Re: [PATCH v3 1/2] leds: core: Introduce generic pattern interface

From: Pavel Machek
Date: Tue Jul 24 2018 - 07:41:54 EST


Hi!

> >> > >Please keep in mind that this is ABI documentation for the pattern file
> >> > >to be exposed by LED core, and not by the pattern trigger, that, as we
> >> > >agreed, will be implemented later. In this case, I'd go for
> >> >
> >> > Gosh, I got completely distracted by the recent discussion about
> >> > pattern synchronization.
> >> >
> >> > So, to recap, we need to decide if we are taking Baolin's solution
> >> > or we're opting for implementing pattern trigger.
> >> >
> >> > If we choose the latter, then we will also need some software
> >> > pattern engine in the trigger, to be applied as a software pattern
> >> > fallback for the devices without hardware pattern support.
> >> > It will certainly delay the contribution process, provided that Baolin
> >> > would find time for this work at all.
> >>
> >> I'd recommend the latter. Yes, software pattern as a fallback would be
> >> nice, but I have that code already... let me get it back to running
> >> state, and figure out where to add interface for "hardware
> >> acceleration". I'd like to have same interface to userland, whether
> >> pattern can be done by hardware or by software.
> >
> > For the record, I'd like something like this. (Software pattern should
> > work. Hardware pattern... needs more work).
>
> Thanks for showing your thoughts. But I failed to compile your code,
> would you like to send out formal patches (Or only including software
> pattern, I will help to add hardware pattern part and do some testing
> with our driver)? Thanks.

This should be a bit better. I attempted to compile it with your
driver, but whether it works is an open question.

Signed-off-by: Pavel Machek <pavel@xxxxxx>


diff --git a/drivers/leds/leds-sc27xx-bltc.c b/drivers/leds/leds-sc27xx-bltc.c
index 9d9b7aa..898f92d 100644
--- a/drivers/leds/leds-sc27xx-bltc.c
+++ b/drivers/leds/leds-sc27xx-bltc.c
@@ -6,6 +6,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/slab.h>
#include <uapi/linux/uleds.h>

/* PMIC global control register definition */
@@ -32,8 +33,13 @@
#define SC27XX_DUTY_MASK GENMASK(15, 0)
#define SC27XX_MOD_MASK GENMASK(7, 0)

+#define SC27XX_CURVE_SHIFT 8
+#define SC27XX_CURVE_L_MASK GENMASK(7, 0)
+#define SC27XX_CURVE_H_MASK GENMASK(15, 8)
+
#define SC27XX_LEDS_OFFSET 0x10
#define SC27XX_LEDS_MAX 3
+#define SC27XX_LEDS_PATTERN_CNT 4

struct sc27xx_led {
char name[LED_MAX_NAME_SIZE];
@@ -122,6 +128,157 @@ static int sc27xx_led_set(struct led_classdev *ldev, enum led_brightness value)
return err;
}

