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 * @work - Work item used to off load the brightness register writes
  95 * @client - Pointer to the I2C client
  96 * @led_dev - led class device pointer
  97 * @regmap - Devices register map
  98 * @eeprom_regmap - EEPROM register map
  99 * @enable_gpio - VDDIO/EN gpio to enable communication interface
 100 * @regulator - LED supply regulator pointer
 101 * @brightness - Current brightness value requested
 102 * @label - LED label
 103**/
 104struct lp8860_led {
 105        struct mutex lock;
 106        struct work_struct work;
 107        struct i2c_client *client;
 108        struct led_classdev led_dev;
 109        struct regmap *regmap;
 110        struct regmap *eeprom_regmap;
 111        struct gpio_desc *enable_gpio;
 112        struct regulator *regulator;
 113        enum led_brightness brightness;
 114        const char *label;
 115};
 116
 117struct lp8860_eeprom_reg {
 118        uint8_t reg;
 119        uint8_t value;
 120};
 121
 122static struct lp8860_eeprom_reg lp8860_eeprom_disp_regs[] = {
 123        { LP8860_EEPROM_REG_0, 0xed },
 124        { LP8860_EEPROM_REG_1, 0xdf },
 125        { LP8860_EEPROM_REG_2, 0xdc },
 126        { LP8860_EEPROM_REG_3, 0xf0 },
 127        { LP8860_EEPROM_REG_4, 0xdf },
 128        { LP8860_EEPROM_REG_5, 0xe5 },
 129        { LP8860_EEPROM_REG_6, 0xf2 },
 130        { LP8860_EEPROM_REG_7, 0x77 },
 131        { LP8860_EEPROM_REG_8, 0x77 },
 132        { LP8860_EEPROM_REG_9, 0x71 },
 133        { LP8860_EEPROM_REG_10, 0x3f },
 134        { LP8860_EEPROM_REG_11, 0xb7 },
 135        { LP8860_EEPROM_REG_12, 0x17 },
 136        { LP8860_EEPROM_REG_13, 0xef },
 137        { LP8860_EEPROM_REG_14, 0xb0 },
 138        { LP8860_EEPROM_REG_15, 0x87 },
 139        { LP8860_EEPROM_REG_16, 0xce },
 140        { LP8860_EEPROM_REG_17, 0x72 },
 141        { LP8860_EEPROM_REG_18, 0xe5 },
 142        { LP8860_EEPROM_REG_19, 0xdf },
 143        { LP8860_EEPROM_REG_20, 0x35 },
 144        { LP8860_EEPROM_REG_21, 0x06 },
 145        { LP8860_EEPROM_REG_22, 0xdc },
 146        { LP8860_EEPROM_REG_23, 0x88 },
 147        { LP8860_EEPROM_REG_24, 0x3E },
 148};
 149
 150static int lp8860_unlock_eeprom(struct lp8860_led *led, int lock)
 151{
 152        int ret;
 153
 154        mutex_lock(&led->lock);
 155
 156        if (lock == LP8860_UNLOCK_EEPROM) {
 157                ret = regmap_write(led->regmap,
 158                        LP8860_EEPROM_UNLOCK,
 159                        LP8860_EEPROM_CODE_1);
 160                if (ret) {
 161                        dev_err(&led->client->dev, "EEPROM Unlock failed\n");
 162                        goto out;
 163                }
 164
 165                ret = regmap_write(led->regmap,
 166                        LP8860_EEPROM_UNLOCK,
 167                        LP8860_EEPROM_CODE_2);
 168                if (ret) {
 169                        dev_err(&led->client->dev, "EEPROM Unlock failed\n");
 170                        goto out;
 171                }
 172                ret = regmap_write(led->regmap,
 173                        LP8860_EEPROM_UNLOCK,
 174                        LP8860_EEPROM_CODE_3);
 175                if (ret) {
 176                        dev_err(&led->client->dev, "EEPROM Unlock failed\n");
 177                        goto out;
 178                }
 179        } else {
 180                ret = regmap_write(led->regmap,
 181                        LP8860_EEPROM_UNLOCK,
 182                        LP8860_LOCK_EEPROM);
 183        }
 184
 185out:
 186        mutex_unlock(&led->lock);
