Re: [PATCH v2 5/6] ARM: AM43xx: clk: Change the cpts ref clock source to dpll_core_m5 clk

[Tero Kristo <t-kristo-l0cyMroinI0@public.gmane.org>]

On 05/02/2014 09:32 AM, George Cherian wrote:
> cpsw_cpts_rft_clk has got the choice of 3 clocksources
>   -dpll_core_m4_ck
>   -dpll_core_m5_ck
>   -dpll_disp_m2_ck
>
> By default dpll_core_m4_ck is selected, witn this as clock
> source the CPTS doesnot work properly. It gives clockcheck errors
> while running PTP.
>
>   clockcheck: clock jumped backward or running slower than expected!
>
> By selecting dpll_core_m5_ck as the clocksource fixes this issue.
> In AM335x dpll_core_m5_ck is the default clocksource.
>
> Signed-off-by: George Cherian <george.cherian-l0cyMroinI0@public.gmane.org>

Acked-by: Tero Kristo <t-kristo-l0cyMroinI0@public.gmane.org>

> ---
>   drivers/clk/ti/clk-43xx.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
>
> diff --git a/drivers/clk/ti/clk-43xx.c b/drivers/clk/ti/clk-43xx.c
> index 67c8de5..b4877e0 100644
> --- a/drivers/clk/ti/clk-43xx.c
> +++ b/drivers/clk/ti/clk-43xx.c
> @@ -110,9 +110,25 @@ static struct ti_dt_clk am43xx_clks[] = {
>
>   int __init am43xx_dt_clk_init(void)
>   {
> +	struct clk *clk1, *clk2;
> +
>   	ti_dt_clocks_register(am43xx_clks);
>
>   	omap2_clk_disable_autoidle_all();
>
> +	/*
> +	 * cpsw_cpts_rft_clk  has got the choice of 3 clocksources
> +	 * dpll_core_m4_ck, dpll_core_m5_ck and dpll_disp_m2_ck.
> +	 * By default dpll_core_m4_ck is selected, witn this as clock
> +	 * source the CPTS doesnot work properly. It gives clockcheck errors
> +	 * while running PTP.
> +	 * clockcheck: clock jumped backward or running slower than expected!
> +	 * By selecting dpll_core_m5_ck as the clocksource fixes this issue.
> +	 * In AM335x dpll_core_m5_ck is the default clocksource.
> +	 */
> +	clk1 = clk_get_sys(NULL, "cpsw_cpts_rft_clk");
> +	clk2 = clk_get_sys(NULL, "dpll_core_m5_ck");
> +	clk_set_parent(clk1, clk2);
> +
>   	return 0;
>   }
>

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