drivers/leds/leds-lm3601x.c

   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
  68 enum 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  */
  87 struct 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
 105 static 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
 112 static 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
 122 static 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
 133 static 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
 138 static 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
 173 static 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);
 204 out:
 205         mutex_unlock(&led->lock);
 206         return ret;
 207 }
 208
 209 static 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);
 241 out:
 242         mutex_unlock(&led->lock);
 243         return ret;
 244 }
 245
 246 static 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);
 267 out:
 268         mutex_unlock(&led->lock);
 269         return ret;
 270 }
 271
 272 static 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
 286 static 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
 300 out:
 301         mutex_unlock(&led->lock);
 302         return ret;
 303 }
 304
 305 static 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
 317 static 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
 325 static 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
 354 static 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
 414 out_err:
 415         fwnode_handle_put(child);
 416         return ret;
 417 }
 418
 419 static 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
 448 static 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
 460 static const struct i2c_device_id lm3601x_id[] = {
 461         { "LM36010", CHIP_LM36010 },
 462         { "LM36011", CHIP_LM36011 },
 463         { }
 464 };
 465 MODULE_DEVICE_TABLE(i2c, lm3601x_id);
 466
 467 static const struct of_device_id of_lm3601x_leds_match[] = {
 468         { .compatible = "ti,lm36010", },
 469         { .compatible = "ti,lm36011", },
 470         { }
 471 };
 472 MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
 473
 474 static 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 };
 483 module_i2c_driver(lm3601x_i2c_driver);
 484
 485 MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
 486 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 487 MODULE_LICENSE("GPL v2");