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

[Bo Shen]

Hi Heiko,

On 03/17/2015 03:45 PM, Heiko Schocher wrote:
> 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>

Thanks.

>> 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

Yes the uart is not ready. And one more thing, if the clock is not setup 
correctly, then the system will run in abnormal status. So, I remove the 
timeout check here.

Best Regards,
Bo Shen

> 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)
>>
>