1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * LED Class Core 4 * 5 * Copyright 2005-2006 Openedhand Ltd. 6 * 7 * Author: Richard Purdie <rpurdie@openedhand.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/led-class-multicolor.h> 12 #include <linux/leds.h> 13 #include <linux/list.h> 14 #include <linux/module.h> 15 #include <linux/mutex.h> 16 #include <linux/of.h> 17 #include <linux/property.h> 18 #include <linux/rwsem.h> 19 #include <linux/slab.h> 20 #include <uapi/linux/uleds.h> 21 #include "leds.h" 22 23 DECLARE_RWSEM(leds_list_lock); 24 EXPORT_SYMBOL_GPL(leds_list_lock); 25 26 LIST_HEAD(leds_list); 27 EXPORT_SYMBOL_GPL(leds_list); 28 29 static const char * const led_colors[LED_COLOR_ID_MAX] = { 30 [LED_COLOR_ID_WHITE] = "white", 31 [LED_COLOR_ID_RED] = "red", 32 [LED_COLOR_ID_GREEN] = "green", 33 [LED_COLOR_ID_BLUE] = "blue", 34 [LED_COLOR_ID_AMBER] = "amber", 35 [LED_COLOR_ID_VIOLET] = "violet", 36 [LED_COLOR_ID_YELLOW] = "yellow", 37 [LED_COLOR_ID_IR] = "ir", 38 [LED_COLOR_ID_MULTI] = "multicolor", 39 [LED_COLOR_ID_RGB] = "rgb", 40 [LED_COLOR_ID_PURPLE] = "purple", 41 [LED_COLOR_ID_ORANGE] = "orange", 42 [LED_COLOR_ID_PINK] = "pink", 43 [LED_COLOR_ID_CYAN] = "cyan", 44 [LED_COLOR_ID_LIME] = "lime", 45 }; 46 47 static int __led_set_brightness(struct led_classdev *led_cdev, unsigned int value) 48 { 49 if (!led_cdev->brightness_set) 50 return -ENOTSUPP; 51 52 led_cdev->brightness_set(led_cdev, value); 53 54 return 0; 55 } 56 57 static int __led_set_brightness_blocking(struct led_classdev *led_cdev, unsigned int value) 58 { 59 if (!led_cdev->brightness_set_blocking) 60 return -ENOTSUPP; 61 62 return led_cdev->brightness_set_blocking(led_cdev, value); 63 } 64 65 static void led_timer_function(struct timer_list *t) 66 { 67 struct led_classdev *led_cdev = from_timer(led_cdev, t, blink_timer); 68 unsigned long brightness; 69 unsigned long delay; 70 71 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { 72 led_set_brightness_nosleep(led_cdev, LED_OFF); 73 clear_bit(LED_BLINK_SW, &led_cdev->work_flags); 74 return; 75 } 76 77 if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP, 78 &led_cdev->work_flags)) { 79 clear_bit(LED_BLINK_SW, &led_cdev->work_flags); 80 return; 81 } 82 83 brightness = led_get_brightness(led_cdev); 84 if (!brightness) { 85 /* Time to switch the LED on. */ 86 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, 87 &led_cdev->work_flags)) 88 brightness = led_cdev->new_blink_brightness; 89 else 90 brightness = led_cdev->blink_brightness; 91 delay = led_cdev->blink_delay_on; 92 } else { 93 /* Store the current brightness value to be able 94 * to restore it when the delay_off period is over. 95 */ 96 led_cdev->blink_brightness = brightness; 97 brightness = LED_OFF; 98 delay = led_cdev->blink_delay_off; 99 } 100 101 led_set_brightness_nosleep(led_cdev, brightness); 102 103 /* Return in next iteration if led is in one-shot mode and we are in 104 * the final blink state so that the led is toggled each delay_on + 105 * delay_off milliseconds in worst case. 106 */ 107 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) { 108 if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) { 109 if (brightness) 110 set_bit(LED_BLINK_ONESHOT_STOP, 111 &led_cdev->work_flags); 112 } else { 113 if (!brightness) 114 set_bit(LED_BLINK_ONESHOT_STOP, 115 &led_cdev->work_flags); 116 } 117 } 118 119 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); 120 } 121 122 static void set_brightness_delayed_set_brightness(struct led_classdev *led_cdev, 123 unsigned int value) 124 { 125 int ret; 126 127 ret = __led_set_brightness(led_cdev, value); 128 if (ret == -ENOTSUPP) { 129 ret = __led_set_brightness_blocking(led_cdev, value); 130 if (ret == -ENOTSUPP) 131 /* No back-end support to set a fixed brightness value */ 132 return; 133 } 134 135 /* LED HW might have been unplugged, therefore don't warn */ 136 if (ret == -ENODEV && led_cdev->flags & LED_UNREGISTERING && 137 led_cdev->flags & LED_HW_PLUGGABLE) 138 return; 139 140 if (ret < 0) 141 dev_err(led_cdev->dev, 142 "Setting an LED's brightness failed (%d)\n", ret); 143 } 144 145 static void set_brightness_delayed(struct work_struct *ws) 146 { 147 struct led_classdev *led_cdev = 148 container_of(ws, struct led_classdev, set_brightness_work); 149 150 if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) { 151 led_stop_software_blink(led_cdev); 152 set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); 153 } 154 155 /* 156 * Triggers may call led_set_brightness(LED_OFF), 157 * led_set_brightness(LED_FULL) in quick succession to disable blinking 158 * and turn the LED on. Both actions may have been scheduled to run 159 * before this work item runs once. To make sure this works properly 160 * handle LED_SET_BRIGHTNESS_OFF first. 161 */ 162 if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) { 163 set_brightness_delayed_set_brightness(led_cdev, LED_OFF); 164 /* 165 * The consecutives led_set_brightness(LED_OFF), 166 * led_set_brightness(LED_FULL) could have been executed out of 167 * order (LED_FULL first), if the work_flags has been set 168 * between LED_SET_BRIGHTNESS_OFF and LED_SET_BRIGHTNESS of this 169 * work. To avoid ending with the LED turned off, turn the LED 170 * on again. 171 */ 172 if (led_cdev->delayed_set_value != LED_OFF) 173 set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); 174 } 175 176 if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags)) 177 set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value); 178 179 if (test_and_clear_bit(LED_SET_BLINK, &led_cdev->work_flags)) { 180 unsigned long delay_on = led_cdev->delayed_delay_on; 181 unsigned long delay_off = led_cdev->delayed_delay_off; 182 183 led_blink_set(led_cdev, &delay_on, &delay_off); 184 } 185 } 186 187 static void led_set_software_blink(struct led_classdev *led_cdev, 188 unsigned long delay_on, 189 unsigned long delay_off) 190 { 191 int current_brightness; 192 193 current_brightness = led_get_brightness(led_cdev); 194 if (current_brightness) 195 led_cdev->blink_brightness = current_brightness; 196 if (!led_cdev->blink_brightness) 197 led_cdev->blink_brightness = led_cdev->max_brightness; 198 199 led_cdev->blink_delay_on = delay_on; 200 led_cdev->blink_delay_off = delay_off; 201 202 /* never on - just set to off */ 203 if (!delay_on) { 204 led_set_brightness_nosleep(led_cdev, LED_OFF); 205 return; 206 } 207 208 /* never off - just set to brightness */ 209 if (!delay_off) { 210 led_set_brightness_nosleep(led_cdev, 211 led_cdev->blink_brightness); 212 return; 213 } 214 215 set_bit(LED_BLINK_SW, &led_cdev->work_flags); 216 mod_timer(&led_cdev->blink_timer, jiffies + 1); 217 } 218 219 220 static void led_blink_setup(struct led_classdev *led_cdev, 221 unsigned long *delay_on, 222 unsigned long *delay_off) 223 { 224 if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) && 225 led_cdev->blink_set && 226 !led_cdev->blink_set(led_cdev, delay_on, delay_off)) 227 return; 228 229 /* blink with 1 Hz as default if nothing specified */ 230 if (!*delay_on && !