1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Simple driver for Texas Instruments LM3630A Backlight driver chip 4 * Copyright (C) 2012 Texas Instruments 5 */ 6 #include <linux/module.h> 7 #include <linux/slab.h> 8 #include <linux/i2c.h> 9 #include <linux/backlight.h> 10 #include <linux/err.h> 11 #include <linux/delay.h> 12 #include <linux/uaccess.h> 13 #include <linux/interrupt.h> 14 #include <linux/regmap.h> 15 #include <linux/gpio/consumer.h> 16 #include <linux/pwm.h> 17 #include <linux/platform_data/lm3630a_bl.h> 18 19 #define REG_CTRL 0x00 20 #define REG_BOOST 0x02 21 #define REG_CONFIG 0x01 22 #define REG_BRT_A 0x03 23 #define REG_BRT_B 0x04 24 #define REG_I_A 0x05 25 #define REG_I_B 0x06 26 #define REG_INT_STATUS 0x09 27 #define REG_INT_EN 0x0A 28 #define REG_FAULT 0x0B 29 #define REG_PWM_OUTLOW 0x12 30 #define REG_PWM_OUTHIGH 0x13 31 #define REG_FILTER_STRENGTH 0x50 32 #define REG_MAX 0x50 33 34 #define INT_DEBOUNCE_MSEC 10 35 36 #define LM3630A_BANK_0 0 37 #define LM3630A_BANK_1 1 38 39 #define LM3630A_NUM_SINKS 2 40 #define LM3630A_SINK_0 0 41 #define LM3630A_SINK_1 1 42 43 struct lm3630a_chip { 44 struct device *dev; 45 struct delayed_work work; 46 47 int irq; 48 struct workqueue_struct *irqthread; 49 struct lm3630a_platform_data *pdata; 50 struct backlight_device *bleda; 51 struct backlight_device *bledb; 52 struct gpio_desc *enable_gpio; 53 struct regmap *regmap; 54 struct pwm_device *pwmd; 55 struct pwm_state pwmd_state; 56 }; 57 58 /* i2c access */ 59 static int lm3630a_read(struct lm3630a_chip *pchip, unsigned int reg) 60 { 61 int rval; 62 unsigned int reg_val; 63 64 rval = regmap_read(pchip->regmap, reg, ®_val); 65 if (rval < 0) 66 return rval; 67 return reg_val & 0xFF; 68 } 69 70 static int lm3630a_write(struct lm3630a_chip *pchip, 71 unsigned int reg, unsigned int data) 72 { 73 return regmap_write(pchip->regmap, reg, data); 74 } 75 76 static int lm3630a_update(struct lm3630a_chip *pchip, 77 unsigned int reg, unsigned int mask, 78 unsigned int data) 79 { 80 return regmap_update_bits(pchip->regmap, reg, mask, data); 81 } 82 83 /* initialize chip */ 84 static int lm3630a_chip_init(struct lm3630a_chip *pchip) 85 { 86 int rval; 87 struct lm3630a_platform_data *pdata = pchip->pdata; 88 89 usleep_range(1000, 2000); 90 /* set Filter Strength Register */ 91 rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03); 92 /* set Cofig. register */ 93 rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl); 94 /* set boost control */ 95 rval |= lm3630a_write(pchip, REG_BOOST, 0x38); 96 /* set current A */ 97 rval |= lm3630a_update(pchip, REG_I_A, 0x1F, 0x1F); 98 /* set current B */ 99 rval |= lm3630a_write(pchip, REG_I_B, 0x1F); 100 /* set control */ 101 rval |= lm3630a_update(pchip, REG_CTRL, 0x14, pdata->leda_ctrl); 102 rval |= lm3630a_update(pchip, REG_CTRL, 0x0B, pdata->ledb_ctrl); 103 usleep_range(1000, 2000); 104 /* set brightness A and B */ 105 rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt); 106 rval |= lm3630a_write(pchip, REG_BRT_B, pdata->ledb_init_brt); 107 108 if (rval < 0) 109 dev_err(pchip->dev, "i2c failed to access register\n"); 110 return rval; 111 } 112 113 /* interrupt handling */ 114 static void lm3630a_delayed_func(struct work_struct *work) 115 { 116 int rval; 117 struct lm3630a_chip *pchip; 118 119 pchip = container_of(work, struct lm3630a_chip, work.work); 120 121 rval = lm3630a_read(pchip, REG_INT_STATUS); 122 if (rval < 0) { 123 dev_err(pchip->dev, 124 "i2c failed to access REG_INT_STATUS Register\n"); 