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-rw-r--r--drivers/leds/trigger/Kconfig7
-rw-r--r--drivers/leds/trigger/Makefile1
-rw-r--r--drivers/leds/trigger/ledtrig-pattern.c411
3 files changed, 419 insertions, 0 deletions
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index 4018af769969..b76fc3cdc8f8 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 f3cfe1950538..9bcb64ee8123 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 000000000000..ce7acd115dd8
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-pattern.c
@@ -0,0 +1,411 @@
+// 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
+/*
+ * When doing gradual dimming, the led brightness will be updated
+ * every 50 milliseconds.
+ */
+#define UPDATE_INTERVAL 50
+
+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;
+ int repeat;
+ int last_repeat;
+ int delta_t;
+ 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++;
+
+ data->delta_t = 0;
+}
+
+static int pattern_trig_compute_brightness(struct pattern_trig_data *data)
+{
+ int step_brightness;
+
+ /*
+ * If current tuple's duration is less than the dimming interval,
+ * we should treat it as a step change of brightness instead of
+ * doing gradual dimming.
+ */
+ if (data->delta_t == 0 || data->curr->delta_t < UPDATE_INTERVAL)
+ return data->curr->brightness;
+
+ step_brightness = abs(data->next->brightness - data->curr->brightness);
+ step_brightness = data->delta_t * step_brightness / data->curr->delta_t;
+
+ if (data->next->brightness > data->curr->brightness)
+ return data->curr->brightness + step_brightness;
+ else
+ return data->curr->brightness - step_brightness;
+}
+
+static void pattern_trig_timer_function(struct timer_list *t)
+{
+ struct pattern_trig_data *data = from_timer(data, t, timer);
+
+ mutex_lock(&data->lock);
+
+ for (;;) {
+ if (!data->is_indefinite && !data->repeat)
+ break;
+
+ if (data->curr->brightness == data->next->brightness) {
+ /* Step change of brightness */
+ led_set_brightness(data->led_cdev,
+ data->curr->brightness);
+ mod_timer(&data->timer,
+ jiffies + msecs_to_jiffies(data->curr->delta_t));
+
+ /* Skip the tuple with zero duration */
+ pattern_trig_update_patterns(data);
+ /* Select next tuple */
+ pattern_trig_update_patterns(data);
+ } else {
+ /* Gradual dimming */
+
+ /*
+ * If the accumulation time is larger than current
+ * tuple's duration, we should go next one and re-check
+ * if we repeated done.
+ */
+ if (data->delta_t > data->curr->delta_t) {
+ pattern_trig_update_patterns(data);
+ continue;
+ }
+
+ led_set_brightness(data->led_cdev,
+ pattern_trig_compute_brightness(data));
+ mod_timer(&data->timer,
+ jiffies + msecs_to_jiffies(UPDATE_INTERVAL));
+
+ /* Accumulate the gradual dimming time */
+ data->delta_t += UPDATE_INTERVAL;
+ }
+
+ break;
+ }
+
+ 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);
+ }
+
+ /* At least 2 tuples for software pattern. */
+ if (data->npatterns < 2)
+ return -EINVAL;
+
+ data->delta_t = 0;
+ data->curr = data->patterns;
+ data->next = data->patterns + 1;
+ 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;
+ int repeat;
+
+ mutex_lock(&data->lock);
+
+ repeat = data->last_repeat;
+
+ mutex_unlock(&data->lock);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\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;
+ int err, res;
+
+ err = kstrtos32(buf, 10, &res);
+ if (err)
+ return err;
+
+ /* Number 0 and negative numbers except -1 are invalid. */
+ if (res < -1 || res == 0)
+ return -EINVAL;
+
+ /*
+ * 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;
+ /* -1 means repeat indefinitely */
+ if (data->repeat == -1)
+ data->is_indefinite = true;
+ else
+ data->is_indefinite = false;
+
+ 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 %u ",
+ 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 %u %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);
+ if (err)
+ data->npatterns = 0;
+
+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;
+ data->last_repeat = -1;
+ 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");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 11:47:04 +0000