+static int sc27xx_led_pattern_clear(struct led_classdev *ldev)
+{
+ struct sc27xx_led *leds = to_sc27xx_led(ldev);
+ struct regmap *regmap = leds->priv->regmap;
+ u32 base = sc27xx_led_get_offset(leds);
+ u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
+ u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
+ int err;
+
+ mutex_lock(&leds->priv->lock);
+
+ /* Reset the rise, high, fall and low time to zero. */
+ regmap_write(regmap, base + SC27XX_LEDS_CURVE0, 0);
+ regmap_write(regmap, base + SC27XX_LEDS_CURVE1, 0);
+
+ err = regmap_update_bits(regmap, ctrl_base,
+ (SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift, 0);
+
+ mutex_unlock(&leds->priv->lock);
+
+ return err;
+}
+
+static int sc27xx_led_pattern_set(struct led_classdev *ldev,
+ struct led_pattern *pattern,
+ int len)
+{
+ struct sc27xx_led *leds = to_sc27xx_led(ldev);
+ u32 base = sc27xx_led_get_offset(leds);
+ u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
+ u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
+ struct regmap *regmap = leds->priv->regmap;
+ int err;
+
+ /*
+ * Must contain 4 patterns to configure the rise time, high time, fall
+ * time and low time to enable the breathing mode.
+ */
+ if (len != SC27XX_LEDS_PATTERN_CNT)
+ return -EINVAL;
+
+ mutex_lock(&leds->priv->lock);
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0,
+ SC27XX_CURVE_L_MASK, pattern[0].delta_t);
+ if (err)
+ goto out;
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1,
+ SC27XX_CURVE_L_MASK, pattern[1].delta_t);
+ if (err)
+ goto out;
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0,
+ SC27XX_CURVE_H_MASK,
+ pattern[2].delta_t << SC27XX_CURVE_SHIFT);
+ if (err)
+ goto out;
+
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1,
+ SC27XX_CURVE_H_MASK,
+ pattern[3].delta_t << SC27XX_CURVE_SHIFT);
+ if (err)
+ goto out;
+
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_DUTY,
+ SC27XX_DUTY_MASK,
+ (pattern[0].brightness << SC27XX_DUTY_SHIFT) |
+ SC27XX_MOD_MASK);
+ if (err)
+ goto out;
+
+ /* Enable the LED breathing mode */
+ err = regmap_update_bits(regmap, ctrl_base,
+ SC27XX_LED_RUN << ctrl_shift,
+ SC27XX_LED_RUN << ctrl_shift);
+
+out:
+ mutex_unlock(&leds->priv->lock);
+
+ return err;
+}
+
+static struct led_pattern *sc27xx_led_pattern_get(struct led_classdev *ldev,
+ int *len)
+{
+ struct sc27xx_led *leds = to_sc27xx_led(ldev);
+ u32 base = sc27xx_led_get_offset(leds);
+ struct regmap *regmap = leds->priv->regmap;
+ struct led_pattern *pattern;
+ int i, err;
+ u32 val;
+
+ /*
+ * Must allocate 4 patterns to show the rise time, high time, fall time
+ * and low time.
+ */
+ pattern = kcalloc(SC27XX_LEDS_PATTERN_CNT, sizeof(*pattern),
+ GFP_KERNEL);
+ if (!pattern)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_lock(&leds->priv->lock);
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE0, &val);
+ if (err)
+ goto out;
+
+ pattern[0].delta_t = val & SC27XX_CURVE_L_MASK;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE1, &val);
+ if (err)
+ goto out;
+
+ pattern[1].delta_t = val & SC27XX_CURVE_L_MASK;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE0, &val);
+ if (err)
+ goto out;
+
+ pattern[2].delta_t = (val & SC27XX_CURVE_H_MASK) >> SC27XX_CURVE_SHIFT;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE1, &val);
+ if (err)
+ goto out;
+
+ pattern[3].delta_t = (val & SC27XX_CURVE_H_MASK) >> SC27XX_CURVE_SHIFT;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_DUTY, &val);
+ if (err)
+ goto out;
+
+ mutex_unlock(&leds->priv->lock);
+
+ val = (val & SC27XX_DUTY_MASK) >> SC27XX_DUTY_SHIFT;
+ for (i = 0; i < SC27XX_LEDS_PATTERN_CNT; i++)
+ pattern[i].brightness = val;
+
+ *len = SC27XX_LEDS_PATTERN_CNT;
+
+ return pattern;
+
+out:
+ mutex_unlock(&leds->priv->lock);
+ kfree(pattern);
+
+ return ERR_PTR(err);
+}
+
static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv)
{
int i, err;
@@ -140,6 +297,9 @@ static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv)
led->priv = priv;
led->ldev.name = led->name;
led->ldev.brightness_set_blocking = sc27xx_led_set;
+ led->ldev.pattern_set = sc27xx_led_pattern_set;
+ led->ldev.pattern_get = sc27xx_led_pattern_get;
+ led->ldev.pattern_clear = sc27xx_led_pattern_clear;

err = devm_led_classdev_register(dev, &led->ldev);
if (err)
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index a2559b4..91ae5b0 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -125,6 +125,16 @@ config LEDS_TRIGGER_CAMERA
This enables direct flash/torch on/off by the driver, kernel space.
If unsure, say Y.

