linux/drivers/leds/leds-lp8860.c
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   1/*
   2 * TI LP8860 4-Channel LED Driver
   3 *
   4 * Copyright (C) 2014 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 */
  13
  14#include <linux/i2c.h>
  15#include <linux/init.h>
  16#include <linux/leds.h>
  17#include <linux/regmap.h>
  18#include <linux/regulator/consumer.h>
  19#include <linux/module.h>
  20#include <linux/mutex.h>
  21#include <linux/of.h>
  22#include <linux/of_gpio.h>
  23#include <linux/gpio/consumer.h>
  24#include <linux/slab.h>
  25
  26#define LP8860_DISP_CL1_BRT_MSB         0x00
  27#define LP8860_DISP_CL1_BRT_LSB         0x01
  28#define LP8860_DISP_CL1_CURR_MSB        0x02
  29#define LP8860_DISP_CL1_CURR_LSB        0x03
  30#define LP8860_CL2_BRT_MSB              0x04
  31#define LP8860_CL2_BRT_LSB              0x05
  32#define LP8860_CL2_CURRENT              0x06
  33#define LP8860_CL3_BRT_MSB              0x07
  34#define LP8860_CL3_BRT_LSB              0x08
  35#define LP8860_CL3_CURRENT              0x09
  36#define LP8860_CL4_BRT_MSB              0x0a
  37#define LP8860_CL4_BRT_LSB              0x0b
  38#define LP8860_CL4_CURRENT              0x0c
  39#define LP8860_CONFIG                   0x0d
  40#define LP8860_STATUS                   0x0e
  41#define LP8860_FAULT                    0x0f
  42#define LP8860_LED_FAULT                0x10
  43#define LP8860_FAULT_CLEAR              0x11
  44#define LP8860_ID                       0x12
  45#define LP8860_TEMP_MSB                 0x13
  46#define LP8860_TEMP_LSB                 0x14
  47#define LP8860_DISP_LED_CURR_MSB        0x15
  48#define LP8860_DISP_LED_CURR_LSB        0x16
  49#define LP8860_DISP_LED_PWM_MSB         0x17
  50#define LP8860_DISP_LED_PWM_LSB         0x18
  51#define LP8860_EEPROM_CNTRL             0x19
  52#define LP8860_EEPROM_UNLOCK            0x1a
  53
  54#define LP8860_EEPROM_REG_0             0x60
  55#define LP8860_EEPROM_REG_1             0x61
  56#define LP8860_EEPROM_REG_2             0x62
  57#define LP8860_EEPROM_REG_3             0x63
  58#define LP8860_EEPROM_REG_4             0x64
  59#define LP8860_EEPROM_REG_5             0x65
  60#define LP8860_EEPROM_REG_6             0x66
  61#define LP8860_EEPROM_REG_7             0x67
  62#define LP8860_EEPROM_REG_8             0x68
  63#define LP8860_EEPROM_REG_9             0x69
  64#define LP8860_EEPROM_REG_10            0x6a
  65#define LP8860_EEPROM_REG_11            0x6b
  66#define LP8860_EEPROM_REG_12            0x6c
  67#define LP8860_EEPROM_REG_13            0x6d
  68#define LP8860_EEPROM_REG_14            0x6e
  69#define LP8860_EEPROM_REG_15            0x6f
  70#define LP8860_EEPROM_REG_16            0x70
  71#define LP8860_EEPROM_REG_17            0x71
  72#define LP8860_EEPROM_REG_18            0x72
  73#define LP8860_EEPROM_REG_19            0x73
  74#define LP8860_EEPROM_REG_20            0x74
  75#define LP8860_EEPROM_REG_21            0x75
  76#define LP8860_EEPROM_REG_22            0x76
  77#define LP8860_EEPROM_REG_23            0x77
  78#define LP8860_EEPROM_REG_24            0x78
  79
  80#define LP8860_LOCK_EEPROM              0x00
  81#define LP8860_UNLOCK_EEPROM            0x01
  82#define LP8860_PROGRAM_EEPROM           0x02
  83#define LP8860_EEPROM_CODE_1            0x08
  84#define LP8860_EEPROM_CODE_2            0xba
  85#define LP8860_EEPROM_CODE_3            0xef
  86
  87#define LP8860_CLEAR_FAULTS             0x01
  88
