// SPDX-License-Identifier: GPL-2.0-only /* * LED Class Core * * Copyright 2005-2006 Openedhand Ltd. * * Author: Richard Purdie <rpurdie@openedhand.com> */ #include <linux/kernel.h> #include <linux/leds.h> #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> #include <linux/property.h> #include <linux/rwsem.h> #include <linux/slab.h> #include <uapi/linux/uleds.h> #include "leds.h" DECLARE_RWSEM(leds_list_lock); EXPORT_SYMBOL_GPL(leds_list_lock); LIST_HEAD(leds_list); EXPORT_SYMBOL_GPL(leds_list); const char * const led_colors[LED_COLOR_ID_MAX] = { [LED_COLOR_ID_WHITE] = "white", [LED_COLOR_ID_RED] = "red", [LED_COLOR_ID_GREEN] = "green", [LED_COLOR_ID_BLUE] = "blue", [LED_COLOR_ID_AMBER] = "amber", [LED_COLOR_ID_VIOLET] = "violet", [LED_COLOR_ID_YELLOW] = "yellow", [LED_COLOR_ID_IR] = "ir", [LED_COLOR_ID_MULTI] = "multicolor", [LED_COLOR_ID_RGB] = "rgb", }; EXPORT_SYMBOL_GPL(led_colors); static int __led_set_brightness(struct led_classdev *led_cdev, unsigned int value) { if (!led_cdev->brightness_set) return -ENOTSUPP; led_cdev->brightness_set(led_cdev, value); return 0; } static int __led_set_brightness_blocking(struct led_classdev *led_cdev, unsigned int value) { if (!led_cdev->brightness_set_blocking) return -ENOTSUPP; return led_cdev->brightness_set_blocking(led_cdev, value); } static void led_timer_function(struct timer_list *t) { struct led_classdev *led_cdev = from_timer(led_cdev, t, blink_timer); unsigned long brightness; unsigned long delay; if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { led_set_brightness_nosleep(led_cdev, LED_OFF); clear_bit(LED_BLINK_SW, &led_cdev->work_flags); return; } if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags)) { clear_bit(LED_BLINK_SW, &led_cdev->work_flags); return; } brightness = led_get_brightness(led_cdev); if (!brightness) { /* Time to switch the LED on. */ if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags)) brightness = led_cdev->new_blink_brightness; else brightness = led_cdev->blink_brightness; delay = led_cdev->blink_delay_on; } else { /* Store the current brightness value to be able * to restore it when the delay_off period is over. */ led_cdev->blink_brightness = brightness; brightness = LED_OFF; delay = led_cdev->blink_delay_off; } led_set_brightness_nosleep(led_cdev, brightness); /* Return in next iteration if led is in one-shot mode and we are in * the final blink state so that the led is toggled each delay_on + * delay_off milliseconds in worst case. */ if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) { if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) { if (brightness) set_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); } else { if (!brightness) set_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); } } mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); } static void set_brightness_delayed(struct work_struct *ws) { struct led_classdev *led_cdev = container_of(ws, struct led_classdev, set_brightness_work); int ret = 0; if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) { led_cdev->delayed_set_value = LED_OFF; led_stop_software_blink(led_cdev); } ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value); if (ret == -ENOTSUPP) ret = __led_set_brightness_blocking(led_cdev, led_cdev->delayed_set_value); if (ret < 0 && /* LED HW might have been unplugged, therefore don't warn */ !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) && (led_cdev->flags & LED_HW_PLUGGABLE))) dev_err(led_cdev->dev, "Setting an LED's brightness failed (%d)\n", ret); } static void led_set_software_blink(struct led_classdev *led_cdev, unsigned long delay_on, unsigned long delay_off) { int current_brightness; current_brightness = led_get_brightness(led_cdev); if (current_brightness) led_cdev->blink_brightness = current_brightness; if (!led_cdev->blink_brightness) led_cdev->blink_brightness = led_cdev->max_brightness; led_cdev->blink_delay_on = delay_on; led_cdev->blink_delay_off = delay_off; /* never on - just set to off */ if (!delay_on) { led_set_brightness_nosleep(led_cdev, LED_OFF); return; } /* never off - just set to brightness */ if (!delay_off) { led_set_brightness_nosleep(led_cdev, led_cdev->blink_brightness); return; } set_bit(LED_BLINK_SW, &led_cdev->work_flags); mod_timer(&led_cdev->blink_timer, jiffies + 1); } static void led_blink_setup(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) && led_cdev->blink_set && !led_cdev->blink_set(led_cdev, delay_on, delay_off)) return; /* blink with 1 Hz as default if nothing specified */ if (!