[PATCH v8 6/9] leds: multicolor: Introduce a multicolor class definition

Dan Murphy
2019-09-20T17:38:41Z

Introduce a multicolor class that groups colored LEDs
within a LED node.

The framework allows for dynamically setting individual LEDs
or setting brightness levels of LEDs and updating them virtually
simultaneously.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---
drivers/leds/Kconfig | 10 +
drivers/leds/Makefile | 1 +
drivers/leds/led-class-multicolor.c | 316 +++++++++++++++++++++++++++
include/linux/led-class-multicolor.h | 76 +++++++
4 files changed, 403 insertions(+)
create mode 100644 drivers/leds/led-class-multicolor.c
create mode 100644 include/linux/led-class-multicolor.h

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6e7703fd03d0..cfb1ebb6517f 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_MULTI_COLOR
+ tristate "LED Mulit Color LED 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 2da39e896ce8..841038cfe35b 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_MULTI_COLOR) += led-class-multicolor.o
obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o

# LED Platform Drivers
diff --git a/drivers/leds/led-class-multicolor.c b/drivers/leds/led-class-multicolor.c
new file mode 100644
index 000000000000..5e0e3fce482b
--- /dev/null
+++ b/drivers/leds/led-class-multicolor.c
@@ -0,0 +1,316 @@
+// SPDX-License-Identifier: GPL-2.0
+// LED Multi Color class interface
+// Copyright (C) 2019 Texas Instruments Incorporated - http://www.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"
+
+#define INTENSITY_NAME "_intensity"
+#define MAX_INTENSITY_NAME "_max_intensity"
+
+struct led_mc_color_entry {
+ struct led_classdev_mc *mcled_cdev;
+
+ struct device_attribute max_intensity_attr;
+ struct device_attribute intensity_attr;
+
+ enum led_brightness max_intensity;
+ enum led_brightness intensity;
+
+ struct list_head list;
+
+ int led_color_id;
+};
+
+void led_mc_calc_brightness(struct led_classdev_mc *mcled_cdev,
+ enum led_brightness brightness,
+ int brightness_val[])
+{
+ struct led_classdev_mc_data *data = mcled_cdev->data;
+ struct led_mc_color_entry *priv;
+ int i = 0;
+
+ list_for_each_entry(priv, &data->color_list, list) {
+ brightness_val[i] = brightness *
+ priv->intensity / priv->max_intensity;
+ i++;
+ }
+}
+EXPORT_SYMBOL_GPL(led_mc_calc_brightness);
+
+static ssize_t intensity_store(struct device *dev,
+ struct device_attribute *intensity_attr,
+ const char *buf, size_t size)
+{
+ struct led_mc_color_entry *priv = container_of(intensity_attr,
+ struct led_mc_color_entry,
+ intensity_attr);
+ struct led_classdev_mc_data *data = priv->mcled_cdev->data;
+ struct led_classdev_mc *mcled_cdev = data->mcled_cdev;
+ struct led_classdev *led_cdev = priv->mcled_cdev->led_cdev;
+ unsigned long value;
+ ssize_t ret;
+
+ mutex_lock(&led_cdev->led_access);
+
+ ret = kstrtoul(buf, 10, &value);
+ if (ret)
+ goto unlock;
+
+ if (value > priv->max_intensity) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ priv->intensity = value;
+
+ if (mcled_cdev->set_color_brightness) {
+ ret = mcled_cdev->set_color_brightness(mcled_cdev,
+ priv->led_color_id,
+ priv->intensity);
+ if (ret)
+ goto unlock;
+ }
+
+ ret = size;
+
+unlock:
+ mutex_unlock(&led_cdev->led_access);
+ return ret;
+}
+
+static ssize_t intensity_show(struct device *dev,
+ struct device_attribute *intensity_attr,
+ char *buf)
+{
+ struct led_mc_color_entry *priv = container_of(intensity_attr,
+ struct led_mc_color_entry,
