drivers/leds/leds-lp8860.c

   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 **/
 104 struct 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
 117 struct lp8860_eeprom_reg {
 118         uint8_t reg;
 119         uint8_t value;
 120 };
 121
 122 static 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
 150 static 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
 185 out:
 186         mutex_unlock(&led->lock);
 187         return ret;
 188 }
 189
 190 static 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);
 211 out:
 212         return ret;
 213 }
 214
 215 static 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         }
 242 out:
 243         mutex_unlock(&led->lock);
 244 }
 245
 246 static 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
 256 static 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");
 298 out:
 299         if (ret)
 300                 if (led->enable_gpio)
 301                         gpiod_direction_output(led->enable_gpio, 0);
 302         return ret;
 303 }
 304
 305 static const 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
 325 static 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
 335 static const 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
 363 static 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
 373 static 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
 445 static 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
 466 static const struct i2c_device_id lp8860_id[] = {
 467         { "lp8860", 0 },
 468         { }
 469 };
 470 MODULE_DEVICE_TABLE(i2c, lp8860_id);
 471
 472 #ifdef CONFIG_OF
 473 static const struct of_device_id of_lp8860_leds_match[] = {
 474         { .compatible = "ti,lp8860", },
 475         {},
 476 };
 477 MODULE_DEVICE_TABLE(of, of_lp8860_leds_match);
 478 #endif
 479
 480 static 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 };
 489 module_i2c_driver(lp8860_driver);
 490
 491 MODULE_DESCRIPTION("Texas Instruments LP8860 LED driver");
 492 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 493 MODULE_LICENSE("GPL");