drivers/leds/leds-lm3692x.c

   1 /*
   2  * TI lm3692x LED Driver
   3  *
   4  * Copyright (C) 2017 Texas Instruments
   5  *
   6  * Author: Dan Murphy <dmurphy@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * Data sheet is located
  13  * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
  14  */
  15
  16 #include <linux/gpio/consumer.h>
  17 #include <linux/i2c.h>
  18 #include <linux/init.h>
  19 #include <linux/leds.h>
  20 #include <linux/module.h>
  21 #include <linux/mutex.h>
  22 #include <linux/of.h>
  23 #include <linux/of_gpio.h>
  24 #include <linux/regmap.h>
  25 #include <linux/regulator/consumer.h>
  26 #include <linux/slab.h>
  27 #include <uapi/linux/uleds.h>
  28
  29 #define LM3692X_REV             0x0
  30 #define LM3692X_RESET           0x1
  31 #define LM3692X_EN              0x10
  32 #define LM3692X_BRT_CTRL        0x11
  33 #define LM3692X_PWM_CTRL        0x12
  34 #define LM3692X_BOOST_CTRL      0x13
  35 #define LM3692X_AUTO_FREQ_HI    0x15
  36 #define LM3692X_AUTO_FREQ_LO    0x16
  37 #define LM3692X_BL_ADJ_THRESH   0x17
  38 #define LM3692X_BRT_LSB         0x18
  39 #define LM3692X_BRT_MSB         0x19
  40 #define LM3692X_FAULT_CTRL      0x1e
  41 #define LM3692X_FAULT_FLAGS     0x1f
  42
  43 #define LM3692X_SW_RESET        BIT(0)
  44 #define LM3692X_DEVICE_EN       BIT(0)
  45 #define LM3692X_LED1_EN         BIT(1)
  46 #define LM3692X_LED2_EN         BIT(2)
  47
  48 /* Brightness Control Bits */
  49 #define LM3692X_BL_ADJ_POL      BIT(0)
  50 #define LM3692X_RAMP_RATE_125us 0x00
  51 #define LM3692X_RAMP_RATE_250us BIT(1)
  52 #define LM3692X_RAMP_RATE_500us BIT(2)
  53 #define LM3692X_RAMP_RATE_1ms   (BIT(1) | BIT(2))
  54 #define LM3692X_RAMP_RATE_2ms   BIT(3)
  55 #define LM3692X_RAMP_RATE_4ms   (BIT(3) | BIT(1))
  56 #define LM3692X_RAMP_RATE_8ms   (BIT(2) | BIT(3))
  57 #define LM3692X_RAMP_RATE_16ms  (BIT(1) | BIT(2) | BIT(3))
  58 #define LM3692X_RAMP_EN         BIT(4)
  59 #define LM3692X_BRHT_MODE_REG   0x00
  60 #define LM3692X_BRHT_MODE_PWM   BIT(5)
  61 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
  62 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
  63 #define LM3692X_MAP_MODE_EXP    BIT(7)
  64
  65 /* PWM Register Bits */
  66 #define LM3692X_PWM_FILTER_100  BIT(0)
  67 #define LM3692X_PWM_FILTER_150  BIT(1)
  68 #define LM3692X_PWM_FILTER_200  (BIT(0) | BIT(1))
  69 #define LM3692X_PWM_HYSTER_1LSB BIT(2)
  70 #define LM3692X_PWM_HYSTER_2LSB BIT(3)
  71 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
  72 #define LM3692X_PWM_HYSTER_4LSB BIT(4)
  73 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
  74 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
  75 #define LM3692X_PWM_POLARITY    BIT(5)
  76 #define LM3692X_PWM_SAMP_4MHZ   BIT(6)
  77 #define LM3692X_PWM_SAMP_24MHZ  BIT(7)
  78
  79 /* Boost Control Bits */
  80 #define LM3692X_OCP_PROT_1A     BIT(0)
  81 #define LM3692X_OCP_PROT_1_25A  BIT(1)
  82 #define LM3692X_OCP_PROT_1_5A   (BIT(0) | BIT(1))
  83 #define LM3692X_OVP_21V         BIT(2)
  84 #define LM3692X_OVP_25V         BIT(3)
  85 #define LM3692X_OVP_29V         (BIT(2) | BIT(3))
  86 #define LM3692X_MIN_IND_22UH    BIT(4)
  87 #define LM3692X_BOOST_SW_1MHZ   BIT(5)
  88 #define LM3692X_BOOST_SW_NO_SHIFT       BIT(6)
  89
  90 /* Fault Control Bits */
  91 #define LM3692X_FAULT_CTRL_OVP BIT(0)
  92 #define LM3692X_FAULT_CTRL_OCP BIT(1)
  93 #define LM3692X_FAULT_CTRL_TSD BIT(2)
  94 #define LM3692X_FAULT_CTRL_OPEN BIT(3)
  95
  96 /* Fault Flag Bits */
  97 #define LM3692X_FAULT_FLAG_OVP BIT(0)
  98 #define LM3692X_FAULT_FLAG_OCP BIT(1)
  99 #define LM3692X_FAULT_FLAG_TSD BIT(2)
 100 #define LM3692X_FAULT_FLAG_SHRT BIT(3)
 101 #define LM3692X_FAULT_FLAG_OPEN BIT(4)
 102
 103 /**
 104  * struct lm3692x_led -
 105  * @lock - Lock for reading/writing the device
 106  * @client - Pointer to the I2C client
 107  * @led_dev - LED class device pointer
 108  * @regmap - Devices register map
 109  * @enable_gpio - VDDIO/EN gpio to enable communication interface
 110  * @regulator - LED supply regulator pointer
 111  * @label - LED label
 112  */
 113 struct lm3692x_led {
