1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LP5521/LP5523/LP55231/LP5562 Common Driver 4 * 5 * Copyright 2012 Texas Instruments 6 * 7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com> 8 * 9 * Derived from leds-lp5521.c, leds-lp5523.c 10 */ 11 12 #include <linux/clk.h> 13 #include <linux/delay.h> 14 #include <linux/firmware.h> 15 #include <linux/i2c.h> 16 #include <linux/leds.h> 17 #include <linux/module.h> 18 #include <linux/platform_data/leds-lp55xx.h> 19 #include <linux/slab.h> 20 #include <linux/gpio.h> 21 #include <linux/of_gpio.h> 22 23 #include "leds-lp55xx-common.h" 24 25 /* External clock rate */ 26 #define LP55XX_CLK_32K 32768 27 28 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev) 29 { 30 return container_of(cdev, struct lp55xx_led, cdev); 31 } 32 33 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev) 34 { 35 return cdev_to_lp55xx_led(dev_get_drvdata(dev)); 36 } 37 38 static void lp55xx_reset_device(struct lp55xx_chip *chip) 39 { 40 struct lp55xx_device_config *cfg = chip->cfg; 41 u8 addr = cfg->reset.addr; 42 u8 val = cfg->reset.val; 43 44 /* no error checking here because no ACK from the device after reset */ 45 lp55xx_write(chip, addr, val); 46 } 47 48 static int lp55xx_detect_device(struct lp55xx_chip *chip) 49 { 50 struct lp55xx_device_config *cfg = chip->cfg; 51 u8 addr = cfg->enable.addr; 52 u8 val = cfg->enable.val; 53 int ret; 54 55 ret = lp55xx_write(chip, addr, val); 56 if (ret) 57 return ret; 58 59 usleep_range(1000, 2000); 60 61 ret = lp55xx_read(chip, addr, &val); 62 if (ret) 63 return ret; 64 65 if (val != cfg->enable.val) 66 return -ENODEV; 67 68 return 0; 69 } 70 71 static int lp55xx_post_init_device(struct lp55xx_chip *chip) 72 { 73 struct lp55xx_device_config *cfg = chip->cfg; 74 75 if (!cfg->post_init_device) 76 return 0; 77 78 return cfg->post_init_device(chip); 79 } 80 81 static ssize_t lp55xx_show_current(struct device *dev, 82 struct device_attribute *attr, 83 char *buf) 84 { 85 struct lp55xx_led *led = dev_to_lp55xx_led(dev); 86 87 return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current); 88 } 89 90 static ssize_t lp55xx_store_current(struct device *dev, 91 struct device_attribute *attr, 92 const char *buf, size_t len) 93 { 94 struct lp55xx_led *led = dev_to_lp55xx_led(dev); 95 struct lp55xx_chip *chip = led->chip; 96 unsigned long curr; 97 98 if (kstrtoul(buf, 0, &curr)) 99 return -EINVAL; 100 101 if (curr > led->max_current) 102 return -EINVAL; 103 104 if (!chip->cfg->set_led_current) 105 return len; 106 107 mutex_lock(&chip->lock); 108 chip->cfg->set_led_current(led, (u8)curr); 109 mutex_unlock(&chip->lock); 110 111 return len; 112 } 113 114 static ssize_t lp55xx_show_max_current(struct device *dev, 115 struct device_attribute *attr, 116 char *buf) 117 { 118 struct lp55xx_led *led = dev_to_lp55xx_led(dev); 119 120 return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current); 121 } 122 123 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current, 124 lp55xx_store_current); 125 static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL); 126 127 static struct attribute *lp55xx_led_attrs[] = { 128 &dev_attr_led_current.attr, 129 &dev_attr_max_current.attr, 130 NULL, 131 }; 132 ATTRIBUTE_GROUPS(lp55xx_led); 133 134 static int lp55xx_set_brightness(struct led_classdev *cdev, 135 enum led_brightness brightness) 136 { 137 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev); 138 struct lp55xx_device_config *cfg = led->chip->cfg; 139 140 led->brightness = (u8)brightness; 141 return cfg->brightness_fn(led); 142 } 143 144 static int lp55xx_init_led(struct lp55xx_led *led, 145 struct lp55xx_chip *chip, int chan) 146 { 147 struct lp55xx_platform_data *pdata = chip->pdata; 148 struct lp55xx_device_config *cfg = chip->cfg; 149 struct device *dev = &chip->cl->dev; 150 char