+config LEDS_TRIGGER_PATTERN
+ tristate "LED Pattern Trigger"
+ depends on LEDS_TRIGGERS
+ help
+ This allows LEDs blinking with an arbitrary pattern. Can be useful
+ on embedded systems with no screen to give out a status code to
+ a human.
+
+ If unsure, say N
+
config LEDS_TRIGGER_PANIC
bool "LED Panic Trigger"
depends on LEDS_TRIGGERS
diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
index f3cfe19..ba6f3b9 100644
--- a/drivers/leds/trigger/Makefile
+++ b/drivers/leds/trigger/Makefile
@@ -11,5 +11,6 @@ obj-$(CONFIG_LEDS_TRIGGER_ACTIVITY) += ledtrig-activity.o
obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON) += ledtrig-default-on.o
obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT) += ledtrig-transient.o
obj-$(CONFIG_LEDS_TRIGGER_CAMERA) += ledtrig-camera.o
+obj-$(CONFIG_LEDS_TRIGGER_PATTERN) += ledtrig-pattern.o
obj-$(CONFIG_LEDS_TRIGGER_PANIC) += ledtrig-panic.o
obj-$(CONFIG_LEDS_TRIGGER_NETDEV) += ledtrig-netdev.o
diff --git a/drivers/leds/trigger/ledtrig-pattern.c b/drivers/leds/trigger/ledtrig-pattern.c
new file mode 100644
index 0000000..3dab050
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-pattern.c
@@ -0,0 +1,395 @@
+/*
+ * Arbitrary pattern trigger
+ *
+ * Copyright 2015, Epsiline
+ *
+ * Author : Raphaël Teysseyre <rteysseyre@xxxxxxxxx>
+ *
+ * Idea discussed with Pavel Machek <pavel@xxxxxx> on
+ * <linux-leds@xxxxxxxxxxxxxxx> (march 2015, thread title
+ * [PATCH RFC] leds: Add status code trigger)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/timer.h>
+#include "../leds.h"
+
+struct pattern_trig_data {
+ struct led_classdev *led_cdev;
+
+ struct led_pattern *steps; /* Array describing the pattern */
+ struct mutex lock;
+ char is_sane;
+ struct led_pattern *curr;
+ struct led_pattern *next;
+ int delta_t; /* Time in current step */
+ int nsteps; /* Number of steps */
+ int repeat; /* < 0 means repeat indefinitely */
+ struct timer_list timer;
+};
+
+#define MAX_NSTEPS (PAGE_SIZE/4)
+/* The "pattern" attribute contains at most PAGE_SIZE characters.
+ Each line in this attribute is at least 4 characters long
+ (a 1-digit number for the led brighntess, a space,
+ a 1-digit number for the time, a semi-colon).
+ Therefore, there is at most PAGE_SIZE/4 steps. */
+
+#define UPDATE_INTERVAL 50
+/* When doing gradual dimming, the led brightness
+ will be updated every UPDATE_INTERVAL milliseconds */
+
+#define PATTERN_SEPARATOR ","
+
+static int pattern_trig_initialize_data(struct pattern_trig_data *data)
+{
+ mutex_init(&data->lock);
+ mutex_lock(&data->lock);
+
+ data->is_sane = 0;
+ data->steps = kzalloc(MAX_NSTEPS*sizeof(struct led_pattern),
+ GFP_KERNEL);
+ if (!data->steps)
+ return -ENOMEM;
+
+ data->curr = NULL;
+ data->next = NULL;
+ data->delta_t = 0;
+ data->nsteps = 0;
+ data->repeat = -1;
+ //data->timer = __TIMER_INITIALIZER(NULL, 0);
+
+ mutex_unlock(&data->lock);
+ return 0;
+}
+
+static void pattern_trig_clear_data(struct pattern_trig_data *data)
+{
+ data->is_sane = 0;
+ kfree(data->steps);
+}
+
+/*
+ * is_sane : pattern checking.
+ * A pattern satisfying these three conditions is reported as sane :
+ * - At least two steps
+ * - At least one step with time >= UPDATE_INTERVAL
+ * - At least two steps with differing brightnesses
+ * When @data isn't sane, a sensible brightness
+ * default is suggested in @brightness
+ *
+ * DO NOT call pattern_trig_update on a not-sane pattern,
+ * you'll be punished with an infinite loop in the kernel.
+ */
+static int is_sane(struct pattern_trig_data *data, int *brightness)
+{
+ int i;
+ char stept_ok = 0;
+ char stepb_ok = 0;
+
+ *brightness = 0;
+ if (data->nsteps < 1)
+ return 0;
+
+ *brightness = data->steps[0].brightness;
