Messages in this thread | | | Subject | Re: [PATCH v2 1/2] led: add oneshot trigger | From | Shuah Khan <> | Date | Tue, 05 Jun 2012 18:51:47 -0600 |
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On Tue, 2012-06-05 at 23:38 +0200, Fabio Baltieri wrote: > Add oneshot trigger to blink a led with configurable parameters via > sysfs.
Fabio,
What are the use-cases for this trigger. Please see comments inline:
> > Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> > Cc: Shuah Khan <shuahkhan@gmail.com> > Cc: Bryan Wu <bryan.wu@canonical.com> > --- > Hi all, > > that's my v2 of the ledtrig-oneshot trigger, with the correction suggested from > Shuah in the original thread. These include some unnecessary initialization > and use of the new "activated" flag. > > I've kept the name to "oneshot" as I think it suits the role of the trigger as > example/test for the led_blink_set_oneshot function but I have expanded a bit > the Kconfig description to better identify the trigger's usage. > > About the namespace question, I think that naming the parameters delay_on and > delay_off is ok as they have the same meaning as timer's ones (they also > uses the same internal fields after all...). > > Also, I added a default set of delay_{on,off} to 100ms on activation, so that > the trigger starts with a valid configuration, like ledtrig-timer does. > > Anything else that should be changed? > > Fabio > > drivers/leds/Kconfig | 14 +++ > drivers/leds/Makefile | 1 + > drivers/leds/ledtrig-oneshot.c | 198 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 213 insertions(+) > create mode 100644 drivers/leds/ledtrig-oneshot.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 04cb8c8..1f151fb 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -443,6 +443,20 @@ config LEDS_TRIGGER_TIMER > > If unsure, say Y. > > +config LEDS_TRIGGER_ONESHOT > + tristate "LED One-shot Trigger" > + depends on LEDS_TRIGGERS > + help > + This allows LEDs to blink in one-shot pulses with parameters > + controlled via sysfs. It's useful to notify the user on > + sporadic events, when there are no clear begin and end trap points, > + or on dense events, where this blinks the LED at constant rate if > + rearmed continuously. > + > + It also shows how to use the led_blink_set_oneshot() function. > + > + If unsure, say Y. > + > config LEDS_TRIGGER_IDE_DISK > bool "LED IDE Disk Trigger" > depends on IDE_GD_ATA > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index f8958cd..9112d51 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o > > # LED Triggers > obj-$(CONFIG_LEDS_TRIGGER_TIMER) += ledtrig-timer.o > +obj-$(CONFIG_LEDS_TRIGGER_ONESHOT) += ledtrig-oneshot.o > obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK) += ledtrig-ide-disk.o > obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT) += ledtrig-heartbeat.o > obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT) += ledtrig-backlight.o > diff --git a/drivers/leds/ledtrig-oneshot.c b/drivers/leds/ledtrig-oneshot.c > new file mode 100644 > index 0000000..1aacdfe > --- /dev/null > +++ b/drivers/leds/ledtrig-oneshot.c > @@ -0,0 +1,198 @@ > +/* > + * One-shot LED Trigger > + * > + * Copyright 2012, Fabio Baltieri <fabio.baltieri@gmail.com> > + * > + * Based on ledtrig-timer.c by Richard Purdie <rpurdie@openedhand.com> > + * > + * 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/device.h> > +#include <linux/ctype.h> > +#include <linux/slab.h> > +#include <linux/leds.h> > + > +#define DEFAULT_DELAY 100 > + > +struct oneshot_trig_data { > + unsigned int invert; > +}; > + > +static ssize_t led_shot(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t size) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; > + > + led_blink_set_oneshot(led_cdev, > + &led_cdev->blink_delay_on, &led_cdev->blink_delay_off, > + oneshot_data->invert);
Here when shot is set
echo n > shot
What are the values for blink_delay_on and blink_delay_off. Does user need to set delay_on and delay_off first? If user doesn't set these then what values are used?
What about invert? Does user need to do echo 1 > invert and then activate shot?
