summaryrefslogtreecommitdiff
path: root/drivers/leds/ledtrig-dim.c
diff options
context:
space:
mode:
authorTodd Doucet <todd.doucet@timesys.com>2010-02-03 17:06:33 -0500
committerTodd Doucet <todd.doucet@timesys.com>2010-02-03 17:06:33 -0500
commitff238a4df84428befc55d49f58864dfc47ff853d (patch)
tree8796b828b396f5b7ed017904ff77b614dbf38677 /drivers/leds/ledtrig-dim.c
parent4a6908a3a050aacc9c3a2f36b276b46c0629ad91 (diff)
Kernel as received from Digi for their Wi-Mx51 SoC running on their
CCWMX51JS carrier board.
Diffstat (limited to 'drivers/leds/ledtrig-dim.c')
-rw-r--r--drivers/leds/ledtrig-dim.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/leds/ledtrig-dim.c b/drivers/leds/ledtrig-dim.c
new file mode 100644
index 000000000000..04dbaf66a49e
--- /dev/null
+++ b/drivers/leds/ledtrig-dim.c
@@ -0,0 +1,95 @@
+/*
+ * LED Dim Trigger
+ *
+ * Copyright (C) 2008 Bill Gatliff <bgat <at> billgatliff.com>
+ *
+ * "Dims" an LED based on system load. Derived from Atsushi Nemoto's
+ * ledtrig-heartbeat.c.
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/leds.h>
+
+#include "leds.h"
+
+struct dim_trig_data {
+ struct timer_list timer;
+};
+
+
+static void
+led_dim_function(unsigned long data)
+{
+ struct led_classdev *led_cdev = (struct led_classdev *)data;
+ struct dim_trig_data *dim_data = led_cdev->trigger_data;
+ unsigned int brightness;
+
+ brightness = ((LED_FULL - LED_OFF) * avenrun[0]) / EXP_1;
+ if (brightness > LED_FULL)
+ brightness = LED_FULL;
+
+ led_set_brightness(led_cdev, brightness);
+ mod_timer(&dim_data->timer, jiffies + msecs_to_jiffies(500));
+}
+
+
+static void
+dim_trig_activate(struct led_classdev *led_cdev)
+{
+ struct dim_trig_data *dim_data;
+
+ dim_data = kzalloc(sizeof(*dim_data), GFP_KERNEL);
+ if (!dim_data)
+ return;
+
+ led_cdev->trigger_data = dim_data;
+ setup_timer(&dim_data->timer,
+ led_dim_function, (unsigned long)led_cdev);
+ led_dim_function(dim_data->timer.data);
+}
+
+
+static void
+dim_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct dim_trig_data *dim_data = led_cdev->trigger_data;
+
+ if (dim_data) {
+ del_timer_sync(&dim_data->timer);
+ kfree(dim_data);
+ }
+}
+
+
+static struct led_trigger dim_led_trigger = {
+ .name = "dim",
+ .activate = dim_trig_activate,
+ .deactivate = dim_trig_deactivate,
+};
+
+
+static int __init dim_trig_init(void)
+{
+ return led_trigger_register(&dim_led_trigger);
+}
+module_init(dim_trig_init);
+
+
+static void __exit dim_trig_exit(void)
+{
+ led_trigger_unregister(&dim_led_trigger);
+}
+module_exit(dim_trig_exit);
+
+
+MODULE_AUTHOR("Bill Gatliff <bgat <at> billgatliff.com>");
+MODULE_DESCRIPTION("Dim LED trigger");
+MODULE_LICENSE("GPL");