+ if (data->nsteps < 2)
+ return 0;
+
+ for (i = 0; i < data->nsteps; i++) {
+ if (data->steps[i].delta_t >= UPDATE_INTERVAL) {
+ /* FIXME: this is wrong */
+ if (stepb_ok)
+ return 1;
+ stept_ok = 1;
+ }
+ if (data->steps[i].brightness != data->steps[0].brightness) {
+ if (stept_ok)
+ return 1;
+ stepb_ok = 1;
+ }
+ }
+
+ return 0;
+}
+
+static void reset_pattern(struct pattern_trig_data *data,
+ struct led_classdev *led_cdev)
+{
+ int brightness;
+
+ if (led_cdev->pattern_clear) {
+ led_cdev->pattern_clear(led_cdev);
+ }
+
+ del_timer_sync(&data->timer);
+
+ if (led_cdev->pattern_set && led_cdev->pattern_set(led_cdev, data->steps, data->nsteps)) {
+ return;
+ }
+
+ if (!is_sane(data, &brightness)) {
+ led_set_brightness(led_cdev, brightness);
+ return;
+ }
+
+ data->curr = data->steps;
+ data->next = data->steps + 1;
+ data->delta_t = 0;
+ data->is_sane = 1;
+
+ data->timer.expires = jiffies;
+ add_timer(&data->timer);
+}
+
+/* --- Sysfs handling --- */
+
+static ssize_t pattern_trig_show_repeat(
+ 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 scnprintf(buf, PAGE_SIZE, "%d\n", data->repeat);
+}
+
+static ssize_t pattern_trig_store_repeat(
+ 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;
+ long res;
+ int err;
+
+ err = kstrtol(buf, 10, &res);
+ if (err)
+ return err;
+
+ data->repeat = res < 0 ? -1 : res;
+ reset_pattern(data, led_cdev);
+
+ return count;
+}
+
+DEVICE_ATTR(repeat, S_IRUGO | S_IWUSR,
+ pattern_trig_show_repeat, pattern_trig_store_repeat);
+
+static ssize_t pattern_trig_show_pattern(
+ 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;
+ ssize_t count = 0;
+ int i;
+
+ if (!data->steps || !data->nsteps)
+ return 0;
+
+ for (i = 0; i < data->nsteps; i++)
+ count += scnprintf(buf + count, PAGE_SIZE - count,
+ "%d %d" PATTERN_SEPARATOR,
+ data->steps[i].brightness,
+ data->steps[i].delta_t);
+ buf[count - 1] = '\n';
+ buf[count] = '\0';
+
+ return count + 1;
+}
+
+static ssize_t pattern_trig_store_pattern(
+ 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;
+ int cr = 0; /* Characters read on one conversion */
+ int tcr = 0; /* Total characters read */
+ int ccount; /* Number of successful conversions */
+
+ mutex_lock(&data->lock);
+ data->is_sane = 0;
+
+ for (data->nsteps = 0; data->nsteps < MAX_NSTEPS; data->nsteps++) {
+ cr = 0;
+ ccount = sscanf(buf + tcr, "%d %d " PATTERN_SEPARATOR "%n",
+ &data->steps[data->nsteps].brightness,
+ &data->steps[data->nsteps].delta_t, &cr);
+
+ if (!cr) { /* Invalid syntax or end of pattern */
+ if (ccount == 2)
+ data->nsteps++;
+ mutex_unlock(&data->lock);
+ reset_pattern(data, led_cdev);
+ return count;
+ }
+
+ tcr += cr;
+ }
+
+ /* Shouldn't reach that */
+ WARN(1, "MAX_NSTEP too small. Please report\n");
+ mutex_unlock(&data->lock);
+ return count;
+}
+
+DEVICE_ATTR(pattern, S_IRUGO | S_IWUSR,
+ pattern_trig_show_pattern, pattern_trig_store_pattern);
+
+static int pattern_trig_create_sysfs_files(struct device *dev)
+{
+ int err;
+
+ err = device_create_file(dev, &dev_attr_repeat);
+ if (err)
+ return err;
+
+ err = device_create_file(dev, &dev_attr_pattern);
+ if (err)
+ device_remove_file(dev, &dev_attr_repeat);
+
+ return err;
+}
+
+static void pattern_trig_remove_sysfs_files(struct device *dev)
+{
+ device_remove_file(dev, &dev_attr_pattern);
+ device_remove_file(dev, &dev_attr_repeat);
+}
+
+/* --- Led intensity updating --- */
+
+static int compute_brightness(struct pattern_trig_data *data)
+{
+ if (data->delta_t == 0)
+ return data->curr->brightness;
+
+ if (data->curr->delta_t == 0)
+ return data->next->brightness;
+
+ return data->curr->brightness + data->delta_t
+ * (data->next->brightness - data->curr->brightness)