 187        return ret;
 188}
 189
 190static int lp8860_fault_check(struct lp8860_led *led)
 191{
 192        int ret, fault;
 193        unsigned int read_buf;
 194
 195        ret = regmap_read(led->regmap, LP8860_LED_FAULT, &read_buf);
 196        if (ret)
 197                goto out;
 198
 199        fault = read_buf;
 200
 201        ret = regmap_read(led->regmap, LP8860_FAULT, &read_buf);
 202        if (ret)
 203                goto out;
 204
 205        fault |= read_buf;
 206
 207        /* Attempt to clear any faults */
 208        if (fault)
 209                ret = regmap_write(led->regmap, LP8860_FAULT_CLEAR,
 210                        LP8860_CLEAR_FAULTS);
 211out:
 212        return ret;
 213}
 214
 215static void lp8860_led_brightness_work(struct work_struct *work)
 216{
 217        struct lp8860_led *led = container_of(work, struct lp8860_led, work);
 218        int ret;
 219        int disp_brightness = led->brightness * 255;
 220
 221        mutex_lock(&led->lock);
 222
 223        ret = lp8860_fault_check(led);
 224        if (ret) {
 225                dev_err(&led->client->dev, "Cannot read/clear faults\n");
 226                goto out;
 227        }
 228
 229        ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_MSB,
 230                        (disp_brightness & 0xff00) >> 8);
 231        if (ret) {
 232                dev_err(&led->client->dev, "Cannot write CL1 MSB\n");
 233                goto out;
 234        }
 235
 236        ret = regmap_write(led->regmap, LP8860_DISP_CL1_BRT_LSB,
 237                        disp_brightness & 0xff);
 238        if (ret) {
 239                dev_err(&led->client->dev, "Cannot write CL1 LSB\n");
 240                goto out;
 241        }
 242out:
 243        mutex_unlock(&led->lock);
 244}
 245
 246static void lp8860_brightness_set(struct led_classdev *led_cdev,
 247                                enum led_brightness brt_val)
 248{
 249        struct lp8860_led *led =
 250                        container_of(led_cdev, struct lp8860_led, led_dev);
 251
 252        led->brightness = brt_val;
 253        schedule_work(&led->work);
 254}
 255
 256static int lp8860_init(struct lp8860_led *led)
 257{
 258        unsigned int read_buf;
 259        int ret, i, reg_count;
 260
 261        if (led->enable_gpio)
 262                gpiod_direction_output(led->enable_gpio, 1);
 263
 264        ret = lp8860_fault_check(led);
 265        if (ret)
 266                goto out;
 267
 268        ret = regmap_read(led->regmap, LP8860_STATUS, &read_buf);
 269        if (ret)
 270                goto out;
 271
 272        ret = lp8860_unlock_eeprom(led, LP8860_UNLOCK_EEPROM);
 273        if (ret) {
 274                dev_err(&led->client->dev, "Failed unlocking EEPROM\n");
 275                goto out;
 276        }
 277
 278        reg_count = ARRAY_SIZE(lp8860_eeprom_disp_regs) / sizeof(lp8860_eeprom_disp_regs[0]);
 279        for (i = 0; i < reg_count; i++) {
 280                ret = regmap_write(led->eeprom_regmap,
 281                                lp8860_eeprom_disp_regs[i].reg,
 282                                lp8860_eeprom_disp_regs[i].value);
 283                if (ret) {
 284                        dev_err(&led->client->dev, "Failed writing EEPROM\n");
 285                        goto out;
 286                }
 287        }
 288
 289        ret = lp8860_unlock_eeprom(led, LP8860_LOCK_EEPROM);
 290        if (ret)
 291                goto out;
 292
 293        ret = regmap_write(led->regmap,
 294                        LP8860_EEPROM_CNTRL,