125 return; 126 } 127 128 dev_info(pchip->dev, "REG_INT_STATUS Register is 0x%x\n", rval); 129 } 130 131 static irqreturn_t lm3630a_isr_func(int irq, void *chip) 132 { 133 int rval; 134 struct lm3630a_chip *pchip = chip; 135 unsigned long delay = msecs_to_jiffies(INT_DEBOUNCE_MSEC); 136 137 queue_delayed_work(pchip->irqthread, &pchip->work, delay); 138 139 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); 140 if (rval < 0) { 141 dev_err(pchip->dev, "i2c failed to access register\n"); 142 return IRQ_NONE; 143 } 144 return IRQ_HANDLED; 145 } 146 147 static int lm3630a_intr_config(struct lm3630a_chip *pchip) 148 { 149 int rval; 150 151 rval = lm3630a_write(pchip, REG_INT_EN, 0x87); 152 if (rval < 0) 153 return rval; 154 155 INIT_DELAYED_WORK(&pchip->work, lm3630a_delayed_func); 156 pchip->irqthread = create_singlethread_workqueue("lm3630a-irqthd"); 157 if (!pchip->irqthread) { 158 dev_err(pchip->dev, "create irq thread fail\n"); 159 return -ENOMEM; 160 } 161 if (request_threaded_irq 162 (pchip->irq, NULL, lm3630a_isr_func, 163 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "lm3630a_irq", pchip)) { 164 dev_err(pchip->dev, "request threaded irq fail\n"); 165 destroy_workqueue(pchip->irqthread); 166 return -ENOMEM; 167 } 168 return rval; 169 } 170 171 static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max) 172 { 173 int err; 174 175 pchip->pwmd_state.period = pchip->pdata->pwm_period; 176 177 err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max); 178 if (err) 179 return err; 180 181 pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false; 182 183 return pwm_apply_state(pchip->pwmd, &pchip->pwmd_state); 184 } 185 186 /* update and get brightness */ 187 static int lm3630a_bank_a_update_status(struct backlight_device *bl) 188 { 189 int ret; 190 struct lm3630a_chip *pchip = bl_get_data(bl); 191 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; 192 193 /* pwm control */ 194 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) 195 return lm3630a_pwm_ctrl(pchip, bl->props.brightness, 196 bl->props.max_brightness); 197 198 /* disable sleep */ 199 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); 200 if (ret < 0) 201 goto out_i2c_err; 202 usleep_range(1000, 2000); 203 /* minimum brightness is 0x04 */ 204 ret = lm3630a_write(pchip, REG_BRT_A, bl->props.brightness); 205 if (bl->props.brightness < 0x4) 206 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDA_ENABLE, 0); 207 else 208 ret |= lm3630a_update(pchip, REG_CTRL, 209 LM3630A_LEDA_ENABLE, LM3630A_LEDA_ENABLE); 210 if (ret < 0) 211 goto out_i2c_err; 212 return 0; 213 214 out_i2c_err: 215 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret)); 216 return ret; 217 } 218 219 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl) 220 { 221 int brightness, rval; 222 struct lm3630a_chip *pchip = bl_get_data(bl); 223 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; 224 225 if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) { 226 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH); 227 if (rval < 0) 228 goto out_i2c_err; 229 brightness = (rval & 0x01) << 8; 230 rval = lm3630a_read(pchip, REG_PWM_OUTLOW); 231 if (rval < 0) 232 goto out_i2c_err; 233 brightness |= rval; 234 goto out; 235 } 236 237 /* disable sleep */ 238 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); 239 if (rval < 0) 240 goto out_i2c_err; 241 usleep_range(1000, 2000); 242 rval = lm3630a_read(pchip, REG_BRT_A); 243 if (rval < 0) 244 goto out_i2c_err; 245 brightness = rval; 246 