+ intensity_attr);
+
+ return sprintf(buf, "%d\n", priv->intensity);
+}
+
+static ssize_t max_intensity_show(struct device *dev,
+ struct device_attribute *max_intensity_attr,
+ char *buf)
+{
+ struct led_mc_color_entry *priv = container_of(max_intensity_attr,
+ struct led_mc_color_entry,
+ max_intensity_attr);
+
+ return sprintf(buf, "%d\n", priv->max_intensity);
+}
+
+static struct attribute *led_color_attrs[] = {
+ NULL,
+};
+
+static struct attribute_group led_color_group = {
+ .name = "colors",
+ .attrs = led_color_attrs,
+};
+
+static int led_multicolor_init_color(struct led_classdev_mc_data *data,
+ struct led_classdev_mc *mcled_cdev,
+ int color_id, int color_index)
+{
+ struct led_classdev *led_cdev = mcled_cdev->led_cdev;
+ struct led_mc_color_entry *mc_priv;
+ char *intensity_file_name;
+ char *max_intensity_file_name;
+ size_t len;
+ int ret;
+
+ mc_priv = devm_kzalloc(led_cdev->dev, sizeof(*mc_priv), GFP_KERNEL);
+ if (!mc_priv)
+ return -ENOMEM;
+
+ mc_priv->led_color_id = color_id;
+ mc_priv->mcled_cdev = mcled_cdev;
+
+ sysfs_attr_init(&mc_priv->intensity_attr.attr);
+ len = strlen(led_colors[color_id]) + strlen(INTENSITY_NAME) + 1;
+ intensity_file_name = kzalloc(len, GFP_KERNEL);
+ if (!intensity_file_name) {
+ ret = -ENOMEM;
+ goto err_out;
+ }
+
+ snprintf(intensity_file_name, len, "%s%s",
+ led_colors[color_id], INTENSITY_NAME);
+ mc_priv->intensity_attr.attr.name = intensity_file_name;
+ mc_priv->intensity_attr.attr.mode = 644;
+ mc_priv->intensity_attr.store = intensity_store;
+ mc_priv->intensity_attr.show = intensity_show;
+ ret = sysfs_add_file_to_group(&led_cdev->dev->kobj,
+ &mc_priv->intensity_attr.attr,
+ led_color_group.name);
+ if (ret)
+ goto intensity_err_out;
+
+ sysfs_attr_init(&mc_priv->max_intensity_attr.attr);
+ len = strlen(led_colors[color_id]) + strlen(MAX_INTENSITY_NAME) + 1;
+ max_intensity_file_name = kzalloc(len, GFP_KERNEL);
+ if (!max_intensity_file_name) {
+ ret = -ENOMEM;
+ goto intensity_err_out;
+ }
+
+ snprintf(max_intensity_file_name, len, "%s%s",
+ led_colors[color_id], MAX_INTENSITY_NAME);
+ mc_priv->max_intensity_attr.attr.name = max_intensity_file_name;
+ mc_priv->max_intensity_attr.attr.mode = 444;
+ mc_priv->max_intensity_attr.show = max_intensity_show;
+ ret = sysfs_add_file_to_group(&led_cdev->dev->kobj,
+ &mc_priv->max_intensity_attr.attr,
+ led_color_group.name);
+ if (ret)
+ goto max_intensity_err_out;
+
+ mc_priv->max_intensity = LED_FULL;
+ list_add_tail(&mc_priv->list, &data->color_list);
+
+max_intensity_err_out:
+ kfree(max_intensity_file_name);
+intensity_err_out:
+ kfree(intensity_file_name);
+err_out:
+ return ret;
+}
+
+static int led_multicolor_init_color_dir(struct led_classdev_mc_data *data,
+ struct led_classdev_mc *mcled_cdev)
+{
+ struct led_classdev *led_cdev = mcled_cdev->led_cdev;
+ u32 color_id;
+ int ret;
+ int i, j = 0;
+
+ data->mcled_cdev = mcled_cdev;
+
+ ret = sysfs_create_group(&led_cdev->dev->kobj, &led_color_group);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < LED_COLOR_ID_MAX; i++) {
+ color_id = (mcled_cdev->available_colors & (1 << i));
+ if (color_id) {
+ ret = led_multicolor_init_color(data, mcled_cdev, i, j);
+ if (ret)
+ break;
+
+ j++;
+ }
+ }
+
+ return ret;
+}
+
+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;
+ struct led_classdev_mc_data *data;
+ int ret;
+
+ if (!mcled_cdev)
+ return -EINVAL;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ mcled_cdev->data = data;
