linux/drivers/leds/leds-lm3601x.c
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   1// SPDX-License-Identifier: GPL-2.0
   2// Flash and torch driver for Texas Instruments LM3601X LED
   3// Flash driver chip family
   4// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
   5
   6#include <linux/delay.h>
   7#include <linux/i2c.h>
   8#include <linux/leds.h>
   9#include <linux/led-class-flash.h>
  10#include <linux/module.h>
  11#include <linux/regmap.h>
  12#include <linux/slab.h>
  13#include <uapi/linux/uleds.h>
  14
  15#define LM3601X_LED_IR          0x0
  16#define LM3601X_LED_TORCH       0x1
  17
  18/* Registers */
  19#define LM3601X_ENABLE_REG      0x01
  20#define LM3601X_CFG_REG         0x02
  21#define LM3601X_LED_FLASH_REG   0x03
  22#define LM3601X_LED_TORCH_REG   0x04
  23#define LM3601X_FLAGS_REG       0x05
  24#define LM3601X_DEV_ID_REG      0x06
  25
  26#define LM3601X_SW_RESET        BIT(7)
  27
  28/* Enable Mode bits */
  29#define LM3601X_MODE_STANDBY    0x00
  30#define LM3601X_MODE_IR_DRV     BIT(0)
  31#define LM3601X_MODE_TORCH      BIT(1)
  32#define LM3601X_MODE_STROBE     (BIT(0) | BIT(1))
  33#define LM3601X_STRB_EN         BIT(2)
  34#define LM3601X_STRB_EDGE_TRIG  BIT(3)
  35#define LM3601X_IVFM_EN         BIT(4)
  36
  37#define LM36010_BOOST_LIMIT_28  BIT(5)
  38#define LM36010_BOOST_FREQ_4MHZ BIT(6)
  39#define LM36010_BOOST_MODE_PASS BIT(7)
  40
  41/* Flag Mask */
  42#define LM3601X_FLASH_TIME_OUT  BIT(0)
  43#define LM3601X_UVLO_FAULT      BIT(1)
  44#define LM3601X_THERM_SHUTDOWN  BIT(2)
  45#define LM3601X_THERM_CURR      BIT(3)
  46#define LM36010_CURR_LIMIT      BIT(4)
  47#define LM3601X_SHORT_FAULT     BIT(5)
  48#define LM3601X_IVFM_TRIP       BIT(6)
  49#define LM36010_OVP_FAULT       BIT(7)
  50
  51#define LM3601X_MAX_TORCH_I_UA  376000
  52#define LM3601X_MIN_TORCH_I_UA  2400
  53#define LM3601X_TORCH_REG_DIV   2965
  54
  55#define LM3601X_MAX_STROBE_I_UA 1500000
  56#define LM3601X_MIN_STROBE_I_UA 11000
  57#define LM3601X_STROBE_REG_DIV  11800
  58
  59#define LM3601X_TIMEOUT_MASK    0x1e
  60#define LM3601X_ENABLE_MASK     (LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)
  61
  62#define LM3601X_LOWER_STEP_US   40000
  63#define LM3601X_UPPER_STEP_US   200000
  64#define LM3601X_MIN_TIMEOUT_US  40000
  65#define LM3601X_MAX_TIMEOUT_US  1600000
  66#define LM3601X_TIMEOUT_XOVER_US 400000
  67
  68enum lm3601x_type {
  69        CHIP_LM36010 = 0,
  70        CHIP_LM36011,
  71};
  72
  73/**
  74 * struct lm3601x_led -
  75 * @fled_cdev: flash LED class device pointer
  76 * @client: Pointer to the I2C client
  77 * @regmap: Devices register map
  78 * @lock: Lock for reading/writing the device
  79 * @led_name: LED label for the Torch or IR LED
  80 * @flash_timeout: the timeout for the flash
  81 * @last_flag: last known flags register value
  82 * @torch_current_max: maximum current for the torch
  83 * @flash_current_max: maximum current for the flash
  84 * @max_flash_timeout: maximum timeout for the flash
  85 * @led_mode: The mode to enable either IR or Torch
  86 */
  87struct lm3601x_led {
  88        struct led_classdev_flash fled_cdev;
  89        struct i2c_client *client;
  90        struct regmap *regmap;
  91        struct mutex lock;
  92
  93        char led_name[LED_MAX_NAME_SIZE];
  94
  95        unsigned int flash_timeout;
  96        unsigned int last_flag;
  97
  98        u32 torch_current_max;
  99        u32 flash_current_max;
 100        u32 max_flash_timeout;
 101
 102        u32 led_mode;
 103};
 104
 105static const struct reg_default lm3601x_regmap_defs[] = {
 106        { LM3601X_ENABLE_REG, 0x20 },
 107        { LM3601X_CFG_REG, 0x15 },
 108        { LM3601X_LED_FLASH_REG, 0x00 },
 109        { LM3601X_LED_TORCH_REG, 0x00 },
 110};
 111
 112static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
 113{
 114        switch (reg) {
 115        case LM3601X_FLAGS_REG:
 116                return true;
 117        default:
 118                return false;
 119        }
 120}
 121
 122static const struct regmap_config lm3601x_regmap = {
 123        .reg_bits = 8,
 124        .val_bits = 8,
 125
 126        .max_register = LM3601X_DEV_ID_REG,
