drivers/leds/flash/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 - 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
  67 enum lm3601x_type {
  68         CHIP_LM36010 = 0,
  69         CHIP_LM36011,
  70 };
  71
  72 /**
  73  * struct lm3601x_led - private lm3601x LED data
  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  * @flash_timeout: the timeout for the flash
  79  * @last_flag: last known flags register value
  80  * @torch_current_max: maximum current for the torch
  81  * @flash_current_max: maximum current for the flash
  82  * @max_flash_timeout: maximum timeout for the flash
  83  * @led_mode: The mode to enable either IR or Torch
  84  */
  85 struct lm3601x_led {
  86         struct led_classdev_flash fled_cdev;
  87         struct i2c_client *client;
  88         struct regmap *regmap;
  89         struct mutex lock;
  90
  91         unsigned int flash_timeout;
  92         unsigned int last_flag;
  93
  94         u32 torch_current_max;
  95         u32 flash_current_max;
  96         u32 max_flash_timeout;
  97
  98         u32 led_mode;
  99 };
 100
 101 static const struct reg_default lm3601x_regmap_defs[] = {
 102         { LM3601X_ENABLE_REG, 0x20 },
 103         { LM3601X_CFG_REG, 0x15 },
 104         { LM3601X_LED_FLASH_REG, 0x00 },
 105         { LM3601X_LED_TORCH_REG, 0x00 },
 106 };
 107
 108 static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
 109 {
 110         switch (reg) {
 111         case LM3601X_FLAGS_REG:
 112                 return true;
 113         default:
 114                 return false;
 115         }
 116 }
 117
 118 static const struct regmap_config lm3601x_regmap = {
 119         .reg_bits = 8,
 120         .val_bits = 8,
 121
 122         .max_register = LM3601X_DEV_ID_REG,
 123         .reg_defaults = lm3601x_regmap_defs,
 124         .num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
 125         .cache_type = REGCACHE_MAPLE,
 126         .volatile_reg = lm3601x_volatile_reg,
 127 };
 128
 129 static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
 130 {
 131         return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
 132 }
 133
 134 static int lm3601x_read_faults(struct lm3601x_led *led)
 135 {
 136         int flags_val;
 137         int ret;
 138
 139         ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
 140         if (ret < 0)
 141                 return -EIO;
 142
 143         led->last_flag = 0;
 144
 145         if (flags_val & LM36010_OVP_FAULT)
 146                 led->last_flag |= LED_FAULT_OVER_VOLTAGE;
 147
 148         if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
 149                 led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
 150
 151         if (flags_val & LM3601X_SHORT_FAULT)
 152                 led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
 153
 154         if (flags_val & LM36010_CURR_LIMIT)
 155                 led->last_flag |= LED_FAULT_OVER_CURRENT;
 156
 157         if (flags_val & LM3601X_UVLO_FAULT)
 158                 led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
 159
 160         if (flags_val & LM3601X_IVFM_TRIP)
 161                 led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
 162
 163         if (flags_val & LM3601X_THERM_SHUTDOWN)
 164                 led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
 165
 166         return led->last_flag;
 167 }
 168
 169 static int lm3601x_brightness_set(struct led_classdev *cdev,
 170                                         enum led_brightness brightness)
 171 {
 172         struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
 173         struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 174         int ret, led_mode_val;
 175
 176         mutex_lock(&led->lock);
 177
 178         ret = lm3601x_read_faults(led);
 179         if (ret < 0)
 180                 goto out;
 181
 182         if (led->led_mode == LM3601X_LED_TORCH)
 183                 led_mode_val = LM3601X_MODE_TORCH;
 184         else
 185                 led_mode_val = LM3601X_MODE_IR_DRV;
 186
 187         if (brightness == LED_OFF) {
 188                 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 189                                         led_mode_val, LED_OFF);
 190                 goto out;
 191         }
 192
 193         ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness - 1);
 194         if (ret < 0)
 195                 goto out;
 196
 197         ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 198                                 LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
 199                                 led_mode_val);
 200 out:
 201         mutex_unlock(&led->lock);
 202         return ret;
 203 }
 204
 205 static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
 206                                 bool state)
 207 {
 208         struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 209         int timeout_reg_val;
 210         int current_timeout;
 211         int ret;
 212
 213         mutex_lock(&led->lock);
 214
 215         ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
 216         if (ret < 0)
 217                 goto out;
 218
 219         if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
 220                 timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
 221         else
 222                 timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
 223
 224         if (led->flash_timeout != current_timeout)
 225                 ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
 226                                         LM3601X_TIMEOUT_MASK, timeout_reg_val);
 227
 228         if (state)
 229                 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 230                                         LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
 231                                         LM3601X_MODE_STROBE);
 232         else
 233                 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 234                                         LM3601X_MODE_STROBE, LED_OFF);
 235
 236         ret = lm3601x_read_faults(led);
 237 out:
 238         mutex_unlock(&led->lock);
 239         return ret;
 240 }
 241
 242 static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
 243                                         u32 brightness)
 244 {
 245         struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 246         u8 brightness_val;
 247         int ret;
 248
 249         mutex_lock(&led->lock);