name[32]; 151 int ret; 152 int max_channel = cfg->max_channel; 153 154 if (chan >= max_channel) { 155 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel); 156 return -EINVAL; 157 } 158 159 if (pdata->led_config[chan].led_current == 0) 160 return 0; 161 162 led->led_current = pdata->led_config[chan].led_current; 163 led->max_current = pdata->led_config[chan].max_current; 164 led->chan_nr = pdata->led_config[chan].chan_nr; 165 led->cdev.default_trigger = pdata->led_config[chan].default_trigger; 166 167 if (led->chan_nr >= max_channel) { 168 dev_err(dev, "Use channel numbers between 0 and %d\n", 169 max_channel - 1); 170 return -EINVAL; 171 } 172 173 led->cdev.brightness_set_blocking = lp55xx_set_brightness; 174 led->cdev.groups = lp55xx_led_groups; 175 176 if (pdata->led_config[chan].name) { 177 led->cdev.name = pdata->led_config[chan].name; 178 } else { 179 snprintf(name, sizeof(name), "%s:channel%d", 180 pdata->label ? : chip->cl->name, chan); 181 led->cdev.name = name; 182 } 183 184 ret = led_classdev_register(dev, &led->cdev); 185 if (ret) { 186 dev_err(dev, "led register err: %d\n", ret); 187 return ret; 188 } 189 190 return 0; 191 } 192 193 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context) 194 { 195 struct lp55xx_chip *chip = context; 196 struct device *dev = &chip->cl->dev; 197 enum lp55xx_engine_index idx = chip->engine_idx; 198 199 if (!fw) { 200 dev_err(dev, "firmware request failed\n"); 201 return; 202 } 203 204 /* handling firmware data is chip dependent */ 205 mutex_lock(&chip->lock); 206 207 chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD; 208 chip->fw = fw; 209 if (chip->cfg->firmware_cb) 210 chip->cfg->firmware_cb(chip); 211 212 mutex_unlock(&chip->lock); 213 214 /* firmware should be released for other channel use */ 215 release_firmware(chip->fw); 216 chip->fw = NULL; 217 } 218 219 static int lp55xx_request_firmware(struct lp55xx_chip *chip) 220 { 221 const char *name = chip->cl->name; 222 struct device *dev = &chip->cl->dev; 223 224 return request_firmware_nowait(THIS_MODULE, false, name, dev, 225 GFP_KERNEL, chip, lp55xx_firmware_loaded); 226 } 227 228 static ssize_t lp55xx_show_engine_select(struct device *dev, 229 struct device_attribute *attr, 230 char *buf) 231 { 232 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 233 struct lp55xx_chip *chip = led->chip; 234 235 return sprintf(buf, "%d\n", chip->engine_idx); 236 } 237 238 static ssize_t lp55xx_store_engine_select(struct device *dev, 239 struct device_attribute *attr, 240 const char *buf, size_t len) 241 { 242 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 243 struct lp55xx_chip *chip = led->chip; 244 unsigned long val; 245 int ret; 246 247 if (kstrtoul(buf, 0, &val)) 248 return -EINVAL; 249 250 /* select the engine to be run */ 251 252 switch (val) { 253 case LP55XX_ENGINE_1: 254 case LP55XX_ENGINE_2: 255 case LP55XX_ENGINE_3: 256 mutex_lock(&chip->lock); 257 chip->engine_idx = val; 258 ret = lp55xx_request_firmware(chip); 259 mutex_unlock(&chip->lock); 260 break; 261 default: 262 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val); 263 return -EINVAL; 264 } 265 266 if (ret) { 267 dev_err(dev, "request firmware err: %d\n", ret); 268 return ret; 269 } 270 271 return len; 272 } 273 274 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start) 275 { 276 if (chip->cfg->run_engine) 277 chip->cfg->run_engine(chip, start); 278 } 279 280 static ssize_t lp55xx_store_engine_run(struct device *dev, 281 struct device_attribute *attr, 282 const char *buf, size_t len) 283 { 284 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev)); 285 struct lp55xx_chip *chip = led->chip; 286 unsigned long val; 287 288 if (kstrtoul(buf, 0, &val)) 289 return -EINVAL; 290 291 /* run or stop the selected engine */ 292 293 if (val <= 0) { 294 lp55xx_run_engine(chip, false); 