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 - http://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/module.h>
  10 #include <linux/mutex.h>
  11 #include <linux/of.h>
  12 #include <linux/of_gpio.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
 119 static const struct reg_default lm3692x_reg_defs[] = {
 120         {LM3692X_EN, 0xf},
 121         {LM3692X_BRT_CTRL, 0x61},
 122         {LM3692X_PWM_CTRL, 0x73},
 123         {LM3692X_BOOST_CTRL, 0x6f},
 124         {LM3692X_AUTO_FREQ_HI, 0x0},
 125         {LM3692X_AUTO_FREQ_LO, 0x0},
 126         {LM3692X_BL_ADJ_THRESH, 0x0},
 127         {LM3692X_BRT_LSB, 0x7},
 128         {LM3692X_BRT_MSB, 0xff},
 129         {LM3692X_FAULT_CTRL, 0x7},
 130 };
 131
 132 static const struct regmap_config lm3692x_regmap_config = {
 133         .reg_bits = 8,
 134         .val_bits = 8,
 135
 136         .max_register = LM3692X_FAULT_FLAGS,
 137         .reg_defaults = lm3692x_reg_defs,
 138         .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
 139         .cache_type = REGCACHE_RBTREE,
 140 };
 141
 142 static int lm3692x_fault_check(struct lm3692x_led *led)
 143 {
 144         int ret;
 145         unsigned int read_buf;
 146
 147         ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 148         if (ret)
 149                 return ret;
 150
 151         if (read_buf)
 152                 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf);
 153
 154         /* The first read may clear the fault.  Check again to see if the fault
 155          * still exits and return that value.
 156          */
 157         regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
 158         if (read_buf)
 159                 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n",
 160                         read_buf);
 161
 162         return read_buf;
 163 }
 164
 165 static int lm3692x_brightness_set(struct led_classdev *led_cdev,
 166                                 enum led_brightness brt_val)
 167 {
 168         struct lm3692x_led *led =
 169                         container_of(led_cdev, struct lm3692x_led, led_dev);
 170         int ret;
 171         int led_brightness_lsb = (brt_val >> 5);
 172
 173         mutex_lock(&led->lock);
 174
 175         ret = lm3692x_fault_check(led);
 176         if (ret) {
 177                 dev_err(&led->client->dev, "Cannot read/clear faults\n");
 178                 goto out;
 179         }
 180
 181         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
 182         if (ret) {
 183                 dev_err(&led->client->dev, "Cannot write MSB\n");
 184                 goto out;
 185         }
 186
 187         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
 188         if (ret) {
 189                 dev_err(&led->client->dev, "Cannot write LSB\n");
 190                 goto out;
 191         }
 192 out:
 193         mutex_unlock(&led->lock);
 194         return ret;
 195 }
 196
 197 static int lm3692x_init(struct lm3692x_led *led)
 198 {
 199         int enable_state;
 200         int ret;
 201
 202         if (led->regulator) {
 203                 ret = regulator_enable(led->regulator);
 204                 if (ret) {
 205                         dev_err(&led->client->dev,
 206                                 "Failed to enable regulator\n");
 207                         return ret;
 208                 }
 209         }
 210
 211         if (led->enable_gpio)
 212                 gpiod_direction_output(led->enable_gpio, 1);
 213
 214         ret = lm3692x_fault_check(led);
 215         if (ret) {
 216                 dev_err(&led->client->dev, "Cannot read/clear faults\n");
 217                 goto out;
 218         }
 219
 220         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
 221         if (ret)
 222                 goto out;
 223
 224         /*
 225          * For glitch free operation, the following data should
 226          * only be written while LEDx enable bits are 0 and the device enable
 227          * bit is set to 1.
 228          * per Section 7.5.14 of the data sheet
 229          */
 230         ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
 231         if (ret)
 232                 goto out;
 233
 234         /* Set the brightness to 0 so when enabled the LEDs do not come
 235          * on with full brightness.