 114         struct mutex lock;
 115         struct i2c_client *client;
 116         struct led_classdev led_dev;
 117         struct regmap *regmap;
 118         struct gpio_desc *enable_gpio;
 119         struct regulator *regulator;
 120         char label[LED_MAX_NAME_SIZE];
 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_brightness_set(struct led_classdev *led_cdev,
 170                                 enum led_brightness brt_val)
 171 {
 172         struct lm3692x_led *led =
 173                         container_of(led_cdev, struct lm3692x_led, led_dev);
 174         int ret;
 175         int led_brightness_lsb = (brt_val >> 5);
 176
 177         mutex_lock(&led->lock);
 178
 179         ret = lm3692x_fault_check(led);
 180         if (ret) {
 181                 dev_err(&led->client->dev, "Cannot read/clear faults\n");
 182                 goto out;
 183         }
 184
 185         ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val);
 186         if (ret) {
 187                 dev_err(&led->client->dev, "Cannot write MSB\n");
 188                 goto out;
 189         }
 190
 191         ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
 192         if (ret) {
 193                 dev_err(&led->client->dev, "Cannot write LSB\n");
 194                 goto out;
 195         }
 196 out:
 197         mutex_unlock(&led->lock);
 198         return ret;
 199 }
 200
 201 static int lm3692x_init(struct lm3692x_led *led)
 202 {
 203         int ret;
 204
 205         if (led->regulator) {
 206                 ret = regulator_enable(led->regulator);
 207                 if (ret) {
 208                         dev_err(&led->client->dev,
 209                                 "Failed to enable regulator\n");
 210                         return ret;
 211                 }
 212         }
 213
 214         if (led->enable_gpio)
 215                 gpiod_direction_output(led->enable_gpio, 1);
 216
 217         ret = lm3692x_fault_check(led);
 218         if (ret) {
 219                 dev_err(&led->client->dev, "Cannot read/clear faults\n");
 220                 goto out;
 221         }
 222
 223         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
 224         if (ret)
 225                 goto out;
 226
 227         /*
 228          * For glitch free operation, the following data should
 229          * only be written while device enable bit is 0
 230          * per Section 7.5.14 of the data sheet
 231          */
 232         ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
 233                 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
 234         if (ret)
 235                 goto out;
 236
 237         ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
 238                         LM3692X_BRHT_MODE_RAMP_MULTI |
 239                         LM3692X_BL_ADJ_POL |
 240                         LM3692X_RAMP_RATE_250us);
 241         if (ret)
 242                 goto out;
 243
 244         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
 245         if (ret)
 246                 goto out;
 247
 248         ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
 249         if (ret)
 250                 goto out;
 251
 252         ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
 253         if (ret)
 254                 goto out;
 255
 256         ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
 257                         LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
 258         if (ret)
 259                 goto out;
 260
 261         return ret;
 262 out:
 263         dev_err(&led->client->dev, "Fail writing initialization values\n");
 264
 265         if (led->enable_gpio)
 266                 gpiod_direction_output(led->enable_gpio, 0);
 267
 268         if (led->regulator) {
 269                 ret = regulator_disable(led->regulator);
 270                 if (ret)
 271                         dev_err(&led->client->dev,
 272                                 "Failed to disable regulator\n");
 273         }
 274
 275         return ret;
 276 }
 277
 278 static int lm3692x_probe(struct i2c_client *client,
