[U-Boot] [PATCH v2] timer: add High Precision Event Timers (HPET) support

[Andy Shevchenko]

On Fri, Mar 30, 2018 at 1:29 AM, Ivan Gorinov <ivan.gorinov at intel.com> wrote:
> Adding HPET as an alternative timer for x86 (default is TSC).
> HPET counter has constant frequency and does not need calibration.
> This change also makes TSC timer driver optional on x86.
> If X86_TSC is disabled, early timer functions are provided by HPET.
>
> Signed-off-by: Ivan Gorinov <ivan.gorinov at intel.com>
> ---

Changelog?

>  arch/Kconfig               |   2 +-

> +config HPET_TIMER
> +       bool "High Precision Event Timers (HPET) support"
> +       depends on TIMER && X86

Does X86 makes any difference from building point of view?

> +       config = readl(regs + HPET_CONFIG_REG);
> +       config &= ~1;
> +       writel(config, regs + HPET_CONFIG_REG);

1  or BIT(0) is magic. Can be fixed in all places?

> +       writel(0, regs + HPET_MAIN_COUNT_L);
> +       writel(0, regs + HPET_MAIN_COUNT_H);

Can we use writeq() here?

> +               tl = readl(regs + HPET_MAIN_COUNT_L);
> +               th = readl(regs + HPET_MAIN_COUNT_H);

Ditto.

-- 
With Best Regards,
Andy Shevchenko