+ / data->curr->delta_t;
+}
+
+static void update_to_next_step(struct pattern_trig_data *data)
+{
+ data->curr = data->next;
+ if (data->curr == data->steps)
+ data->repeat--;
+
+ if (data->next == data->steps + data->nsteps - 1)
+ data->next = data->steps;
+ else
+ data->next++;
+
+ data->delta_t = 0;
+}
+
+static void pattern_trig_update(struct timer_list *t)
+{
+ struct pattern_trig_data *data = from_timer(data, t, timer);
+
+ mutex_lock(&data->lock);
+
+ if (!data->is_sane || !data->repeat) {
+ mutex_unlock(&data->lock);
+ return;
+ }
+
+ if (data->delta_t > data->curr->delta_t)
+ update_to_next_step(data);
+
+ /* is_sane() checked that there is at least
+ one step with delta_t >= UPDATE_INTERVAL
+ so we won't go in an infinite loop */
+ while (data->curr->delta_t < UPDATE_INTERVAL)
+ update_to_next_step(data);
+
+ if (data->next->brightness == data->curr->brightness) {
+ /* Constant brightness for this step */
+ led_set_brightness(data->led_cdev, data->curr->brightness);
+ mod_timer(&data->timer, jiffies
+ + msecs_to_jiffies(data->curr->delta_t));
+ update_to_next_step(data);
+ } else {
+ /* Gradual dimming */
+ led_set_brightness(data->led_cdev, compute_brightness(data));
+ data->delta_t += UPDATE_INTERVAL;
+ mod_timer(&data->timer, jiffies
+ + msecs_to_jiffies(UPDATE_INTERVAL));
+ }
+
+ mutex_unlock(&data->lock);
+}
+
+/* --- Trigger activation --- */
+
+static void pattern_trig_activate(struct led_classdev *led_cdev)
+{
+ struct pattern_trig_data *data = NULL;
+ int err;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return;
+
+ err = pattern_trig_initialize_data(data);
+ if (err) {
+ kfree(data);
+ return;
+ }
+
+ data->led_cdev = led_cdev;
+ led_cdev->trigger_data = data;
+ timer_setup(&data->timer, pattern_trig_update, 0);
+ pattern_trig_create_sysfs_files(led_cdev->dev);
+}
+
+static void pattern_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct pattern_trig_data *data = led_cdev->trigger_data;
+
+ if (data) {
+ pattern_trig_remove_sysfs_files(led_cdev->dev);
+ del_timer_sync(&data->timer);
+ led_set_brightness(led_cdev, LED_OFF);
+ pattern_trig_clear_data(data);
+ kfree(data);
+ led_cdev->trigger_data = NULL;
+ }
+}
+
+static struct led_trigger pattern_led_trigger = {
+ .name = "pattern",
+ .activate = pattern_trig_activate,
+ .deactivate = pattern_trig_deactivate,
+};
+
+/* --- Module loading/unloading --- */
+
+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@xxxxxxxxx");
+MODULE_DESCRIPTION("Pattern LED trigger");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 2fce962..39908ba 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
*/
@@ -91,6 +92,14 @@ 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);
+
+ int (*pattern_clear)(struct led_classdev *led_cdev);
+
+ struct led_pattern *(*pattern_get)(struct led_classdev *led_cdev,
+ int *len);
+
struct device *dev;
const struct attribute_group **groups;

@@ -104,7 +113,7 @@ struct led_classdev {
void (*flash_resume)(struct led_classdev *led_cdev);

struct work_struct set_brightness_work;
- int delayed_set_value;
+ enum led_brightness delayed_set_value;

#ifdef CONFIG_LEDS_TRIGGERS
/* Protects the trigger data below */
@@ -471,4 +480,14 @@ static inline void led_classdev_notify_brightness_hw_changed(
struct led_classdev *led_cdev, enum led_brightness brightness) { }
#endif

+/**
+ * struct led_pattern - brightness value in a pattern
+ * @delta_t: delay until next entry, in milliseconds
+ * @brightness: brightness at time = 0
+ */
+struct led_pattern {
+ int delta_t;
+ int brightness;
+};
+
#endif /* __LINUX_LEDS_H_INCLUDED */


--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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