 279                         const struct i2c_device_id *id)
 280 {
 281         int ret;
 282         struct lm3692x_led *led;
 283         struct device_node *np = client->dev.of_node;
 284         struct device_node *child_node;
 285         const char *name;
 286
 287         led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 288         if (!led)
 289                 return -ENOMEM;
 290
 291         for_each_available_child_of_node(np, child_node) {
 292                 led->led_dev.default_trigger = of_get_property(child_node,
 293                                                     "linux,default-trigger",
 294                                                     NULL);
 295
 296                 ret = of_property_read_string(child_node, "label", &name);
 297                 if (!ret)
 298                         snprintf(led->label, sizeof(led->label),
 299                                  "%s:%s", id->name, name);
 300                 else
 301                         snprintf(led->label, sizeof(led->label),
 302                                  "%s::backlight_cluster", id->name);
 303         };
 304
 305         led->enable_gpio = devm_gpiod_get_optional(&client->dev,
 306                                                    "enable", GPIOD_OUT_LOW);
 307         if (IS_ERR(led->enable_gpio)) {
 308                 ret = PTR_ERR(led->enable_gpio);
 309                 dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
 310                 return ret;
 311         }
 312
 313         led->regulator = devm_regulator_get(&client->dev, "vled");
 314         if (IS_ERR(led->regulator))
 315                 led->regulator = NULL;
 316
 317         led->client = client;
 318         led->led_dev.name = led->label;
 319         led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
 320
 321         mutex_init(&led->lock);
 322
 323         i2c_set_clientdata(client, led);
 324
 325         led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
 326         if (IS_ERR(led->regmap)) {
 327                 ret = PTR_ERR(led->regmap);
 328                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 329                         ret);
 330                 return ret;
 331         }
 332
 333         ret = lm3692x_init(led);
 334         if (ret)
 335                 return ret;
 336
 337         ret = devm_led_classdev_register(&client->dev, &led->led_dev);
 338         if (ret) {
 339                 dev_err(&client->dev, "led register err: %d\n", ret);
 340                 return ret;
 341         }
 342
 343         return 0;
 344 }
 345
 346 static int lm3692x_remove(struct i2c_client *client)
 347 {
 348         struct lm3692x_led *led = i2c_get_clientdata(client);
 349         int ret;
 350
 351         if (led->enable_gpio)
 352                 gpiod_direction_output(led->enable_gpio, 0);
 353
 354         if (led->regulator) {
 355                 ret = regulator_disable(led->regulator);
 356                 if (ret)
 357                         dev_err(&led->client->dev,
 358                                 "Failed to disable regulator\n");
 359         }
 360
 361         mutex_destroy(&led->lock);
 362
 363         return 0;
 364 }
 365
 366 static const struct i2c_device_id lm3692x_id[] = {
 367         { "lm36922", 0 },
 368         { "lm36923", 1 },
 369         { }
 370 };
 371 MODULE_DEVICE_TABLE(i2c, lm3692x_id);
 372
 373 static const struct of_device_id of_lm3692x_leds_match[] = {
 374         { .compatible = "ti,lm36922", },
 375         { .compatible = "ti,lm36923", },
 376         {},
 377 };
 378 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
 379
 380 static struct i2c_driver lm3692x_driver = {
 381         .driver = {
 382                 .name   = "lm3692x",
 383                 .of_match_table = of_lm3692x_leds_match,
 384         },
 385         .probe          = lm3692x_probe,
 386         .remove         = lm3692x_remove,
 387         .id_table       = lm3692x_id,
 388 };
 389 module_i2c_driver(lm3692x_driver);
 390
 391 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
 392 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 393 MODULE_LICENSE("GPL v2");