1 // SPDX-License-Identifier: GPL-2.0 2 // TI LM3692x LED chip family driver 3 // Copyright (C) 2017-18 Texas Instruments Incorporated - https://www.ti.com/ 4 5 #include <linux/gpio/consumer.h> 6 #include <linux/i2c.h> 7 #include <linux/init.h> 8 #include <linux/leds.h> 9 #include <linux/log2.h> 10 #include <linux/mod_devicetable.h> 11 #include <linux/module.h> 12 #include <linux/mutex.h> 13 #include <linux/regmap.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/slab.h> 16 17 #define LM36922_MODEL 0 18 #define LM36923_MODEL 1 19 20 #define LM3692X_REV 0x0 21 #define LM3692X_RESET 0x1 22 #define LM3692X_EN 0x10 23 #define LM3692X_BRT_CTRL 0x11 24 #define LM3692X_PWM_CTRL 0x12 25 #define LM3692X_BOOST_CTRL 0x13 26 #define LM3692X_AUTO_FREQ_HI 0x15 27 #define LM3692X_AUTO_FREQ_LO 0x16 28 #define LM3692X_BL_ADJ_THRESH 0x17 29 #define LM3692X_BRT_LSB 0x18 30 #define LM3692X_BRT_MSB 0x19 31 #define LM3692X_FAULT_CTRL 0x1e 32 #define LM3692X_FAULT_FLAGS 0x1f 33 34 #define LM3692X_SW_RESET BIT(0) 35 #define LM3692X_DEVICE_EN BIT(0) 36 #define LM3692X_LED1_EN BIT(1) 37 #define LM3692X_LED2_EN BIT(2) 38 #define LM36923_LED3_EN BIT(3) 39 #define LM3692X_ENABLE_MASK (LM3692X_DEVICE_EN | LM3692X_LED1_EN | \ 40 LM3692X_LED2_EN | LM36923_LED3_EN) 41 42 /* Brightness Control Bits */ 43 #define LM3692X_BL_ADJ_POL BIT(0) 44 #define LM3692X_RAMP_RATE_125us 0x00 45 #define LM3692X_RAMP_RATE_250us BIT(1) 46 #define LM3692X_RAMP_RATE_500us BIT(2) 47 #define LM3692X_RAMP_RATE_1ms (BIT(1) | BIT(2)) 48 #define LM3692X_RAMP_RATE_2ms BIT(3) 49 #define LM3692X_RAMP_RATE_4ms (BIT(3) | BIT(1)) 50 #define LM3692X_RAMP_RATE_8ms (BIT(2) | BIT(3)) 51 #define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3)) 52 #define LM3692X_RAMP_EN BIT(4) 53 #define LM3692X_BRHT_MODE_REG 0x00 54 #define LM3692X_BRHT_MODE_PWM BIT(5) 55 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6) 56 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6)) 57 #define LM3692X_MAP_MODE_EXP BIT(7) 58 59 /* PWM Register Bits */ 60 #define LM3692X_PWM_FILTER_100 BIT(0) 61 #define LM3692X_PWM_FILTER_150 BIT(1) 62 #define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1)) 63 #define LM3692X_PWM_HYSTER_1LSB BIT(2) 64 #define LM3692X_PWM_HYSTER_2LSB BIT(3) 65 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2)) 66 #define LM3692X_PWM_HYSTER_4LSB BIT(4) 67 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2)) 68 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3)) 69 #define LM3692X_PWM_POLARITY BIT(5) 70 #define LM3692X_PWM_SAMP_4MHZ BIT(6) 71 #define LM3692X_PWM_SAMP_24MHZ BIT(7) 72 73 /* Boost Control Bits */ 74 #define LM3692X_OCP_PROT_1A BIT(0) 75 #define LM3692X_OCP_PROT_1_25A BIT(1) 76 #define LM3692X_OCP_PROT_1_5A (BIT(0) | BIT(1)) 77 #define LM3692X_OVP_21V BIT(2) 78 #define LM3692X_OVP_25V BIT(3) 79 #define LM3692X_OVP_29V (BIT(2) | BIT(3)) 80 #define LM3692X_MIN_IND_22UH BIT(4) 81 #define LM3692X_BOOST_SW_1MHZ BIT(5) 82 #define LM3692X_BOOST_SW_NO_SHIFT BIT(6) 83 84 /* Fault Control Bits */ 85 #define LM3692X_FAULT_CTRL_OVP BIT(0) 86 #define LM3692X_FAULT_CTRL_OCP BIT(1) 87 #define LM3692X_FAULT_CTRL_TSD BIT(2) 88 #define LM3692X_FAULT_CTRL_OPEN BIT(3) 89 90 /* Fault Flag Bits */ 91 #define LM3692X_FAULT_FLAG_OVP BIT(0) 92 #define LM3692X_FAULT_FLAG_OCP BIT(1) 93 #define LM3692X_FAULT_FLAG_TSD BIT(2) 94 #define LM3692X_FAULT_FLAG_SHRT BIT(3) 95 #define LM3692X_FAULT_FLAG_OPEN BIT(4) 96 97 /** 98 * struct lm3692x_led 99 * @lock: Lock for reading/writing the device 100 * @client: Pointer to the I2C client 101 * @led_dev: LED class device pointer 102 * @regmap: Devices register map 103 * @enable_gpio: VDDIO/EN gpio to enable