 127        .reg_defaults = lm3601x_regmap_defs,
 128        .num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
 129        .cache_type = REGCACHE_RBTREE,
 130        .volatile_reg = lm3601x_volatile_reg,
 131};
 132
 133static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
 134{
 135        return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
 136}
 137
 138static int lm3601x_read_faults(struct lm3601x_led *led)
 139{
 140        int flags_val;
 141        int ret;
 142
 143        ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
 144        if (ret < 0)
 145                return -EIO;
 146
 147        led->last_flag = 0;
 148
 149        if (flags_val & LM36010_OVP_FAULT)
 150                led->last_flag |= LED_FAULT_OVER_VOLTAGE;
 151
 152        if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
 153                led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
 154
 155        if (flags_val & LM3601X_SHORT_FAULT)
 156                led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
 157
 158        if (flags_val & LM36010_CURR_LIMIT)
 159                led->last_flag |= LED_FAULT_OVER_CURRENT;
 160
 161        if (flags_val & LM3601X_UVLO_FAULT)
 162                led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
 163
 164        if (flags_val & LM3601X_IVFM_TRIP)
 165                led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
 166
 167        if (flags_val & LM3601X_THERM_SHUTDOWN)
 168                led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
 169
 170        return led->last_flag;
 171}
 172
 173static int lm3601x_brightness_set(struct led_classdev *cdev,
 174                                        enum led_brightness brightness)
 175{
 176        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
 177        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 178        int ret, led_mode_val;
 179
 180        mutex_lock(&led->lock);
 181
 182        ret = lm3601x_read_faults(led);
 183        if (ret < 0)
 184                goto out;
 185
 186        if (led->led_mode == LM3601X_LED_TORCH)
 187                led_mode_val = LM3601X_MODE_TORCH;
 188        else
 189                led_mode_val = LM3601X_MODE_IR_DRV;
 190
 191        if (brightness == LED_OFF) {
 192                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 193                                        led_mode_val, LED_OFF);
 194                goto out;
 195        }
 196
 197        ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
 198        if (ret < 0)
 199                goto out;
 200
 201        ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 202                                LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
 203                                led_mode_val);
 204out:
 205        mutex_unlock(&led->lock);
 206        return ret;
 207}
 208
 209static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
 210                                bool state)
 211{
 212        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 213        int timeout_reg_val;
 214        int current_timeout;
 215        int ret;
 216
 217        mutex_lock(&led->lock);
 218
 219        ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
 220        if (ret < 0)
 221                goto out;
 222
 223        if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
 224                timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
 225        else
 226                timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
 227
 228        if (led->flash_timeout != current_timeout)
 229                ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
 230                                        LM3601X_TIMEOUT_MASK, timeout_reg_val);
 231
 232        if (state)
 233                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 234                                        LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
 235                                        LM3601X_MODE_STROBE);
 236        else
 237                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 238                                        LM3601X_MODE_STROBE, LED_OFF);