 295                        LP8860_PROGRAM_EEPROM);
 296        if (ret)
 297                dev_err(&led->client->dev, "Failed programming EEPROM\n");
 298out:
 299        if (ret)
 300                if (led->enable_gpio)
 301                        gpiod_direction_output(led->enable_gpio, 0);
 302        return ret;
 303}
 304
 305static struct reg_default lp8860_reg_defs[] = {
 306        { LP8860_DISP_CL1_BRT_MSB, 0x00},
 307        { LP8860_DISP_CL1_BRT_LSB, 0x00},
 308        { LP8860_DISP_CL1_CURR_MSB, 0x00},
 309        { LP8860_DISP_CL1_CURR_LSB, 0x00},
 310        { LP8860_CL2_BRT_MSB, 0x00},
 311        { LP8860_CL2_BRT_LSB, 0x00},
 312        { LP8860_CL2_CURRENT, 0x00},
 313        { LP8860_CL3_BRT_MSB, 0x00},
 314        { LP8860_CL3_BRT_LSB, 0x00},
 315        { LP8860_CL3_CURRENT, 0x00},
 316        { LP8860_CL4_BRT_MSB, 0x00},
 317        { LP8860_CL4_BRT_LSB, 0x00},
 318        { LP8860_CL4_CURRENT, 0x00},
 319        { LP8860_CONFIG, 0x00},
 320        { LP8860_FAULT_CLEAR, 0x00},
 321        { LP8860_EEPROM_CNTRL, 0x80},
 322        { LP8860_EEPROM_UNLOCK, 0x00},
 323};
 324
 325static const struct regmap_config lp8860_regmap_config = {
 326        .reg_bits = 8,
 327        .val_bits = 8,
 328
 329        .max_register = LP8860_EEPROM_UNLOCK,
 330        .reg_defaults = lp8860_reg_defs,
 331        .num_reg_defaults = ARRAY_SIZE(lp8860_reg_defs),
 332        .cache_type = REGCACHE_NONE,
 333};
 334
 335static struct reg_default lp8860_eeprom_defs[] = {
 336        { LP8860_EEPROM_REG_0, 0x00 },
 337        { LP8860_EEPROM_REG_1, 0x00 },
 338        { LP8860_EEPROM_REG_2, 0x00 },
 339        { LP8860_EEPROM_REG_3, 0x00 },
 340        { LP8860_EEPROM_REG_4, 0x00 },
 341        { LP8860_EEPROM_REG_5, 0x00 },
 342        { LP8860_EEPROM_REG_6, 0x00 },
 343        { LP8860_EEPROM_REG_7, 0x00 },
 344        { LP8860_EEPROM_REG_8, 0x00 },
 345        { LP8860_EEPROM_REG_9, 0x00 },
 346        { LP8860_EEPROM_REG_10, 0x00 },
 347        { LP8860_EEPROM_REG_11, 0x00 },
 348        { LP8860_EEPROM_REG_12, 0x00 },
 349        { LP8860_EEPROM_REG_13, 0x00 },
 350        { LP8860_EEPROM_REG_14, 0x00 },
 351        { LP8860_EEPROM_REG_15, 0x00 },
 352        { LP8860_EEPROM_REG_16, 0x00 },
 353        { LP8860_EEPROM_REG_17, 0x00 },
 354        { LP8860_EEPROM_REG_18, 0x00 },
 355        { LP8860_EEPROM_REG_19, 0x00 },
 356        { LP8860_EEPROM_REG_20, 0x00 },
 357        { LP8860_EEPROM_REG_21, 0x00 },
 358        { LP8860_EEPROM_REG_22, 0x00 },
 359        { LP8860_EEPROM_REG_23, 0x00 },
 360        { LP8860_EEPROM_REG_24, 0x00 },
 361};
 362
 363static const struct regmap_config lp8860_eeprom_regmap_config = {
 364        .reg_bits = 8,
 365        .val_bits = 8,
 366
 367        .max_register = LP8860_EEPROM_REG_24,
 368        .reg_defaults = lp8860_eeprom_defs,
 369        .num_reg_defaults = ARRAY_SIZE(lp8860_eeprom_defs),
 370        .cache_type = REGCACHE_NONE,
 371};
 372
 373static int lp8860_probe(struct i2c_client *client,
 374                        const struct i2c_device_id *id)
 375{
 376        int ret;
 377        struct lp8860_led *led;
 378        struct device_node *np = client->dev.of_node;
 379
 380        led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 381        if (!led)
 382                return -ENOMEM;
 383
 384        led->label = LP8860_DISP_LED_NAME;
 385
 386        if (client->dev.of_node) {
 387                ret = of_property_read_string(np, "label", &led->label);
 388                if (ret) {
 389                        dev_err(&client->dev, "Missing label in dt\n");