communication interface 104 * @regulator: LED supply regulator pointer 105 * @led_enable: LED sync to be enabled 106 * @model_id: Current device model ID enumerated 107 * @boost_ctrl: Cached configuration for the boost control register 108 * @brightness_ctrl: Cached configuration for brightness/brightness control 109 * @enabled: Cached enable state of the device 110 */ 111 struct lm3692x_led { 112 struct mutex lock; 113 struct i2c_client *client; 114 struct led_classdev led_dev; 115 struct regmap *regmap; 116 struct gpio_desc *enable_gpio; 117 struct regulator *regulator; 118 int led_enable; 119 int model_id; 120 121 u8 boost_ctrl, brightness_ctrl; 122 bool enabled; 123 }; 124 125 static const struct reg_default lm3692x_reg_defs[] = { 126 {LM3692X_EN, 0xf}, 127 {LM3692X_BRT_CTRL, 0x61}, 128 {LM3692X_PWM_CTRL, 0x73}, 129 {LM3692X_BOOST_CTRL, 0x6f}, 130 {LM3692X_AUTO_FREQ_HI, 0x0}, 131 {LM3692X_AUTO_FREQ_LO, 0x0}, 132 {LM3692X_BL_ADJ_THRESH, 0x0}, 133 {LM3692X_BRT_LSB, 0x7}, 134 {LM3692X_BRT_MSB, 0xff}, 135 {LM3692X_FAULT_CTRL, 0x7}, 136 }; 137 138 static const struct regmap_config lm3692x_regmap_config = { 139 .reg_bits = 8, 140 .val_bits = 8, 141 142 .max_register = LM3692X_FAULT_FLAGS, 143 .reg_defaults = lm3692x_reg_defs, 144 .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs), 145 .cache_type = REGCACHE_MAPLE, 146 }; 147 148 static int lm3692x_fault_check(struct lm3692x_led *led) 149 { 150 int ret; 151 unsigned int read_buf; 152 153 ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 154 if (ret) 155 return ret; 156 157 if (read_buf) 158 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf); 159 160 /* The first read may clear the fault. Check again to see if the fault 161 * still exits and return that value. 162 */ 163 regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 164 if (read_buf) 165 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n", 166 read_buf); 167 168 return read_buf; 169 } 170 171 static int lm3692x_leds_enable(struct lm3692x_led *led) 172 { 173 int enable_state; 174 int ret, reg_ret; 175 176 if (led->enabled) 177 return 0; 178 179 if (led->regulator) { 180 ret = regulator_enable(led->regulator); 181 if (ret) { 182 dev_err(&led->client->dev, 183 "Failed to enable regulator: %d\n", ret); 184 return ret; 185 } 186 } 187 188 if (led->enable_gpio) 189 gpiod_direction_output(led->enable_gpio, 1); 190 191 ret = lm3692x_fault_check(led); 192 if (ret) { 193 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", 194 ret); 195 goto out; 196 } 197 198 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); 199 if (ret) 200 goto out; 201 202 /* 203 * For glitch free operation, the following data should 204 * only be written while LEDx enable bits are 0 and the device enable 205 * bit is set to 1. 206 * per Section 7.5.14 of the data sheet 207 */ 208 ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN); 209 if (ret) 210 goto out; 211 212 /* Set the brightness to 0 so when enabled the LEDs do not come 213 * on with full brightness. 214 */ 215 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0); 216 if (ret) 217 goto out; 218 219 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0); 220 if (ret) 221 goto out; 222 223 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, 224 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); 225 if (ret) 226 goto out; 227 228 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl); 229 if (ret) 230 goto out; 231 232 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); 233 if (ret) 234 goto out; 235 236 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); 237 if (ret) 238 goto out; 239 240 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); 