*delay_on && !*delay_off) *delay_on = *delay_off = 500; led_set_software_blink(led_cdev, *delay_on, *delay_off); } void led_init_core(struct led_classdev *led_cdev) { INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); timer_setup(&led_cdev->blink_timer, led_timer_function, 0); } EXPORT_SYMBOL_GPL(led_init_core); void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { del_timer_sync(&led_cdev->blink_timer); clear_bit(LED_BLINK_SW, &led_cdev->work_flags); clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags); clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); led_blink_setup(led_cdev, delay_on, delay_off); } EXPORT_SYMBOL_GPL(led_blink_set); void led_blink_set_oneshot(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off, int invert) { if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) && timer_pending(&led_cdev->blink_timer)) return; set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags); clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags); if (invert) set_bit(LED_BLINK_INVERT, &led_cdev->work_flags); else clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags); led_blink_setup(led_cdev, delay_on, delay_off); } EXPORT_SYMBOL_GPL(led_blink_set_oneshot); void led_stop_software_blink(struct led_classdev *led_cdev) { del_timer_sync(&led_cdev->blink_timer); led_cdev->blink_delay_on = 0; led_cdev->blink_delay_off = 0; clear_bit(LED_BLINK_SW, &led_cdev->work_flags); } EXPORT_SYMBOL_GPL(led_stop_software_blink); void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness) { /* * If software blink is active, delay brightness setting * until the next timer tick. */ if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) { /* * If we need to disable soft blinking delegate this to the * work queue task to avoid problems in case we are called * from hard irq context. */ if (!brightness) { set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags); schedule_work(&led_cdev->set_brightness_work); } else { set_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags); led_cdev->new_blink_brightness = brightness; } return; } led_set_brightness_nosleep(led_cdev, brightness); } EXPORT_SYMBOL_GPL(led_set_brightness); void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value) { /* Use brightness_set op if available, it is guaranteed not to sleep */ if (!__led_set_brightness(led_cdev, value)) return; /* If brightness setting can sleep, delegate it to a work queue task */ led_cdev->delayed_set_value = value; schedule_work(&led_cdev->set_brightness_work); } EXPORT_SYMBOL_GPL(led_set_brightness_nopm); void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value) { led_cdev->brightness = min(value, led_cdev->max_brightness); if (led_cdev->flags & LED_SUSPENDED) return; led_set_brightness_nopm(led_cdev, led_cdev->brightness); } EXPORT_SYMBOL_GPL(led_set_brightness_nosleep); int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value) { if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) return -EBUSY; led_cdev->brightness = min(value, led_cdev->max_brightness); if (led_cdev->flags & LED_SUSPENDED) return 0; return __led_set_brightness_blocking(led_cdev, led_cdev->brightness); } EXPORT_SYMBOL_GPL(led_set_brightness_sync); int led_update_brightness(struct led_classdev *led_cdev) { int ret = 0; if (led_cdev->brightness_get) { ret = led_cdev->brightness_get(led_cdev); if (ret >= 0) { led_cdev->brightness = ret; return 0; } } return ret; } EXPORT_SYMBOL_GPL(led_update_brightness); u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size) { struct fwnode_handle *fwnode = led_cdev->dev->fwnode; u32 *pattern; int count; count = fwnode_property_count_u32(fwnode, "led-pattern"); if (count < 0) return NULL; pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL); if (!pattern) return NULL; if (fwnode_property_read_u32_array(fwnode, "led-pattern", pattern, count)) { kfree(pattern); return NULL; } *size = count; return pattern; } EXPORT_SYMBOL_GPL(led_get_default_pattern); /* Caller must ensure led_cdev->led_access held */ void led_sysfs_disable(struct led_classdev *led_cdev) { lockdep_assert_held(&led_cdev->led_access); led_cdev->flags |= LED_SYSFS_DISABLE; } EXPORT_SYMBOL_GPL(led_sysfs_disable); /* Caller must ensure led_cdev->led_access held */ void led_sysfs_enable(struct led_classdev *led_cdev) { lockdep_assert_held(&led_cdev->led_access); led_cdev->flags &= ~LED_SYSFS_DISABLE; } EXPORT_SYMBOL_GPL(led_sysfs_enable); static void led_parse_fwnode_props(struct device *dev, struct fwnode_handle *fwnode, struct led_properties *props) { int ret; if (!fwnode) return; if (fwnode_property_present(fwnode, "label")) { ret = fwnode_property_read_string(fwnode, "label", &props->label); if (ret) dev_err(dev, "Error parsing 'label' property (%d)\n", ret); return; } if (fwnode_property_present(fwnode, "color")) { ret = fwnode_property_read_u32(fwnode, "color", &props->color); if (ret) dev_err(dev, "Error parsing 'color' property (%d)\n", ret); else if (props->color >= LED_COLOR_ID_MAX) dev_err(dev, "LED color identifier out of range\n"); else props->color_present = true; } if (!fwnode_property_present(fwnode, "function")) return; ret = fwnode_property_read_string(fwnode, "function", &props->function); if (ret) { dev_err(dev, "Error parsing 'function' property (%d)\n", ret); } if (!fwnode_property_present(fwnode, "function-enumerator")) return; ret = fwnode_property_read_u32(fwnode, "function-enumerator", &props->func_enum); if (ret) { dev_err(dev, "Error parsing 'function-enumerator' property (%d)\n", ret); } else { props->func_enum_present = true; } } int led_compose_name(struct device *dev, struct led_init_data *init_data, char *led_classdev_name) { struct led_properties props = {}; struct fwnode_handle *fwnode = init_data->fwnode; const char *devicename = init_data->devicename; if (!led_classdev_name) return -EINVAL; led_parse_fwnode_props(dev, fwnode, &props); if (props.label) { /* * If init_data.devicename is NULL, then it indicates that * DT label should be used as-is for LED class device name. * Otherwise the label is prepended with devicename to compose * the final LED class device name. */ if (!devicename) { strscpy(led_classdev_name, props.label, LED_MAX_NAME_SIZE); } else { snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", devicename, props.label); } } else if (props.function || props.color_present) { char tmp_buf[LED_MAX_NAME_SIZE]; if (props.func_enum_present) { snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d", props.color_present ? led_colors[props.color] : "", props.function ?: "", props.func_enum); } else { snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s", props.color_present ? led_colors[props.color] : "", props.function ?: ""); } if (init_data->devname_mandatory) { snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", devicename, tmp_buf); } else { strscpy(led_classdev_name, tmp_buf, LED_MAX_NAME_SIZE); } } else if (init_data->default_label) { if (!devicename) { dev_err(dev, "Legacy LED naming requires devicename segment"); return -EINVAL; } snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", devicename, init_data->default_label); } else if (is_of_node(fwnode)) { strscpy(led_classdev_name, to_of_node(fwnode)->name, LED_MAX_NAME_SIZE); } else return -EINVAL; return 0; } EXPORT_SYMBOL_GPL(led_compose_name); enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode) { const char *state = NULL; if (!fwnode_property_read_string(fwnode, "default-state", &state)) { if (!strcmp(state, "keep")) return LEDS_DEFSTATE_KEEP; if (!strcmp(state, "on")) return LEDS_DEFSTATE_ON; } return LEDS_DEFSTATE_OFF; } EXPORT_SYMBOL_GPL(led_init_default_state_get);