Re: [PATCH v6 2/2] leds: rt5033: Add RT5033 Flash led device driver

[Jacek Anaszewski]

Hi Ingi,

On 11/30/2015 03:31 AM, Ingi Kim wrote:
> Hi Jacek,
>
> On 2015ë 11ì 26ì 18:43, Jacek Anaszewski wrote:
> > Hi Ingi,
> >
> > On 11/26/2015 09:02 AM, Ingi Kim wrote:
> > [...]
> > > > > +torch_unlock:
> > > > > +    mutex_unlock(&led->lock);
> > > > > +    return ret;
> > > > > +}
> > > > > +
> > > > > +static int rt5033_led_flash_brightness_set(struct led_classdev_flash *fled_cdev,
> > > > > +                       u32 brightness)
> > > > > +{
> > > > > +    struct rt5033_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
> > > > > +    struct rt5033_led *led = sub_led_to_led(sub_led);
> > > > > +
> > > > > +    mutex_lock(&led->lock);
> > > > > +    sub_led->flash_brightness = brightness;
> > > > > +    mutex_unlock(&led->lock);
> > > >
> > > > Mutex protection is redundant in this case. You would need it if device
> > > > state was also changed here.
> > >
> > > Okay, I'll remove it.
> > >
> > > > BTW why flash brightness can't be written to the device here?
> > >
> > > Flash brightness is only affected when FLED flashed (strobing).
> > > So, I think it is better to be written in rt5033_led_flash_strobe_set function.
> >
> > strobe_set op should strobe the flash ASAP, and delegating brightness
> > setting there extends a delay between calling strobe_set op
> > and actual flash strobe. If you set the brightness here, then you
> > wouldn't have to do that in the strobe_set op, of course unless the
> > the brightness is altered through the API of the other LED, in two
> > separate LEDs case.
>
> The brightness may be able to change its brightness in two separate LEDs case as you see.
> So, I think it would be better to write brightness setting in strobe_op.

Could you motivate your statement, please? Why would it be better?

> In consideration of delay, of course, the brightness is set just when it would be changed.

I think that joint iout arrangement will be prevailing - this is the
case for your board, isn't it? With the modification I am proposing
the gain is clear.

> > > > > +
> > > > > +    return 0;
> > > > > +}
> > > > > +
> > > > > +static int rt5033_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
> > > > > +                    u32 timeout)
> > > > > +{
> > > > > +    struct rt5033_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
> > > > > +    struct rt5033_led *led = sub_led_to_led(sub_led);
> > > > > +
> > > > > +    mutex_lock(&led->lock);
> > > > > +    sub_led->flash_timeout = timeout;
> > > > > +    mutex_unlock(&led->lock);
> > > >
> > > > Ditto.
> >
> > Timeout should be also written here.
>
> The timeout may be able to change its flash timeout in two separate LEDs case as you see.
> So, I think it would be better to write timeout setting in strobe_op.
> In consideration of delay, of course, the timeout is set just when it would be changed.
>
> > If you will add regmap_write in both ops, then mutex protection will
> > have to be preserved, to assure consistency between registers state
> > and sub_led->flash_brightness and sub_led->flash_timeout state.
>
> Thanks, but mutex protection is useless in this case.
> so I try to remove it.
>
> > > > > +#define RT5033_FLED_CTRL4_VTRREG_MAX    0x60
> > > >
> > > > Rename DEF to MASK.
> >
> > Hmm, here it should be: Rename MAX to MASK.
>
> Oh
> Okay, Thanks :)


--
Best Regards,
Jacek Anaszewski
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