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/leds.h> 12 #include <linux/list.h> 13 #include <linux/module.h> 14 #include <linux/mutex.h> 15 #include <linux/of.h> 16 #include <linux/property.h> 17 #include <linux/rwsem.h> 18 #include <linux/slab.h> 19 #include <uapi/linux/uleds.h> 20 #include "leds.h" 21 22 DECLARE_RWSEM(leds_list_lock); 23 EXPORT_SYMBOL_GPL(leds_list_lock); 24 25 LIST_HEAD(leds_list); 26 EXPORT_SYMBOL_GPL(leds_list); 27 28 const char * const led_colors[LED_COLOR_ID_MAX] = { 29 [LED_COLOR_ID_WHITE] = "white", 30 [LED_COLOR_ID_RED] = "red", 31 [LED_COLOR_ID_GREEN] = "green", 32 [LED_COLOR_ID_BLUE] = "blue", 33 [LED_COLOR_ID_AMBER] = "amber", 34 [LED_COLOR_ID_VIOLET] = "violet", 35 [LED_COLOR_ID_YELLOW] = "yellow", 36 [LED_COLOR_ID_IR] = "ir", 37 [LED_COLOR_ID_MULTI] = "multicolor", 38 [LED_COLOR_ID_RGB] = "rgb", 39 [LED_COLOR_ID_PURPLE] = "purple", 40 [LED_COLOR_ID_ORANGE] = "orange", 41 [LED_COLOR_ID_PINK] = "pink", 42 [LED_COLOR_ID_CYAN] = "cyan", 43 [LED_COLOR_ID_LIME] = "lime", 44 }; 45 EXPORT_SYMBOL_GPL(led_colors); 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 = 0; 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 < 0 && 131 /* LED HW might have been unplugged, therefore don't warn */ 132 !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) && 133 (led_cdev->flags & LED_HW_PLUGGABLE))) 134 dev_err(led_cdev->dev, 135 "Setting an LED's brightness failed (%d)\n", ret); 136 } 137 138 static void set_brightness_delayed(struct work_struct *ws) 139 { 140 struct led_classdev *led_cdev = 141 container_of(ws, struct led_classdev, set_brightness_work); 142 143 if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) { 144 led_stop_software_blink(led_cdev); 145 set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); 146 } 147 148 /* 149 * Triggers may call led_set_brightness(LED_OFF), 150 * led_set_brightness(LED_FULL) in quick succession to disable blinking 151 * and turn the LED on. Both actions may have been scheduled to run 152 * before this work item runs once. To make sure this works properly 153 * handle LED_SET_BRIGHTNESS_OFF first. 154 */ 155 if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) 156 set_brightness_delayed_set_brightness(led_cdev, LED_OFF); 157 158 if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags)) 159 set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value); 160 161 if (test_and_clear_bit(LED_SET_BLINK, &led_cdev->work_flags)) { 162 unsigned long delay_on = led_cdev->delayed_delay_on; 163 unsigned long delay_off = led_cdev->delayed_delay_off; 164 165 led_blink_set(led_cdev, &delay_on, &delay_off); 166 } 167 } 168 169 static void led_set_software_blink(struct led_classdev *led_cdev, 170 unsigned long delay_on, 171 unsigned long delay_off) 172 { 173 int current_brightness; 174 175 current_brightness = led_get_brightness(led_cdev); 176 if (current_brightness) 177 led_cdev->blink_brightness = current_brightness; 178 if (!led_cdev->blink_brightness) 179 led_cdev->blink_brightness = led_cdev->max_brightness; 180 181 led_cdev->blink_delay_on = delay_on; 182 led_cdev->blink_delay_off = delay_off; 183 184 /* never on - just set to off */ 185 if (!delay_on) { 186 led_set_brightness_nosleep(led_cdev, LED_OFF); 187 return; 188 } 189 190 /* never off - just set to brightness */ 191 if (!delay_off) { 192 led_set_brightness_nosleep(led_cdev, 193 led_cdev->blink_brightness); 194 return; 195 } 196 197 set_bit(LED_BLINK_SW, &led_cdev->work_flags); 198 mod_timer(&led_cdev->blink_timer, jiffies + 1); 199 } 200 201 202 static void led_blink_setup(struct led_classdev *led_cdev, 203 unsigned long *delay_on, 204 unsigned long *delay_off) 205 { 206 if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) && 207 led_cdev->blink_set && 208 !led_cdev->blink_set(led_cdev, delay_on, delay_off)) 209 return; 210 211 /* blink with 1 Hz as default if nothing specified */ 212 if (!