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: %d\n",
 178                         ret);
 179                 goto out;
 180         }
 181
 182         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
 183         if (ret) {
 184                 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret);
 185                 goto out;
 186         }
 187
 188         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
 189         if (ret) {
 190                 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret);
 191                 goto out;
 192         }
 193 out:
 194         mutex_unlock(&led->lock);
 195         return ret;
 196 }
 197
 198 static int lm3692x_init(struct lm3692x_led *led)
 199 {
 200         int enable_state;
 201         int ret, reg_ret;
 202
 203         if (led->regulator) {
 204                 ret = regulator_enable(led->regulator);
 205                 if (ret) {
 206                         dev_err(&led->client->dev,
 207                                 "Failed to enable regulator: %d\n", ret);
 208                         return ret;
 209                 }
 210         }
 211
 212         if (led->enable_gpio)
 213                 gpiod_direction_output(led->enable_gpio, 1);
 214
 215         ret = lm3692x_fault_check(led);
 216         if (ret) {
 217                 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n",
 218                         ret);
 219                 goto out;
 220         }
 221
 222         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
 223         if (ret)
 224                 goto out;
 225
 226         /*
 227          * For glitch free operation, the following data should
 228          * only be written while LEDx enable bits are 0 and the device enable
 229          * bit is set to 1.
 230          * per Section 7.5.14 of the data sheet
 231          */
 232         ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN);
 233         if (ret)
 234                 goto out;
 235
 236         /* Set the brightness to 0 so when enabled the LEDs do not come
 237          * on with full brightness.
 238          */
 239         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0);
 240         if (ret)
 241                 goto out;
 242
 243         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0);
 244         if (ret)
 245                 goto out;
 246
 247         ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
 248                 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
 249         if (ret)
 250                 goto out;
 251
 252         ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
 253                         LM3692X_BOOST_SW_1MHZ |
 254                         LM3692X_BOOST_SW_NO_SHIFT |
 255                         LM3692X_OCP_PROT_1_5A);
 256         if (ret)
 257                 goto out;
 258
 259         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
 260         if (ret)
 261                 goto out;
 262
 263         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
 264         if (ret)
 265                 goto out;
 266
 267         ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
 268         if (ret)
 269                 goto out;
 270
 271         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
 272                         LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN);
 273         if (ret)
 274                 goto out;
 275
 276         switch (led->led_enable) {
 277         case 0:
 278         default:
 279                 if (led->model_id == LM36923_MODEL)
 280                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN |
 281                                LM36923_LED3_EN;
 282                 else
 283                         enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN;
 284
 285                 break;
 286         case 1:
 287                 enable_state = LM3692X_LED1_EN;
 288                 break;
 289         case 2:
 290                 enable_state = LM3692X_LED2_EN;
 291                 break;
 292
 293         case 3:
 294                 if (led->model_id == LM36923_MODEL) {
 295                         enable_state = LM36923_LED3_EN;
 296                         break;
 297                 }
 298
 299                 ret = -EINVAL;
 300                 dev_err(&led->client->dev,
 301                         "LED3 sync not available on this device\n");
 302                 goto out;
 303         }
 304
 305         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK,
 306                                  enable_state | LM3692X_DEVICE_EN);
 307
 308         return ret;
 309 out:
 310         dev_err(&led->client->dev, "Fail writing initialization values\n");
 311
 312         if (led->enable_gpio)
 313                 gpiod_direction_output(led->enable_gpio, 0);
 314
 315         if (led->regulator) {
 316                 reg_ret = regulator_disable(led->regulator);
 317                 if (reg_ret)
 318                         dev_err(&led->client->dev,
 319                                 "Failed to disable regulator: %d\n", reg_ret);
 320         }
 321
 322         return ret;
 323 }
 324
 325 static int lm3692x_probe_dt(struct lm3692x_led *led)
