1 /* 2 * TI lm3692x LED Driver 3 * 4 * Copyright (C) 2017 Texas Instruments 5 * 6 * Author: Dan Murphy <dmurphy@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * version 2 as published by the Free Software Foundation. 11 * 12 * Data sheet is located 13 * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf 14 */ 15 16 #include <linux/gpio/consumer.h> 17 #include <linux/i2c.h> 18 #include <linux/init.h> 19 #include <linux/leds.h> 20 #include <linux/module.h> 21 #include <linux/mutex.h> 22 #include <linux/of.h> 23 #include <linux/of_gpio.h> 24 #include <linux/regmap.h> 25 #include <linux/regulator/consumer.h> 26 #include <linux/slab.h> 27 #include <uapi/linux/uleds.h> 28 29 #define LM3692X_REV 0x0 30 #define LM3692X_RESET 0x1 31 #define LM3692X_EN 0x10 32 #define LM3692X_BRT_CTRL 0x11 33 #define LM3692X_PWM_CTRL 0x12 34 #define LM3692X_BOOST_CTRL 0x13 35 #define LM3692X_AUTO_FREQ_HI 0x15 36 #define LM3692X_AUTO_FREQ_LO 0x16 37 #define LM3692X_BL_ADJ_THRESH 0x17 38 #define LM3692X_BRT_LSB 0x18 39 #define LM3692X_BRT_MSB 0x19 40 #define LM3692X_FAULT_CTRL 0x1e 41 #define LM3692X_FAULT_FLAGS 0x1f 42 43 #define LM3692X_SW_RESET BIT(0) 44 #define LM3692X_DEVICE_EN BIT(0) 45 #define LM3692X_LED1_EN BIT(1) 46 #define LM3692X_LED2_EN BIT(2) 47 48 /* Brightness Control Bits */ 49 #define LM3692X_BL_ADJ_POL BIT(0) 50 #define LM3692X_RAMP_RATE_125us 0x00 51 #define LM3692X_RAMP_RATE_250us BIT(1) 52 #define LM3692X_RAMP_RATE_500us BIT(2) 53 #define LM3692X_RAMP_RATE_1ms (BIT(1) | BIT(2)) 54 #define LM3692X_RAMP_RATE_2ms BIT(3) 55 #define LM3692X_RAMP_RATE_4ms (BIT(3) | BIT(1)) 56 #define LM3692X_RAMP_RATE_8ms (BIT(2) | BIT(3)) 57 #define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3)) 58 #define LM3692X_RAMP_EN BIT(4) 59 #define LM3692X_BRHT_MODE_REG 0x00 60 #define LM3692X_BRHT_MODE_PWM BIT(5) 61 #define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6) 62 #define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6)) 63 #define LM3692X_MAP_MODE_EXP BIT(7) 64 65 /* PWM Register Bits */ 66 #define LM3692X_PWM_FILTER_100 BIT(0) 67 #define LM3692X_PWM_FILTER_150 BIT(1) 68 #define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1)) 69 #define LM3692X_PWM_HYSTER_1LSB BIT(2) 70 #define LM3692X_PWM_HYSTER_2LSB BIT(3) 71 #define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2)) 72 #define LM3692X_PWM_HYSTER_4LSB BIT(4) 73 #define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2)) 74 #define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3)) 75 #define LM3692X_PWM_POLARITY BIT(5) 76 #define LM3692X_PWM_SAMP_4MHZ BIT(6) 77 #define LM3692X_PWM_SAMP_24MHZ BIT(7) 78 79 /* Boost Control Bits */ 80 #define LM3692X_OCP_PROT_1A BIT(0) 81 #define LM3692X_OCP_PROT_1_25A BIT(1) 82 #define LM3692X_OCP_PROT_1_5A (BIT(0) | BIT(1)) 83 #define LM3692X_OVP_21V BIT(2) 84 #define LM3692X_OVP_25V BIT(3) 85 #define LM3692X_OVP_29V (BIT(2) | BIT(3)) 86 #define LM3692X_MIN_IND_22UH BIT(4) 87 #define LM3692X_BOOST_SW_1MHZ BIT(5) 88 #define LM3692X_BOOST_SW_NO_SHIFT BIT(6) 89 90 /* Fault Control Bits */ 91 #define LM3692X_FAULT_CTRL_OVP BIT(0) 92 #define LM3692X_FAULT_CTRL_OCP BIT(1) 93 #define LM3692X_FAULT_CTRL_TSD BIT(2) 94 #define LM3692X_FAULT_CTRL_OPEN BIT(3) 95 96 /* Fault Flag Bits */ 97 #define LM3692X_FAULT_FLAG_OVP BIT(0) 98 #define LM3692X_FAULT_FLAG_OCP BIT(1) 99 #define LM3692X_FAULT_FLAG_TSD BIT(2) 100 #define LM3692X_FAULT_FLAG_SHRT BIT(3) 101 #define LM3692X_FAULT_FLAG_OPEN BIT(4) 102 103 /** 104 * struct lm3692x_led - 105 * @lock - Lock for reading/writing the device 106 * @client - Pointer to the I2C client 107 * @led_dev - LED class device pointer 108 * @regmap - Devices register map 109 * @enable_gpio - VDDIO/EN