diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led-multicolor | 35 | ||||
| -rw-r--r-- | Documentation/leds/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/leds/leds-class-multicolor.rst | 86 | ||||
| -rw-r--r-- | drivers/leds/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/leds/Makefile | 1 | ||||
| -rw-r--r-- | drivers/leds/led-class-multicolor.c | 203 | ||||
| -rw-r--r-- | include/linux/led-class-multicolor.h | 121 |
7 files changed, 457 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-led-multicolor b/Documentation/ABI/testing/sysfs-class-led-multicolor new file mode 100644 index 000000000000..eeeddcbdbbe3 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-multicolor @@ -0,0 +1,35 @@ +What: /sys/class/leds/<led>/brightness +Date: March 2020 +KernelVersion: 5.9 +Contact: Dan Murphy <dmurphy@ti.com> +Description: read/write + Writing to this file will update all LEDs within the group to a + calculated percentage of what each color LED intensity is set + to. The percentage is calculated for each grouped LED via the + equation below: + + led_brightness = brightness * multi_intensity/max_brightness + + For additional details please refer to + Documentation/leds/leds-class-multicolor.rst. + + The value of the LED is from 0 to + /sys/class/leds/<led>/max_brightness. + +What: /sys/class/leds/<led>/multi_index +Date: March 2020 +KernelVersion: 5.9 +Contact: Dan Murphy <dmurphy@ti.com> +Description: read + The multi_index array, when read, will output the LED colors + as an array of strings as they are indexed in the + multi_intensity file. + +What: /sys/class/leds/<led>/multi_intensity +Date: March 2020 +KernelVersion: 5.9 +Contact: Dan Murphy <dmurphy@ti.com> +Description: read/write + This file contains array of integers. Order of components is + described by the multi_index array. The maximum intensity should + not exceed /sys/class/leds/<led>/max_brightness. diff --git a/Documentation/leds/index.rst b/Documentation/leds/index.rst index 060f4e485897..bc70c6aa7138 100644 --- a/Documentation/leds/index.rst +++ b/Documentation/leds/index.rst @@ -9,6 +9,7 @@ LEDs leds-class leds-class-flash + leds-class-multicolor ledtrig-oneshot ledtrig-transient ledtrig-usbport diff --git a/Documentation/leds/leds-class-multicolor.rst b/Documentation/leds/leds-class-multicolor.rst new file mode 100644 index 000000000000..c57b98bfd387 --- /dev/null +++ b/Documentation/leds/leds-class-multicolor.rst @@ -0,0 +1,86 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================================== +Multicolor LED handling under Linux +==================================== + +Description +=========== +The multicolor class groups monochrome LEDs and allows controlling two +aspects of the final combined color: hue and lightness. The former is +controlled via the multi_intensity array file and the latter is controlled +via brightness file. + +Multicolor Class Control +======================== +The multicolor class presents files that groups the colors as indexes in an +array. These files are children under the LED parent node created by the +led_class framework. The led_class framework is documented in led-class.rst +within this documentation directory. + +Each colored LED will be indexed under the multi_* files. The order of the +colors will be arbitrary. The multi_index file can be read to determine the +color name to indexed value. + +The multi_index file is an array that contains the string list of the colors as +they are defined in each multi_* array file. + +The multi_intensity is an array that can be read or written to for the +individual color intensities. All elements within this array must be written in +order for the color LED intensities to be updated. + +Directory Layout Example +======================== +root:/sys/class/leds/multicolor:status# ls -lR +-rw-r--r-- 1 root root 4096 Oct 19 16:16 brightness +-r--r--r-- 1 root root 4096 Oct 19 16:16 max_brightness +-r--r--r-- 1 root root 4096 Oct 19 16:16 multi_index +-rw-r--r-- 1 root root 4096 Oct 19 16:16 multi_intensity + +Multicolor Class Brightness Control +=================================== +The brightness level for each LED is calculated based on the color LED +intensity setting divided by the global max_brightness setting multiplied by +the requested brightness. + +led_brightness = brightness * multi_intensity/max_brightness + +Example: +A user first writes the multi_intensity file with the brightness levels +for each LED that are necessary to achieve a certain color output from a +multicolor LED group. + +cat /sys/class/leds/multicolor:status/multi_index +green blue red + +echo 43 226 138 > /sys/class/leds/multicolor:status/multi_intensity + +red - + intensity = 138 + max_brightness = 255 +green - + intensity = 43 + max_brightness = 255 +blue - + intensity = 226 + max_brightness = 255 + +The user can control the brightness of that multicolor LED group by writing the +global 'brightness' control. Assuming a max_brightness of 255 the user +may want to dim the LED color group to half. The user would write a value of +128 to the global brightness file then the values written to each LED will be +adjusted base on this value. + +cat /sys/class/leds/multicolor:status/max_brightness +255 +echo 128 > /sys/class/leds/multicolor:status/brightness + +adjusted_red_value = 128 * 138/255 = 69 +adjusted_green_value = 128 * 43/255 = 21 +adjusted_blue_value = 128 * 226/255 = 113 + +Reading the global brightness file will return the current brightness value of +the color LED group. + +cat /sys/class/leds/multicolor:status/brightness +128 diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index ed943140e1fd..1de6e8e264a0 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -30,6 +30,16 @@ config LEDS_CLASS_FLASH for the flash related features of a LED device. It can be built as a module. +config LEDS_CLASS_MULTICOLOR + tristate "LED Multicolor Class Support" + depends on LEDS_CLASS + help + This option enables the multicolor LED sysfs class in /sys/class/leds. + It wraps LED class and adds multicolor LED specific sysfs attributes + and kernel internal API to it. You'll need this to provide support + for multicolor LEDs that are grouped together. This class is not + intended for single color LEDs. It can be built as a module. + config LEDS_BRIGHTNESS_HW_CHANGED bool "LED Class brightness_hw_changed attribute support" depends on LEDS_CLASS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index d6b8a792c936..d684bc76d2b2 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_NEW_LEDS) += led-core.o obj-$(CONFIG_LEDS_CLASS) += led-class.o obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o +obj-$(CONFIG_LEDS_CLASS_MULTICOLOR) += led-class-multicolor.o obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o # LED Platform Drivers (keep this sorted, M-| sort) diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c new file mode 100644 index 000000000000..e317408583df --- /dev/null +++ b/drivers/leds/led-class-multicolor.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0 +// LED Multicolor class interface +// Copyright (C) 2019-20 Texas Instruments Incorporated - http://www.ti.com/ +// Author: Dan Murphy <dmurphy@ti.com> + +#include <linux/device.h> +#include <linux/init.h> +#include <linux/led-class-multicolor.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/uaccess.h> + +#include "leds.h" + +int led_mc_calc_color_components(struct led_classdev_mc *mcled_cdev, + enum led_brightness brightness) +{ + struct led_classdev *led_cdev = &mcled_cdev->led_cdev; + int i; + + for (i = 0; i < mcled_cdev->num_colors; i++) + mcled_cdev->subled_info[i].brightness = brightness * + mcled_cdev->subled_info[i].intensity / + led_cdev->max_brightness; + + return 0; +} +EXPORT_SYMBOL_GPL(led_mc_calc_color_components); + +static ssize_t multi_intensity_store(struct device *dev, + struct device_attribute *intensity_attr, + const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_mc *mcled_cdev = lcdev_to_mccdev(led_cdev); + int nrchars, offset = 0; + int intensity_value[LED_COLOR_ID_MAX]; + int i; + ssize_t ret; + + mutex_lock(&led_cdev->led_access); + + for (i = 0; i < mcled_cdev->num_colors; i++) { + ret = sscanf(buf + offset, "%i%n", + &intensity_value[i], &nrchars); + if (ret != 1) { + ret = -EINVAL; + goto err_out; + } + offset += nrchars; + } + + offset++; + if (offset < size) { + ret = -EINVAL; + goto err_out; + } + + for (i = 0; i < mcled_cdev->num_colors; i++) + mcled_cdev->subled_info[i].intensity = intensity_value[i]; + + led_set_brightness(led_cdev, led_cdev->brightness); + ret = size; +err_out: + mutex_unlock(&led_cdev->led_access); + return ret; +} + +static ssize_t multi_intensity_show(struct device *dev, + struct device_attribute *intensity_attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_mc *mcled_cdev = lcdev_to_mccdev(led_cdev); + int len = 0; + int i; + + for (i = 0; i < mcled_cdev->num_colors; i++) { + len += sprintf(buf + len, "%d", + mcled_cdev->subled_info[i].intensity); + if (i < mcled_cdev->num_colors - 1) + len += sprintf(buf + len, " "); + } + + buf[len++] = '\n'; + return len; +} +static DEVICE_ATTR_RW(multi_intensity); + +static ssize_t multi_index_show(struct device *dev, + struct device_attribute *multi_index_attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_mc *mcled_cdev = lcdev_to_mccdev(led_cdev); + int len = 0; + int index; + int i; + + for (i = 0; i < mcled_cdev->num_colors; i++) { + index = mcled_cdev->subled_info[i].color_index; + len += sprintf(buf + len, "%s", led_colors[index]); + if (i < mcled_cdev->num_colors - 1) + len += sprintf(buf + len, " "); + } + + buf[len++] = '\n'; + return len; +} +static DEVICE_ATTR_RO(multi_index); + +static struct attribute *led_multicolor_attrs[] = { + &dev_attr_multi_intensity.attr, + &dev_attr_multi_index.attr, + NULL, +}; +ATTRIBUTE_GROUPS(led_multicolor); + +int led_classdev_multicolor_register_ext(struct device *parent, + struct led_classdev_mc *mcled_cdev, + struct led_init_data *init_data) +{ + struct led_classdev *led_cdev; + + if (!mcled_cdev) + return -EINVAL; + + if (mcled_cdev->num_colors <= 0) + return -EINVAL; + + if (mcled_cdev->num_colors > LED_COLOR_ID_MAX) + return -EINVAL; + + led_cdev = &mcled_cdev->led_cdev; + mcled_cdev->led_cdev.groups = led_multicolor_groups; + + return led_classdev_register_ext(parent, led_cdev, init_data); +} +EXPORT_SYMBOL_GPL(led_classdev_multicolor_register_ext); + +void led_classdev_multicolor_unregister(struct led_classdev_mc *mcled_cdev) +{ + if (!mcled_cdev) + return; + + led_classdev_unregister(&mcled_cdev->led_cdev); +} +EXPORT_SYMBOL_GPL(led_classdev_multicolor_unregister); + +static void devm_led_classdev_multicolor_release(struct device *dev, void *res) +{ + led_classdev_multicolor_unregister(*(struct led_classdev_mc **)res); +} + +int devm_led_classdev_multicolor_register_ext(struct device *parent, + struct led_classdev_mc *mcled_cdev, + struct led_init_data *init_data) +{ + struct led_classdev_mc **dr; + int ret; + + dr = devres_alloc(devm_led_classdev_multicolor_release, + sizeof(*dr), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + ret = led_classdev_multicolor_register_ext(parent, mcled_cdev, + init_data); + if (ret) { + devres_free(dr); + return ret; + } + + *dr = mcled_cdev; + devres_add(parent, dr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_led_classdev_multicolor_register_ext); + +static int devm_led_classdev_multicolor_match(struct device *dev, + void *res, void *data) +{ + struct led_classdev_mc **p = res; + + if (WARN_ON(!p || !