Subject: [PATCH v4 02/20] clocksource: samsung_pwm_timer: Correct definition of AUTORELOAD bit

From: [email-masked] (Tomasz Figa)
Date: Mon, 22 Jul 2013 09:43:23 +0200

On Monday 22 of July 2013 05:50:09 Daniel Lezcano wrote:
> On 07/20/2013 02:04 AM, Tomasz Figa wrote:
> > PWM channel 4 has its autoreload bit located at different position.
> > This patch fixes the driver to account for that.
> > 
> > This fixes a problem with the clocksource hanging after it overflows
> > because it is not reloaded any more.
> > 
> > Signed-off-by: Tomasz Figa <[email-masked]>
> > ---
> > 
> >  drivers/clocksource/samsung_pwm_timer.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clocksource/samsung_pwm_timer.c
> > b/drivers/clocksource/samsung_pwm_timer.c index 3fa5b07..e238fb0
> > 100644
> > --- a/drivers/clocksource/samsung_pwm_timer.c
> > +++ b/drivers/clocksource/samsung_pwm_timer.c
> > @@ -47,7 +47,8 @@
> > 
> >  #define TCON_START(chan)		(1 << (4 * (chan) + 0))
> >  #define TCON_MANUALUPDATE(chan)		(1 << (4 * (chan) + 1))
> >  #define TCON_INVERT(chan)		(1 << (4 * (chan) + 2))
> > 
> > -#define TCON_AUTORELOAD(chan)		(1 << (4 * (chan) + 3))
> > +#define TCON_AUTORELOAD(chan)		(1 << (4 * (chan) \
> > +						+ (((chan) < 5) ? 3 : 2)))
> 
> This macro is not readable. Please, fix it up with a comment please.

/*
 * Channel 4 (logically 5 in TCON register) has different position
 * of autoreload bit.
 */
#define _TCON_AUTORELOAD(chan)			(1 << (4 * (chan) + 3))
#define _TCON_AUTORELOAD4(chan)			(1 << (4 * (chan) + 2))
#define TCON_AUTORELOAD(chan)			((chan < 5) ? 
		_TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan))

What do you think?

Best regards,
Tomasz