*delay_off) 231 *delay_on = *delay_off = 500; 232 233 led_set_software_blink(led_cdev, *delay_on, *delay_off); 234 } 235 236 void led_init_core(struct led_classdev *led_cdev) 237 { 238 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); 239 240 timer_setup(&led_cdev->blink_timer, led_timer_function, 0); 241 } 242 EXPORT_SYMBOL_GPL(led_init_core); 243 244 void led_blink_set(struct led_classdev *led_cdev, 245 unsigned long *delay_on, 246 unsigned long *delay_off) 247 { 248 del_timer_sync(&led_cdev->blink_timer); 249 250 clear_bit(LED_BLINK_SW, &led_cdev->work_flags); 251 clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags); 252 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); 253 254 led_blink_setup(led_cdev, delay_on, delay_off); 255 } 256 EXPORT_SYMBOL_GPL(led_blink_set); 257 258 void led_blink_set_oneshot(struct led_classdev *led_cdev, 259 unsigned long *delay_on, 260 unsigned long *delay_off, 261 int invert) 262 { 263 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) && 264 timer_pending(&led_cdev->blink_timer)) 265 return; 266 267 set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags); 268 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); 269 270 if (invert) 271 set_bit(LED_BLINK_INVERT, &led_cdev->work_flags); 272 else 273 clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags); 274 275 led_blink_setup(led_cdev, delay_on, delay_off); 276 } 277 EXPORT_SYMBOL_GPL(led_blink_set_oneshot); 278 279 void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on, 280 unsigned long delay_off) 281 { 282 /* If necessary delegate to a work queue task. */ 283 if (led_cdev->blink_set && led_cdev->brightness_set_blocking) { 284 led_cdev->delayed_delay_on = delay_on; 285 led_cdev->delayed_delay_off = delay_off; 286 set_bit(LED_SET_BLINK, &led_cdev->work_flags); 287 queue_work(led_cdev->wq, &led_cdev->set_brightness_work); 288 return; 289 } 290 291 led_blink_set(led_cdev, &delay_on, &delay_off); 292 } 293 EXPORT_SYMBOL_GPL(led_blink_set_nosleep); 294 295 void led_stop_software_blink(struct led_classdev *led_cdev) 296 { 297 del_timer_sync(&led_cdev->blink_timer); 298 led_cdev->blink_delay_on = 0; 299 led_cdev->blink_delay_off = 0; 300 clear_bit(LED_BLINK_SW, &led_cdev->work_flags); 301 } 302 EXPORT_SYMBOL_GPL(led_stop_software_blink); 303 304 void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness) 305 { 306 /* 307 * If software blink is active, delay brightness setting 308 * until the next timer tick. 309 */ 310 if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) { 311 /* 312 * If we need to disable soft blinking delegate this to the 313 * work queue task to avoid problems in case we are called 314 * from hard irq context. 315 */ 316 if (!brightness) { 317 set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags); 318 queue_work(led_cdev->wq, &led_cdev->set_brightness_work); 319 } else { 320 set_bit(LED_BLINK_BRIGHTNESS_CHANGE, 321 &led_cdev->work_flags); 322 led_cdev->new_blink_brightness = brightness; 323 } 324 return; 325 } 326 327 led_set_brightness_nosleep(led_cdev, brightness); 328 } 329 EXPORT_SYMBOL_GPL(led_set_brightness); 330 331 void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value) 332 { 333 /* Use brightness_set op if available, it is guaranteed not to sleep */ 334 if (!__led_set_brightness(led_cdev, value)) 335 return; 336 337 /* 338 * Brightness setting can sleep, delegate it to a work queue task. 339 * value 0 / LED_OFF is special, since it also disables hw-blinking 340 * (sw-blink disable is handled in led_set_brightness()). 