 236          */
 237         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
 238         if (ret)
 239                 goto out;
 240
 241         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
 242         if (ret)
 243                 goto out;
 244
 245         ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
 246                 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
 247         if (ret)
 248                 goto out;
 249
 250         ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
 251                         LM3692X_BRHT_MODE_RAMP_MULTI |
 252                         LM3692X_BL_ADJ_POL |
 253                         LM3692X_RAMP_RATE_250us);
 254         if (ret)
 255                 goto out;
 256
 257         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
 258         if (ret)
 259                 goto out;
 260
 261         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
 262         if (ret)
 263                 goto out;
 264
 265         ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
 266         if (ret)
 267                 goto out;
 268
 269         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
 270                         LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
 271         if (ret)
 272                 goto out;
 273
 274         switch (led->led_enable) {
 275         case 0:
 276         default:
 277                 if (led->model_id == LM36923_MODEL)
 278                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
 279                                LM36923_LED3_EN;
 280                 else
 281                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
 282
 283                 break;
 284         case 1:
 285                 enable_state = LM3692X_LED1_EN;
 286                 break;
 287         case 2:
 288                 enable_state = LM3692X_LED2_EN;
 289                 break;
 290
 291         case 3:
 292                 if (led->model_id == LM36923_MODEL) {
 293                         enable_state = LM36923_LED3_EN;
 294                         break;
 295                 }
 296
 297                 ret = -EINVAL;
 298                 dev_err(&led->client->dev,
 299                         "LED3 sync not available on this device\n");
 300                 goto out;
 301         }
 302
 303         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
 304                                  enable_state | LM3692X_DEVICE_EN);
 305
 306         return ret;
 307 out:
 308         dev_err(&led->client->dev, "Fail writing initialization values\n");
 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\n");
 318         }
 319
 320         return ret;
 321 }
 322 static int lm3692x_probe_dt(struct lm3692x_led *led)
 323 {
 324         struct fwnode_handle *child = NULL;
 325         struct led_init_data init_data = {};
 326         int ret;
 327
 328         led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
 329                                                    "enable", GPIOD_OUT_LOW);
 330         if (IS_ERR(led->enable_gpio)) {
 331                 ret = PTR_ERR(led->enable_gpio);
 332                 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
 333                         ret);
 334                 return ret;
 335         }
 336
 337         led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
 338         if (IS_ERR(led->regulator)) {
 339                 ret = PTR_ERR(led->regulator);
 340                 if (ret != -ENODEV) {
 341                         if (ret != -EPROBE_DEFER)
 342                                 dev_err(&led->client->dev,
 343                                         "Failed to get vled regulator: %d\n",
 344                                         ret);
 345                         return ret;
 346                 }
 347                 led->regulator = NULL;
 348         }
 349
 350         child = device_get_next_child_node(&led->client->dev, child);
 351         if (!child) {
 352                 dev_err(&led->client->dev, "No LED Child node\n");
 353                 return -ENODEV;
 354         }
 355
 356         fwnode_property_read_string(child, "linux,default-trigger",
 357                                     &led->led_dev.default_trigger);
 358
 359         ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
 360         if (ret) {
 361                 dev_err(&led->client->dev, "reg DT property missing\n");
 362                 return ret;
 363         }
 364
 365         init_data.fwnode = child;
 366         init_data.devicename = led->client->name;
 367         init_data.default_label = ":";
 368
 369         ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
 370                                              &init_data);
 371         if (ret) {
 372                 dev_err(&led->client->dev, "led register err: %d\n", ret);
 373                 return ret;
 374         }
 375
 376         return 0;
 377 }
 378
 379 static int lm3692x_probe(struct i2c_client *client,
 380                         const struct i2c_device_id *id)
 381 {
 382         struct lm3692x_led *led;
 383         int ret;
 384
 385         led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 386         if (!led)
 387                 return -ENOMEM;
 388
 389         mutex_init(&led->lock);
 390         led->client = client;
 391         led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
 392         led->model_id = id->driver_data;
 393         i2c_set_clientdata(client, led);
 394
 395         led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
 396         if (IS_ERR(led->regmap)) {
 397                 ret = PTR_ERR(led->regmap);
 398                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 399                         ret);
 400                 return ret;
 401         }
 402
 403         ret = lm3692x_probe_dt(led);
 404         if (ret)
 405                 return ret;
 406
 407         ret = lm3692x_init(led);
 408         if (ret)
 409                 return ret;
 410
 411         return 0;
 412 }
 413
 414 static int lm3692x_remove(struct i2c_client *client)
 415 {
 416         struct lm3692x_led *led = i2c_get_clientdata(client);
 417         int ret;
 418
 419         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
 420         if (ret) {
 421                 dev_err(&led->client->dev, "Failed to disable regulator\n");
 422                 return ret;
 423         }
 424
 425         if (led->enable_gpio)
 426                 gpiod_direction_output(led->enable_gpio, 0);
 427
 428         if (led->regulator) {
 429                 ret = regulator_disable(led->regulator);
 430                 if (ret)
 431                         dev_err(&led->client->dev,
 432                                 "Failed to disable regulator\n");
 433         }
 434
 435         mutex_destroy(&led->lock);
 436
 437         return 0;
 438 }
 439
 440 static const struct i2c_device_id lm3692x_id[] = {
 441         { "lm36922", LM36922_MODEL },
 442         { "lm36923", LM36923_MODEL },
 443         { }
 444 };
 445 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
 446
 447 static const struct of_device_id of_lm3692x_leds_match[] = {
 448         { .compatible = "ti,lm36922", },
 449         { .compatible = "ti,lm36923", },
 450         {},
 451 };
 452 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
 453
 454 static struct i2c_driver lm3692x_driver = {
 455         .driver = {
 456                 .name   = "lm3692x",
 457                 .of_match_table = of_lm3692x_leds_match,
 458         },
 459         .probe          = lm3692x_probe,
 460         .remove         = lm3692x_remove,
 461         .id_table       = lm3692x_id,
 462 };
 463 module_i2c_driver(lm3692x_driver);
 464
 465 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
 466 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 467 MODULE_LICENSE("GPL v2");