 239
 240        ret = lm3601x_read_faults(led);
 241out:
 242        mutex_unlock(&led->lock);
 243        return ret;
 244}
 245
 246static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
 247                                        u32 brightness)
 248{
 249        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 250        u8 brightness_val;
 251        int ret;
 252
 253        mutex_lock(&led->lock);
 254        ret = lm3601x_read_faults(led);
 255        if (ret < 0)
 256                goto out;
 257
 258        if (brightness == LED_OFF) {
 259                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 260                                        LM3601X_MODE_STROBE, LED_OFF);
 261                goto out;
 262        }
 263
 264        brightness_val = brightness / LM3601X_STROBE_REG_DIV;
 265
 266        ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
 267out:
 268        mutex_unlock(&led->lock);
 269        return ret;
 270}
 271
 272static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
 273                                u32 timeout)
 274{
 275        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 276
 277        mutex_lock(&led->lock);
 278
 279        led->flash_timeout = timeout;
 280
 281        mutex_unlock(&led->lock);
 282
 283        return 0;
 284}
 285
 286static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
 287{
 288        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 289        int strobe_state;
 290        int ret;
 291
 292        mutex_lock(&led->lock);
 293
 294        ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
 295        if (ret < 0)
 296                goto out;
 297
 298        *state = strobe_state & LM3601X_MODE_STROBE;
 299
 300out:
 301        mutex_unlock(&led->lock);
 302        return ret;
 303}
 304
 305static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
 306                                u32 *fault)
 307{
 308        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 309
 310        lm3601x_read_faults(led);
 311
 312        *fault = led->last_flag;
 313
 314        return 0;
 315}
 316
 317static const struct led_flash_ops flash_ops = {
 318        .flash_brightness_set   = lm3601x_flash_brightness_set,
 319        .strobe_set             = lm3601x_strobe_set,
 320        .strobe_get             = lm3601x_strobe_get,
 321        .timeout_set            = lm3601x_flash_timeout_set,
 322        .fault_get              = lm3601x_flash_fault_get,
 323};
 324
 325static int lm3601x_register_leds(struct lm3601x_led *led)
 326{
 327        struct led_classdev *led_cdev;
 328        struct led_flash_setting *setting;
 329
 330        led->fled_cdev.ops = &flash_ops;
 331
 332        setting = &led->fled_cdev.timeout;
 333        setting->min = LM3601X_MIN_TIMEOUT_US;
 334        setting->max = led->max_flash_timeout;
 335        setting->step = LM3601X_LOWER_STEP_US;
 336        setting->val = led->max_flash_timeout;
 337
 338        setting = &led->fled_cdev.brightness;
 339        setting->min = LM3601X_MIN_STROBE_I_UA;
 340        setting->max = led->flash_current_max;
 341        setting->step = LM3601X_TORCH_REG_DIV;
 342        setting->val = led->flash_current_max;
 343
 344        led_cdev = &led->fled_cdev.led_cdev;
 345        led_cdev->name = led->led_name;
 346        led_cdev->brightness_set_blocking = lm3601x_brightness_set;
 347        led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
 348                                                LM3601X_TORCH_REG_DIV);
 349        led_cdev->flags |= LED_DEV_CAP_FLASH;
 350
 351        return led_classdev_flash_register(&led->client->dev, &led->fled_cdev);
 352}
 353
 354static int lm3601x_parse_node(struct lm3601x_led *led)
 355{
 356        struct fwnode_handle *child = NULL;
 357        int ret = -ENODEV;
 358        const char *name;
 359
 360        child = device_get_next_child_node(&led->client->dev, child);
 361        if (!child) {
 362                dev_err(&led->client->dev, "No LED Child node\n");
 363                return ret;
 364        }
 365
 366        ret = fwnode_property_read_u32(child, "reg", &led->led_mode);