+ led_cdev = mcled_cdev->led_cdev;
+ INIT_LIST_HEAD(&data->color_list);
+
+ /* Register led class device */
+ ret = led_classdev_register_ext(parent, led_cdev, init_data);
+ if (ret)
+ return ret;
+
+ return led_multicolor_init_color_dir(data, mcled_cdev);
+}
+EXPORT_SYMBOL_GPL(led_classdev_multicolor_register_ext);
+
+void led_classdev_multicolor_unregister(struct led_classdev_mc *mcled_cdev)
+{
+ if (!mcled_cdev)
+ return;
+
+ sysfs_remove_group(&mcled_cdev->led_cdev->dev->kobj, &led_color_group);
+ 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);
+}
+
+/**
+ * devm_of_led_classdev_register - resource managed led_classdev_register()
+ *
+ * @parent: parent of LED device
+ * @led_cdev: the led_classdev structure for this device.
+ */
+int devm_led_classdev_multicolor_register(struct device *parent,
+ struct led_classdev_mc *mcled_cdev)
+{
+ 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(parent, mcled_cdev);
+ if (ret) {
+ devres_free(dr);
+ return ret;
+ }
+
+ *dr = mcled_cdev;
+ devres_add(parent, dr);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_led_classdev_multicolor_register);
+
+static int devm_led_classdev_multicolor_match(struct device *dev,
+ void *res, void *data)
+{
+ struct mcled_cdev **p = res;
+
+ if (WARN_ON(!p || !*p))
+ return 0;
+
+ return *p == data;
+}
+
+/**
+ * devm_led_classdev_multicolor_unregister() - resource managed
+ * led_classdev_multicolor_unregister()
+ * @parent: The device to unregister.
+ * @mcled_cdev: the led_classdev_mc structure for this device.
+ */
+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("Multi Color 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..afcaf429fba5
--- /dev/null
+++ b/include/linux/led-class-multicolor.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* LED Multicolor class interface
+ * Copyright (C) 2019 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 led_classdev_mc;
+
+struct led_classdev_mc_data {
+ struct led_classdev_mc *mcled_cdev;
+ struct list_head color_list;
+};
+
+struct led_classdev_mc {
+ /* led class device */
+ struct led_classdev *led_cdev;
+
+ /* Set brightness for a specific color id */
+ int (*set_color_brightness)(struct led_classdev_mc *mcled_cdev,
+ int color_id, int value);
+
+ struct led_classdev_mc_data *data;
+
+ unsigned long available_colors;
+ int num_leds;
+};
+
+static inline struct led_classdev_mc *lcdev_to_mccdev(
+ struct led_classdev *lcdev)
+{
+ return container_of(lcdev, struct led_classdev_mc, led_cdev);
+}
+
+/**
+ * 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 Multi color device initialization data
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_classdev_multicolor_register_ext(struct device *parent,
+ struct led_classdev_mc *mcled_cdev,
+ struct led_init_data *init_data);
+
+#define led_classdev_multicolor_register(parent, mcled_cdev) \
+ 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
+ */
+extern void led_classdev_multicolor_unregister(struct led_classdev_mc *mcled_cdev);
+
+extern int devm_led_classdev_multicolor_register(struct device *parent,
+ struct led_classdev_mc *mcled_cdev);
+
+extern void devm_led_classdev_multicolor_unregister(struct device *parent,
+ struct led_classdev_mc *mcled_cdev);
+
+/* Set brightness for the monochrome LED cluster */
+extern void led_mc_calc_brightness(struct led_classdev_mc *mcled_cdev,
+ enum led_brightness brightness,
+ int brightness_val[]);
+
+#endif /* __LINUX_MULTICOLOR_LEDS_H_INCLUDED */
--
2.22.0.214.g8dca754b1e