[v8,1/2] leds: core: Introduce LED pattern trigger

Message ID	5a502ec29251c019ddad8f3314ab45fc0f6feaf7.1536027873.git.baolin.wang@linaro.org
State	Superseded
Headers	show Delivered-To: patch@linaro.org Received-SPF: pass (google.com: best guess record for domain of linux-leds-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; From: Baolin Wang <baolin.wang@linaro.org> To: jacek.anaszewski@gmail.com, pavel@ucw.cz Cc: rteysseyre@gmail.com, bjorn.andersson@linaro.org, baolin.wang@linaro.org, broonie@kernel.org, linus.walleij@linaro.org, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v8 1/2] leds: core: Introduce LED pattern trigger Date: Tue, 4 Sep 2018 19:01:30 +0800 Message-Id: <5a502ec29251c019ddad8f3314ab45fc0f6feaf7.1536027873.git.baolin.wang@linaro.org> Sender: linux-leds-owner@vger.kernel.org Precedence: bulk
Series	[v8,1/2] leds: core: Introduce LED pattern trigger \| expand [v8,1/2] leds: core: Introduce LED pattern trigger

diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-pattern b/Documentation/ABI/testing/sysfs-class-led-trigger-pattern new file mode 100644 index 0000000..8cc5099 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-pattern @@ -0,0 +1,38 @@ +What: /sys/class/leds/<led>/pattern +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a software pattern for the LED, that supports altering + the brightness for the specified duration with one software + timer. + + The pattern is given by a series of tuples, of brightness and + duration (ms). The LED is expected to traverse the series and + each brightness value for the specified duration. Duration of + 0 means brightness should immediately change to new value. + + The format of the software pattern values should be: + "brightness_1 duration_1 brightness_2 duration_2 brightness_3 + duration_3 ...". + +What: /sys/class/leds/<led>/hw_pattern +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a hardware pattern for the LED, for LED hardware that + supports autonomously controlling brightness over time, according + to some preprogrammed hardware patterns. + + Since different LED hardware can have different semantics of + hardware patterns, each driver is expected to provide its own + description for the hardware patterns in their ABI documentation + file. + +What: /sys/class/leds/<led>/repeat +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a pattern repeat number. 0 means repeat indefinitely. + + This file will always return the originally written repeat + number. diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index 4018af7..b76fc3c 100644 --- a/drivers/leds/trigger/Kconfig +++ b/drivers/leds/trigger/Kconfig @@ -129,4 +129,11 @@ config LEDS_TRIGGER_NETDEV This allows LEDs to be controlled by network device activity. If unsure, say Y. +config LEDS_TRIGGER_PATTERN + tristate "LED Pattern Trigger" + help + This allows LEDs to be controlled by a software or hardware pattern + which is a series of tuples, of brightness and duration (ms). + If unsure, say N + endif # LEDS_TRIGGERS diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile index f3cfe19..9bcb64e 100644 --- a/drivers/leds/trigger/Makefile +++ b/drivers/leds/trigger/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT) += ledtrig-transient.o obj-$(CONFIG_LEDS_TRIGGER_CAMERA) += ledtrig-camera.o obj-$(CONFIG_LEDS_TRIGGER_PANIC) += ledtrig-panic.o obj-$(CONFIG_LEDS_TRIGGER_NETDEV) += ledtrig-netdev.o +obj-$(CONFIG_LEDS_TRIGGER_PATTERN) += ledtrig-pattern.o diff --git a/drivers/leds/trigger/ledtrig-pattern.c b/drivers/leds/trigger/ledtrig-pattern.c new file mode 100644 index 0000000..0179191 --- /dev/null +++ b/drivers/leds/trigger/ledtrig-pattern.c @@ -0,0 +1,337 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * LED pattern trigger + * + * Idea discussed with Pavel Machek. Raphael Teysseyre implemented + * the first version, Baolin Wang simplified and improved the approach. + */ + +#include <linux/kernel.