 326 {
 327         struct fwnode_handle *child = NULL;
 328         struct led_init_data init_data = {};
 329         int ret;
 330
 331         led->enable_gpio = devm_gpiod_get_optional(&led->client->dev,
 332                                                    "enable", GPIOD_OUT_LOW);
 333         if (IS_ERR(led->enable_gpio)) {
 334                 ret = PTR_ERR(led->enable_gpio);
 335                 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n",
 336                         ret);
 337                 return ret;
 338         }
 339
 340         led->regulator = devm_regulator_get_optional(&led->client->dev, "vled");
 341         if (IS_ERR(led->regulator)) {
 342                 ret = PTR_ERR(led->regulator);
 343                 if (ret != -ENODEV) {
 344                         if (ret != -EPROBE_DEFER)
 345                                 dev_err(&led->client->dev,
 346                                         "Failed to get vled regulator: %d\n",
 347                                         ret);
 348                         return ret;
 349                 }
 350                 led->regulator = NULL;
 351         }
 352
 353         child = device_get_next_child_node(&led->client->dev, child);
 354         if (!child) {
 355                 dev_err(&led->client->dev, "No LED Child node\n");
 356                 return -ENODEV;
 357         }
 358
 359         fwnode_property_read_string(child, "linux,default-trigger",
 360                                     &led->led_dev.default_trigger);
 361
 362         ret = fwnode_property_read_u32(child, "reg", &led->led_enable);
 363         if (ret) {
 364                 dev_err(&led->client->dev, "reg DT property missing\n");
 365                 return ret;
 366         }
 367
 368         init_data.fwnode = child;
 369         init_data.devicename = led->client->name;
 370         init_data.default_label = ":";
 371
 372         ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev,
 373                                              &init_data);
 374         if (ret) {
 375                 dev_err(&led->client->dev, "led register err: %d\n", ret);
 376                 return ret;
 377         }
 378
 379         return 0;
 380 }
 381
 382 static int lm3692x_probe(struct i2c_client *client,
 383                         const struct i2c_device_id *id)
 384 {
 385         struct lm3692x_led *led;
 386         int ret;
 387
 388         led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 389         if (!led)
 390                 return -ENOMEM;
 391
 392         mutex_init(&led->lock);
 393         led->client = client;
 394         led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
 395         led->model_id = id->driver_data;
 396         i2c_set_clientdata(client, led);
 397
 398         led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
 399         if (IS_ERR(led->regmap)) {
 400                 ret = PTR_ERR(led->regmap);
 401                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 402                         ret);
 403                 return ret;
 404         }
 405
 406         ret = lm3692x_probe_dt(led);
 407         if (ret)
 408                 return ret;
 409
 410         ret = lm3692x_init(led);
 411         if (ret)
 412                 return ret;
 413
 414         return 0;
 415 }
 416
 417 static int lm3692x_remove(struct i2c_client *client)
 418 {
 419         struct lm3692x_led *led = i2c_get_clientdata(client);
 420         int ret;
 421
 422         ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0);
 423         if (ret) {
 424                 dev_err(&led->client->dev, "Failed to disable regulator: %d\n",
 425                         ret);
 426                 return ret;
 427         }
 428
 429         if (led->enable_gpio)
 430                 gpiod_direction_output(led->enable_gpio, 0);
 431
 432         if (led->regulator) {
 433                 ret = regulator_disable(led->regulator);
 434                 if (ret)
 435                         dev_err(&led->client->dev,
 436                                 "Failed to disable regulator: %d\n", ret);
 437         }
 438
 439         mutex_destroy(&led->lock);
 440
 441         return 0;
 442 }
 443
 444 static const struct i2c_device_id lm3692x_id[] = {
 445         { "lm36922", LM36922_MODEL },
 446         { "lm36923", LM36923_MODEL },
 447         { }
 448 };
 449 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
 450
 451 static const struct of_device_id of_lm3692x_leds_match[] = {
 452         { .compatible = "ti,lm36922", },
 453         { .compatible = "ti,lm36923", },
 454         {},
 455 };
 456 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
 457
 458 static struct i2c_driver lm3692x_driver = {
 459         .driver = {
 460                 .name   = "lm3692x",
 461                 .of_match_table = of_lm3692x_leds_match,
 462         },
 463         .probe          = lm3692x_probe,
 464         .remove         = lm3692x_remove,
 465         .id_table       = lm3692x_id,
 466 };
 467 module_i2c_driver(lm3692x_driver);
 468
 469 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
 470 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 471 MODULE_LICENSE("GPL v2");