  55 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
  56 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
  57 #define LM3692X_MAP_MODE_EXP    BIT(7)
  58
  59 /* PWM Register Bits */
  60 #define LM3692X_PWM_FILTER_100  BIT(0)
  61 #define LM3692X_PWM_FILTER_150  BIT(1)
  62 #define LM3692X_PWM_FILTER_200  (BIT(0) | BIT(1))
  63 #define LM3692X_PWM_HYSTER_1LSB BIT(2)
  64 #define LM3692X_PWM_HYSTER_2LSB BIT(3)
  65 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
  66 #define LM3692X_PWM_HYSTER_4LSB BIT(4)
  67 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
  68 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
  69 #define LM3692X_PWM_POLARITY    BIT(5)
  70 #define LM3692X_PWM_SAMP_4MHZ   BIT(6)
  71 #define LM3692X_PWM_SAMP_24MHZ  BIT(7)
  72
  73 /* Boost Control Bits */
  74 #define LM3692X_OCP_PROT_1A     BIT(0)
  75 #define LM3692X_OCP_PROT_1_25A  BIT(1)
  76 #define LM3692X_OCP_PROT_1_5A   (BIT(0) | BIT(1))
  77 #define LM3692X_OVP_21V         BIT(2)
  78 #define LM3692X_OVP_25V         BIT(3)
  79 #define LM3692X_OVP_29V         (BIT(2) | BIT(3))
  80 #define LM3692X_MIN_IND_22UH    BIT(4)
  81 #define LM3692X_BOOST_SW_1MHZ   BIT(5)
  82 #define LM3692X_BOOST_SW_NO_SHIFT       BIT(6)
  83
  84 /* Fault Control Bits */
  85 #define LM3692X_FAULT_CTRL_OVP BIT(0)
  86 #define LM3692X_FAULT_CTRL_OCP BIT(1)
  87 #define LM3692X_FAULT_CTRL_TSD BIT(2)
  88 #define LM3692X_FAULT_CTRL_OPEN BIT(3)
  89
  90 /* Fault Flag Bits */
  91 #define LM3692X_FAULT_FLAG_OVP BIT(0)
  92 #define LM3692X_FAULT_FLAG_OCP BIT(1)
  93 #define LM3692X_FAULT_FLAG_TSD BIT(2)
  94 #define LM3692X_FAULT_FLAG_SHRT BIT(3)
  95 #define LM3692X_FAULT_FLAG_OPEN BIT(4)
  96
  97 /**
  98  * struct lm3692x_led
  99  * @lock: Lock for reading/writing the device
 100  * @client: Pointer to the I2C client
 101  * @led_dev: LED class device pointer
 102  * @regmap: Devices register map
 103  * @enable_gpio: VDDIO/EN gpio to enable communication interface
 104  * @regulator: LED supply regulator pointer
 105  * @led_enable: LED sync to be enabled
 106  * @model_id: Current device model ID enumerated
 107  */
 108 struct lm3692x_led {
 109         struct mutex lock;
 110         struct i2c_client *client;
 111         struct led_classdev led_dev;
 112         struct regmap *regmap;
 113         struct gpio_desc *enable_gpio;
 114         struct regulator *regulator;
 115         int led_enable;
 116         int model_id;
 117
 118         u8 boost_ctrl, brightness_ctrl;
 119         bool enabled;
 120 };
 121
 122 static const struct reg_default lm3692x_reg_defs[] = {
 123         {LM3692X_EN, 0xf},
 124         {LM3692X_BRT_CTRL, 0x61},
 125         {LM3692X_PWM_CTRL, 0x73},
 126         {LM3692X_BOOST_CTRL, 0x6f},
 127         {LM3692X_AUTO_FREQ_HI, 0x0},
 128         {LM3692X_AUTO_FREQ_LO, 0x0},
 129         {LM3692X_BL_ADJ_THRESH, 0x0},
 130         {LM3692X_BRT_LSB, 0x7},
 131         {LM3692X_BRT_MSB, 0xff},
 132         {LM3692X_FAULT_CTRL, 0x7},
 133 };
 134
 135 static const struct regmap_config lm3692x_regmap_config = {
 136         .reg_bits = 8,
 137         .val_bits = 8,
 138
 139         .max_register = LM3692X_FAULT_FLAGS,
 140         .reg_defaults = lm3692x_reg_defs,
 141         .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
 142         .cache_type = REGCACHE_RBTREE,
 143 };
 144
 145 static int lm3692x_fault_check(struct lm3692x_led *led)
 146 {
 147         int ret;
 148         unsigned int read_buf;
 149
 150         ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 151         if (ret)
 152                 return ret;
 153
 154         if (read_buf)
 155                 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
 156
 157         /* The first read may clear the fault.  Check again to see if the fault
 158          * still exits and return that value.