 390                        return -EINVAL;
 391                }
 392        }
 393
 394        led->enable_gpio = devm_gpiod_get_optional(&client->dev,
 395                                                   "enable", GPIOD_OUT_LOW);
 396        if (IS_ERR(led->enable_gpio)) {
 397                ret = PTR_ERR(led->enable_gpio);
 398                dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
 399                return ret;
 400        }
 401
 402        led->regulator = devm_regulator_get(&client->dev, "vled");
 403        if (IS_ERR(led->regulator))
 404                led->regulator = NULL;
 405
 406        led->client = client;
 407        led->led_dev.name = led->label;
 408        led->led_dev.max_brightness = LED_FULL;
 409        led->led_dev.brightness_set = lp8860_brightness_set;
 410
 411        mutex_init(&led->lock);
 412        INIT_WORK(&led->work, lp8860_led_brightness_work);
 413
 414        i2c_set_clientdata(client, led);
 415
 416        led->regmap = devm_regmap_init_i2c(client, &lp8860_regmap_config);
 417        if (IS_ERR(led->regmap)) {
 418                ret = PTR_ERR(led->regmap);
 419                dev_err(&client->dev, "Failed to allocate register map: %d\n",
 420                        ret);
 421                return ret;
 422        }
 423
 424        led->eeprom_regmap = devm_regmap_init_i2c(client, &lp8860_eeprom_regmap_config);
 425        if (IS_ERR(led->eeprom_regmap)) {
 426                ret = PTR_ERR(led->eeprom_regmap);
 427                dev_err(&client->dev, "Failed to allocate register map: %d\n",
 428                        ret);
 429                return ret;
 430        }
 431
 432        ret = lp8860_init(led);
 433        if (ret)
 434                return ret;
 435
 436        ret = led_classdev_register(&client->dev, &led->led_dev);
 437        if (ret) {
 438                dev_err(&client->dev, "led register err: %d\n", ret);
 439                return ret;
 440        }
 441
 442        return 0;
 443}
 444
 445static int lp8860_remove(struct i2c_client *client)
 446{
 447        struct lp8860_led *led = i2c_get_clientdata(client);
 448        int ret;
 449
 450        led_classdev_unregister(&led->led_dev);
 451        cancel_work_sync(&led->work);
 452
 453        if (led->enable_gpio)
 454                gpiod_direction_output(led->enable_gpio, 0);
 455
 456        if (led->regulator) {
 457                ret = regulator_disable(led->regulator);
 458                if (ret)
 459                        dev_err(&led->client->dev,
 460                                "Failed to disable regulator\n");
 461        }
 462
 463        return 0;
 464}
 465
 466static const struct i2c_device_id lp8860_id[] = {
 467        { "lp8860", 0 },
 468        { }
 469};
 470MODULE_DEVICE_TABLE(i2c, lp8860_id);
 471
 472#ifdef CONFIG_OF
 473static const struct of_device_id of_lp8860_leds_match[] = {
 474        { .compatible = "ti,lp8860", },
 475        {},
 476};
 477MODULE_DEVICE_TABLE(of, of_lp8860_leds_match);
 478#endif
 479
 480static struct i2c_driver lp8860_driver = {
 481        .driver = {
 482                .name   = "lp8860",
 483                .of_match_table = of_match_ptr(of_lp8860_leds_match),
 484        },
 485        .probe          = lp8860_probe,
 486        .remove         = lp8860_remove,
 487        .id_table       = lp8860_id,
 488};
 489module_i2c_driver(lp8860_driver);
 490
 491MODULE_DESCRIPTION("Texas Instruments LP8860 LED driver");
 492MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 493MODULE_LICENSE("GPL");
 494