341 * To avoid a hw-blink-disable getting lost when a second brightness 342 * change is done immediately afterwards (before the work runs), 343 * it uses a separate work_flag. 344 */ 345 led_cdev->delayed_set_value = value; 346 /* Ensure delayed_set_value is seen before work_flags modification */ 347 smp_mb__before_atomic(); 348 349 if (value) 350 set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); 351 else { 352 clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); 353 clear_bit(LED_SET_BLINK, &led_cdev->work_flags); 354 set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); 355 } 356 357 queue_work(led_cdev->wq, &led_cdev->set_brightness_work); 358 } 359 EXPORT_SYMBOL_GPL(led_set_brightness_nopm); 360 361 void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value) 362 { 363 led_cdev->brightness = min(value, led_cdev->max_brightness); 364 365 if (led_cdev->flags & LED_SUSPENDED) 366 return; 367 368 led_set_brightness_nopm(led_cdev, led_cdev->brightness); 369 } 370 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep); 371 372 int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value) 373 { 374 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) 375 return -EBUSY; 376 377 led_cdev->brightness = min(value, led_cdev->max_brightness); 378 379 if (led_cdev->flags & LED_SUSPENDED) 380 return 0; 381 382 return __led_set_brightness_blocking(led_cdev, led_cdev->brightness); 383 } 384 EXPORT_SYMBOL_GPL(led_set_brightness_sync); 385 386 /* 387 * This is a led-core function because just like led_set_brightness() 388 * it is used in the kernel by e.g. triggers. 389 */ 390 void led_mc_set_brightness(struct led_classdev *led_cdev, 391 unsigned int *intensity_value, unsigned int num_colors, 392 unsigned int brightness) 393 { 394 struct led_classdev_mc *mcled_cdev; 395 unsigned int i; 396 397 if (!(led_cdev->flags & LED_MULTI_COLOR)) { 398 dev_err_once(led_cdev->dev, "error not a multi-color LED\n"); 399 return; 400 } 401 402 mcled_cdev = lcdev_to_mccdev(led_cdev); 403 if (num_colors != mcled_cdev->num_colors) { 404 dev_err_once(led_cdev->dev, "error num_colors mismatch %u != %u\n", 405 num_colors, mcled_cdev->num_colors); 406 return; 407 } 408 409 for (i = 0; i < mcled_cdev->num_colors; i++) 410 mcled_cdev->subled_info[i].intensity = intensity_value[i]; 411 412 led_set_brightness(led_cdev, brightness); 413 } 414 EXPORT_SYMBOL_GPL(led_mc_set_brightness); 415 416 int led_update_brightness(struct led_classdev *led_cdev) 417 { 418 int ret; 419 420 if (led_cdev->brightness_get) { 421 ret = led_cdev->brightness_get(led_cdev); 422 if (ret < 0) 423 return ret; 424 425 led_cdev->brightness = ret; 426 } 427 428 return 0; 429 } 430 EXPORT_SYMBOL_GPL(led_update_brightness); 431 432 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size) 433 { 434 struct fwnode_handle *fwnode = led_cdev->dev->fwnode; 435 u32 *pattern; 436 int count; 437 438 count = fwnode_property_count_u32(fwnode, "led-pattern"); 439 if (count < 0) 440 return NULL; 441 442 pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL); 443 if (!pattern) 444 return NULL; 445 446 if (fwnode_property_read_u32_array(fwnode, "led-pattern", pattern, count)) { 447 kfree(pattern); 448 return NULL; 449 } 450 451 *size = count; 452 453 return pattern; 454 } 455 EXPORT_SYMBOL_GPL(led_get_default_pattern); 456 457 /* Caller must ensure led_cdev->led_access held */ 458 void led_sysfs_disable(struct led_classdev *led_cdev) 459 { 460 lockdep_assert_held(&led_cdev->led_access); 461 462 led_cdev->flags |= LED_SYSFS_DISABLE; 463 } 464 EXPORT_SYMBOL_GPL(led_sysfs_disable); 465 466 /* Caller must ensure led_cdev->led_access held */ 467 void led_sysfs_enable(struct led_classdev *led_cdev) 468 { 469 lockdep_assert_held(&led_cdev->led_access); 470 471 led_cdev->flags &= ~LED_SYSFS_DISABLE; 472 } 473 EXPORT_SYMBOL_GPL(led_sysfs_enable); 474 475 static void led_parse_fwnode_props(struct device *dev, 476 struct fwnode_handle *fwnode, 477 struct led_properties *props) 478 { 479 int ret; 480 481 if (!fwnode) 482 return; 483 484 if (fwnode_property_present(fwnode, "label")) { 485 ret = fwnode_property_read_string(fwnode, "label", &props->label); 486 if (ret) 487 dev_err(dev, "Error parsing 'label' property (%d)\n", ret); 488 return; 489 } 490 491 if (fwnode_property_present(fwnode, "color")) { 492 ret = fwnode_property_read_u32(fwnode, "color", &props->color); 493 if (ret) 494 dev_err(dev, "Error parsing 'color' property (%d)\n", ret); 495 else if (props->color >= LED_COLOR_ID_MAX) 496 dev_err(dev, "LED color identifier out of range\n"); 497 else 498 props->color_present = true; 499 } 500 501 502 if (!fwnode_property_present(fwnode, "function")) 503 return; 504 505 ret = fwnode_property_read_string(fwnode, "function", &props->function); 506 if (ret) { 507 dev_err(dev, 508 "Error parsing 'function' property (%d)\n", 509 ret); 510 } 511 512 if (!fwnode_property_present(fwnode, "function-enumerator")) 513 return; 514 515 ret = fwnode_property_read_u32(fwnode, "function-enumerator", 516 &props->func_enum); 517 if (ret) { 518 dev_err(dev, 519 "Error parsing 'function-enumerator' property (%d)\n", 520 ret); 521 } else { 522 props->func_enum_present = true; 523 } 524 } 525 526 int led_compose_name(struct device *dev, struct led_init_data *init_data, 527 char *led_classdev_name) 528 { 529 struct led_properties props = {}; 530 struct fwnode_handle *fwnode = init_data->fwnode; 531 const char *devicename = init_data->devicename; 532 533 if (!led_classdev_name) 534 return -EINVAL; 535 536 led_parse_fwnode_props(dev, fwnode, &props); 537 538 if (props.label) { 539 /* 540 * If init_data.devicename is NULL, then it indicates that 541 * DT label should be used as-is for LED class device name. 542 * Otherwise the label is prepended with devicename to compose 543 * the final LED class device name. 544 */ 545 if (!devicename) { 546 strscpy(led_classdev_name, props.label, 547 LED_MAX_NAME_SIZE); 548 } else { 549 snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", 550 devicename, props.label); 551 } 552 } else if (props.function || props.color_present) { 553 char tmp_buf[LED_MAX_NAME_SIZE]; 554 555 if (props.func_enum_present) { 556 snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d", 557 props.color_present ? led_colors[props.color] : "", 558 props.function ?: "", props.func_enum); 559 } else { 560 snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s", 561 props.color_present ? led_colors[props.color] : "", 562 props.function ?: ""); 563 } 564 if (init_data->devname_mandatory) { 565 snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", 566 devicename, tmp_buf); 567 } else { 568 strscpy(led_classdev_name, tmp_buf, LED_MAX_NAME_SIZE); 569 570 } 571 } else if (init_data->default_label) { 572 if (!devicename) { 573 dev_err(dev, "Legacy LED naming requires devicename segment"); 574 return -EINVAL; 575 } 576 snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", 577 devicename, init_data->default_label); 578 } else if (is_of_node(fwnode)) { 579 strscpy(led_classdev_name, to_of_node(fwnode)->name, 580 LED_MAX_NAME_SIZE); 581 } else 582 return -EINVAL; 583 584 return 0; 585 } 586 EXPORT_SYMBOL_GPL(led_compose_name); 587 588 const char *led_get_color_name(u8 color_id) 589 { 590 if (color_id >= ARRAY_SIZE(led_colors)) 591 return NULL; 592 593 return led_colors[color_id]; 594 } 595 EXPORT_SYMBOL_GPL(led_get_color_name); 596 597 enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode) 598 { 599 const char *state = NULL; 600 601 if (!fwnode_property_read_string(fwnode, "default-state", &state)) { 602 if (!strcmp(state, "keep")) 603 return LEDS_DEFSTATE_KEEP; 604 if (!strcmp(state, "on")) 605 return LEDS_DEFSTATE_ON; 606 } 607 608 return LEDS_DEFSTATE_OFF; 609 } 610 EXPORT_SYMBOL_GPL(led_init_default_state_get); 611