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/module.h>
  11 #include <linux/mutex.h>
  12 #include <linux/of.h>
  13 #include <linux/of_gpio.h>
  14 #include <linux/regmap.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/slab.h>
  17
  18 #define LM36922_MODEL   0
  19 #define LM36923_MODEL   1
  20
  21 #define LM3692X_REV             0x0
  22 #define LM3692X_RESET           0x1
  23 #define LM3692X_EN              0x10
  24 #define LM3692X_BRT_CTRL        0x11
  25 #define LM3692X_PWM_CTRL        0x12
  26 #define LM3692X_BOOST_CTRL      0x13
  27 #define LM3692X_AUTO_FREQ_HI    0x15
  28 #define LM3692X_AUTO_FREQ_LO    0x16
  29 #define LM3692X_BL_ADJ_THRESH   0x17
  30 #define LM3692X_BRT_LSB         0x18
  31 #define LM3692X_BRT_MSB         0x19
  32 #define LM3692X_FAULT_CTRL      0x1e
  33 #define LM3692X_FAULT_FLAGS     0x1f
  34
  35 #define LM3692X_SW_RESET        BIT(0)
  36 #define LM3692X_DEVICE_EN       BIT(0)
  37 #define LM3692X_LED1_EN         BIT(1)
  38 #define LM3692X_LED2_EN         BIT(2)
  39 #define LM36923_LED3_EN         BIT(3)
  40 #define LM3692X_ENABLE_MASK     (LM3692X_DEVICE_EN | LM3692X_LED1_EN | \
  41                                  LM3692X_LED2_EN | LM36923_LED3_EN)
  42
  43 /* Brightness Control Bits */
  44 #define LM3692X_BL_ADJ_POL      BIT(0)
  45 #define LM3692X_RAMP_RATE_125us 0x00
  46 #define LM3692X_RAMP_RATE_250us BIT(1)
  47 #define LM3692X_RAMP_RATE_500us BIT(2)
  48 #define LM3692X_RAMP_RATE_1ms   (BIT(1) | BIT(2))
  49 #define LM3692X_RAMP_RATE_2ms   BIT(3)
  50 #define LM3692X_RAMP_RATE_4ms   (BIT(3) | BIT(1))
  51 #define LM3692X_RAMP_RATE_8ms   (BIT(2) | BIT(3))
  52 #define LM3692X_RAMP_RATE_16ms  (BIT(1) | BIT(2) | BIT(3))
  53 #define LM3692X_RAMP_EN         BIT(4)
  54 #define LM3692X_BRHT_MODE_REG   0x00
  55 #define LM3692X_BRHT_MODE_PWM   BIT(5)
  56 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
  57 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
  58 #define LM3692X_MAP_MODE_EXP    BIT(7)
  59
  60 /* PWM Register Bits */
  61 #define LM3692X_PWM_FILTER_100  BIT(0)
  62 #define LM3692X_PWM_FILTER_150  BIT(1)
  63 #define LM3692X_PWM_FILTER_200  (BIT(0) | BIT(1))
  64 #define LM3692X_PWM_HYSTER_1LSB BIT(2)
  65 #define LM3692X_PWM_HYSTER_2LSB BIT(3)
  66 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
  67 #define LM3692X_PWM_HYSTER_4LSB BIT(4)
  68 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
  69 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
  70 #define LM3692X_PWM_POLARITY    BIT(5)
  71 #define LM3692X_PWM_SAMP_4MHZ   BIT(6)
  72 #define LM3692X_PWM_SAMP_24MHZ  BIT(7)
  73
  74 /* Boost Control Bits */
  75 #define LM3692X_OCP_PROT_1A     BIT(0)
  76 #define LM3692X_OCP_PROT_1_25A  BIT(1)
  77 #define LM3692X_OCP_PROT_1_5A   (BIT(0) | BIT(1))
  78 #define LM3692X_OVP_21V         BIT(2)
  79 #define LM3692X_OVP_25V         BIT(3)
  80 #define LM3692X_OVP_29V         (BIT(2) | BIT(3))
  81 #define LM3692X_MIN_IND_22UH    BIT(4)
  82 #define LM3692X_BOOST_SW_1MHZ   BIT(5)
  83 #define LM3692X_BOOST_SW_NO_SHIFT       BIT(6)
  84
  85 /* Fault Control Bits */
  86 #define LM3692X_FAULT_CTRL_OVP BIT(0)
  87 #define LM3692X_FAULT_CTRL_OCP BIT(1)
  88 #define LM3692X_FAULT_CTRL_TSD BIT(2)
  89 #define LM3692X_FAULT_CTRL_OPEN BIT(3)
  90
  91 /* Fault Flag Bits */
  92 #define LM3692X_FAULT_FLAG_OVP BIT(0)
  93 #define LM3692X_FAULT_FLAG_OCP BIT(1)
  94 #define LM3692X_FAULT_FLAG_TSD BIT(2)
  95 #define LM3692X_FAULT_FLAG_SHRT BIT(3)
  96 #define LM3692X_FAULT_FLAG_OPEN BIT(4)
  97
  98 /**
  99  * struct lm3692x_led -