*p)) + return 0; + + return *p == data; +} + +void devm_led_classdev_multicolor_unregister(struct device *dev, + struct led_classdev_mc *mcled_cdev) +{ + WARN_ON(devres_release(dev, + devm_led_classdev_multicolor_release, + devm_led_classdev_multicolor_match, mcled_cdev)); +} +EXPORT_SYMBOL_GPL(devm_led_classdev_multicolor_unregister); + +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); +MODULE_DESCRIPTION("Multicolor LED class interface"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/led-class-multicolor.h b/include/linux/led-class-multicolor.h new file mode 100644 index 000000000000..5116f9a866cc --- /dev/null +++ b/include/linux/led-class-multicolor.h @@ -0,0 +1,121 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* LED Multicolor class interface + * Copyright (C) 2019-20 Texas Instruments Incorporated - http://www.ti.com/ + */ + +#ifndef _LINUX_MULTICOLOR_LEDS_H_INCLUDED +#define _LINUX_MULTICOLOR_LEDS_H_INCLUDED + +#include <linux/leds.h> +#include <dt-bindings/leds/common.h> + +struct mc_subled { + unsigned int color_index; + unsigned int brightness; + unsigned int intensity; + unsigned int channel; +}; + +struct led_classdev_mc { + /* led class device */ + struct led_classdev led_cdev; + unsigned int num_colors; + + struct mc_subled *subled_info; +}; + +static inline struct led_classdev_mc *lcdev_to_mccdev( + struct led_classdev *led_cdev) +{ + return container_of(led_cdev, struct led_classdev_mc, led_cdev); +} + +#if IS_ENABLED(CONFIG_LEDS_CLASS_MULTICOLOR) +/** + * led_classdev_multicolor_register_ext - register a new object of led_classdev + * class with support for multicolor LEDs + * @parent: the multicolor LED to register + * @mcled_cdev: the led_classdev_mc structure for this device + * @init_data: the LED class multicolor device initialization data + * + * Returns: 0 on success or negative error value on failure + */ +int led_classdev_multicolor_register_ext(struct device *parent, + struct led_classdev_mc *mcled_cdev, + struct led_init_data *init_data); + +static inline int led_classdev_multicolor_register(struct device *parent, + struct led_classdev_mc *mcled_cdev) +{ + return led_classdev_multicolor_register_ext(parent, mcled_cdev, NULL); +} + +/** + * led_classdev_multicolor_unregister - unregisters an object of led_classdev + * class with support for multicolor LEDs + * @mcled_cdev: the multicolor LED to unregister + * + * Unregister a previously registered via led_classdev_multicolor_register + * object + */ +void led_classdev_multicolor_unregister(struct led_classdev_mc *mcled_cdev); + +/* Calculate brightness for the monochrome LED cluster */ +int led_mc_calc_color_components(struct led_classdev_mc *mcled_cdev, + enum led_brightness brightness); + +int devm_led_classdev_multicolor_register_ext(struct device *parent, + struct led_classdev_mc *mcled_cdev, + struct led_init_data *init_data); + +static inline int devm_led_classdev_multicolor_register(struct device *parent, + struct led_classdev_mc *mcled_cdev) +{ + return devm_led_classdev_multicolor_register_ext(parent, mcled_cdev, + NULL); +} + +void devm_led_classdev_multicolor_unregister(struct device *parent, + struct led_classdev_mc *mcled_cdev); +#else + +static inline int led_classdev_multicolor_register_ext(struct device *parent, + struct led_classdev_mc *mcled_cdev, + struct led_init_data *init_data) +{ + return -EINVAL; +} + +static inline int led_classdev_multicolor_register(struct device *parent, + struct led_classdev_mc *mcled_cdev) +{ + return led_classdev_multicolor_register_ext(parent, mcled_cdev, NULL); +} + +static inline void led_classdev_multicolor_unregister(struct led_classdev_mc *mcled_cdev) {}; +static inline int led_mc_calc_color_components(struct led_classdev_mc *mcled_cdev, + enum led_brightness brightness) +{ + return -EINVAL; +} + +static inline int devm_led_classdev_multicolor_register_ext(struct device *parent, + struct led_classdev_mc *mcled_cdev, + struct led_init_data *init_data) +{ + return -EINVAL; +} + +static inline int devm_led_classdev_multicolor_register(struct device *parent, + struct led_classdev_mc *mcled_cdev) +{ + return devm_led_classdev_multicolor_register_ext(parent, mcled_cdev, + NULL); +} + +static inline void devm_led_classdev_multicolor_unregister(struct device *parent, + struct led_classdev_mc *mcled_cdev) +{}; + +#endif /* IS_ENABLED(CONFIG_LEDS_CLASS_MULTICOLOR) */ +#endif /* _LINUX_MULTICOLOR_LEDS_H_INCLUDED */ |