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 */ 108 struct lm3692x_led { 109 struct mutex lock; 110 struct i2c_client *client; 111 struct led_classdev led_dev; 112 struct regmap *regmap; 113 struct gpio_desc *enable_gpio; 114 struct regulator *regulator; 115 int led_enable; 116 int model_id; 117 118 u8 boost_ctrl, brightness_ctrl; 119 bool enabled; 120 }; 121 122 static const struct reg_default lm3692x_reg_defs[] = { 123 {LM3692X_EN, 0xf}, 124 {LM3692X_BRT_CTRL, 0x61}, 125 {LM3692X_PWM_CTRL, 0x73}, 126 {LM3692X_BOOST_CTRL, 0x6f}, 127 {LM3692X_AUTO_FREQ_HI, 0x0}, 128 {LM3692X_AUTO_FREQ_LO, 0x0}, 129 {LM3692X_BL_ADJ_THRESH, 0x0}, 130 {LM3692X_BRT_LSB, 0x7}, 131 {LM3692X_BRT_MSB, 0xff}, 132 {LM3692X_FAULT_CTRL, 0x7}, 133 }; 134 135 static const struct regmap_config lm3692x_regmap_config = { 136 .reg_bits = 8, 137 .val_bits = 8, 138 139 .max_register = LM3692X_FAULT_FLAGS, 140 .reg_defaults = lm3692x_reg_defs, 141 .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs), 142 .cache_type = REGCACHE_RBTREE, 143 }; 144 145 static int lm3692x_fault_check(struct lm3692x_led *led) 146 { 147 int ret; 148 unsigned int read_buf; 149 150 ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 151 if (ret) 152 return ret; 153 154 if (read_buf) 155 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf); 156 157 /* The first read may clear the fault. Check again to see if the fault 158 * still exits and return that value. 159 */ 160 regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 161 if (read_buf) 162 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n", 163 read_buf); 164 165 return read_buf; 166 } 167 168 static int lm3692x_leds_enable(struct lm3692x_led *led) 169 { 170 int enable_state; 171 int ret, reg_ret; 172 173 if (led->enabled) 174 return 0; 175 176 if (led->regulator) { 177 ret = regulator_enable(led->regulator); 178 if (ret) { 179 dev_err(&led->client->dev, 180 "Failed to enable regulator: %d\n", ret); 181 return ret; 182 } 183 } 184 185 if (led->enable_gpio) 186 gpiod_direction_output(led->enable_gpio, 1); 187 188 ret = lm3692x_fault_check(led); 189 if (ret) { 190 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", 191 ret); 192 goto out; 193 } 194 195 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); 196 if (ret) 197 goto out; 198 199 /* 200 * For glitch free operation, the following data should 201 * only be written while LEDx enable bits are 0 and the device enable 202 * bit is set to 1. 203 * per Section 7.5.14 of the data sheet 204 */ 205 ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN); 206 if (ret) 207 goto out; 208 209 /* Set the brightness to 0 so when enabled the LEDs do not come 210 * on with full brightness. 211 */ 212 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0); 213 if (ret) 214 goto out; 215 216 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0); 217 if (ret) 218 goto out; 219 220 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, 221 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); 222 if (ret) 223 goto out; 224 225 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, led->boost_ctrl); 226 if (ret) 227 goto out; 228 229 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); 230 if (ret) 231 goto out; 232 233 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); 234 if (ret) 235 goto out; 236 237 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); 238 if (ret) 239 goto out; 240 241 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 242 LM3692X_BL_ADJ_POL | LM3692X_RAMP_EN); 243 if (ret) 244 goto out; 245 246 switch (led->led_enable) { 247 case 0: 248 default: 249 if (led->model_id == LM36923_MODEL) 250 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN | 251 LM36923_LED3_EN; 252 else 253 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN; 254 255 break; 256 case 1: 257 enable_state = LM3692X_LED1_EN; 258 break; 259 case 2: 260 enable_state = LM3692X_LED2_EN; 261 break; 262 263 case 3: 264 if (led->model_id == LM36923_MODEL) { 265 enable_state = LM36923_LED3_EN; 266 break; 267 } 268 269 ret = -EINVAL; 270 dev_err(&led->client->dev, 271 "LED3 sync not available on this device\n"); 272 goto out; 273 } 274 275 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK, 276 enable_state | LM3692X_DEVICE_EN); 277 278 led->enabled = true; 279 return ret; 280 out: 281 dev_err(&led->client->dev, "Fail writing initialization values\n"); 282 283 if (led->enable_gpio) 284 gpiod_direction_output(led->enable_gpio, 0); 285 286 if (led->regulator) { 287 reg_ret = regulator_disable(led->regulator); 288 if (reg_ret) 289 dev_err(&led->client->dev, 290 "Failed to disable regulator: %d\n", reg_ret); 291 } 292 293 return ret; 294 } 295 296 static int lm3692x_leds_disable(struct lm3692x_led *led) 297 { 298 int ret; 299 300 if (!led->enabled) 301 return 0; 302 303 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0); 304 if (ret) { 305 dev_err(&led->client->dev, "Failed to disable regulator: %d\n", 306 ret); 307 return ret; 308 } 309 310 if (led->enable_gpio) 311 gpiod_direction_output(led->enable_gpio, 0); 312 313 if (led->regulator) { 314 ret = regulator_disable(led->regulator); 315 if (ret) 316 dev_err(&led->client->dev, 317 "Failed to disable regulator: %d\n", ret); 318 } 319 320 led->enabled = false; 321 return ret; 322 } 323 324 static int lm3692x_brightness_set(struct led_classdev *led_cdev, 325 enum led_brightness brt_val) 326 { 327 struct lm3692x_led *led = 328 container_of(led_cdev, struct lm3692x_led, led_dev); 329 int ret; 330 int led_brightness_lsb = (brt_val >> 5); 331 332 mutex_lock(&led->lock); 333 334 if (brt_val == 0) { 335 ret = lm3692x_leds_disable(led); 336 goto out; 337 } else { 338 lm3692x_leds_enable(led); 339 } 340 341 ret = lm3692x_fault_check(led); 342 if (ret) { 343 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", 344 ret); 345 goto out; 346 } 347 348 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); 349 if (ret) { 350 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret); 351 goto out; 352 } 353 354 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); 355 if (ret) { 356 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret); 357 goto out; 358 } 359 out: 360 mutex_unlock(&led->lock); 361 return ret; 362 } 363 364 static enum led_brightness lm3692x_max_brightness(struct lm3692x_led *led, 365 u32 max_cur) 366 { 367 u32 max_code; 368 369 /* see p.12 of LM36922 data sheet for brightness formula */ 370 max_code = ((max_cur * 1000) - 37806) / 12195; 371 if (max_code > 0x7FF) 372 max_code = 0x7FF; 373 374 return max_code >> 3; 375 } 376 377 static int lm3692x_probe_dt(struct lm3692x_led *led) 378 { 379 struct fwnode_handle *child = NULL; 380 struct led_init_data init_data = {}; 381 u32 ovp, max_cur; 382 int ret; 383 384 led->enable_gpio = devm_gpiod_get_optional(&led->client->dev, 385 "enable", GPIOD_OUT_LOW); 386 if (IS_ERR(led->enable_gpio)) { 387 ret = PTR_ERR(led->enable_gpio); 388 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n", 389 ret); 390 return ret; 391 } 392 393 led->regulator = devm_regulator_get_optional(&led->client->dev, "vled"); 394 if (IS_ERR(led->regulator)) { 395 ret = PTR_ERR(led->regulator); 396 if (ret != -ENODEV) 397 return dev_err_probe(&led->client->dev, ret, 398 "Failed to get vled regulator\n"); 399 400 led->regulator = NULL; 401 } 402 403 led->boost_ctrl = LM3692X_BOOST_SW_1MHZ | 404 LM3692X_BOOST_SW_NO_SHIFT | 405 LM3692X_OCP_PROT_1_5A; 406 ret = device_property_read_u32(&led->client->dev, 407 "ti,ovp-microvolt", &ovp); 408 if (ret) { 409 led->boost_ctrl |= LM3692X_OVP_29V; 410 } else { 411 switch (ovp) { 412 case 17000000: 413 break; 414 case 21000000: 415 led->boost_ctrl |= LM3692X_OVP_21V; 416 break; 417 case 25000000: 418 led->boost_ctrl |= LM3692X_OVP_25V; 419 break; 420 case 29000000: 421 led->boost_ctrl |= LM3692X_OVP_29V; 422 break; 423 default: 424 dev_err(&led->client->dev, "Invalid OVP %d\n", ovp); 425 return -EINVAL; 426 } 427 } 428 429 child = device_get_next_child_node(&led->client->dev, child); 430 if (!child) { 431 dev_err(&led->client->dev, "No LED Child node\n"); 432 return -ENODEV; 433 } 434 435 ret = fwnode_property_read_u32(child, "reg", &led->led_enable); 436 if (ret) { 437 fwnode_handle_put(child); 438 dev_err(&led->client->dev, "reg DT property missing\n"); 439 return ret; 440 } 441 442 ret = fwnode_property_read_u32(child, "led-max-microamp", &max_cur); 443 led->led_dev.max_brightness = ret ? LED_FULL : 444 lm3692x_max_brightness(led, max_cur); 445 446 init_data.fwnode = child; 447 init_data.devicename = led->client->name; 448 init_data.default_label = ":"; 449 450 ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev, 451 &init_data); 452 if (ret) 453 dev_err(&led->client->dev, "led register err: %d\n", ret); 454 455 fwnode_handle_put(init_data.fwnode); 456 return ret; 457 } 458 459 static int lm3692x_probe(struct i2c_client *client) 460 { 461 const struct i2c_device_id *id = i2c_client_get_device_id(client); 462 struct lm3692x_led *led; 463 int ret; 464 465 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); 466 if (!led) 467 return -ENOMEM; 468 469 mutex_init(&led->lock); 470 led->client = client; 471 led->led_dev.brightness_set_blocking = lm3692x_brightness_set; 472 led->model_id = id->driver_data; 473 i2c_set_clientdata(client, led); 474 475 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); 476 if (IS_ERR(led->regmap)) { 477 ret = PTR_ERR(led->regmap); 478 dev_err(&client->dev, "Failed to allocate register map: %d\n", 479 ret); 480 return ret; 481 } 482 483 ret = lm3692x_probe_dt(led); 484 if (ret) 485 return ret; 486 487 ret = lm3692x_leds_enable(led); 488 if (ret) 489 return ret; 490 491 return 0; 492 } 493 494 static void lm3692x_remove(struct i2c_client *client) 495 { 496 struct lm3692x_led *led = i2c_get_clientdata(client); 497 498 lm3692x_leds_disable(led); 499 mutex_destroy(&led->lock); 500 } 501 502 static const struct i2c_device_id lm3692x_id[] = { 503 { "lm36922", LM36922_MODEL }, 504 { "lm36923", LM36923_MODEL }, 505 { } 506 }; 507 MODULE_DEVICE_TABLE(i2c, lm3692x_id); 508 509 static const struct of_device_id of_lm3692x_leds_match[] = { 510 { .compatible = "ti,lm36922", }, 511 { .compatible = "ti,lm36923", }, 512 {}, 513 }; 514 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); 515 516 static struct i2c_driver lm3692x_driver = { 517 .driver = { 518 .name = "lm3692x", 519 .of_match_table = of_lm3692x_leds_match, 520 }, 521 .probe = lm3692x_probe, 522 .remove = lm3692x_remove, 523 .id_table = lm3692x_id, 524 }; 525 module_i2c_driver(lm3692x_driver); 526 527 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); 528 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 529 MODULE_LICENSE("GPL v2"); 530