 100  * @lock - Lock for reading/writing the device
 101  * @client - Pointer to the I2C client
 102  * @led_dev - LED class device pointer
 103  * @regmap - Devices register map
 104  * @enable_gpio - VDDIO/EN gpio to enable communication interface
 105  * @regulator - LED supply regulator pointer
 106  * @led_enable - LED sync to be enabled
 107  * @model_id - Current device model ID enumerated
 108  */
 109 struct lm3692x_led {
 110         struct mutex lock;
 111         struct i2c_client *client;
 112         struct led_classdev led_dev;
 113         struct regmap *regmap;
 114         struct gpio_desc *enable_gpio;
 115         struct regulator *regulator;
 116         int led_enable;
 117         int model_id;
 118
 119         u8 boost_ctrl, brightness_ctrl;
 120         bool enabled;
 121 };
 122
 123 static const struct reg_default lm3692x_reg_defs[] = {
 124         {LM3692X_EN, 0xf},
 125         {LM3692X_BRT_CTRL, 0x61},
 126         {LM3692X_PWM_CTRL, 0x73},
 127         {LM3692X_BOOST_CTRL, 0x6f},
 128         {LM3692X_AUTO_FREQ_HI, 0x0},
 129         {LM3692X_AUTO_FREQ_LO, 0x0},
 130         {LM3692X_BL_ADJ_THRESH, 0x0},
 131         {LM3692X_BRT_LSB, 0x7},
 132         {LM3692X_BRT_MSB, 0xff},
 133         {LM3692X_FAULT_CTRL, 0x7},
 134 };
 135
 136 static const struct regmap_config lm3692x_regmap_config = {
 137         .reg_bits = 8,
 138         .val_bits = 8,
 139
 140         .max_register = LM3692X_FAULT_FLAGS,
 141         .reg_defaults = lm3692x_reg_defs,
 142         .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
 143         .cache_type = REGCACHE_RBTREE,
 144 };
 145
 146 static int lm3692x_fault_check(struct lm3692x_led *led)
 147 {
 148         int ret;
 149         unsigned int read_buf;
 150
 151         ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 152         if (ret)
 153                 return ret;
 154
 155         if (read_buf)
 156                 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
 157
 158         /* The first read may clear the fault.  Check again to see if the fault
 159          * still exits and return that value.
 160          */
 161         regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 162         if (read_buf)
 163                 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
 164                         read_buf);
 165
 166         return read_buf;
 167 }
 168
 169 static int lm3692x_leds_enable(struct lm3692x_led *led)
 170 {
 171         int enable_state;
 172         int ret, reg_ret;
 173
 174         if (led->enabled)
 175                 return 0;
 176
 177         if (led->regulator) {
 178                 ret = regulator_enable(led->regulator);
 179                 if (ret) {
 180                         dev_err(&led->client->dev,
 181                                 "Failed to enable regulator: %d\n", ret);
 182                         return ret;
 183                 }
 184         }
 185
 186         if (led->enable_gpio)
 187                 gpiod_direction_output(led->enable_gpio, 1);
 188
 189         ret = lm3692x_fault_check(led);
 190         if (ret) {
 191                 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
 192                         ret);
 193                 goto out;
 194         }
 195
 196         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
 197         if (ret)
 198                 goto out;
 199
 200         /*
 201          * For glitch free operation, the following data should
 202          * only be written while LEDx enable bits are 0 and the device enable
 203          * bit is set to 1.