*delay_on && !*delay_off) 213 *delay_on = *delay_off = 500; 214 215 led_set_software_blink(led_cdev, *delay_on, *delay_off); 216 } 217 218 void led_init_core(struct led_classdev *led_cdev) 219 { 220 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); 221 222 timer_setup(&led_cdev->blink_timer, led_timer_function, 0); 223 } 224 EXPORT_SYMBOL_GPL(led_init_core); 225 226 void led_blink_set(struct led_classdev *led_cdev, 227 unsigned long *delay_on, 228 unsigned long *delay_off) 229 { 230 del_timer_sync(&led_cdev->blink_timer); 231 232 clear_bit(LED_BLINK_SW, &led_cdev->work_flags); 233 clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags); 234 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); 235 236 led_blink_setup(led_cdev, delay_on, delay_off); 237 } 238 EXPORT_SYMBOL_GPL(led_blink_set); 239 240 void led_blink_set_oneshot(struct led_classdev *led_cdev, 241 unsigned long *delay_on, 242 unsigned long *delay_off, 243 int invert) 244 { 245 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) && 246 timer_pending(&led_cdev->blink_timer)) 247 return; 248 249 set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags); 250 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); 251 252 if (invert) 253 set_bit(LED_BLINK_INVERT, &led_cdev->work_flags); 254 else 255 clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags); 256 257 led_blink_setup(led_cdev, delay_on, delay_off); 258 } 259 EXPORT_SYMBOL_GPL(led_blink_set_oneshot); 260 261 void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on, 262 unsigned long delay_off) 263 { 264 /* If necessary delegate to a work queue task. */ 265 if (led_cdev->blink_set && led_cdev->brightness_set_blocking) { 266 led_cdev->delayed_delay_on = delay_on; 267 led_cdev->delayed_delay_off = delay_off; 268 set_bit(LED_SET_BLINK, &led_cdev->work_flags); 269 schedule_work(&led_cdev->set_brightness_work); 270 return; 271 } 272 273 led_blink_set(led_cdev, &delay_on, &delay_off); 274 } 275 EXPORT_SYMBOL_GPL(led_blink_set_nosleep); 276 277 void led_stop_software_blink(struct led_classdev *led_cdev) 278 { 279 del_timer_sync(&led_cdev->blink_timer); 280 led_cdev->blink_delay_on = 0; 281 led_cdev->blink_delay_off = 0; 282 clear_bit(LED_BLINK_SW, &led_cdev->work_flags); 283 } 284 EXPORT_SYMBOL_GPL(led_stop_software_blink); 285 286 void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness) 287 { 288 /* 289 * If software blink is active, delay brightness setting 290 * until the next timer tick. 291 */ 292 if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) { 293 /* 294 * If we need to disable soft blinking delegate this to the 295 * work queue task to avoid problems in case we are called 296 * from hard irq context. 297 */ 298 if (!brightness) { 299 set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags); 300 schedule_work(&led_cdev->set_brightness_work); 301 } else { 302 set_bit(LED_BLINK_BRIGHTNESS_CHANGE, 303 &led_cdev->work_flags); 304 led_cdev->new_blink_brightness = brightness; 305 } 306 return; 307 } 308 309 led_set_brightness_nosleep(led_cdev, brightness); 310 } 311 EXPORT_SYMBOL_GPL(led_set_brightness); 312 313 void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value) 314 { 315 /* Use brightness_set op if available, it is guaranteed not to sleep */ 316 if (!