Re: [PATCH v2 1/3] leds: add oneshot blink functions

From: Fabio Baltieri
Date: Thu May 31 2012 - 17:06:49 EST

Hi Shuah,

On Sun, May 27, 2012 at 10:13:46AM -0600, Shuah Khan wrote:
> On Sun, 2012-05-27 at 01:19 +0200, Fabio Baltieri wrote:
> > Add two new functions, led_blink_set_oneshot and
> > led_trigger_blink_oneshot, to be used by triggers for one-shot blink of
> > led devices.
> >
> > This is implemented extending the existing software-blink code, and uses
> > the same timer and handler function.
> >
> > The behavior of the code is to do a blink-on, blink-off sequence when
> > the function is called, ignoring other calls until the sequence is
> > completed so that the leds keep blinking at constant rate if the
> > functions are called repeatedly.
> >
> > This is meant to be used by drivers which needs to trigger on sporadic
> > event, but doesn't have clear busy/idle trigger points.
> >
> > After the blink sequence the led remains off. This behavior can be
> > inverted setting the "invert" argument, which blink the led off, than on
> > and leave the led on after the sequence.
> >
> > Signed-off-by: Fabio Baltieri <fabio.baltieri@xxxxxxxxx>
> > Cc: Bryan Wu <bryan.wu@xxxxxxxxxxxxx>
> > ---
> >
> > Same patch as v1 but rebased on Bryan's linux-leds tree.
>
> Fabio/Bryan,
>
> Please take a look at linux-next. I am concerned that this work
> conflicts with LEDS_TRIGGER_TIMER implementation. Anyways using

There should be no compatibity issues with current timer-trigger calls,
can you be more specific?

> linux-next is more appropriate here, as there were a few patches that
> went in while Andrew Morton was acting as a maintainer for leds
> sub-system.

Ok, anyway v1 of the patch should apply cleanly on current mainline
until linus pulls from Bryan.

