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