__led_set_brightness(led_cdev, value)) 317 return; 318 319 /* 320 * Brightness setting can sleep, delegate it to a work queue task. 321 * value 0 / LED_OFF is special, since it also disables hw-blinking 322 * (sw-blink disable is handled in led_set_brightness()). 323 * To avoid a hw-blink-disable getting lost when a second brightness 324 * change is done immediately afterwards (before the work runs), 325 * it uses a separate work_flag. 326 */ 327 if (value) { 328 led_cdev->delayed_set_value = value; 329 set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); 330 } else { 331 clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); 332 clear_bit(LED_SET_BLINK, &led_cdev->work_flags); 333 set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); 334 } 335 336 schedule_work(&led_cdev->set_brightness_work); 337 } 338 EXPORT_SYMBOL_GPL(led_set_brightness_nopm); 339 340 void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value) 341 { 342 led_cdev->brightness = min(value, led_cdev->max_brightness); 343 344 if (led_cdev->flags & LED_SUSPENDED) 345 return; 346 347 led_set_brightness_nopm(led_cdev, led_cdev->brightness); 348 } 349 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep); 350 351 int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value) 352 { 353 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) 354 return -EBUSY; 355 356 led_cdev->brightness = min(value, led_cdev->max_brightness); 357 358 if (led_cdev->flags & LED_SUSPENDED) 359 return 0; 360 361 return __led_set_brightness_blocking(led_cdev, led_cdev->brightness); 362 } 363 EXPORT_SYMBOL_GPL(led_set_brightness_sync); 364 365 int led_update_brightness(struct led_classdev *led_cdev) 366 { 367 int ret; 368 369 if (led_cdev->brightness_get) { 370 ret = led_cdev->brightness_get(led_cdev); 371 if (ret < 0) 372 return ret; 373 374 led_cdev->brightness = ret; 375 } 376 377 return 0; 378 } 379 EXPORT_SYMBOL_GPL(led_update_brightness); 380 381 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size) 382 { 383 struct fwnode_handle *fwnode = led_cdev->dev->fwnode; 384 u32 *pattern; 385 int count; 386 387 count = fwnode_property_count_u32(fwnode, "led-pattern"); 388 if (count < 0) 389 return NULL; 390 391 pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL); 392 if (!pattern) 393 return NULL; 394 395 if (fwnode_property_read_u32_array(fwnode, "led-pattern", pattern, count)) { 396 kfree(pattern); 397 return NULL; 398 } 399 400 *size = count; 401 402 return pattern; 403 } 404 EXPORT_SYMBOL_GPL(led_get_default_pattern); 405 406 /* Caller must ensure led_cdev->led_access held */ 407 void led_sysfs_disable(struct led_classdev *led_cdev) 408 { 409 lockdep_assert_held(&led_cdev->led_access); 410 411 led_cdev->flags |= LED_SYSFS_DISABLE; 412 } 413 EXPORT_SYMBOL_GPL(led_sysfs_disable); 414 415 /* Caller must ensure led_cdev->led_access held */ 416 void led_sysfs_enable(struct led_classdev *led_cdev) 417 { 418 lockdep_assert_held(&led_cdev->led_access); 419 420 led_cdev->flags &= ~LED_SYSFS_DISABLE; 421 } 422 EXPORT_SYMBOL_GPL(led_sysfs_enable); 423 424 static void led_parse_fwnode_props(struct device *dev, 425 struct fwnode_handle *fwnode, 426 struct led_properties *props) 427 { 428 int ret; 429 430 if (!fwnode) 431 return; 432 433 if (fwnode_property_present(fwnode, "label")) { 434 