 159          */
 160         regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 161         if (read_buf)
 162                 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
 163                         read_buf);
 164
 165         return read_buf;
 166 }
 167
 168 static int lm3692x_leds_enable(struct lm3692x_led *led)
 169 {
 170         int enable_state;
 171         int ret, reg_ret;
 172
 173         if (led->enabled)
 174                 return 0;
 175
 176         if (led->regulator) {
 177                 ret = regulator_enable(led->regulator);
 178                 if (ret) {
 179                         dev_err(&led->client->dev,
 180                                 "Failed to enable regulator: %d\n", ret);
 181                         return ret;
 182                 }
 183         }
 184
 185         if (led->enable_gpio)
 186                 gpiod_direction_output(led->enable_gpio, 1);
 187
 188         ret = lm3692x_fault_check(led);
 189         if (ret) {
 190                 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
 191                         ret);
 192                 goto out;
 193         }
 194
 195         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
 196         if (ret)
 197                 goto out;
 198
 199         /*
 200          * For glitch free operation, the following data should
 201          * only be written while LEDx enable bits are 0 and the device enable
 202          * bit is set to 1.
 203          * per Section 7.5.14 of the data sheet
 204          */
 205         ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
 206         if (ret)
 207                 goto out;
 208
 209         /* Set the brightness to 0 so when enabled the LEDs do not come
 210          * on with full brightness.
 211          */
 212         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
 213         if (ret)
 214                 goto out;
 215
 216         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
 217         if (ret)
 218                 goto out;
 219
 220         ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
 221                 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
 222         if (ret)
 223                 goto out;
 224
 225         ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
 226         if (ret)
 227                 goto out;
 228
 229         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
 230         if (ret)
 231                 goto out;
 232
 233         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
 234         if (ret)
 235                 goto out;
 236
 237         ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
 238         if (ret)
 239                 goto out;
 240
 241         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
 242                         LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
 243         if (ret)
 244                 goto out;
 245
 246         switch (led->led_enable) {
 247         case 0:
 248         default:
 249                 if (led->model_id == LM36923_MODEL)
 250                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
 251                                LM36923_LED3_EN;
 252                 else
 253                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
 254
 255                 break;
 256         case 1:
 257                 enable_state = LM3692X_LED1_EN;
 258                 break;
 259         case 2:
 260                 enable_state = LM3692X_LED2_EN;
 261                 break;
 262
 263         case 3:
 264                 if (led->model_id == LM36923_MODEL) {
 265                         enable_state = LM36923_LED3_EN;
 266                         break;
 267                 }
 268
 269                 ret = -EINVAL;
 270                 dev_err(&led->client->dev,
 271                         "LED3 sync not available on this device\n");
 272                 goto out;
 273         }
 274
 275         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
 276                                  enable_state | LM3692X_DEVICE_EN);
 277
 278         led->enabled = true;
 279         return ret;
 280 out:
 281         dev_err(&led->client->dev, "Fail writing initialization values\n");
 282
 283         if (led->enable_gpio)
 284                 gpiod_direction_output(led->enable_gpio, 0);
 285
 286         if (led->regulator) {
 287                 reg_ret = regulator_disable(led->regulator);
 288                 if (reg_ret)
 289                         dev_err(&led->client->dev,
 290                                 "Failed to disable regulator: %d\n", reg_ret);
 291         }
 292
 293         return ret;
 294 }
 295
 296 static int lm3692x_leds_disable(struct lm3692x_led *led)
 297 {
 298         int ret;
 299
 300         if (!led->enabled)
 301                 return 0;
 302
 303         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
 304         if (ret) {
 305                 dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
 306                         ret);
 307                 return ret;
 308         }
 309
 310         if (led->enable_gpio)
 311                 gpiod_direction_output(led->enable_gpio, 0);
 312
 313         if (led->regulator) {
 314                 ret = regulator_disable(led->regulator);
 315                 if (ret)
 316                         dev_err(&led->client->dev,
 317                                 "Failed to disable regulator: %d\n", ret);
 318         }
 319
 320         led->enabled = false;
 321         return ret;
 322 }
 323
 324 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
 325                                 enum led_brightness brt_val)
 326 {
 327         struct lm3692x_led *led =
 328                         container_of(led_cdev, struct lm3692x_led, led_dev);
 329         int ret;
 330         int led_brightness_lsb = (brt_val >> 5);
 331
 332         mutex_lock(&led->lock);
 333
 334         if (brt_val == 0) {
 335                 ret = lm3692x_leds_disable(led);
 336                 goto out;
 337         } else {
 338                 lm3692x_leds_enable(led);
 339         }
 340
 341         ret = lm3692x_fault_check(led);
 342         if (ret) {
 343                 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
 344                         ret);
 345                 goto out;
 346         }
 347
 348         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
 349         if (ret) {
