1 // SPDX-License-Identifier: GPL-2.0 2 // TI LM3692x LED chip family driver 3 // Copyright (C) 2017-18 Texas Instruments Incorporated - http://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/module.h> 10 #include <linux/mutex.h> 11 #include <linux/of.h> 12 #include <linux/of_gpio.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 }; 118 119 static const struct reg_default lm3692x_reg_defs[] = { 120 {LM3692X_EN, 0xf}, 121 {LM3692X_BRT_CTRL, 0x61}, 122 {LM3692X_PWM_CTRL, 0x73}, 123 {LM3692X_BOOST_CTRL, 0x6f}, 124 {LM3692X_AUTO_FREQ_HI, 0x0}, 125 {LM3692X_AUTO_FREQ_LO, 0x0}, 126 {LM3692X_BL_ADJ_THRESH, 0x0}, 127 {LM3692X_BRT_LSB, 0x7}, 128 {LM3692X_BRT_MSB, 0xff}, 129 {LM3692X_FAULT_CTRL, 0x7}, 130 }; 131 132 static const struct regmap_config lm3692x_regmap_config = { 133 .reg_bits = 8, 134 .val_bits = 8, 135 136 .max_register = LM3692X_FAULT_FLAGS, 137 .reg_defaults = lm3692x_reg_defs, 138 .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs), 139 .cache_type = REGCACHE_RBTREE, 140 }; 141 142 static int lm3692x_fault_check(struct lm3692x_led *led) 143 { 144 int ret; 145 unsigned int read_buf; 146 147 ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 148 if (ret) 149 return ret; 150 151 if (read_buf) 152 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf); 153 154 /* The first read may clear the fault. Check again to see if the fault 155 * still exits and return that value. 156 */ 157 regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 158 if (read_buf) 159 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n", 160 read_buf); 161 162 return read_buf; 163 } 164 165 static int lm3692x_brightness_set(struct led_classdev *led_cdev, 166 enum led_brightness brt_val) 167 { 168 struct lm3692x_led *led = 169 container_of(led_cdev, struct lm3692x_led, led_dev); 170 int ret; 171 int led_brightness_lsb = (brt_val >> 5); 172 173 mutex_lock(&led->lock); 174 175 ret = lm3692x_fault_check(led); 176 if (ret) { 177 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", 178 ret); 179 goto out; 180 } 181 182 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); 183 if (ret) { 184 dev_err(&led->client->dev, "Cannot write MSB: %d\n", ret); 185 goto out; 186 } 187 188 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); 189 if (ret) { 190 dev_err(&led->client->dev, "Cannot write LSB: %d\n", ret); 191 goto out; 192 } 193 out: 194 mutex_unlock(&led->lock); 195 return ret; 196 } 197 198 static int lm3692x_init(struct lm3692x_led *led) 199 { 200 int enable_state; 201 int ret, reg_ret; 202 203 if (led->regulator) { 204 ret = regulator_enable(led->regulator); 205 if (ret) { 206 dev_err(&led->client->dev, 207 "Failed to enable regulator: %d\n", ret); 208 return ret; 209 } 210 } 211 212 if (led->enable_gpio) 213 gpiod_direction_output(led->enable_gpio, 1); 214 215 ret = lm3692x_fault_check(led); 216 if (ret) { 217 dev_err(&led->client->dev, "Cannot read/clear faults: %d\n", 218 ret); 219 goto out; 220 } 221 222 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); 223 if (ret) 224 goto out; 225 226 /* 227 * For glitch free operation, the following data should 228 * only be written while LEDx enable bits are 0 and the device enable 229 * bit is set to 1. 230 * per Section 7.5.14 of the data sheet 231 */ 232 ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN); 233 if (ret) 234 goto out; 235 236 /* Set the brightness to 0 so when enabled the LEDs do not come 237 * on with full brightness. 238 */ 239 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0); 240 if (ret) 241 goto out; 242 243 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0); 244 if (ret) 245 goto out; 246 247 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, 248 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); 249 if (ret) 250 goto out; 251 252 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, 253 LM3692X_BRHT_MODE_RAMP_MULTI | 254 LM3692X_BL_ADJ_POL | 255 LM3692X_RAMP_RATE_250us); 256 if (ret) 257 goto out; 258 259 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); 260 if (ret) 261 goto out; 262 263 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); 264 if (ret) 265 goto out; 266 267 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); 268 if (ret) 269 goto out; 270 271 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 272 LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB); 273 if (ret) 274 goto out; 275 276 switch (led->led_enable) { 277 case 0: 278 default: 279 if (led->model_id == LM36923_MODEL) 280 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN | 281 LM36923_LED3_EN; 282 else 283 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN; 284 285 break; 286 case 1: 287 enable_state = LM3692X_LED1_EN; 288 break; 289 case 2: 290 enable_state = LM3692X_LED2_EN; 291 break; 292 293 case 3: 294 if (led->model_id == LM36923_MODEL) { 295 enable_state = LM36923_LED3_EN; 296 break; 297 } 298 299 ret = -EINVAL; 300 dev_err(&led->client->dev, 301 "LED3 sync not available on this device\n"); 302 goto out; 303 } 304 305 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK, 306 enable_state | LM3692X_DEVICE_EN); 307 308 return ret; 309 out: 310 dev_err(&led->client->dev, "Fail writing initialization values\n"); 311 312 if (led->enable_gpio) 313 gpiod_direction_output(led->enable_gpio, 0); 314 315 if (led->regulator) { 316 reg_ret = regulator_disable(led->regulator); 317 if (reg_ret) 318 dev_err(&led->client->dev, 319 "Failed to disable regulator: %d\n", reg_ret); 320 } 321 322 return ret; 323 } 324 325 static int lm3692x_probe_dt(struct lm3692x_led *led) 326 { 327 struct fwnode_handle *child = NULL; 328 struct led_init_data init_data = {}; 329 int ret; 330 331 led->enable_gpio = devm_gpiod_get_optional(&led->client->dev, 332 "enable", GPIOD_OUT_LOW); 333 if (IS_ERR(led->enable_gpio)) { 334 ret = PTR_ERR(led->enable_gpio); 335 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n", 336 ret); 337 return ret; 338 } 339 340 led->regulator = devm_regulator_get(&led->client->dev, "vled"); 341 if (IS_ERR(led->regulator)) 342 led->regulator = NULL; 343 344 child = device_get_next_child_node(&led->client->dev, child); 345 if (!child) { 346 dev_err(&led->client->dev, "No LED Child node\n"); 347 return -ENODEV; 348 } 349 350 fwnode_property_read_string(child, "linux,default-trigger", 351 &led->led_dev.default_trigger); 352 353 ret = fwnode_property_read_u32(child, "reg", &led->led_enable); 354 if (ret) { 355 dev_err(&led->client->dev, "reg DT property missing\n"); 356 return ret; 357 } 358 359 init_data.fwnode = child; 360 init_data.devicename = led->client->name; 361 init_data.default_label = ":"; 362 363 ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev, 364 &init_data); 365 if (ret) { 366 dev_err(&led->client->dev, "led register err: %d\n", ret); 367 return ret; 368 } 369 370 return 0; 371 } 372 373 static int lm3692x_probe(struct i2c_client *client, 374 const struct i2c_device_id *id) 375 { 376 struct lm3692x_led *led; 377 int ret; 378 379 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); 380 if (!led) 381 return -ENOMEM; 382 383 mutex_init(&led->lock); 384 led->client = client; 385 led->led_dev.brightness_set_blocking = lm3692x_brightness_set; 386 led->model_id = id->driver_data; 387 i2c_set_clientdata(client, led); 388 389 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); 390 if (IS_ERR(led->regmap)) { 391 ret = PTR_ERR(led->regmap); 392 dev_err(&client->dev, "Failed to allocate register map: %d\n", 393 ret); 394 return ret; 395 } 396 397 ret = lm3692x_probe_dt(led); 398 if (ret) 399 return ret; 400 401 ret = lm3692x_init(led); 402 if (ret) 403 return ret; 404 405 return 0; 406 } 407 408 static int lm3692x_remove(struct i2c_client *client) 409 { 410 struct lm3692x_led *led = i2c_get_clientdata(client); 411 int ret; 412 413 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0); 414 if (ret) { 415 dev_err(&led->client->dev, "Failed to disable regulator: %d\n", 416 ret); 417 return ret; 418 } 419 420 if (led->enable_gpio) 421 gpiod_direction_output(led->enable_gpio, 0); 422 423 if (led->regulator) { 424 ret = regulator_disable(led->regulator); 425 if (ret) 426 dev_err(&led->client->dev, 427 "Failed to disable regulator: %d\n", ret); 428 } 429 430 mutex_destroy(&led->lock); 431 432 return 0; 433 } 434 435 static const struct i2c_device_id lm3692x_id[] = { 436 { "lm36922", LM36922_MODEL }, 437 { "lm36923", LM36923_MODEL }, 438 { } 439 }; 440 MODULE_DEVICE_TABLE(i2c, lm3692x_id); 441 442 static const struct of_device_id of_lm3692x_leds_match[] = { 443 { .compatible = "ti,lm36922", }, 444 { .compatible = "ti,lm36923", }, 445 {}, 446 }; 447 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); 448 449 static struct i2c_driver lm3692x_driver = { 450 .driver = { 451 .name = "lm3692x", 452 .of_match_table = of_lm3692x_leds_match, 453 }, 454 .probe = lm3692x_probe, 455 .remove = lm3692x_remove, 456 .id_table = lm3692x_id, 457 }; 458 module_i2c_driver(lm3692x_driver); 459 460 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); 461 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 462 MODULE_LICENSE("GPL v2"); 463