ret = fwnode_property_read_string(fwnode, "label", &props->label); 435 if (ret) 436 dev_err(dev, "Error parsing 'label' property (%d)\n", ret); 437 return; 438 } 439 440 if (fwnode_property_present(fwnode, "color")) { 441 ret = fwnode_property_read_u32(fwnode, "color", &props->color); 442 if (ret) 443 dev_err(dev, "Error parsing 'color' property (%d)\n", ret); 444 else if (props->color >= LED_COLOR_ID_MAX) 445 dev_err(dev, "LED color identifier out of range\n"); 446 else 447 props->color_present = true; 448 } 449 450 451 if (!fwnode_property_present(fwnode, "function")) 452 return; 453 454 ret = fwnode_property_read_string(fwnode, "function", &props->function); 455 if (ret) { 456 dev_err(dev, 457 "Error parsing 'function' property (%d)\n", 458 ret); 459 } 460 461 if (!fwnode_property_present(fwnode, "function-enumerator")) 462 return; 463 464 ret = fwnode_property_read_u32(fwnode, "function-enumerator", 465 &props->func_enum); 466 if (ret) { 467 dev_err(dev, 468 "Error parsing 'function-enumerator' property (%d)\n", 469 ret); 470 } else { 471 props->func_enum_present = true; 472 } 473 } 474 475 int led_compose_name(struct device *dev, struct led_init_data *init_data, 476 char *led_classdev_name) 477 { 478 struct led_properties props = {}; 479 struct fwnode_handle *fwnode = init_data->fwnode; 480 const char *devicename = init_data->devicename; 481 482 if (!led_classdev_name) 483 return -EINVAL; 484 485 led_parse_fwnode_props(dev, fwnode, &props); 486 487 if (props.label) { 488 /* 489 * If init_data.devicename is NULL, then it indicates that 490 * DT label should be used as-is for LED class device name. 491 * Otherwise the label is prepended with devicename to compose 492 * the final LED class device name. 493 */ 494 if (!devicename) { 495 strscpy(led_classdev_name, props.label, 496 LED_MAX_NAME_SIZE); 497 } else { 498 snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", 499 devicename, props.label); 500 } 501 } else if (props.function || props.color_present) { 502 char tmp_buf[LED_MAX_NAME_SIZE]; 503 504 if (props.func_enum_present) { 505 snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d", 506 props.color_present ? led_colors[props.color] : "", 507 props.function ?: "", props.func_enum); 508 } else { 509 snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s", 510 props.color_present ? led_colors[props.color] : "", 511 props.function ?: ""); 512 } 513 if (init_data->devname_mandatory) { 514 snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", 515 devicename, tmp_buf); 516 } else { 517 strscpy(led_classdev_name, tmp_buf, LED_MAX_NAME_SIZE); 518 519 } 520 } else if (init_data->default_label) { 521 if (!devicename) { 522 dev_err(dev, "Legacy LED naming requires devicename segment"); 523 return -EINVAL; 524 } 525 snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", 526 devicename, init_data->default_label); 527 } else if (is_of_node(fwnode)) { 528 strscpy(led_classdev_name, to_of_node(fwnode)->name, 529 LED_MAX_NAME_SIZE); 530 } else 531 return -EINVAL; 532 533 return 0; 534 } 535 EXPORT_SYMBOL_GPL(led_compose_name); 536 537 enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode) 538 { 539 const char *state = NULL; 540 541 if (!fwnode_property_read_string(fwnode, "default-state", &state)) { 542 if (!strcmp(state, "keep")) 543 return LEDS_DEFSTATE_KEEP; 544 if (!strcmp(state, "on")) 545 return LEDS_DEFSTATE_ON; 546 } 547 548 return LEDS_DEFSTATE_OFF; 549 } 550 EXPORT_SYMBOL_GPL(led_init_default_state_get); 551