Re: [PATCH 2/2] gpiolib: introduce gpio_set_deglitch

[Jean-Christophe PLAGNIOL-VILLARD]

On 16:14 Fri 25 Nov     , Felipe Balbi wrote:
> Hi,
> 
> On Fri, Nov 25, 2011 at 03:08:40PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > this will allow to manage the Glitch Input Filter
> > as present on AT91 as example
> > 
> > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx>
> > Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
> > Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> > ---
> >  drivers/gpio/gpiolib.c     |   44 ++++++++++++++++++++++++++++++++++++++++++++
> >  include/asm-generic/gpio.h |    4 ++++
> >  include/linux/gpio.h       |    5 +++++
> >  3 files changed, 53 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> > index b7e5e75..d2b1833 100644
> > --- a/drivers/gpio/gpiolib.c
> > +++ b/drivers/gpio/gpiolib.c
> > @@ -1563,6 +1563,50 @@ fail:
> >  }
> >  EXPORT_SYMBOL_GPL(gpio_set_pullup);
> >  
> > +/**
> > + * gpio_set_deglitch - sets @deglitch for a @gpio
> > + * @gpio: the gpio to set deglitch
> > + * @deglitch: deglitch level
> > + */
> > +int gpio_set_deglitch(unsigned gpio, unsigned deglitch)
> 
> sounds a lot like debounce, what's the difference ?
deglitch allow you to filter the fact that the line take time to be stable
go to 1 and 0

debounce will set 2 different threshold for changing the state from 0 to 1 and
invertly

Best Regards,
J.
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