diff options
Diffstat (limited to 'drivers/leds/led-core.c')
| -rw-r--r-- | drivers/leds/led-core.c | 545 |
1 files changed, 545 insertions, 0 deletions
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c new file mode 100644 index 000000000..214ed81eb --- /dev/null +++ b/drivers/leds/led-core.c @@ -0,0 +1,545 @@ +// 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_set_brightness(struct led_classdev *led_cdev, + unsigned int value) +{ + int ret = 0; + + ret = __led_set_brightness(led_cdev, value); + if (ret == -ENOTSUPP) + ret = __led_set_brightness_blocking(led_cdev, 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 set_brightness_delayed(struct work_struct *ws) +{ + struct led_classdev *led_cdev = + container_of(ws, struct led_classdev, set_brightness_work); + + if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) { + led_stop_software_blink(led_cdev); + set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); + } + + /* + * Triggers may call led_set_brightness(LED_OFF), + * led_set_brightness(LED_FULL) in quick succession to disable blinking + * and turn the LED on. Both actions may have been scheduled to run + * before this work item runs once. To make sure this works properly + * handle LED_SET_BRIGHTNESS_OFF first. + */ + if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) + set_brightness_delayed_set_brightness(led_cdev, LED_OFF); + + if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags)) + set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value); + + if (test_and_clear_bit(LED_SET_BLINK, &led_cdev->work_flags)) { + unsigned long delay_on = led_cdev->delayed_delay_on; + unsigned long delay_off = led_cdev->delayed_delay_off; + + led_blink_set(led_cdev, &delay_on, &delay_off); + } +} + +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_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on, + unsigned long delay_off) +{ + /* If necessary delegate to a work queue task. */ + if (led_cdev->blink_set && led_cdev->brightness_set_blocking) { + led_cdev->delayed_delay_on = delay_on; + led_cdev->delayed_delay_off = delay_off; + set_bit(LED_SET_BLINK, &led_cdev->work_flags); + schedule_work(&led_cdev->set_brightness_work); + return; + } + + led_blink_set(led_cdev, &delay_on, &delay_off); +} +EXPORT_SYMBOL_GPL(led_blink_set_nosleep); + +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; + + /* + * Brightness setting can sleep, delegate it to a work queue task. + * value 0 / LED_OFF is special, since it also disables hw-blinking + * (sw-blink disable is handled in led_set_brightness()). + * To avoid a hw-blink-disable getting lost when a second brightness + * change is done immediately afterwards (before the work runs), + * it uses a separate work_flag. + */ + if (value) { + led_cdev->delayed_set_value = value; + set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); + } else { + clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags); + clear_bit(LED_SET_BLINK, &led_cdev->work_flags); + set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags); + } + + 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); |