241 if (ret) 242 goto out; 243 244 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 245 LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN); 246 if (ret) 247 goto out; 248 249 switch (led->led_enable) { 250 case 0: 251 default: 252 if (led->model_id == LM36923_MODEL) 253 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN | 254 LM36923_LED3_EN; 255 else 256 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN; 257 258 break; 259 case 1: 260 enable_state = LM3692X_LED1_EN; 261 break; 262 case 2: 263 enable_state = LM3692X_LED2_EN; 264 break; 265 266 case 3: 267 if (led->model_id == LM36923_MODEL) { 268 enable_state = LM36923_LED3_EN; 269 break; 270 } 271 272 ret = -EINVAL; 273 dev_err(&led->client->dev, 274 "LED3 sync not available on this device\n"); 275 goto out; 276 } 277 278 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK, 279 enable_state | LM3692X_DEVICE_EN); 280 281 led->enabled = true; 282 return ret; 283 out: 284 dev_err(&led->client->dev, "Fail writing initialization values\n"); 285 286 if (led->enable_gpio) 287 gpiod_direction_output(led->enable_gpio, 0); 288 289 if (led->regulator) { 290 reg_ret = regulator_disable(led->regulator); 291 if (reg_ret) 292 dev_err(&led->client->dev, 293 "Failed to disable regulator: %d\n", reg_ret); 294 } 295 296 return ret; 297 } 298 299 static int lm3692x_leds_disable(struct lm3692x_led *led) 300 { 301 int ret; 302 303 if (!led->enabled) 304 return 0; 305 306 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0); 307 if (ret) { 308 dev_err(&led->client->dev, "Failed to disable regulator: %d\n", 309 ret); 310 return ret; 311 } 312 313 if (led->enable_gpio) 314 gpiod_direction_output(led->enable_gpio, 0); 315 316 if (led->regulator) { 317 ret = regulator_disable(led->regulator); 318 if (ret) 319 dev_err(&led->client->dev, 320 "Failed to disable regulator: %d\n", ret); 321 } 322 323 led->enabled = false; 324 return ret; 325 } 326 327 static int lm3692x_brightness_set(struct led_classdev *led_cdev, 328 enum led_brightness brt_val) 329 { 330 struct lm3692x_led *led = 331 container_of(led_cdev, struct lm3692x_led, led_dev); 332 int ret; 333 int led_brightness_lsb = (brt_val >> 5); 334 335 mutex_lock(&led->lock); 336 337 if (brt_val == 0) { 338 ret = lm3692x_leds_disable(led); 339 goto out; 340 } else { 341 lm3692x_leds_enable(led); 342 } 343 344 ret = lm3692x_fault_check(led); 345 if (ret) { 346 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", 347 ret); 348 goto out; 349 } 350 351 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); 352 if (ret) { 353 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret); 354 goto out; 355 } 356 357 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); 358 if (ret) { 359 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret); 360 goto out; 361 } 362 out: 363 mutex_unlock(&led->lock); 364 return ret; 365 } 366 367 static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led, 368 u32 max_cur) 369 { 370 u32 max_code; 371 372 /* see p.12 of LM36922 data sheet for brightness formula */ 373 max_code = ((max_cur * 1000) - 37806) / 12195; 374 if (max_code > 0x7FF) 375 max_code = 0x7FF; 376 377 return max_code >> 3; 378 } 379 380 static int lm3692x_probe_dt(struct lm3692x_led *led) 381 { 382 struct fwnode_handle *child = NULL; 383 struct led_init_data init_data = {}; 384 u32 ovp, max_cur; 385 int ret; 386 387 led->enable_gpio = devm_gpiod_get_optional(&led->client->dev, 388 "enable", GPIOD_OUT_LOW); 389 if (IS_ERR(led->enable_gpio)) { 390 ret = PTR_ERR(led->enable_gpio); 391 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n", 392 ret); 393 return ret; 394 } 395 396 