  89#define LP8860_DISP_LED_NAME            "display_cluster"
  90
  91/**
  92 * struct lp8860_led -
  93 * @lock - Lock for reading/writing the device
  94 * @client - Pointer to the I2C client
  95 * @led_dev - led class device pointer
  96 * @regmap - Devices register map
  97 * @eeprom_regmap - EEPROM register map
  98 * @enable_gpio - VDDIO/EN gpio to enable communication interface
  99 * @regulator - LED supply regulator pointer
 100 * @label - LED label
 101**/
 102struct lp8860_led {
 103        struct mutex lock;
 104        struct i2c_client *client;
 105        struct led_classdev led_dev;
 106        struct regmap *regmap;
 107        struct regmap *eeprom_regmap;
 108        struct gpio_desc *enable_gpio;
 109        struct regulator *regulator;
 110        const char *label;
 111};
 112
 113struct lp8860_eeprom_reg {
 114        uint8_t reg;
 115        uint8_t value;
 116};
 117
 118static struct lp8860_eeprom_reg lp8860_eeprom_disp_regs[] = {
 119        { LP8860_EEPROM_REG_0, 0xed },
 120        { LP8860_EEPROM_REG_1, 0xdf },
 121        { LP8860_EEPROM_REG_2, 0xdc },
 122        { LP8860_EEPROM_REG_3, 0xf0 },
 123        { LP8860_EEPROM_REG_4, 0xdf },
 124        { LP8860_EEPROM_REG_5, 0xe5 },
 125        { LP8860_EEPROM_REG_6, 0xf2 },
 126        { LP8860_EEPROM_REG_7, 0x77 },
 127        { LP8860_EEPROM_REG_8, 0x77 },
 128        { LP8860_EEPROM_REG_9, 0x71 },
 129        { LP8860_EEPROM_REG_10, 0x3f },
 130        { LP8860_EEPROM_REG_11, 0xb7 },
 131        { LP8860_EEPROM_REG_12, 0x17 },
 132        { LP8860_EEPROM_REG_13, 0xef },
 133        { LP8860_EEPROM_REG_14, 0xb0 },
 134        { LP8860_EEPROM_REG_15, 0x87 },
 135        { LP8860_EEPROM_REG_16, 0xce },
 136        { LP8860_EEPROM_REG_17, 0x72 },
 137        { LP8860_EEPROM_REG_18, 0xe5 },
 138        { LP8860_EEPROM_REG_19, 0xdf },
 139        { LP8860_EEPROM_REG_20, 0x35 },
 140        { LP8860_EEPROM_REG_21, 0x06 },
 141        { LP8860_EEPROM_REG_22, 0xdc },
 142        { LP8860_EEPROM_REG_23, 0x88 },
 143        { LP8860_EEPROM_REG_24, 0x3E },
 144};
 145
 146static int lp8860_unlock_eeprom(struct lp8860_led *led, int lock)
 147{
 148        int ret;
 149
 150        mutex_lock(&led->lock);
 151
 152        if (lock == LP8860_UNLOCK_EEPROM) {
 153                ret = regmap_write(led->regmap,
 154                        LP8860_EEPROM_UNLOCK,
 155                        LP8860_EEPROM_CODE_1);
 156                if (ret) {
 157                        dev_err(&led->client->dev, "EEPROM Unlock failed\n");
 158                        goto out;
 159                }
 160
 161                ret = regmap_write(led->regmap,
 162                        LP8860_EEPROM_UNLOCK,
 163                        LP8860_EEPROM_CODE_2);
 164                if (ret) {
 165                        dev_err(&led->client->dev, "EEPROM Unlock failed\n");
 166                        goto out;
 167                }
 168                ret = regmap_write(led->regmap,
 169                        LP8860_EEPROM_UNLOCK,
 170                        LP8860_EEPROM_CODE_3);
 171                if (ret) {
 172                        dev_err(&led->client->dev, "EEPROM Unlock failed\n");
 173                        goto out;
 174                }
 175        } else {
 176                ret = regmap_write(led->regmap,
 177                        LP8860_EEPROM_UNLOCK,
 178                        LP8860_LOCK_EEPROM);
 179        }
 180
 181out:
 182        mutex_unlock(&led->lock);
