[U-Boot] [PATCH v5 4/5] mips: ath79: add spi driver

[Wills Wang]

On 12/29/2015 09:00 PM, Thomas Chou wrote:
> Hi Wills,
>
> On 2015年12月29日 19:17, Wills Wang wrote:
>> diff --git a/arch/mips/mach-ath79/Kconfig b/arch/mips/mach-ath79/Kconfig
>> index 1d92a5b..b5668e9 100644
>> --- a/arch/mips/mach-ath79/Kconfig
>> +++ b/arch/mips/mach-ath79/Kconfig
>> @@ -15,6 +15,7 @@ config SOC_AR933X
>>       select SYS_MIPS_CACHE_INIT_RAM_LOAD
>>       select MIPS_TUNE_24KC
>>       select AR933X_UART
>> +    select ATH79_SPI
>
> Both AR933X_UART and ATH79_SPI should not be selected with mach 
> Kconfig. They should go with board defconfig.
>
Ok.
>> diff --git a/drivers/spi/ath79_spi.c b/drivers/spi/ath79_spi.c
>
>> +static inline void ath79_spi_delay(int max_hz)
>> +{
>> +    uint64_t tick = get_tbclk();
>> +
>> +    do_div(tick, max_hz);
>> +    tick = get_ticks() + tick + 1;    /* get current timestamp */
>> +    while (get_ticks() < tick)    /* loop till event */
>> +         /*NOP*/;
>> +}
>
> Use udelay() instead.
>
The minimum interval is 1usec if using udelay(), the max speed of SPI 
was really limited to 1MHz.
> Best regards,
> Thomas
>

-- 
Best Regards
Wills