 250         ret = lm3601x_read_faults(led);
 251         if (ret < 0)
 252                 goto out;
 253
 254         if (brightness == LED_OFF) {
 255                 ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 256                                         LM3601X_MODE_STROBE, LED_OFF);
 257                 goto out;
 258         }
 259
 260         brightness_val = brightness / LM3601X_STROBE_REG_DIV;
 261
 262         ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
 263 out:
 264         mutex_unlock(&led->lock);
 265         return ret;
 266 }
 267
 268 static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
 269                                 u32 timeout)
 270 {
 271         struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 272
 273         mutex_lock(&led->lock);
 274
 275         led->flash_timeout = timeout;
 276
 277         mutex_unlock(&led->lock);
 278
 279         return 0;
 280 }
 281
 282 static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
 283 {
 284         struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 285         int strobe_state;
 286         int ret;
 287
 288         mutex_lock(&led->lock);
 289
 290         ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
 291         if (ret < 0)
 292                 goto out;
 293
 294         *state = strobe_state & LM3601X_MODE_STROBE;
 295
 296 out:
 297         mutex_unlock(&led->lock);
 298         return ret;
 299 }
 300
 301 static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
 302                                 u32 *fault)
 303 {
 304         struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
 305
 306         lm3601x_read_faults(led);
 307
 308         *fault = led->last_flag;
 309
 310         return 0;
 311 }
 312
 313 static const struct led_flash_ops flash_ops = {
 314         .flash_brightness_set   = lm3601x_flash_brightness_set,
 315         .strobe_set             = lm3601x_strobe_set,
 316         .strobe_get             = lm3601x_strobe_get,
 317         .timeout_set            = lm3601x_flash_timeout_set,
 318         .fault_get              = lm3601x_flash_fault_get,
 319 };
 320
 321 static int lm3601x_register_leds(struct lm3601x_led *led,
 322                                  struct fwnode_handle *fwnode)
 323 {
 324         struct led_classdev *led_cdev;
 325         struct led_flash_setting *setting;
 326         struct led_init_data init_data = {};
 327
 328         led->fled_cdev.ops = &flash_ops;
 329
 330         setting = &led->fled_cdev.timeout;
 331         setting->min = LM3601X_MIN_TIMEOUT_US;
 332         setting->max = led->max_flash_timeout;
 333         setting->step = LM3601X_LOWER_STEP_US;
 334         setting->val = led->max_flash_timeout;
 335
 336         setting = &led->fled_cdev.brightness;
 337         setting->min = LM3601X_MIN_STROBE_I_UA;
 338         setting->max = led->flash_current_max;
 339         setting->step = LM3601X_TORCH_REG_DIV;
 340         setting->val = led->flash_current_max;
 341
 342         led_cdev = &led->fled_cdev.led_cdev;
 343         led_cdev->brightness_set_blocking = lm3601x_brightness_set;
 344         led_cdev->max_brightness =
 345                         DIV_ROUND_UP(led->torch_current_max - LM3601X_MIN_TORCH_I_UA + 1,
 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
 357 static 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         if (led->torch_current_max > LM3601X_MAX_TORCH_I_UA) {
 391                 dev_warn(&led->client->dev,
 392                          "Max torch current set too high (%d vs %d)\n",
 393                          led->torch_current_max,
 394                          LM3601X_MAX_TORCH_I_UA);
 395                 led->torch_current_max = LM3601X_MAX_TORCH_I_UA;
 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         *fwnode = child;
 415
 416 out_err:
 417         fwnode_handle_put(child);
 418         return ret;
 419 }
 420
 421 static int lm3601x_probe(struct i2c_client *client)
 422 {
 423         struct lm3601x_led *led;
 424         struct fwnode_handle *fwnode;
 425         int ret;
 426
 427         led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
 428         if (!led)
 429                 return -ENOMEM;
 430
 431         led->client = client;
 432         i2c_set_clientdata(client, led);
 433
 434         ret = lm3601x_parse_node(led, &fwnode);
 435         if (ret)
 436                 return -ENODEV;
 437
 438         led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
 439         if (IS_ERR(led->regmap)) {
 440                 ret = PTR_ERR(led->regmap);
 441                 dev_err(&client->dev,
 442                         "Failed to allocate register map: %d\n", ret);
 443                 return ret;
 444         }
 445
 446         ret = regmap_write(led->regmap, LM3601X_DEV_ID_REG, LM3601X_SW_RESET);
 447         if (ret)
 448                 dev_warn(&client->dev, "Failed to reset the LED controller\n");
 449
 450         mutex_init(&led->lock);
 451
 452         return lm3601x_register_leds(led, fwnode);
 453 }
 454
 455 static void lm3601x_remove(struct i2c_client *client)
 456 {
 457         struct lm3601x_led *led = i2c_get_clientdata(client);
 458         int ret;
 459
 460         ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
 461                                  LM3601X_ENABLE_MASK, LM3601X_MODE_STANDBY);
 462         if (ret)
 463                 dev_warn(&client->dev,
 464                          "Failed to put into standby (%pe)\n", ERR_PTR(ret));
 465 }
 466
 467 static const struct i2c_device_id lm3601x_id[] = {
 468         { "LM36010", CHIP_LM36010 },
 469         { "LM36011", CHIP_LM36011 },
 470         { }
 471 };
 472 MODULE_DEVICE_TABLE(i2c, lm3601x_id);
 473
 474 static const struct of_device_id of_lm3601x_leds_match[] = {
 475         { .compatible = "ti,lm36010", },
 476         { .compatible = "ti,lm36011", },
 477         { }
 478 };
 479 MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
 480
 481 static struct i2c_driver lm3601x_i2c_driver = {
 482         .driver = {
 483                 .name = "lm3601x",
 484                 .of_match_table = of_lm3601x_leds_match,
 485         },
 486         .probe = lm3601x_probe,
 487         .remove = lm3601x_remove,
 488         .id_table = lm3601x_id,
 489 };
 490 module_i2c_driver(lm3601x_i2c_driver);
 491
 492 MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
 493 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 494 MODULE_LICENSE("GPL v2");