 183        return ret;
 184}
 185
 186static int lp8860_fault_check(struct lp8860_led *led)
 187{
 188        int ret, fault;
 189        unsigned int read_buf;
 190
 191        ret = regmap_read(led->regmap, LP8860_LED_FAULT, &read_buf);
 192        if (ret)
 193                goto out;
 194
 195        fault = read_buf;
 196
 197        ret = regmap_read(led->regmap, LP8860_FAULT, &read_buf);
 198        if (ret)
 199                goto out;
 200
 201        fault |= read_buf;
 202
 203        /* Attempt to clear any faults */
 204        if (fault)
 205                ret = regmap_write(led->regmap, LP8860_FAULT_CLEAR,
 206                        LP8860_CLEAR_FAULTS);
 207out:
 208        return ret;
 209}
 210
 211static int lp8860_brightness_set(struct led_classdev *led_cdev,
 212                                enum led_brightness brt_val)
 213{
 214        struct lp8860_led *led =
 215                        container_of(led_cdev, struct lp8860_led, led_dev);
 216        int disp_brightness = brt_val * 255;
 217        int ret;
 218
 219        mutex_lock(&led->lock);
 220
 221        ret = lp8860_fault_check(led);
 222        if (ret) {
 223                dev_err(&led->client->dev, "Cannot read/clear faults\n");
 224                goto out;
 225        }
 226
 227        ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_MSB,
 228                        (disp_brightness & 0xff00) >> 8);
 229        if (ret) {
 230                dev_err(&led->client->dev, "Cannot write CL1 MSB\n");
 231                goto out;
 232        }
 233
 234        ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_LSB,
 235                        disp_brightness & 0xff);
 236        if (ret) {
 237                dev_err(&led->client->dev, "Cannot write CL1 LSB\n");
 238                goto out;
 239        }
 240out:
 241        mutex_unlock(&led->lock);
 242        return ret;
 243}
 244
 245static int lp8860_init(struct lp8860_led *led)
 246{
 247        unsigned int read_buf;
 248        int ret, i, reg_count;
 249
 250        if (led->enable_gpio)
 251                gpiod_direction_output(led->enable_gpio, 1);
 252
 253        ret = lp8860_fault_check(led);
 254        if (ret)
 255                goto out;
 256
 257        ret = regmap_read(led->regmap, LP8860_STATUS, &read_buf);
 258        if (ret)
 259                goto out;
 260
 261        ret = lp8860_unlock_eeprom(led, LP8860_UNLOCK_EEPROM);
 262        if (ret) {
 263                dev_err(&led->client->dev, "Failed unlocking EEPROM\n");
 264                goto out;
 265        }
 266
 267        reg_count = ARRAY_SIZE(lp8860_eeprom_disp_regs) / sizeof(lp8860_eeprom_disp_regs[0]);
 268        for (i = 0; i < reg_count; i++) {
 269                ret = regmap_write(led->eeprom_regmap,
 270                                lp8860_eeprom_disp_regs[i].reg,
 271                                lp8860_eeprom_disp_regs[i].value);
 272                if (ret) {
 273                        dev_err(&led->client->dev, "Failed writing EEPROM\n");
 274                        goto out;
 275                }
 276        }
 277
 278        ret = lp8860_unlock_eeprom(led, LP8860_LOCK_EEPROM);
 279        if (ret)
 280                goto out;
 281
 282        ret = regmap_write(led->regmap,
 283                        LP8860_EEPROM_CNTRL,
 284                        LP8860_PROGRAM_EEPROM);
 285        if (ret)
 286                dev_err(&led->client->dev, "Failed programming EEPROM\n");