gpio to enable communication interface 110 * @regulator - LED supply regulator pointer 111 * @label - LED label 112 */ 113 struct lm3692x_led { 114 struct mutex lock; 115 struct i2c_client *client; 116 struct led_classdev led_dev; 117 struct regmap *regmap; 118 struct gpio_desc *enable_gpio; 119 struct regulator *regulator; 120 char label[LED_MAX_NAME_SIZE]; 121 }; 122 123 static const struct reg_default lm3692x_reg_defs[] = { 124 {LM3692X_EN, 0xf}, 125 {LM3692X_BRT_CTRL, 0x61}, 126 {LM3692X_PWM_CTRL, 0x73}, 127 {LM3692X_BOOST_CTRL, 0x6f}, 128 {LM3692X_AUTO_FREQ_HI, 0x0}, 129 {LM3692X_AUTO_FREQ_LO, 0x0}, 130 {LM3692X_BL_ADJ_THRESH, 0x0}, 131 {LM3692X_BRT_LSB, 0x7}, 132 {LM3692X_BRT_MSB, 0xff}, 133 {LM3692X_FAULT_CTRL, 0x7}, 134 }; 135 136 static const struct regmap_config lm3692x_regmap_config = { 137 .reg_bits = 8, 138 .val_bits = 8, 139 140 .max_register = LM3692X_FAULT_FLAGS, 141 .reg_defaults = lm3692x_reg_defs, 142 .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs), 143 .cache_type = REGCACHE_RBTREE, 144 }; 145 146 static int lm3692x_fault_check(struct lm3692x_led *led) 147 { 148 int ret; 149 unsigned int read_buf; 150 151 ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 152 if (ret) 153 return ret; 154 155 if (read_buf) 156 dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf); 157 158 /* The first read may clear the fault. Check again to see if the fault 159 * still exits and return that value. 160 */ 161 regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); 162 if (read_buf) 163 dev_err(&led->client->dev, "Second read of fault flags 0x%X\n", 164 read_buf); 165 166 return read_buf; 167 } 168 169 static int lm3692x_brightness_set(struct led_classdev *led_cdev, 170 enum led_brightness brt_val) 171 { 172 struct lm3692x_led *led = 173 container_of(led_cdev, struct lm3692x_led, led_dev); 174 int ret; 175 int led_brightness_lsb = (brt_val >> 5); 176 177 mutex_lock(&led->lock); 178 179 ret = lm3692x_fault_check(led); 180 if (ret) { 181 dev_err(&led->client->dev, "Cannot read/clear faults\n"); 182 goto out; 183 } 184 185 ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); 186 if (ret) { 187 dev_err(&led->client->dev, "Cannot write MSB\n"); 188 goto out; 189 } 190 191 ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); 192 if (ret) { 193 dev_err(&led->client->dev, "Cannot write LSB\n"); 194 goto out; 195 } 196 out: 197 mutex_unlock(&led->lock); 198 return ret; 199 } 200 201 static int lm3692x_init(struct lm3692x_led *led) 202 { 203 int ret; 204 205 if (led->regulator) { 206 ret = regulator_enable(led->regulator); 207 if (ret) { 208 dev_err(&led->client->dev, 209 "Failed to enable regulator\n"); 210 return ret; 211 } 212 } 213 214 if (led->enable_gpio) 215 gpiod_direction_output(led->enable_gpio, 1); 216 217 ret = lm3692x_fault_check(led); 218 if (ret) { 219 dev_err(&led->client->dev, "Cannot read/clear faults\n"); 220 goto out; 221 } 222 223 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); 224 if (ret) 225 goto out; 226 227 /* 228 * For glitch free operation, the following data should 229 * only be written while device enable bit is 0 230 * per Section 7.5.14 of the data sheet 231 */ 232 ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, 233 LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); 234 if (ret) 235 goto out; 236 237 ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, 238 LM3692X_BRHT_MODE_RAMP_MULTI | 239 LM3692X_BL_ADJ_POL | 240 LM3692X_RAMP_RATE_250us); 241 if (ret) 242 goto out; 243 244 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); 245 if (ret) 246 goto out; 247 248 ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); 249 if (ret) 250 goto out; 251 252 ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); 253 if (ret) 254 goto out; 255 256 ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 257 LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB); 258 if (ret) 259 goto out; 260 261 return ret; 262 out: 263 dev_err(&led->client->dev, "Fail writing initialization values\n"); 264 265 if (led->enable_gpio) 266 gpiod_direction_output(led->enable_gpio, 0); 267 268 if (led->regulator) { 269 ret = regulator_disable(led->regulator); 270 if (ret) 271 dev_err(&led->client->dev, 272 "Failed to disable regulator\n"); 273 } 274 275 return ret; 276 } 277 278 static int lm3692x_probe(struct i2c_client *client, 279 const struct i2c_device_id *id) 280 { 281 int ret; 282 struct lm3692x_led *led; 283 struct device_node *np = client->dev.of_node; 284 struct device_node *child_node; 285 const char *name; 286 287 led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); 288 if (!led) 289 return -ENOMEM; 290 291 for_each_available_child_of_node(np, child_node) { 292 led->led_dev.default_trigger = of_get_property(child_node, 293 "linux,default-trigger", 294 NULL); 295 296 ret = of_property_read_string(child_node, "label", &name); 297 if (!ret) 298 snprintf(led->label, sizeof(led->label), 299 "%s:%s", id->name, name); 300 else 301 snprintf(led->label, sizeof(led->label), 302 "%s::backlight_cluster", id->name); 303 }; 304 305 led->enable_gpio = devm_gpiod_get_optional(&client->dev, 306 "enable", GPIOD_OUT_LOW); 307 if (IS_ERR(led->enable_gpio)) { 308 ret = PTR_ERR(led->enable_gpio); 309 dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret); 310 return ret; 311 } 312 313 led->regulator = devm_regulator_get(&client->dev, "vled"); 314 if (IS_ERR(led->regulator)) 315 led->regulator = NULL; 316 317 led->client = client; 318 led->led_dev.name = led->label; 319 led->led_dev.brightness_set_blocking = lm3692x_brightness_set; 320 321 mutex_init(&led->lock); 322 323 i2c_set_clientdata(client, led); 324 325 led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); 326 if (IS_ERR(led->regmap)) { 327 ret = PTR_ERR(led->regmap); 328 dev_err(&client->dev, "Failed to allocate register map: %d\n", 329 ret); 330 return ret; 331 } 332 333 ret = lm3692x_init(led); 334 if (ret) 335 return ret; 336 337 ret = devm_led_classdev_register(&client->dev, &led->led_dev); 338 if (ret) { 339 dev_err(&client->dev, "led register err: %d\n", ret); 340 return ret; 341 } 342 343 return 0; 344 } 345 346 static int lm3692x_remove(struct i2c_client *client) 347 { 348 struct lm3692x_led *led = i2c_get_clientdata(client); 349 int ret; 350 351 if (led->enable_gpio) 352 gpiod_direction_output(led->enable_gpio, 0); 353 354 if (led->regulator) { 355 ret = regulator_disable(led->regulator); 356 if (ret) 357 dev_err(&led->client->dev, 358 "Failed to disable regulator\n"); 359 } 360 361 mutex_destroy(&led->lock); 362 363 return 0; 364 } 365 366 static const struct i2c_device_id lm3692x_id[] = { 367 { "lm36922", 0 }, 368 { "lm36923", 1 }, 369 { } 370 }; 371 MODULE_DEVICE_TABLE(i2c, lm3692x_id); 372 373 static const struct of_device_id of_lm3692x_leds_match[] = { 374 { .compatible = "ti,lm36922", }, 375 { .compatible = "ti,lm36923", }, 376 {}, 377 }; 378 MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); 379 380 static struct i2c_driver lm3692x_driver = { 381 .driver = { 382 .name = "lm3692x", 383 .of_match_table = of_lm3692x_leds_match, 384 }, 385 .probe = lm3692x_probe, 386 .remove = lm3692x_remove, 387 .id_table = lm3692x_id, 388 }; 389 module_i2c_driver(lm3692x_driver); 390 391 MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); 392 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 393 MODULE_LICENSE("GPL v2"); 394