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/timer.h> + +#define MAX_PATTERNS 1024 + +struct pattern_trig_data { + struct led_classdev *led_cdev; + struct led_pattern patterns[MAX_PATTERNS]; + struct led_pattern *curr; + struct led_pattern *next; + struct mutex lock; + u32 npatterns; + u32 repeat; + u32 last_repeat; + bool is_indefinite; + bool is_hw_pattern; + struct timer_list timer; +}; + +static void pattern_trig_update_patterns(struct pattern_trig_data *data) +{ + data->curr = data->next; + if (!data->is_indefinite && data->curr == data->patterns) + data->repeat--; + + if (data->next == data->patterns + data->npatterns - 1) + data->next = data->patterns; + else + data->next++; +} + +static void pattern_trig_timer_function(struct timer_list *t) +{ + struct pattern_trig_data *data = from_timer(data, t, timer); + + mutex_lock(&data->lock); + + if (!data->is_indefinite && !data->repeat) { + mutex_unlock(&data->lock); + return; + } + + led_set_brightness(data->led_cdev, data->curr->brightness); + mod_timer(&data->timer, jiffies + msecs_to_jiffies(data->curr->delta_t)); + pattern_trig_update_patterns(data); + + mutex_unlock(&data->lock); +} + +static int pattern_trig_start_pattern(struct led_classdev *led_cdev) +{ + struct pattern_trig_data *data = led_cdev->trigger_data; + + if (!data->npatterns) + return 0; + + if (data->is_hw_pattern) { + return led_cdev->pattern_set(led_cdev, data->patterns, + data->npatterns, data->repeat); + } + + data->curr = data->patterns; + data->next = data->npatterns > 1 ? data->patterns + 1 : data->patterns; + data->timer.expires = jiffies; + add_timer(&data->timer); + + return 0; +} + +static ssize_t repeat_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + u32 repeat; + + mutex_lock(&data->lock); + + repeat = data->last_repeat; + + mutex_unlock(&data->lock); + + return scnprintf(buf, PAGE_SIZE, "%u\n", repeat); +} + +static ssize_t repeat_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + unsigned long res; + int err; + + err = kstrtoul(buf, 10, &res); + if (err) + return err; + + /* + * Clear previous patterns' performence firstly, and remove the timer + * without mutex lock to avoid dead lock. + */ + del_timer_sync(&data->timer); + + mutex_lock(&data->lock); + + if (data->is_hw_pattern) + led_cdev->pattern_clear(led_cdev); + + data->last_repeat = data->repeat = res; + /* 0 means repeat indefinitely */ + data->is_indefinite = !data->repeat; + + err = pattern_trig_start_pattern(led_cdev); + + mutex_unlock(&data->lock); + return err < 0 ? err : count; +} + +static DEVICE_ATTR_RW(repeat); + +static ssize_t pattern_trig_show_patterns(struct pattern_trig_data *data, + char *buf, bool hw_pattern) +{ + ssize_t count = 0; + int i; + + mutex_lock(&data->lock); + + if (!data->npatterns || (data->is_hw_pattern ^ hw_pattern)) + goto out; + + for (i = 0; i < data->npatterns; i++) { + count += scnprintf(buf + count, PAGE_SIZE - count, + "%d %d ", + data->patterns[i].brightness, + data->patterns[i].delta_t); + } + + buf[count - 1] = '\n'; + +out: + mutex_unlock(&data->lock); + return count; +} + +static ssize_t pattern_trig_store_patterns(struct led_classdev *led_cdev, + const char *buf, size_t count, + bool hw_pattern) +{ + struct pattern_trig_data *data = led_cdev->trigger_data; + int ccount, cr, offset = 0, err = 0; + + /* + * Clear previous patterns' performence firstly, and remove the timer + * without mutex lock to avoid dead lock. + */ + del_timer_sync(&data->timer); + + mutex_lock(&data->lock); + + if (data->is_hw_pattern) + led_cdev->pattern_clear(led_cdev); + + data->is_hw_pattern = hw_pattern; + data->npatterns = 0; + + while (offset < count - 1 && data->npatterns < MAX_PATTERNS) { + cr = 0; + ccount = sscanf(buf + offset, "%d %d %n", + &data->patterns[data->npatterns].brightness, + &data->patterns[data->npatterns].delta_t, &cr); + if (ccount != 2) { + data->npatterns = 0; + err = -EINVAL; + goto out; + } + + offset += cr; + data->npatterns++; + } + + err = pattern_trig_start_pattern(led_cdev); + +out: + mutex_unlock(&data->lock); + return err < 0 ? err : count; +} + +static ssize_t pattern_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + + return pattern_trig_show_patterns(data, buf, false); +} + +static ssize_t pattern_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + return pattern_trig_store_patterns(led_cdev, buf, count, false); +} + +static DEVICE_ATTR_RW(pattern); + +static ssize_t hw_pattern_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct pattern_trig_data *data = led_cdev->trigger_data; + + return pattern_trig_show_patterns(data, buf, true); +} + +static ssize_t hw_pattern_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + return pattern_trig_store_patterns(led_cdev, buf, count, true); +} + +static DEVICE_ATTR_RW(hw_pattern); + +static umode_t pattern_trig_attrs_mode(struct kobject *kobj, + struct attribute *attr, int index) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct led_classdev *led_cdev = dev_get_drvdata(dev); + + if (attr == &dev_attr_repeat.attr || attr == &dev_attr_pattern.attr) + return attr->mode; + else if (attr == &dev_attr_hw_pattern.attr && led_cdev->pattern_set) + return attr->mode; + + return 0; +} + +static struct attribute *pattern_trig_attrs[] = { + &dev_attr_pattern.attr, + &dev_attr_hw_pattern.attr, + &dev_attr_repeat.attr, + NULL +}; + +static const struct attribute_group pattern_trig_group = { + .attrs = pattern_trig_attrs, + .is_visible = pattern_trig_attrs_mode, +}; + +static const struct attribute_group *pattern_trig_groups[] = { + &pattern_trig_group, + NULL, +}; + +static int pattern_trig_activate(struct led_classdev *led_cdev) +{ + struct pattern_trig_data *data; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + if (!!led_cdev->pattern_set ^ !!led_cdev->pattern_clear) { + dev_warn(led_cdev->dev, + "Hardware pattern ops validation failed\n"); + led_cdev->pattern_set = NULL; + led_cdev->pattern_clear = NULL; + } + + data->is_indefinite = true; + mutex_init(&data->lock); + data->led_cdev = led_cdev; + led_set_trigger_data(led_cdev, data); + timer_setup(&data->timer, pattern_trig_timer_function, 0); + led_cdev->activated = true; + + return 0; +} + +static void pattern_trig_deactivate(struct led_classdev *led_cdev) +{ + struct pattern_trig_data *data = led_cdev->trigger_data; + + if (!led_cdev->activated) + return; + + if (led_cdev->pattern_clear) + led_cdev->pattern_clear(led_cdev); + + del_timer_sync(&data->timer); + + led_set_brightness(led_cdev, LED_OFF); + kfree(data); + led_cdev->activated = false; +} + +static struct led_trigger pattern_led_trigger = { + .name = "pattern", + .activate = pattern_trig_activate, + .deactivate = pattern_trig_deactivate, + .groups = pattern_trig_groups, +}; + +static int __init pattern_trig_init(void) +{ + return led_trigger_register(&pattern_led_trigger); +} + +static void __exit pattern_trig_exit(void) +{ + led_trigger_unregister(&pattern_led_trigger); +} + +module_init(pattern_trig_init); +module_exit(pattern_trig_exit); + +MODULE_AUTHOR("Raphael Teysseyre <rteysseyre@gmail.com"); +MODULE_AUTHOR("Baolin Wang <baolin.wang@linaro.org"); +MODULE_DESCRIPTION("LED Pattern trigger"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/leds.h b/include/linux/leds.h index 834683d..74fc2c6 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -22,6 +22,7 @@ #include <linux/workqueue.h> struct device; +struct led_pattern; /* * LED Core */ @@ -88,6 +89,11 @@ struct led_classdev { unsigned long *delay_on, unsigned long *delay_off); + int (*pattern_set)(struct led_classdev *led_cdev, + struct led_pattern *pattern, int len, + unsigned int repeat); + int (*pattern_clear)(struct led_classdev *led_cdev); + struct device *dev; const struct attribute_group **groups; @@ -472,4 +478,14 @@ static inline void led_classdev_notify_brightness_hw_changed( struct led_classdev *led_cdev, enum led_brightness brightness) { } #endif +/** + * struct led_pattern - pattern interval settings + * @delta_t: pattern interval delay, in milliseconds + * @brightness: pattern interval brightness + */ +struct led_pattern { + int delta_t; + int brightness; +}; + #endif /* __LINUX_LEDS_H_INCLUDED */

[v8,1/2] leds: core: Introduce LED pattern trigger

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