[PATCH 1/1] ARM: mxc: change timer clock to perclk

[Sascha Hauer]

On Tue, May 15, 2012 at 03:34:40PM +0800, Richard Zhao wrote:
> fix system time goes too fast.
> perclk rate not changed or gated in low power mode, so we
> choose perclk for gpt.

On which systems did you test this?

It seems I fixed the timer clock handling in a way that the gpt timer
now gets both of its two clocks. Now we have two clocks, but the TCTL
register setting does not match the clock on which we do a clk_get_rate
anymore. Your patch fixes this, but not by changing the clk_get_rate
back to the old clock, but instead by switching the hardware to use the
other clock.

Your patch seems to do the right thing, but we should be a bit more
verbose about it in the commit log.

Sascha


> 
> Signed-off-by: Richard Zhao <richard.zhao at freescale.com>
> ---
>  arch/arm/plat-mxc/time.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
> index 99f958c..d865f79 100644
> --- a/arch/arm/plat-mxc/time.c
> +++ b/arch/arm/plat-mxc/time.c
> @@ -58,6 +58,7 @@
>  /* MX31, MX35, MX25, MX5 */
>  #define V2_TCTL_WAITEN		(1 << 3) /* Wait enable mode */
>  #define V2_TCTL_CLK_IPG		(1 << 6)
> +#define V2_TCTL_CLK_PER		(2 << 6)
>  #define V2_TCTL_FRR		(1 << 9)
>  #define V2_IR			0x0c
>  #define V2_TSTAT		0x08
> @@ -309,7 +310,7 @@ void __init mxc_timer_init(struct clk *timer_clk, void __iomem *base, int irq)
>  	__raw_writel(0, timer_base + MXC_TPRER); /* see datasheet note */
>  
>  	if (timer_is_v2())
> -		tctl_val = V2_TCTL_CLK_IPG | V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
> +		tctl_val = V2_TCTL_CLK_PER | V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
>  	else
>  		tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
>  
> -- 
> 1.7.5.4
> 
> 
> 

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