 287out:
 288        if (ret)
 289                if (led->enable_gpio)
 290                        gpiod_direction_output(led->enable_gpio, 0);
 291        return ret;
 292}
 293
 294static const struct reg_default lp8860_reg_defs[] = {
 295        { LP8860_DISP_CL1_BRT_MSB, 0x00},
 296        { LP8860_DISP_CL1_BRT_LSB, 0x00},
 297        { LP8860_DISP_CL1_CURR_MSB, 0x00},
 298        { LP8860_DISP_CL1_CURR_LSB, 0x00},
 299        { LP8860_CL2_BRT_MSB, 0x00},
 300        { LP8860_CL2_BRT_LSB, 0x00},
 301        { LP8860_CL2_CURRENT, 0x00},
 302        { LP8860_CL3_BRT_MSB, 0x00},
 303        { LP8860_CL3_BRT_LSB, 0x00},
 304        { LP8860_CL3_CURRENT, 0x00},
 305        { LP8860_CL4_BRT_MSB, 0x00},
 306        { LP8860_CL4_BRT_LSB, 0x00},
 307        { LP8860_CL4_CURRENT, 0x00},
 308        { LP8860_CONFIG, 0x00},
 309        { LP8860_FAULT_CLEAR, 0x00},
 310        { LP8860_EEPROM_CNTRL, 0x80},
 311        { LP8860_EEPROM_UNLOCK, 0x00},
 312};
 313
 314static const struct regmap_config lp8860_regmap_config = {
 315        .reg_bits = 8,
 316        .val_bits = 8,
 317
 318        .max_register = LP8860_EEPROM_UNLOCK,
 319        .reg_defaults = lp8860_reg_defs,
 320        .num_reg_defaults = ARRAY_SIZE(lp8860_reg_defs),
 321        .cache_type = REGCACHE_NONE,
 322};
 323
 324static const struct reg_default lp8860_eeprom_defs[] = {
 325        { LP8860_EEPROM_REG_0, 0x00 },
 326        { LP8860_EEPROM_REG_1, 0x00 },
 327        { LP8860_EEPROM_REG_2, 0x00 },
 328        { LP8860_EEPROM_REG_3, 0x00 },
 329        { LP8860_EEPROM_REG_4, 0x00 },
 330        { LP8860_EEPROM_REG_5, 0x00 },
 331        { LP8860_EEPROM_REG_6, 0x00 },
 332        { LP8860_EEPROM_REG_7, 0x00 },
 333        { LP8860_EEPROM_REG_8, 0x00 },
 334        { LP8860_EEPROM_REG_9, 0x00 },
 335        { LP8860_EEPROM_REG_10, 0x00 },
 336        { LP8860_EEPROM_REG_11, 0x00 },
 337        { LP8860_EEPROM_REG_12, 0x00 },
 338        { LP8860_EEPROM_REG_13, 0x00 },
 339        { LP8860_EEPROM_REG_14, 0x00 },
 340        { LP8860_EEPROM_REG_15, 0x00 },
 341        { LP8860_EEPROM_REG_16, 0x00 },
 342        { LP8860_EEPROM_REG_17, 0x00 },
 343        { LP8860_EEPROM_REG_18, 0x00 },
 344        { LP8860_EEPROM_REG_19, 0x00 },
 345        { LP8860_EEPROM_REG_20, 0x00 },
 346        { LP8860_EEPROM_REG_21, 0x00 },
 347        { LP8860_EEPROM_REG_22, 0x00 },
 348        { LP8860_EEPROM_REG_23, 0x00 },
 349        { LP8860_EEPROM_REG_24, 0x00 },
 350};
 351
 352static const struct regmap_config lp8860_eeprom_regmap_config = {
 353        .reg_bits = 8,
 354        .val_bits = 8,
 355
 356        .max_register = LP8860_EEPROM_REG_24,
 357        .reg_defaults = lp8860_eeprom_defs,
 358        .num_reg_defaults = ARRAY_SIZE(lp8860_eeprom_defs),
 359        .cache_type = REGCACHE_NONE,
 360};
 361
 362static int lp8860_probe(struct i2c_client *client,
 363                        const struct i2c_device_id *id)
 364{
 365        int ret;
 366        struct lp8860_led *led;
 367        struct device_node *np = client->dev.of_node;
 368
 369        led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 370        if (!led)
 371                return -ENOMEM;
 372
 373        led->label = LP8860_DISP_LED_NAME;
 374
 375        if (client->dev.of_node) {
 376                ret = of_property_read_string(np, "label", &led->label);
 377                if (ret) {
 378                        dev_err(&client->dev, "Missing label in dt\n");