295 return len; 296 } 297 298 mutex_lock(&chip->lock); 299 lp55xx_run_engine(chip, true); 300 mutex_unlock(&chip->lock); 301 302 return len; 303 } 304 305 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR, 306 lp55xx_show_engine_select, lp55xx_store_engine_select); 307 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run); 308 309 static struct attribute *lp55xx_engine_attributes[] = { 310 &dev_attr_select_engine.attr, 311 &dev_attr_run_engine.attr, 312 NULL, 313 }; 314 315 static const struct attribute_group lp55xx_engine_attr_group = { 316 .attrs = lp55xx_engine_attributes, 317 }; 318 319 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val) 320 { 321 return i2c_smbus_write_byte_data(chip->cl, reg, val); 322 } 323 EXPORT_SYMBOL_GPL(lp55xx_write); 324 325 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val) 326 { 327 s32 ret; 328 329 ret = i2c_smbus_read_byte_data(chip->cl, reg); 330 if (ret < 0) 331 return ret; 332 333 *val = ret; 334 return 0; 335 } 336 EXPORT_SYMBOL_GPL(lp55xx_read); 337 338 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val) 339 { 340 int ret; 341 u8 tmp; 342 343 ret = lp55xx_read(chip, reg, &tmp); 344 if (ret) 345 return ret; 346 347 tmp &= ~mask; 348 tmp |= val & mask; 349 350 return lp55xx_write(chip, reg, tmp); 351 } 352 EXPORT_SYMBOL_GPL(lp55xx_update_bits); 353 354 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip) 355 { 356 struct clk *clk; 357 int err; 358 359 clk = devm_clk_get(&chip->cl->dev, "32k_clk"); 360 if (IS_ERR(clk)) 361 goto use_internal_clk; 362 363 err = clk_prepare_enable(clk); 364 if (err) 365 goto use_internal_clk; 366 367 if (clk_get_rate(clk) != LP55XX_CLK_32K) { 368 clk_disable_unprepare(clk); 369 goto use_internal_clk; 370 } 371 372 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K); 373 374 chip->clk = clk; 375 return true; 376 377 use_internal_clk: 378 dev_info(&chip->cl->dev, "internal clock used\n"); 379 return false; 380 } 381 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used); 382 383 int lp55xx_init_device(struct lp55xx_chip *chip) 384 { 385 struct lp55xx_platform_data *pdata; 386 struct lp55xx_device_config *cfg; 387 struct device *dev = &chip->cl->dev; 388 int ret = 0; 389 390 WARN_ON(!chip); 391 392 pdata = chip->pdata; 393 cfg = chip->cfg; 394 395 if (!pdata || !cfg) 396 return -EINVAL; 397 398 if (gpio_is_valid(pdata->enable_gpio)) { 399 ret = devm_gpio_request_one(dev, pdata->enable_gpio, 400 GPIOF_DIR_OUT, "lp5523_enable"); 401 if (ret < 0) { 402 dev_err(dev, "could not acquire enable gpio (err=%d)\n", 403 ret); 404 goto err; 405 } 406 407 gpio_set_value(pdata->enable_gpio, 0); 408 usleep_range(1000, 2000); /* Keep enable down at least 1ms */ 409 gpio_set_value(pdata->enable_gpio, 1); 410 usleep_range(1000, 2000); /* 500us abs min. */ 411 } 412 413 lp55xx_reset_device(chip); 414 415 /* 416 * Exact value is not available. 10 - 20ms 417 * appears to be enough for reset. 418 */ 419 usleep_range(10000, 20000); 420 421 ret = lp55xx_detect_device(chip); 422 if (ret) { 423 dev_err(dev, "device detection err: %d\n", ret); 424 goto err; 425 } 426 427 /* chip specific initialization */ 428 ret = lp55xx_post_init_device(chip); 429 if (ret) { 430 dev_err(dev, "post init device err: %d\n", ret); 431 goto err_post_init; 432 } 433 434 return 0; 435 436 err_post_init: 437 lp55xx_deinit_device(chip); 438 err: 439 return ret; 440 } 441 EXPORT_SYMBOL_GPL(lp55xx_init_device); 442 443 void lp55xx_deinit_device(struct lp55xx_chip *chip) 444 { 445 struct lp55xx_platform_data *pdata = chip->pdata; 446 447 if (chip->clk) 448 clk_disable_unprepare(chip->clk); 449 450 if (gpio_is_valid(pdata->enable_gpio)) 451 gpio_set_value(pdata->enable_gpio, 0); 452 } 453 EXPORT_SYMBOL_GPL(lp55xx_deinit_device); 454 455 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip) 