 350                 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
 351                 goto out;
 352         }
 353
 354         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
 355         if (ret) {
 356                 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
 357                 goto out;
 358         }
 359 out:
 360         mutex_unlock(&led->lock);
 361         return ret;
 362 }
 363
 364 static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led,
 365                                                   u32 max_cur)
 366 {
 367         u32 max_code;
 368
 369         /* see p.12 of LM36922 data sheet for brightness formula */
 370         max_code = ((max_cur * 1000) - 37806) / 12195;
 371         if (max_code > 0x7FF)
 372                 max_code = 0x7FF;
 373
 374         return max_code >> 3;
 375 }
 376
 377 static int lm3692x_probe_dt(struct lm3692x_led *led)
 378 {
 379         struct fwnode_handle *child = NULL;
 380         struct led_init_data init_data = {};
 381         u32 ovp, max_cur;
 382         int ret;
 383
 384         led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
 385                                                    "enable", GPIOD_OUT_LOW);
 386         if (IS_ERR(led->enable_gpio)) {
 387                 ret = PTR_ERR(led->enable_gpio);
 388                 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
 389                         ret);
 390                 return ret;
 391         }
 392
 393         led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
 394         if (IS_ERR(led->regulator)) {
 395                 ret = PTR_ERR(led->regulator);
 396                 if (ret != -ENODEV)
 397                         return dev_err_probe(&led->client->dev, ret,
 398                                              "Failed to get vled regulator\n");
 399
 400                 led->regulator = NULL;
 401         }
 402
 403         led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
 404                 LM3692X_BOOST_SW_NO_SHIFT |
 405                 LM3692X_OCP_PROT_1_5A;
 406         ret = device_property_read_u32(&led->client->dev,
 407                                        "ti,ovp-microvolt", &ovp);
 408         if (ret) {
 409                 led->boost_ctrl |= LM3692X_OVP_29V;
 410         } else {
 411                 switch (ovp) {
 412                 case 17000000:
 413                         break;
 414                 case 21000000:
 415                         led->boost_ctrl |= LM3692X_OVP_21V;
 416                         break;
 417                 case 25000000:
 418                         led->boost_ctrl |= LM3692X_OVP_25V;
 419                         break;
 420                 case 29000000:
 421                         led->boost_ctrl |= LM3692X_OVP_29V;
 422                         break;
 423                 default:
 424                         dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
 425                         return -EINVAL;
 426                 }
 427         }
 428
 429         child = device_get_next_child_node(&led->client->dev, child);
 430         if (!child) {
 431                 dev_err(&led->client->dev, "No LED Child node\n");
 432                 return -ENODEV;
 433         }
 434
 435         ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
 436         if (ret) {
 437                 fwnode_handle_put(child);
 438                 dev_err(&led->client->dev, "reg DT property missing\n");
 439                 return ret;
 440         }
 441
 442         ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur);
 443         led->led_dev.max_brightness = ret ? LED_FULL :
 444                 lm3692x_max_brightness(led, max_cur);
 445
 446         init_data.fwnode = child;
 447         init_data.devicename = led->client->name;
 448         init_data.default_label = ":";
 449
 450         ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
 451                                              &init_data);
 452         if (ret)
 453                 dev_err(&led->client->dev, "led register err: %d\n", ret);
 454
 455         fwnode_handle_put(init_data.fwnode);
 456         return ret;
 457 }
 458
 459 static int lm3692x_probe(struct i2c_client *client,
 460                         const struct i2c_device_id *id)
 461 {
 462         struct lm3692x_led *led;
 463         int ret;
 464
 465         led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 466         if (!led)
 467                 return -ENOMEM;
 468
 469         mutex_init(&led->lock);
 470         led->client = client;
 471         led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
 472         led->model_id = id->driver_data;
 473         i2c_set_clientdata(client, led);
 474
 475         led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
 476         if (IS_ERR(led->regmap)) {
 477                 ret = PTR_ERR(led->regmap);
 478                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 479                         ret);
 480                 return ret;
 481         }
 482
 483         ret = lm3692x_probe_dt(led);
 484         if (ret)
 485                 return ret;
 486
 487         ret = lm3692x_leds_enable(led);
 488         if (ret)
 489                 return ret;
 490
 491         return 0;
 492 }
 493
 494 static void lm3692x_remove(struct i2c_client *client)
 495 {
 496         struct lm3692x_led *led = i2c_get_clientdata(client);
 497
 498         lm3692x_leds_disable(led);
 499         mutex_destroy(&led->lock);
 500 }
 501
 502 static const struct i2c_device_id lm3692x_id[] = {
 503         { "lm36922", LM36922_MODEL },
 504         { "lm36923", LM36923_MODEL },
 505         { }
 506 };
 507 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
 508
 509 static const struct of_device_id of_lm3692x_leds_match[] = {
 510         { .compatible = "ti,lm36922", },
 511         { .compatible = "ti,lm36923", },
 512         {},
 513 };
 514 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
 515
 516 static struct i2c_driver lm3692x_driver = {
 517         .driver = {
 518                 .name   = "lm3692x",
 519                 .of_match_table = of_lm3692x_leds_match,
 520         },
 521         .probe          = lm3692x_probe,
 522         .remove         = lm3692x_remove,
 523         .id_table       = lm3692x_id,
 524 };
 525 module_i2c_driver(lm3692x_driver);
 526
 527 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
 528 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 529 MODULE_LICENSE("GPL v2");