led->regulator = devm_regulator_get_optional(&led->client->dev, "vled"); 397 if (IS_ERR(led->regulator)) { 398 ret = PTR_ERR(led->regulator); 399 if (ret != -ENODEV) 400 return dev_err_probe(&led->client->dev, ret, 401 "Failed to get vled regulator\n"); 402 403 led->regulator = NULL; 404 } 405 406 led->boost_ctrl = LM3692X_BOOST_SW_1MHZ | 407 LM3692X_BOOST_SW_NO_SHIFT | 408 LM3692X_OCP_PROT_1_5A; 409 ret = device_property_read_u32(&led->client->dev, 410 "ti,ovp-microvolt", &ovp); 411 if (ret) { 412 led->boost_ctrl |= LM3692X_OVP_29V; 413 } else { 414 switch (ovp) { 415 case 17000000: 416 break; 417 case 21000000: 418 led->boost_ctrl |= LM3692X_OVP_21V; 419 break; 420 case 25000000: 421 led->boost_ctrl |= LM3692X_OVP_25V; 422 break; 423 case 29000000: 424 led->boost_ctrl |= LM3692X_OVP_29V; 425 break; 426 default: 427 dev_err(&led->client->dev, "Invalid OVP %d\n", ovp); 428 return -EINVAL; 429 } 430 } 431 432 child = device_get_next_child_node(&led->client->dev, child); 433 if (!child) { 434 dev_err(&led->client->dev, "No LED Child node\n"); 435 return -ENODEV; 436 } 437 438 ret = fwnode_property_read_u32(child, "reg", &led->led_enable); 439 if (ret) { 440 fwnode_handle_put(child); 441 dev_err(&led->client->dev, "reg DT property missing\n"); 442 return ret; 443 } 444 445 ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur); 446 led->led_dev.max_brightness = ret ? LED_FULL : 447 lm3692x_max_brightness(led, max_cur); 448 449 init_data.fwnode = child; 450 init_data.devicename = led->client->name; 451 init_data.default_label = ":"; 452 453 ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev, 454 &init_data); 455 if (ret) 456 dev_err(&led->client->dev, "led register err: %d\n", ret); 457 458 fwnode_handle_put(init_data.fwnode); 459 return ret; 460 } 461 462 static int lm3692x_probe(struct i2c_client *client) 463 { 464 const struct i2c_device_id *id = i2c_client_get_device_id(client); 465 struct lm3692x_led *led; 466 int ret; 467 468 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); 469 if (!led) 470 return -ENOMEM; 471 472 mutex_init(&led->lock); 473 led->client = client; 474 led->led_dev.brightness_set_blocking = lm3692x_brightness_set; 475 led->model_id = id->driver_data; 476 i2c_set_clientdata(client, led); 477 478 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); 479 if (IS_ERR(led->regmap)) { 480 ret = PTR_ERR(led->regmap); 481 dev_err(&client->dev, "Failed to allocate register map: %d\n", 482 ret); 483 return ret; 484 } 485 486 ret = lm3692x_probe_dt(led); 487 if (ret) 488 return ret; 489 490 ret = lm3692x_leds_enable(led); 491 if (ret) 492 return ret; 493 494 return 0; 495 } 496 497 static void lm3692x_remove(struct i2c_client *client) 498 { 499 struct lm3692x_led *led = i2c_get_clientdata(client); 500 501 lm3692x_leds_disable(led); 502 mutex_destroy(&led->lock); 503 } 504 505 static const struct i2c_device_id lm3692x_id[] = { 506 { "lm36922", LM36922_MODEL }, 507 { "lm36923", LM36923_MODEL }, 508 { } 509 }; 510 MODULE_DEVICE_TABLE(i2c, lm3692x_id); 511 512 static const struct of_device_id of_lm3692x_leds_match[] = { 513 { .compatible = "ti,lm36922", }, 514 { .compatible = "ti,lm36923", }, 515 {}, 516 }; 517 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); 518 519 static struct i2c_driver lm3692x_driver = { 520 .driver = { 521 .name = "lm3692x", 522 .of_match_table = of_lm3692x_leds_match, 523 }, 524 .probe = lm3692x_probe, 525 .remove = lm3692x_remove, 526 .id_table = lm3692x_id, 527 }; 528 module_i2c_driver(lm3692x_driver); 529 530 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); 531 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 532 MODULE_LICENSE("GPL v2"); 533