Re: [PATCH] leds: triggers: add invert to heartbeat

[JiÅÃ Prchal]

Hi Jacek,
comments below...

On 7.10.2015 15:32, Jacek Anaszewski wrote:
> Hi Jiri,
>
> Thanks for the patch. It's nice in general, but please see my
> comments below.
>
> On 10/07/2015 11:31 AM, Jiri Prchal wrote:
> > This patcht adds possibility to invert heartbeat blinking. The inverted LED is
> > more time ON then OFF.
> > It's because it looks better when the heartbeat LED is next to other LED which
> > is most time ON.
> > The invert value is exported same way via sysfs in file invert like oneshot. I
> > get inspiration from this trigger.
>
> Please adjust commit message so as it wouldn't exceed 75 characters line
> length limit. scripts/checkpatch.pl is useful for  catching this kind of
> problems.
>
> > Signed-off-by: Jiri Prchal <jiri.prchal@xxxxxxxxxxx>
> > ---
> >   drivers/leds/trigger/ledtrig-heartbeat.c | 49 ++++++++++++++++++++++++++++++--
> >   1 file changed, 47 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/leds/trigger/ledtrig-heartbeat.c b/drivers/leds/trigger/ledtrig-heartbeat.c
> > index fea6871..c09c30b 100644
> > --- a/drivers/leds/trigger/ledtrig-heartbeat.c
> > +++ b/drivers/leds/trigger/ledtrig-heartbeat.c
> > @@ -27,6 +27,7 @@ struct heartbeat_trig_data {
> >       unsigned int phase;
> >       unsigned int period;
> >       struct timer_list timer;
> > +    unsigned int invert;
> >   };
> >
> >   static void led_heartbeat_function(unsigned long data)
> > @@ -56,21 +57,27 @@ static void led_heartbeat_function(unsigned long data)
> >               msecs_to_jiffies(heartbeat_data->period);
> >           delay = msecs_to_jiffies(70);
> >           heartbeat_data->phase++;
> > -        brightness = led_cdev->max_brightness;
> > +        if (!heartbeat_data->invert)
> > +            brightness = led_cdev->max_brightness;
> >           break;
> >       case 1:
> >           delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
> >           heartbeat_data->phase++;
> > +        if (heartbeat_data->invert)
> > +            brightness = led_cdev->max_brightness;
>
> As you are at it, could you change, in a separate patch,
> led_cdev->max_brightness to led_cdev->brightness? I think there is no
> reason for which we shouldn't allow other values than max.
I changed it but it doesn't blink at all.

> >           break;
> >       case 2:
> >           delay = msecs_to_jiffies(70);
> >           heartbeat_data->phase++;
> > -        brightness = led_cdev->max_brightness;
> > +        if (!heartbeat_data->invert)
> > +            brightness = led_cdev->max_brightness;
> >           break;
> >       default:
> >           delay = heartbeat_data->period - heartbeat_data->period / 4 -
> >               msecs_to_jiffies(70);
> >           heartbeat_data->phase = 0;
> > +        if (heartbeat_data->invert)
> > +            brightness = led_cdev->max_brightness;
> >           break;
> >       }
> >
> > @@ -78,15 +85,50 @@ static void led_heartbeat_function(unsigned long data)
> >       mod_timer(&heartbeat_data->timer, jiffies + delay);
> >   }
> >
> > +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 heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
> > +
> > +    return sprintf(buf, "%u\n", heartbeat_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 heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
> > +    unsigned long state;
> > +    int ret;
> > +
> > +    ret = kstrtoul(buf, 0, &state);
> > +    if (ret)
> > +        return ret;
> > +
> > +    heartbeat_data->invert = !!state;
> > +
> > +    return size;
> > +}
> > +
> > +static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
> > +
> >   static void heartbeat_trig_activate(struct led_classdev *led_cdev)
> >   {
> >       struct heartbeat_trig_data *heartbeat_data;
> > +    int rc;
> >
> >       heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
> >       if (!heartbeat_data)
> >           return;
> >
> >       led_cdev->trigger_data = heartbeat_data;
> > +    rc = device_create_file(led_cdev->dev, &dev_attr_invert);
> > +    if (rc) {
> > +        kfree(led_cdev->trigger_data);
> > +        return;
> > +    }
> > +
> >       setup_timer(&heartbeat_data->timer,
> >               led_heartbeat_function, (unsigned long) led_cdev);
> >       heartbeat_data->phase = 0;
> > @@ -100,9 +142,12 @@ static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
> >
> >       if (led_cdev->activated) {
> >           del_timer_sync(&heartbeat_data->timer);
> > +        device_remove_file(led_cdev->dev, &dev_attr_invert);
> >           kfree(heartbeat_data);
> >           led_cdev->activated = false;
> >       }
> > +
> > +    led_set_brightness(led_cdev, LED_OFF);
>
> I believe this is a fix. Could you split it into a separate patch
> and explain its merit?
I'm not sure of necessity of it, I copied it from oneshot.
Without it could leave LED in ON state. But never happens to me.
Should I produce separate patch to discuss it in separate thread?

> >   }
> >
> >   static struct led_trigger heartbeat_led_trigger = {
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