 367        if (ret) {
 368                dev_err(&led->client->dev, "reg DT property missing\n");
 369                goto out_err;
 370        }
 371
 372        if (led->led_mode > LM3601X_LED_TORCH ||
 373            led->led_mode < LM3601X_LED_IR) {
 374                dev_warn(&led->client->dev, "Invalid led mode requested\n");
 375                ret = -EINVAL;
 376                goto out_err;
 377        }
 378
 379        ret = fwnode_property_read_string(child, "label", &name);
 380        if (ret) {
 381                if (led->led_mode == LM3601X_LED_TORCH)
 382                        name = "torch";
 383                else
 384                        name = "infrared";
 385        }
 386
 387        snprintf(led->led_name, sizeof(led->led_name),
 388                "%s:%s", led->client->name, name);
 389
 390        ret = fwnode_property_read_u32(child, "led-max-microamp",
 391                                        &led->torch_current_max);
 392        if (ret) {
 393                dev_warn(&led->client->dev,
 394                        "led-max-microamp DT property missing\n");
 395                goto out_err;
 396        }
 397
 398        ret = fwnode_property_read_u32(child, "flash-max-microamp",
 399                                &led->flash_current_max);
 400        if (ret) {
 401                dev_warn(&led->client->dev,
 402                         "flash-max-microamp DT property missing\n");
 403                goto out_err;
 404        }
 405
 406        ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
 407                                &led->max_flash_timeout);
 408        if (ret) {
 409                dev_warn(&led->client->dev,
 410                         "flash-max-timeout-us DT property missing\n");
 411                goto out_err;
 412        }
 413
 414out_err:
 415        fwnode_handle_put(child);
 416        return ret;
 417}
 418
 419static int lm3601x_probe(struct i2c_client *client)
 420{
 421        struct lm3601x_led *led;
 422        int ret;
 423
 424        led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 425        if (!led)
 426                return -ENOMEM;
 427
 428        led->client = client;
 429        i2c_set_clientdata(client, led);
 430
 431        ret = lm3601x_parse_node(led);
 432        if (ret)
 433                return -ENODEV;
 434
 435        led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
 436        if (IS_ERR(led->regmap)) {
 437                ret = PTR_ERR(led->regmap);
 438                dev_err(&client->dev,
 439                        "Failed to allocate register map: %d\n", ret);
 440                return ret;
 441        }
 442
 443        mutex_init(&led->lock);
 444
 445        return lm3601x_register_leds(led);
 446}
 447
 448static int lm3601x_remove(struct i2c_client *client)
 449{
 450        struct lm3601x_led *led = i2c_get_clientdata(client);
 451
 452        led_classdev_flash_unregister(&led->fled_cdev);
 453        mutex_destroy(&led->lock);
 454
 455        return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 456                           LM3601X_ENABLE_MASK,
 457                           LM3601X_MODE_STANDBY);
 458}
 459
 460static const struct i2c_device_id lm3601x_id[] = {
 461        { "LM36010", CHIP_LM36010 },
 462        { "LM36011", CHIP_LM36011 },
 463        { }
 464};
 465MODULE_DEVICE_TABLE(i2c, lm3601x_id);
 466
 467static const struct of_device_id of_lm3601x_leds_match[] = {
 468        { .compatible = "ti,lm36010", },
 469        { .compatible = "ti,lm36011", },
 470        { }
 471};
 472MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
 473
 474static struct i2c_driver lm3601x_i2c_driver = {
 475        .driver = {
 476                .name = "lm3601x",
 477                .of_match_table = of_lm3601x_leds_match,
 478        },
 479        .probe_new = lm3601x_probe,
 480        .remove = lm3601x_remove,
 481        .id_table = lm3601x_id,
 482};
 483module_i2c_driver(lm3601x_i2c_driver);
 484
 485MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
 486MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 487MODULE_LICENSE("GPL v2");
 488