[U-Boot] [PATCH 1/4] ARM: atmel: arm926ejs: fix clock configuration

[Heiko Schocher]

Hello Bo,

Am 13.03.2015 10:19, schrieb Bo Shen:
> Config MCKR according to the datasheet sequence, or else it
> will cause the MCKR configuration failed.
>
> Remove timeout checking for clock configuration, if configure
> the clock failed, let the system hang while not run in wrong
> clock configuration.
>
> Signed-off-by: Bo Shen <voice.shen at atmel.com>
> ---
>
>   arch/arm/mach-at91/arm926ejs/clock.c | 54 +++++++++++++++++++-----------------
>   1 file changed, 28 insertions(+), 26 deletions(-)

Tested on the corvus and taurus board.

Tested-by: Heiko Schocher <hs at denx.de>

> diff --git a/arch/arm/mach-at91/arm926ejs/clock.c b/arch/arm/mach-at91/arm926ejs/clock.c
> index f363982..8d6934e 100644
> --- a/arch/arm/mach-at91/arm926ejs/clock.c
> +++ b/arch/arm/mach-at91/arm926ejs/clock.c
> @@ -195,50 +195,52 @@ int at91_clock_init(unsigned long main_clock)
>   void at91_plla_init(u32 pllar)
>   {
>   	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
> -	int timeout = AT91_PLL_LOCK_TIMEOUT;
>
>   	writel(pllar, &pmc->pllar);
> -	while (!(readl(&pmc->sr) & (AT91_PMC_LOCKA | AT91_PMC_MCKRDY))) {
> -		timeout--;
> -		if (timeout == 0)
> -			break;
> -	}
> +	while (!(readl(&pmc->sr) & AT91_PMC_LOCKA))
> +		;

just hanging is maybe also bad ... could we hang with adding a

		if (timeout == 0) {
			debug("could not set PLL(A|B)\n");
			timeout = AT91_PLL_LOCK_TIMEOUT;
		}

Thinking about it ... have we setup here the debug uart already?
If not, forget my comment

bye,
Heiko
>   }
>   void at91_pllb_init(u32 pllbr)
>   {
>   	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
> -	int timeout = AT91_PLL_LOCK_TIMEOUT;
>
>   	writel(pllbr, &pmc->pllbr);
> -	while (!(readl(&pmc->sr) & (AT91_PMC_LOCKB | AT91_PMC_MCKRDY))) {
> -		timeout--;
> -		if (timeout == 0)
> -			break;
> -	}
> +	while (!(readl(&pmc->sr) & AT91_PMC_LOCKB))
> +		;
>   }
>
>   void at91_mck_init(u32 mckr)
>   {
>   	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
> -	int timeout = AT91_PLL_LOCK_TIMEOUT;
>   	u32 tmp;
>
>   	tmp = readl(&pmc->mckr);
> -	tmp &= ~(AT91_PMC_MCKR_PRES_MASK |
> -		 AT91_PMC_MCKR_MDIV_MASK |
> -		 AT91_PMC_MCKR_PLLADIV_MASK |
> -		 AT91_PMC_MCKR_CSS_MASK);
> -	tmp |= mckr & (AT91_PMC_MCKR_PRES_MASK |
> -		       AT91_PMC_MCKR_MDIV_MASK |
> -		       AT91_PMC_MCKR_PLLADIV_MASK |
> -		       AT91_PMC_MCKR_CSS_MASK);
> +	tmp &= ~AT91_PMC_MCKR_PRES_MASK;
> +	tmp |= mckr & AT91_PMC_MCKR_PRES_MASK;
>   	writel(tmp, &pmc->mckr);
> +	while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
> +		;
>
> -	while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY)) {
> -		timeout--;
> -		if (timeout == 0)
> -			break;
> -	}
> +	tmp = readl(&pmc->mckr);
> +	tmp &= ~AT91_PMC_MCKR_MDIV_MASK;
> +	tmp |= mckr & AT91_PMC_MCKR_MDIV_MASK;
> +	writel(tmp, &pmc->mckr);
> +	while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
> +		;
> +
> +	tmp = readl(&pmc->mckr);
> +	tmp &= ~AT91_PMC_MCKR_PLLADIV_MASK;
> +	tmp |= mckr & AT91_PMC_MCKR_PLLADIV_MASK;
> +	writel(tmp, &pmc->mckr);
> +	while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
> +		;
> +
> +	tmp = readl(&pmc->mckr);
> +	tmp &= ~AT91_PMC_MCKR_CSS_MASK;
> +	tmp |= mckr & AT91_PMC_MCKR_CSS_MASK;
> +	writel(tmp, &pmc->mckr);
> +	while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
> +		;
>   }
>
>   void at91_periph_clk_enable(int id)
>

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