Thanks, -- Shuah > + > + /* content is ignored */ > + return size; > +} > +static ssize_t led_invert_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; > + > + return sprintf(buf, "%u\n", oneshot_data->invert); > +} > + > +static ssize_t led_invert_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t size) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; > + unsigned long state; > + int ret; > + > + ret = kstrtoul(buf, 0, &state); > + if (ret) > + return ret; > + > + oneshot_data->invert = !!state; > + > + return size; > +} > + > +static ssize_t led_delay_on_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + > + return sprintf(buf, "%lu\n", led_cdev->blink_delay_on); > +} > + > +static ssize_t led_delay_on_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t size) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + unsigned long state; > + int ret; > + > + ret = kstrtoul(buf, 0, &state); > + if (ret) > + return ret; > + > + led_cdev->blink_delay_on = state; > + > + return size; > +} > +static ssize_t led_delay_off_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + > + return sprintf(buf, "%lu\n", led_cdev->blink_delay_off); > +} > + > +static ssize_t led_delay_off_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t size) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(dev); > + unsigned long state; > + int ret; > + > + ret = kstrtoul(buf, 0, &state); > + if (ret) > + return ret; > + > + led_cdev->blink_delay_off = state; > + > + return size; > +} > + > +static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store); > +static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store); > +static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store); > +static DEVICE_ATTR(shot, 0200, NULL, led_shot); > + > +static void oneshot_trig_activate(struct led_classdev *led_cdev) > +{ > + struct oneshot_trig_data *oneshot_data; > + int rc; > + > + oneshot_data = kzalloc(sizeof(*oneshot_data), GFP_KERNEL); > + if (!oneshot_data) > + return; > + > + led_cdev->trigger_data = oneshot_data; > + > + rc = device_create_file(led_cdev->dev, &dev_attr_delay_on); > + if (rc) > + goto err_out_trig_data; > + rc = device_create_file(led_cdev->dev, &dev_attr_delay_off); > + if (rc) > + goto err_out_delayon; > + rc = device_create_file(led_cdev->dev, &dev_attr_invert); > + if (rc) > + goto err_out_delayoff; > + rc = device_create_file(led_cdev->dev, &dev_attr_shot); > + if (rc) > + goto err_out_invert; > + > + led_cdev->blink_delay_on = DEFAULT_DELAY; > + led_cdev->blink_delay_off = DEFAULT_DELAY; > + > + led_cdev->activated = true; > + > + return; > + > +err_out_invert: > + device_remove_file(led_cdev->dev, &dev_attr_invert); > +err_out_delayoff: > + device_remove_file(led_cdev->dev, &dev_attr_delay_off); > +err_out_delayon: > + device_remove_file(led_cdev->dev, &dev_attr_delay_on); > +err_out_trig_data: > + kfree(led_cdev->trigger_data); > +} > + > +static void oneshot_trig_deactivate(struct led_classdev *led_cdev) > +{ > + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; > + > + if (led_cdev->activated) { > + device_remove_file(led_cdev->dev, &dev_attr_delay_on); > + device_remove_file(led_cdev->dev, &dev_attr_delay_off); > + device_remove_file(led_cdev->dev, &dev_attr_invert); > + device_remove_file(led_cdev->dev, &dev_attr_shot); > + kfree(oneshot_data); > + led_cdev->activated = false; > + } > + > + /* Stop blinking */ > + led_brightness_set(led_cdev, LED_OFF); > +} > + > +static struct led_trigger oneshot_led_trigger = { > + .name = "oneshot", > + .activate = oneshot_trig_activate, > + .deactivate = oneshot_trig_deactivate, > +}; > + > +static int __init oneshot_trig_init(void) > +{ > + return led_trigger_register(&oneshot_led_trigger); > +} > + > +static void __exit oneshot_trig_exit(void) > +{ > + led_trigger_unregister(&oneshot_led_trigger); > +} > + > +module_init(oneshot_trig_init); > +module_exit(oneshot_trig_exit); > + > +MODULE_AUTHOR("Fabio Baltieri <fabio.baltieri@gmail.com>"); > +MODULE_DESCRIPTION("One-shot LED trigger"); > +MODULE_LICENSE("GPL");
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