Messages in this thread | | | Subject | Re: [PATCH 3/3] led: add oneshot trigger | From | Shuah Khan <> | Date | Sun, 27 May 2012 10:09:49 -0600 |
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On Sun, 2012-05-27 at 01:19 +0200, Fabio Baltieri wrote: > Add oneshot trigger to blink a led with configurable parameters via > sysfs. > > Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> > Cc: Bryan Wu <bryan.wu@canonical.com> > Cc: Shuah Khan <shuahkhan@gmail.com> > --- > > That's (a cleaned up version of) what I used to test the first patch. Should > we also consider this one for integration? Shuah Khan was working on > something similar, I'll add him in CC.
Fabio,
Thanks for including me in the review. If you haven't already looked at the the LEDS_TRIGGER_TRANSIENT I implemented, please take a look. It is in linux-next and is queued up for 3.5-rc1 inclusion. It is also a one shot timer, howver it holds the LED in a transient state (could be on or off depending on its permanent state) for a specified period of time and then goes back to the original state. Your use-case is different in that the trigger you are implementing it holds it in blink state. These two are distinct use-cases that address different needs and we will need both.
However, the in the interest of reducing confusion, I would recommend changing the name of the trigger you are adding to something that reflects that it holds the blink state. You could call it LED_TRIGGER_PULSEONCE or LED_TRIGGER_BLINKONCE.
Also could you please outline the use-cases. Might be a good idea to add a documentation file for this new trigger.
Did you look at LEDS_TRIGGER_TIMER to see if the name-space you are using conflicts with that triggers name-space. I think it does unless I am missing something.
Also you probably need to base your patch on linux-next so you can pick up one other infrastructure change I made to add a new activated flag to led_classdev structure. This new flag is used to keep track of trigger activated state and free memory and do cleanup.
More comments in-line.
> > Fabio > > drivers/leds/Kconfig | 9 ++ > drivers/leds/Makefile | 1 + > drivers/leds/ledtrig-oneshot.c | 190 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 200 insertions(+) > create mode 100644 drivers/leds/ledtrig-oneshot.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index ff4b8cf..17c3cf2 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -422,6 +422,15 @@ config LEDS_TRIGGER_TIMER > > If unsure, say Y. > > +config LEDS_TRIGGER_ONESHOT > + tristate "One-Shot Trigger" > + depends on LEDS_TRIGGERS > + help > + This allows LEDs to blink in one-shot pulses with parameters > + controlled via sysfs. > + > + 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 890481c..ec8ff79 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -51,6 +51,7 @@ 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..7d9a052 > --- /dev/null > +++ b/drivers/leds/ledtrig-oneshot.c > @@ -0,0 +1,190 @@ > +/* > + * 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> > + > +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); > + > + /* 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 = -EINVAL; This initialization is not necessary. > + > + 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 = -EINVAL; This initialization is not necessary. > + > + 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 = -EINVAL;
This initialization is not necessary. > + > + 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);
Doesn't this conflict with LEDS_TRIGGER_TIMER namespace
> +static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
Doesn't this conflict with LEDS_TRIGGER_TIMER namespace > +static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
This probably conflict with > +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; > +
This is where you can set activated flag to true and check the flag from your deactivate routine. Please check linux-next leds code. I also updated all led triggers to use this new flag.
> + 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 (oneshot_data) {
You can check activated flag instead of onshot_data like the rest of the led triggers.
> + 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(led_cdev->trigger_data); > + } > + > + /* 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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