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\n"); 178 goto out; 179 } 180 181 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); 182 if (ret) { 183 dev_err(&led->client->dev, "Cannot write MSB\n"); 184 goto out; 185 } 186 187 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); 188 if (ret) { 189 dev_err(&led->client->dev, "Cannot write LSB\n"); 190 goto out; 191 } 192 out: 193 mutex_unlock(&led->lock); 194 return ret; 195 } 196 197 static int lm3692x_init(struct lm3692x_led *led) 198 { 199 int enable_state; 200 int ret; 201 202 if (led->regulator) { 203 ret = regulator_enable(led->regulator); 204 if (ret) { 205 dev_err(&led->client->dev, 206 "Failed to enable regulator\n"); 207 return ret; 208 } 209 } 210 211 if (led->enable_gpio) 212 gpiod_direction_output(led->enable_gpio, 1); 213 214 ret = lm3692x_fault_check(led); 215 if (ret) { 216 dev_err(&led->client->dev, "Cannot read/clear faults\n"); 217 goto out; 218 } 219 220 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); 221 if (ret) 222 goto out; 223 224 /* 225 * For glitch free operation, the following data should 226 * only be written while LEDx enable bits are 0 and the device enable 227 * bit is set to 1. 228 * per Section 7.5.14 of the data sheet 229 */ 230 ret = regmap_write(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN); 231 if (ret) 232 goto out; 233 234 /* Set the brightness to 0 so when enabled the LEDs do not come 235 * on with full brightness. 236 */ 237 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, 0); 238 if (ret) 239 goto out; 240 241 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, 0); 242 if (ret) 243 goto out; 244 245 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, 246 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); 247 if (ret) 248 goto out; 249 250 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, 251 LM3692X_BRHT_MODE_RAMP_MULTI | 252 LM3692X_BL_ADJ_POL | 253 LM3692X_RAMP_RATE_250us); 254 if (ret) 255 goto out; 256 257 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); 258 if (ret) 259 goto out; 260 261 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); 262 if (ret) 263 goto out; 264 265 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); 266 if (ret) 267 goto out; 268 269 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 270 LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB); 271 if (ret) 272 goto out; 273 274 switch (led->led_enable) { 275 case 0: 276 default: 277 if (led->model_id == LM36923_MODEL) 278 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN | 279 LM36923_LED3_EN; 280 else 281 enable_state = LM3692X_LED1_EN | LM3692X_LED2_EN; 282 283 break; 284 case 1: 285 enable_state = LM3692X_LED1_EN; 286 break; 287 case 2: 288 enable_state = LM3692X_LED2_EN; 289 break; 290 291 case 3: 292 if (led->model_id == LM36923_MODEL) { 293 enable_state = LM36923_LED3_EN; 294 break; 295 } 296 297 ret = -EINVAL; 298 dev_err(&led->client->dev, 299 "LED3 sync not available on this device\n"); 300 goto out; 301 } 302 303 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_ENABLE_MASK, 304 enable_state | LM3692X_DEVICE_EN); 305 306 return ret; 307 out: 308 dev_err(&led->client->dev, "Fail writing initialization values\n"); 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\n"); 318 } 319 320 return ret; 321 } 322 static int lm3692x_probe_dt(struct lm3692x_led *led) 323 { 324 struct fwnode_handle *child = NULL; 325 struct led_init_data init_data = {}; 326 int ret; 327 328 led->enable_gpio = devm_gpiod_get_optional(&led->client->dev, 329 "enable", GPIOD_OUT_LOW); 330 if (IS_ERR(led->enable_gpio)) { 331 ret = PTR_ERR(led->enable_gpio); 332 dev_err(&led->client->dev, "Failed to get enable gpio: %d\n", 333 ret); 334 return ret; 335 } 336 337 led->regulator = devm_regulator_get(&led->client->dev, "vled"); 338 if (IS_ERR(led->regulator)) 339 led->regulator = NULL; 340 341 child = device_get_next_child_node(&led->client->dev, child); 342 if (!child) { 343 dev_err(&led->client->dev, "No LED Child node\n"); 344 return -ENODEV; 345 } 346 347 fwnode_property_read_string(child, "linux,default-trigger", 348 &led->led_dev.default_trigger); 349 350 ret = fwnode_property_read_u32(child, "reg", &led->led_enable); 351 if (ret) { 352 dev_err(&led->client->dev, "reg DT property missing\n"); 353 return ret; 354 } 355 356 init_data.fwnode = child; 357 init_data.devicename = led->client->name; 358 init_data.default_label = ":"; 359 360 ret = devm_led_classdev_register_ext(&led->client->dev, &led->led_dev, 361 &init_data); 362 if (ret) { 363 dev_err(&led->client->dev, "led register err: %d\n", ret); 364 return ret; 365 } 366 367 return 0; 368 } 369 370 static int lm3692x_probe(struct i2c_client *client, 371 const struct i2c_device_id *id) 372 { 373 struct lm3692x_led *led; 374 int ret; 375 376 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); 377 if (!led) 378 return -ENOMEM; 379 380 mutex_init(&led->lock); 381 led->client = client; 382 led->led_dev.brightness_set_blocking = lm3692x_brightness_set; 383 led->model_id = id->driver_data; 384 i2c_set_clientdata(client, led); 385 386 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); 387 if (IS_ERR(led->regmap)) { 388 ret = PTR_ERR(led->regmap); 389 dev_err(&client->dev, "Failed to allocate register map: %d\n", 390 ret); 391 return ret; 392 } 393 394 ret = lm3692x_probe_dt(led); 395 if (ret) 396 return ret; 397 398 ret = lm3692x_init(led); 399 if (ret) 400 return ret; 401 402 return 0; 403 } 404 405 static int lm3692x_remove(struct i2c_client *client) 406 { 407 struct lm3692x_led *led = i2c_get_clientdata(client); 408 int ret; 409 410 ret = regmap_update_bits(led->regmap, LM3692X_EN, LM3692X_DEVICE_EN, 0); 411 if (ret) { 412 dev_err(&led->client->dev, "Failed to disable regulator\n"); 413 return ret; 414 } 415 416 if (led->enable_gpio) 417 gpiod_direction_output(led->enable_gpio, 0); 418 419 if (led->regulator) { 420 ret = regulator_disable(led->regulator); 421 if (ret) 422 dev_err(&led->client->dev, 423 "Failed to disable regulator\n"); 424 } 425 426 mutex_destroy(&led->lock); 427 428 return 0; 429 } 430 431 static const struct i2c_device_id lm3692x_id[] = { 432 { "lm36922", LM36922_MODEL }, 433 { "lm36923", LM36923_MODEL }, 434 { } 435 }; 436 MODULE_DEVICE_TABLE(i2c, lm3692x_id); 437 438 static const struct of_device_id of_lm3692x_leds_match[] = { 439 { .compatible = "ti,lm36922", }, 440 { .compatible = "ti,lm36923", }, 441 {}, 442 }; 443 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); 444 445 static struct i2c_driver lm3692x_driver = { 446 .driver = { 447 .name = "lm3692x", 448 .of_match_table = of_lm3692x_leds_match, 449 }, 450 .probe = lm3692x_probe, 451 .remove = lm3692x_remove, 452 .id_table = lm3692x_id, 453 }; 454 module_i2c_driver(lm3692x_driver); 455 456 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); 457 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 458 MODULE_LICENSE("GPL v2"); 459