 204          * per Section 7.5.14 of the data sheet
 205          */
 206         ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
 207         if (ret)
 208                 goto out;
 209
 210         /* Set the brightness to 0 so when enabled the LEDs do not come
 211          * on with full brightness.
 212          */
 213         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
 214         if (ret)
 215                 goto out;
 216
 217         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
 218         if (ret)
 219                 goto out;
 220
 221         ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
 222                 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
 223         if (ret)
 224                 goto out;
 225
 226         ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl);
 227         if (ret)
 228                 goto out;
 229
 230         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
 231         if (ret)
 232                 goto out;
 233
 234         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
 235         if (ret)
 236                 goto out;
 237
 238         ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
 239         if (ret)
 240                 goto out;
 241
 242         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
 243                         LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
 244         if (ret)
 245                 goto out;
 246
 247         switch (led->led_enable) {
 248         case 0:
 249         default:
 250                 if (led->model_id == LM36923_MODEL)
 251                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
 252                                LM36923_LED3_EN;
 253                 else
 254                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
 255
 256                 break;
 257         case 1:
 258                 enable_state = LM3692X_LED1_EN;
 259                 break;
 260         case 2:
 261                 enable_state = LM3692X_LED2_EN;
 262                 break;
 263
 264         case 3:
 265                 if (led->model_id == LM36923_MODEL) {
 266                         enable_state = LM36923_LED3_EN;
 267                         break;
 268                 }
 269
 270                 ret = -EINVAL;
 271                 dev_err(&led->client->dev,
 272                         "LED3 sync not available on this device\n");
 273                 goto out;
 274         }
 275
 276         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
 277                                  enable_state | LM3692X_DEVICE_EN);
 278
 279         led->enabled = true;
 280         return ret;
 281 out:
 282         dev_err(&led->client->dev, "Fail writing initialization values\n");
 283
 284         if (led->enable_gpio)
 285                 gpiod_direction_output(led->enable_gpio, 0);
 286
 287         if (led->regulator) {
 288                 reg_ret = regulator_disable(led->regulator);
 289                 if (reg_ret)
 290                         dev_err(&led->client->dev,
 291                                 "Failed to disable regulator: %d\n", reg_ret);
 292         }
 293
 294         return ret;
 295 }
 296
 297 static int lm3692x_leds_disable(struct lm3692x_led *led)
 298 {
 299         int ret;
 300
 301         if (!led->enabled)
 302                 return 0;
 303
 304         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
 305         if (ret) {
 306                 dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
 307                         ret);
 308                 return ret;
 309         }
 310
 311         if (led->enable_gpio)
 312                 gpiod_direction_output(led->enable_gpio, 0);
 313
 314         if (led->regulator) {
 315                 ret = regulator_disable(led->regulator);
 316                 if (ret)
 317                         dev_err(&led->client->dev,
 318                                 "Failed to disable regulator: %d\n", ret);
 319         }
 320
 321         led->enabled = false;
 322         return ret;
 323 }
 324
 325 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
 326                                 enum led_brightness brt_val)
 327 {
 328         struct lm3692x_led *led =
 329                         container_of(led_cdev, struct lm3692x_led, led_dev);
 330         int ret;
 331         int led_brightness_lsb = (brt_val >> 5);
 332
 333         mutex_lock(&led->lock);
 334
 335         if (brt_val == 0) {
 336                 ret = lm3692x_leds_disable(led);
 337                 goto out;
 338         } else {
 339                 lm3692x_leds_enable(led);
 340         }
 341
 342         ret = lm3692x_fault_check(led);
 343         if (ret) {
 344                 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
 345                         ret);
 346                 goto out;
 347         }
 348
 349         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
 350         if (ret) {
 351                 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
 352                 goto out;
 353         }
 354
 355         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
 356         if (ret) {
 357                 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
 358                 goto out;
 359         }
 360 out:
 361         mutex_unlock(&led->lock);
 362         return ret;
 363 }
 364
 365 static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led,