247 out: 248 bl->props.brightness = brightness; 249 return bl->props.brightness; 250 out_i2c_err: 251 dev_err(pchip->dev, "i2c failed to access register\n"); 252 return 0; 253 } 254 255 static const struct backlight_ops lm3630a_bank_a_ops = { 256 .options = BL_CORE_SUSPENDRESUME, 257 .update_status = lm3630a_bank_a_update_status, 258 .get_brightness = lm3630a_bank_a_get_brightness, 259 }; 260 261 /* update and get brightness */ 262 static int lm3630a_bank_b_update_status(struct backlight_device *bl) 263 { 264 int ret; 265 struct lm3630a_chip *pchip = bl_get_data(bl); 266 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; 267 268 /* pwm control */ 269 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) 270 return lm3630a_pwm_ctrl(pchip, bl->props.brightness, 271 bl->props.max_brightness); 272 273 /* disable sleep */ 274 ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); 275 if (ret < 0) 276 goto out_i2c_err; 277 usleep_range(1000, 2000); 278 /* minimum brightness is 0x04 */ 279 ret = lm3630a_write(pchip, REG_BRT_B, bl->props.brightness); 280 if (bl->props.brightness < 0x4) 281 ret |= lm3630a_update(pchip, REG_CTRL, LM3630A_LEDB_ENABLE, 0); 282 else 283 ret |= lm3630a_update(pchip, REG_CTRL, 284 LM3630A_LEDB_ENABLE, LM3630A_LEDB_ENABLE); 285 if (ret < 0) 286 goto out_i2c_err; 287 return 0; 288 289 out_i2c_err: 290 dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret)); 291 return ret; 292 } 293 294 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl) 295 { 296 int brightness, rval; 297 struct lm3630a_chip *pchip = bl_get_data(bl); 298 enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl; 299 300 if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) { 301 rval = lm3630a_read(pchip, REG_PWM_OUTHIGH); 302 if (rval < 0) 303 goto out_i2c_err; 304 brightness = (rval & 0x01) << 8; 305 rval = lm3630a_read(pchip, REG_PWM_OUTLOW); 306 if (rval < 0) 307 goto out_i2c_err; 308 brightness |= rval; 309 goto out; 310 } 311 312 /* disable sleep */ 313 rval = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00); 314 if (rval < 0) 315 goto out_i2c_err; 316 usleep_range(1000, 2000); 317 rval = lm3630a_read(pchip, REG_BRT_B); 318 if (rval < 0) 319 goto out_i2c_err; 320 brightness = rval; 321 322 out: 323 bl->props.brightness = brightness; 324 return bl->props.brightness; 325 out_i2c_err: 326 dev_err(pchip->dev, "i2c failed to access register\n"); 327 return 0; 328 } 329 330 static const struct backlight_ops lm3630a_bank_b_ops = { 331 .options = BL_CORE_SUSPENDRESUME, 332 .update_status = lm3630a_bank_b_update_status, 333 .get_brightness = lm3630a_bank_b_get_brightness, 334 }; 335 336 static int lm3630a_backlight_register(struct lm3630a_chip *pchip) 337 { 338 struct lm3630a_platform_data *pdata = pchip->pdata; 339 struct backlight_properties props; 340 const char *label; 341 342 props.type = BACKLIGHT_RAW; 343 if (pdata->leda_ctrl != LM3630A_LEDA_DISABLE) { 344 props.brightness = pdata->leda_init_brt; 345 props.max_brightness = pdata->leda_max_brt; 346 label = pdata->leda_label ? pdata->leda_label : "lm3630a_leda"; 347 pchip->bleda = 348 devm_backlight_device_register(pchip->dev, label, 349 pchip->dev, pchip, 350 &lm3630a_bank_a_ops, &props); 351 if (IS_ERR(pchip->bleda)) 352 return PTR_ERR(pchip->bleda); 353 } 354 355 if ((pdata->ledb_ctrl != LM3630A_LEDB_DISABLE) && 356 (pdata->ledb_ctrl != LM3630A_LEDB_ON_A)) { 357 props.brightness = pdata->ledb_init_brt; 358 props.max_brightness = pdata->ledb_max_brt; 359 label = pdata->ledb_label ? pdata->ledb_label : "lm3630a_ledb"; 360 pchip->bledb = 361 devm_backlight_device_register(pchip->dev, label, 362 pchip->dev, pchip, 363 &lm3630a_bank_b_ops, &props); 364 if (IS_ERR(pchip->bledb)) 365 return PTR_ERR(pchip->bledb); 366 } 367 return 0; 368 } 369 370 static const struct regmap_config lm3630a_regmap = { 371 .reg_bits = 8, 372 .val_bits = 8, 373 .max_register = REG_MAX, 374 }; 375 376 static int lm3630a_parse_led_sources(struct fwnode_handle *node, 377 int default_led_sources) 378 { 379 u32 sources[LM3630A_NUM_SINKS]; 380 int ret, num_sources, i; 381 382 num_sources = fwnode_property_count_u32(node, "led-sources"); 383 if (num_sources < 0) 384 return default_led_sources; 385 else if (num_sources > ARRAY_SIZE(sources)) 386 return -EINVAL; 387 388 ret = fwnode_property_read_u32_array(node, "led-sources", sources, 389 num_sources); 390 if (ret) 391 return ret; 392 393 for (i = 0; i < num_sources; i++) { 394 if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1) 395 return -EINVAL; 396 397 ret |= BIT(sources[i]); 398 } 399 400 return ret; 401 } 402 403 static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata, 404 struct fwnode_handle *node, int *seen_led_sources) 405 { 406 int led_sources, ret; 407 const char *label; 408 u32 bank, val; 409 bool linear; 410 411 ret = fwnode_property_read_u32(node, "reg", &bank); 412 if (ret) 413 return ret; 414 415 if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1) 416 return -EINVAL; 417 418 led_sources = lm3630a_parse_led_sources(node, BIT(bank)); 419 if (led_sources < 0) 420 return led_sources; 421 422 if (*seen_led_sources & led_sources) 423 return -EINVAL; 424 425 *seen_led_sources |= led_sources; 426 427 linear = fwnode_property_read_bool(node, 428 "ti,linear-mapping-mode"); 429 if (bank) { 430 if (led_sources & BIT(LM3630A_SINK_0) || 431 !(led_sources & BIT(LM3630A_SINK_1))) 432 return -EINVAL; 433 434 pdata->ledb_ctrl = linear ? 435 LM3630A_LEDB_ENABLE_LINEAR : 436 LM3630A_LEDB_ENABLE; 437 } else { 438 if (!(led_sources & BIT(LM3630A_SINK_0))) 439 return -EINVAL; 440 441 pdata->leda_ctrl = linear ? 442 LM3630A_LEDA_ENABLE_LINEAR : 443 LM3630A_LEDA_ENABLE; 444 445 if (led_sources & BIT(LM3630A_SINK_1)) 446 pdata->ledb_ctrl = LM3630A_LEDB_ON_A; 447 } 448 449 ret = fwnode_property_read_string(node, "label", &label); 450 if (!ret) { 451 if (bank) 452 pdata->ledb_label = label; 453 else 454 pdata->leda_label = label; 455 } 456 457 ret = fwnode_property_read_u32(node, "default-brightness", 458 &val); 459 if (!ret) { 460 if (bank) 461 pdata->ledb_init_brt = val; 462 else 463 pdata->leda_init_brt = val; 464 } 465 466 ret = fwnode_property_read_u32(node, "max-brightness", &val); 467 if (!ret) { 468 if (bank) 469 pdata->ledb_max_brt = val; 470 else 471 pdata->leda_max_brt = val; 472 } 473 474 return 0; 475 } 476 477 static int lm3630a_parse_node(struct lm3630a_chip *pchip, 478 struct lm3630a_platform_data *pdata) 479 { 480 int ret = -ENODEV, seen_led_sources = 0; 481 struct fwnode_handle *node; 482 483 device_for_each_child_node(pchip->dev, node) { 484 ret = lm3630a_parse_bank(pdata, node, &seen_led_sources); 485 if (ret) { 486 fwnode_handle_put(node); 487 return ret; 488 } 489 } 490 491 return ret; 492 } 493 494 static int lm3630a_probe(struct i2c_client *client, 495 const struct i2c_device_id *id) 496 { 497 struct lm3630a_platform_data *pdata = dev_get_platdata(&client->dev); 498 struct lm3630a_chip *pchip; 499 int rval; 500 501 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 502 dev_err(&client->dev, "fail : i2c functionality check\n"); 503 return -EOPNOTSUPP; 504 } 505 506 pchip = devm_kzalloc(&client->dev, sizeof(struct lm3630a_chip), 507 GFP_KERNEL); 508 if (!pchip) 509 return -ENOMEM; 510 pchip->dev = &client->dev; 511 512 pchip->regmap = devm_regmap_init_i2c(client, &lm3630a_regmap); 513 if (IS_ERR(pchip->regmap)) { 514 rval = PTR_ERR(pchip->regmap); 515 dev_err(&client->dev, "fail : allocate reg. map: %d\n", rval); 516 return rval; 517 } 518 519 i2c_set_clientdata(client, pchip); 520 if (pdata == NULL) { 521 pdata = devm_kzalloc(pchip->dev, 522 sizeof(struct lm3630a_platform_data), 523 GFP_KERNEL); 524 if (pdata == NULL) 525 return -ENOMEM; 526 527 /* default values */ 528 pdata->leda_max_brt = LM3630A_MAX_BRIGHTNESS; 529 pdata->ledb_max_brt = LM3630A_MAX_BRIGHTNESS; 530 pdata->leda_init_brt = LM3630A_MAX_BRIGHTNESS; 531 pdata->ledb_init_brt = LM3630A_MAX_BRIGHTNESS; 532 533 rval = lm3630a_parse_node(pchip, pdata); 534 if (rval) { 535 dev_err(&client->dev, "fail : parse node\n"); 536 return rval; 537 } 538 } 539 pchip->pdata = pdata; 540 541 pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", 542 GPIOD_OUT_HIGH); 543 if (IS_ERR(pchip->enable_gpio)) { 544 rval = PTR_ERR(pchip->enable_gpio); 545 return rval; 546 } 547 548 /* chip initialize */ 549 rval = lm3630a_chip_init(pchip); 550 if (rval < 0) { 551 dev_err(&client->dev, "fail : init chip\n"); 552 return rval; 553 } 554 /* backlight register */ 555 rval = lm3630a_backlight_register(pchip); 556 if (rval < 0) { 557 dev_err(&client->dev, "fail : backlight register.\n"); 558 return rval; 559 } 560 /* pwm */ 561 if (pdata->pwm_ctrl != LM3630A_PWM_DISABLE) { 562 pchip->pwmd = devm_pwm_get(pchip->dev, "lm3630a-pwm"); 563 if (IS_ERR(pchip->pwmd)) { 564 dev_err(&client->dev, "fail : get pwm device\n"); 565 return PTR_ERR(pchip->pwmd); 566 } 567 568 pwm_init_state(pchip->pwmd, &pchip->pwmd_state); 569 } 570 571 /* interrupt enable : irq 0 is not allowed */ 572 pchip->irq = client->irq; 573 if (pchip->irq) { 574 rval = lm3630a_intr_config(pchip); 575 if (rval < 0) 576 return rval; 577 } 578 dev_info(&client->dev, "LM3630A backlight register OK.\n"); 579 return 0; 580 } 581 582 static void lm3630a_remove(struct i2c_client *client) 583 { 584 int rval; 585 struct lm3630a_chip *pchip = i2c_get_clientdata(client); 586 587 rval = lm3630a_write(pchip, REG_BRT_A, 0); 588 if (rval < 0) 589 dev_err(pchip->dev, "i2c failed to access register\n"); 590 591 rval = lm3630a_write(pchip, REG_BRT_B, 0); 592 if (rval < 0) 593 dev_err(pchip->dev, "i2c failed to access register\n"); 594 595 if (pchip->irq) { 596 free_irq(pchip->irq, pchip); 597 destroy_workqueue(pchip->irqthread); 598 } 599 } 600 601 static const struct i2c_device_id lm3630a_id[] = { 602 {LM3630A_NAME, 0}, 603 {} 604 }; 605 606 MODULE_DEVICE_TABLE(i2c, lm3630a_id); 607 608 static const struct of_device_id lm3630a_match_table[] = { 609 { .compatible = "ti,lm3630a", }, 610 { }, 611 }; 612 613 MODULE_DEVICE_TABLE(of, lm3630a_match_table); 614 615 static struct i2c_driver lm3630a_i2c_driver = { 616 .driver = { 617 .name = LM3630A_NAME, 618 .of_match_table = lm3630a_match_table, 619 }, 620 .probe = lm3630a_probe, 621 .remove = lm3630a_remove, 622 .id_table = lm3630a_id, 623 }; 624 625 module_i2c_driver(lm3630a_i2c_driver); 626 627 MODULE_DESCRIPTION("Texas Instruments Backlight driver for LM3630A"); 628 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>"); 629 MODULE_AUTHOR("LDD MLP <ldd-mlp@list.ti.com>"); 630 MODULE_LICENSE("GPL v2"); 631