456 { 457 struct lp55xx_platform_data *pdata = chip->pdata; 458 struct lp55xx_device_config *cfg = chip->cfg; 459 int num_channels = pdata->num_channels; 460 struct lp55xx_led *each; 461 u8 led_current; 462 int ret; 463 int i; 464 465 if (!cfg->brightness_fn) { 466 dev_err(&chip->cl->dev, "empty brightness configuration\n"); 467 return -EINVAL; 468 } 469 470 for (i = 0; i < num_channels; i++) { 471 472 /* do not initialize channels that are not connected */ 473 if (pdata->led_config[i].led_current == 0) 474 continue; 475 476 led_current = pdata->led_config[i].led_current; 477 each = led + i; 478 ret = lp55xx_init_led(each, chip, i); 479 if (ret) 480 goto err_init_led; 481 482 chip->num_leds++; 483 each->chip = chip; 484 485 /* setting led current at each channel */ 486 if (cfg->set_led_current) 487 cfg->set_led_current(each, led_current); 488 } 489 490 return 0; 491 492 err_init_led: 493 lp55xx_unregister_leds(led, chip); 494 return ret; 495 } 496 EXPORT_SYMBOL_GPL(lp55xx_register_leds); 497 498 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip) 499 { 500 int i; 501 struct lp55xx_led *each; 502 503 for (i = 0; i < chip->num_leds; i++) { 504 each = led + i; 505 led_classdev_unregister(&each->cdev); 506 } 507 } 508 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds); 509 510 int lp55xx_register_sysfs(struct lp55xx_chip *chip) 511 { 512 struct device *dev = &chip->cl->dev; 513 struct lp55xx_device_config *cfg = chip->cfg; 514 int ret; 515 516 if (!cfg->run_engine || !cfg->firmware_cb) 517 goto dev_specific_attrs; 518 519 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group); 520 if (ret) 521 return ret; 522 523 dev_specific_attrs: 524 return cfg->dev_attr_group ? 525 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0; 526 } 527 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs); 528 529 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip) 530 { 531 struct device *dev = &chip->cl->dev; 532 struct lp55xx_device_config *cfg = chip->cfg; 533 534 if (cfg->dev_attr_group) 535 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group); 536 537 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group); 538 } 539 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs); 540 541 struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev, 542 struct device_node *np) 543 { 544 struct device_node *child; 545 struct lp55xx_platform_data *pdata; 546 struct lp55xx_led_config *cfg; 547 int num_channels; 548 int i = 0; 549 550 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); 551 if (!pdata) 552 return ERR_PTR(-ENOMEM); 553 554 num_channels = of_get_child_count(np); 555 if (num_channels == 0) { 556 dev_err(dev, "no LED channels\n"); 557 return ERR_PTR(-EINVAL); 558 } 559 560 cfg = devm_kcalloc(dev, num_channels, sizeof(*cfg), GFP_KERNEL); 561 if (!cfg) 562 return ERR_PTR(-ENOMEM); 563 564 pdata->led_config = &cfg[0]; 565 pdata->num_channels = num_channels; 566 567 for_each_child_of_node(np, child) { 568 cfg[i].chan_nr = i; 569 570 of_property_read_string(child, "chan-name", &cfg[i].name); 571 of_property_read_u8(child, "led-cur", &cfg[i].led_current); 572 of_property_read_u8(child, "max-cur", &cfg[i].max_current); 573 cfg[i].default_trigger = 574 of_get_property(child, "linux,default-trigger", NULL); 575 576 i++; 577 } 578 579 of_property_read_string(np, "label", &pdata->label); 580 of_property_read_u8(np, "clock-mode", &pdata->clock_mode); 581 582 pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0); 583 584 /* LP8501 specific */ 585 of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel); 586 587 return pdata; 588 } 589 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata); 590 591 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>"); 592 MODULE_DESCRIPTION("LP55xx Common Driver"); 593 MODULE_LICENSE("GPL"); 594