Hi, On 29 March 2018 at 18:52, Andy Shevchenko <[email protected]> wrote: > On Wed, 2018-03-28 at 17:58 -0700, Ivan Gorinov wrote: >> Adding HPET as an alternative timer for x86 (default is TSC). >> HPET main counter has constant clock frequency, calibration is not >> required. >> This change also makes TSC timer driver optional on x86 platforms. >> If X86_TSC is disabled, early timer functions are provided by HPET. >> >> HPET can be selected as the tick timer in the Device Tree "chosen" >> node: >> >> /include/ "hpet.dtsi" >> >> chosen { >> tick-timer = "/hpet0"; >> }; >> > > > First question is how this will work in case of Broadwell and Ivybridge > that have something to do with HPET in their CPU code, i.e. > > arch/x86/cpu/broadwell/pch.c > arch/x86/cpu/ivybridge/lpc.c > > ? > > Look for > > clrsetbits_le32(RCB_REG(HPTC), 3, 1 << 7); > >> +static int hpet_timer_get_count(struct udevice *dev, u64 *count) > >> +static int hpet_timer_probe(struct udevice *dev) > >> +#ifndef CONFIG_X86_TSC_TIMER > >> +#define EARLY_HPET_BASE 0xfed00000 > > HPET address is fixed, AFAIU, on x86, and provided by config option in > U-Boot. > >> +unsigned long notrace timer_early_get_rate(void) > >> +u64 notrace timer_early_get_count(void) > >> +int timer_init(void) > > These functions have too much code duplication with above.
Perhaps that code can be removed in favour of this driver? I am happy to test on these platforms if it helps. Regards, Simon _______________________________________________ U-Boot mailing list [email protected] https://lists.denx.de/listinfo/u-boot