Fabio

> -- Shuah
> >
> > More info in original thread:
> > http://marc.info/?l=linux-kernel&m=133763247601381&w=2
> >
> > Tested on an x86 system with a custom usb-led device (http://wp.me/p1M1k7-fZ
> > for the curious).
> >
> > Fabio
> >
> > drivers/leds/led-class.c | 19 +++++++++++++++++
> > drivers/leds/led-core.c | 50 ++++++++++++++++++++++++++++++++++-----------
> > drivers/leds/led-triggers.c | 30 +++++++++++++++++++++++----
> > include/linux/leds.h | 25 +++++++++++++++++++++++
> > 4 files changed, 108 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> > index 5bff843..42d9359 100644
> > --- a/drivers/leds/led-class.c
> > +++ b/drivers/leds/led-class.c
> > @@ -91,6 +91,11 @@ static void led_timer_function(unsigned long data)
> > return;
> > }
> >
> > + if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
> > + led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
> > + return;
> > + }
> > +
> > brightness = led_get_brightness(led_cdev);
> > if (!brightness) {
> > /* Time to switch the LED on. */
> > @@ -107,6 +112,20 @@ static void led_timer_function(unsigned long data)
> >
> > led_set_brightness(led_cdev, brightness);
> >
> > + /* Return in next iteration if led is in one-shot mode and we are in
> > + * the final blink state so that the led is toggled each delay_on +
> > + * delay_off milliseconds in worst case.
> > + */
> > + if (led_cdev->flags & LED_BLINK_ONESHOT) {
> > + if (led_cdev->flags & LED_BLINK_INVERT) {
> > + if (brightness)
> > + led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
> > + } else {
> > + if (!brightness)
> > + led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
> > + }
> > + }
> > +
> > mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
> > }
> >
> > diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
> > index d686004..579eb78 100644
> > --- a/drivers/leds/led-core.c
> > +++ b/drivers/leds/led-core.c
> > @@ -27,7 +27,6 @@ EXPORT_SYMBOL_GPL(leds_list);
> > static void led_stop_software_blink(struct led_classdev *led_cdev)
> > {
> > /* deactivate previous settings */
> > - del_timer_sync(&led_cdev->blink_timer);
> > led_cdev->blink_delay_on = 0;
> > led_cdev->blink_delay_off = 0;
> > }
> > @@ -44,11 +43,6 @@ static void led_set_software_blink(struct led_classdev *led_cdev,
> > if (!led_cdev->blink_brightness)
> > led_cdev->blink_brightness = led_cdev->max_brightness;
> >
> > - if (led_get_trigger_data(led_cdev) &&
> > - delay_on == led_cdev->blink_delay_on &&
> > - delay_off == led_cdev->blink_delay_off)
> > - return;
> > -
> > led_stop_software_blink(led_cdev);
> >
> > led_cdev->blink_delay_on = delay_on;
> > @@ -68,13 +62,12 @@ static void led_set_software_blink(struct led_classdev *led_cdev,
> > }
> >
> >
> > -void led_blink_set(struct led_classdev *led_cdev,
> > - unsigned long *delay_on,
> > - unsigned long *delay_off)
> > +void led_blink_setup(struct led_classdev *led_cdev,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off)
> > {
> > - del_timer_sync(&led_cdev->blink_timer);
> > -
> > - if (led_cdev->blink_set &&
> > + if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
> > + led_cdev->blink_set &&
> > !led_cdev->blink_set(led_cdev, delay_on, delay_off))
> > return;
> >
> > @@ -84,8 +77,41 @@ void led_blink_set(struct led_classdev *led_cdev,
> >
> > led_set_software_blink(led_cdev, *delay_on, *delay_off);
> > }
> > +
> > +void led_blink_set(struct led_classdev *led_cdev,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off)
> > +{
> > + del_timer_sync(&led_cdev->blink_timer);
> > +
> > + led_cdev->flags &= ~LED_BLINK_ONESHOT;
> > + led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
> > +
> > + led_blink_setup(led_cdev, delay_on, delay_off);
> > +}
> > EXPORT_SYMBOL(led_blink_set);
> >
> > +void led_blink_set_oneshot(struct led_classdev *led_cdev,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off,
> > + int invert)
> > +{
> > + if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
> > + timer_pending(&led_cdev->blink_timer))
> > + return;
> > +
> > + led_cdev->flags |= LED_BLINK_ONESHOT;
> > + led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
> > +
> > + if (invert)
> > + led_cdev->flags |= LED_BLINK_INVERT;
> > + else
> > + led_cdev->flags &= ~LED_BLINK_INVERT;
> > +
> > + led_blink_setup(led_cdev, delay_on, delay_off);
> > +}
> > +EXPORT_SYMBOL(led_blink_set_oneshot);
> > +
> > void led_brightness_set(struct led_classdev *led_cdev,
> > enum led_brightness brightness)
> > {
> > diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
> > index b449ed8..fa0b9be 100644
> > --- a/drivers/leds/led-triggers.c
> > +++ b/drivers/leds/led-triggers.c
> > @@ -230,9 +230,11 @@ void led_trigger_event(struct led_trigger *trig,
> > }
> > EXPORT_SYMBOL_GPL(led_trigger_event);
> >
> > -void led_trigger_blink(struct led_trigger *trig,
> > - unsigned long *delay_on,
> > - unsigned long *delay_off)
> > +void led_trigger_blink_setup(struct led_trigger *trig,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off,
> > + int oneshot,
> > + int invert)
> > {
> > struct list_head *entry;
> >
> > @@ -244,12 +246,32 @@ void led_trigger_blink(struct led_trigger *trig,
> > struct led_classdev *led_cdev;
> >
> > led_cdev = list_entry(entry, struct led_classdev, trig_list);
> > - led_blink_set(led_cdev, delay_on, delay_off);
> > + if (oneshot)
> > + led_blink_set_oneshot(led_cdev, delay_on, delay_off,
> > + invert);
> > + else
> > + led_blink_set(led_cdev, delay_on, delay_off);
> > }
> > read_unlock(&trig->leddev_list_lock);
> > }
> > +
> > +void led_trigger_blink(struct led_trigger *trig,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off)
> > +{
> > + led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
> > +}
> > EXPORT_SYMBOL_GPL(led_trigger_blink);
> >
> > +void led_trigger_blink_oneshot(struct led_trigger *trig,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off,
> > + int invert)
> > +{
> > + led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
> > +}
> > +EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
> > +
> > void led_trigger_register_simple(const char *name, struct led_trigger **tp)
> > {
> > struct led_trigger *trig;
> > diff --git a/include/linux/leds.h b/include/linux/leds.h
> > index 5884def..f252438 100644
> > --- a/include/linux/leds.h
> > +++ b/include/linux/leds.h
> > @@ -38,6 +38,9 @@ struct led_classdev {
> > #define LED_SUSPENDED (1 << 0)
> > /* Upper 16 bits reflect control information */
> > #define LED_CORE_SUSPENDRESUME (1 << 16)
> > +#define LED_BLINK_ONESHOT (1 << 17)
> > +#define LED_BLINK_ONESHOT_STOP (1 << 18)
> > +#define LED_BLINK_INVERT (1 << 19)
> >
> > /* Set LED brightness level */
> > /* Must not sleep, use a workqueue if needed */
> > @@ -101,6 +104,24 @@ extern void led_blink_set(struct led_classdev *led_cdev,
> > unsigned long *delay_on,
> > unsigned long *delay_off);
> > /**
> > + * led_blink_set_oneshot - do a oneshot software blink
> > + * @led_cdev: the LED to start blinking
> > + * @delay_on: the time it should be on (in ms)
> > + * @delay_off: the time it should ble off (in ms)
> > + * @invert: blink off, then on, leaving the led on
> > + *
> > + * This function makes the LED blink one time for delay_on +
> > + * delay_off time, ignoring the request if another one-shot
> > + * blink is already in progress.
> > + *
> > + * If invert is set, led blinks for delay_off first, then for
> > + * delay_on and leave the led on after the on-off cycle.
> > + */
> > +extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off,
> > + int invert);
> > +/**
> > * led_brightness_set - set LED brightness
> > * @led_cdev: the LED to set
> > * @brightness: the brightness to set it to
> > @@ -148,6 +169,10 @@ extern void led_trigger_event(struct led_trigger *trigger,
> > extern void led_trigger_blink(struct led_trigger *trigger,
> > unsigned long *delay_on,
> > unsigned long *delay_off);
> > +extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
> > + unsigned long *delay_on,
> > + unsigned long *delay_off,
> > + int invert);
> >
> > #else
> >
>
>
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