Re: [PATCH v6 02/20] clocksource: samsung_pwm_timer: Correct definition of AUTORELOAD bit

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 07/24/2013 01:32 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 <tomasz.figa@gmail.com>
> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> ---

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>


>  drivers/clocksource/samsung_pwm_timer.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> Changes since v5:
>  - Added more detailed comment about bit layout in TCON register.
> 
> diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c
> index 3fa5b07..5d0049f 100644
> --- a/drivers/clocksource/samsung_pwm_timer.c
> +++ b/drivers/clocksource/samsung_pwm_timer.c
> @@ -44,10 +44,21 @@
>  #define TCFG1_SHIFT(x)	  		((x) * 4)
>  #define TCFG1_MUX_MASK	  		0xf
>  
> +/*
> + * Each channel occupies 4 bits in TCON register, but there is a gap of 4
> + * bits (one channel) after channel 0, so channels have different numbering
> + * when accessing TCON register.
> + *
> + * In addition, the location of autoreload bit for channel 4 (TCON channel 5)
> + * in its set of bits is 2 as opposed to 3 for other channels.
> + */
>  #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) + 3))
> +#define _TCON_AUTORELOAD4(chan)		(1 << (4 * (chan) + 2))
> +#define TCON_AUTORELOAD(chan)		\
> +	((chan < 5) ? _TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan))
>  
>  DEFINE_SPINLOCK(samsung_pwm_lock);
>  EXPORT_SYMBOL(samsung_pwm_lock);
> 


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