 379                        return -EINVAL;
 380                }
 381        }
 382
 383        led->enable_gpio = devm_gpiod_get_optional(&client->dev,
 384                                                   "enable", GPIOD_OUT_LOW);
 385        if (IS_ERR(led->enable_gpio)) {
 386                ret = PTR_ERR(led->enable_gpio);
 387                dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
 388                return ret;
 389        }
 390
 391        led->regulator = devm_regulator_get(&client->dev, "vled");
 392        if (IS_ERR(led->regulator))
 393                led->regulator = NULL;
 394
 395        led->client = client;
 396        led->led_dev.name = led->label;
 397        led->led_dev.max_brightness = LED_FULL;
 398        led->led_dev.brightness_set_blocking = lp8860_brightness_set;
 399
 400        mutex_init(&led->lock);
 401
 402        i2c_set_clientdata(client, led);
 403
 404        led->regmap = devm_regmap_init_i2c(client, &lp8860_regmap_config);
 405        if (IS_ERR(led->regmap)) {
 406                ret = PTR_ERR(led->regmap);
 407                dev_err(&client->dev, "Failed to allocate register map: %d\n",
 408                        ret);
 409                return ret;
 410        }
 411
 412        led->eeprom_regmap = devm_regmap_init_i2c(client, &lp8860_eeprom_regmap_config);
 413        if (IS_ERR(led->eeprom_regmap)) {
 414                ret = PTR_ERR(led->eeprom_regmap);
 415                dev_err(&client->dev, "Failed to allocate register map: %d\n",
 416                        ret);
 417                return ret;
 418        }
 419
 420        ret = lp8860_init(led);
 421        if (ret)
 422                return ret;
 423
 424        ret = led_classdev_register(&client->dev, &led->led_dev);
 425        if (ret) {
 426                dev_err(&client->dev, "led register err: %d\n", ret);
 427                return ret;
 428        }
 429
 430        return 0;
 431}
 432
 433static int lp8860_remove(struct i2c_client *client)
 434{
 435        struct lp8860_led *led = i2c_get_clientdata(client);
 436        int ret;
 437
 438        led_classdev_unregister(&led->led_dev);
 439
 440        if (led->enable_gpio)
 441                gpiod_direction_output(led->enable_gpio, 0);
 442
 443        if (led->regulator) {
 444                ret = regulator_disable(led->regulator);
 445                if (ret)
 446                        dev_err(&led->client->dev,
 447                                "Failed to disable regulator\n");
 448        }
 449
 450        return 0;
 451}
 452
 453static const struct i2c_device_id lp8860_id[] = {
 454        { "lp8860", 0 },
 455        { }
 456};
 457MODULE_DEVICE_TABLE(i2c, lp8860_id);
 458
 459#ifdef CONFIG_OF
 460static const struct of_device_id of_lp8860_leds_match[] = {
 461        { .compatible = "ti,lp8860", },
 462        {},
 463};
 464MODULE_DEVICE_TABLE(of, of_lp8860_leds_match);
 465#endif
 466
 467static struct i2c_driver lp8860_driver = {
 468        .driver = {
 469                .name   = "lp8860",
 470                .of_match_table = of_match_ptr(of_lp8860_leds_match),
 471        },
 472        .probe          = lp8860_probe,
 473        .remove         = lp8860_remove,
 474        .id_table       = lp8860_id,
 475};
 476module_i2c_driver(lp8860_driver);
 477
 478MODULE_DESCRIPTION("Texas Instruments LP8860 LED driver");
 479MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 480MODULE_LICENSE("GPL");
 481