 366                                                   u32 max_cur)
 367 {
 368         u32 max_code;
 369
 370         /* see p.12 of LM36922 data sheet for brightness formula */
 371         max_code = ((max_cur * 1000) - 37806) / 12195;
 372         if (max_code > 0x7FF)
 373                 max_code = 0x7FF;
 374
 375         return max_code >> 3;
 376 }
 377
 378 static int lm3692x_probe_dt(struct lm3692x_led *led)
 379 {
 380         struct fwnode_handle *child = NULL;
 381         struct led_init_data init_data = {};
 382         u32 ovp, max_cur;
 383         int ret;
 384
 385         led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
 386                                                    "enable", GPIOD_OUT_LOW);
 387         if (IS_ERR(led->enable_gpio)) {
 388                 ret = PTR_ERR(led->enable_gpio);
 389                 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
 390                         ret);
 391                 return ret;
 392         }
 393
 394         led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
 395         if (IS_ERR(led->regulator)) {
 396                 ret = PTR_ERR(led->regulator);
 397                 if (ret != -ENODEV)
 398                         return dev_err_probe(&led->client->dev, ret,
 399                                              "Failed to get vled regulator\n");
 400
 401                 led->regulator = NULL;
 402         }
 403
 404         led->boost_ctrl = LM3692X_BOOST_SW_1MHZ |
 405                 LM3692X_BOOST_SW_NO_SHIFT |
 406                 LM3692X_OCP_PROT_1_5A;
 407         ret = device_property_read_u32(&led->client->dev,
 408                                        "ti,ovp-microvolt", &ovp);
 409         if (ret) {
 410                 led->boost_ctrl |= LM3692X_OVP_29V;
 411         } else {
 412                 switch (ovp) {
 413                 case 17000000:
 414                         break;
 415                 case 21000000:
 416                         led->boost_ctrl |= LM3692X_OVP_21V;
 417                         break;
 418                 case 25000000:
 419                         led->boost_ctrl |= LM3692X_OVP_25V;
 420                         break;
 421                 case 29000000:
 422                         led->boost_ctrl |= LM3692X_OVP_29V;
 423                         break;
 424                 default:
 425                         dev_err(&led->client->dev, "Invalid OVP %d\n", ovp);
 426                         return -EINVAL;
 427                 }
 428         }
 429
 430         child = device_get_next_child_node(&led->client->dev, child);
 431         if (!child) {
 432                 dev_err(&led->client->dev, "No LED Child node\n");
 433                 return -ENODEV;
 434         }
 435
 436         ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
 437         if (ret) {
 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                 return ret;
 455         }
 456
 457         return 0;
 458 }
 459
 460 static int lm3692x_probe(struct i2c_client *client,
 461                         const struct i2c_device_id *id)
 462 {
 463         struct lm3692x_led *led;
 464         int ret;
 465
 466         led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 467         if (!led)
 468                 return -ENOMEM;
 469
 470         mutex_init(&led->lock);
 471         led->client = client;
 472         led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
 473         led->model_id = id->driver_data;
 474         i2c_set_clientdata(client, led);
 475
 476         led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
 477         if (IS_ERR(led->regmap)) {
 478                 ret = PTR_ERR(led->regmap);
 479                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 480                         ret);
 481                 return ret;
 482         }
 483
 484         ret = lm3692x_probe_dt(led);
 485         if (ret)
 486                 return ret;
 487
 488         ret = lm3692x_leds_enable(led);
 489         if (ret)
 490                 return ret;
 491
 492         return 0;
 493 }
 494
 495 static int lm3692x_remove(struct i2c_client *client)
 496 {
 497         struct lm3692x_led *led = i2c_get_clientdata(client);
 498         int ret;
 499
 500         ret = lm3692x_leds_disable(led);
 501         if (ret)
 502                 return ret;
 503         mutex_destroy(&led->lock);
 504
 505         return 0;
 506 }
 507
 508 static const struct i2c_device_id lm3692x_id[] = {
 509         { "lm36922", LM36922_MODEL },
 510         { "lm36923", LM36923_MODEL },
 511         { }
 512 };
 513 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
 514
 515 static const struct of_device_id of_lm3692x_leds_match[] = {
 516         { .compatible = "ti,lm36922", },
 517         { .compatible = "ti,lm36923", },
 518         {},
 519 };
 520 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
 521
 522 static struct i2c_driver lm3692x_driver = {
 523         .driver = {
 524                 .name   = "lm3692x",
 525                 .of_match_table = of_lm3692x_leds_match,
 526         },
 527         .probe          = lm3692x_probe,
 528         .remove         = lm3692x_remove,
 529         .id_table       = lm3692x_id,
 530 };
 531 module_i2c_driver(lm3692x_driver);
 532
 533 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
 534 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 535 MODULE_LICENSE("GPL v2");