Hi,
On 8 April 2018 at 19:22, Bin Meng bmeng.cn@gmail.com wrote:
Hi Ivan,
On Sat, Apr 7, 2018 at 3:18 AM, Ivan Gorinov ivan.gorinov@intel.com wrote:
Add HPET driver 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. New HPET driver can also be selected as the early timer on x86.
HPET can be selected as the tick timer in the Device Tree "chosen" node:
/include/ "hpet.dtsi"...
chosen { tick-timer = "/hpet"; };Signed-off-by: Ivan Gorinov ivan.gorinov@intel.com
arch/Kconfig | 2 +- arch/x86/Kconfig | 21 ++++++ arch/x86/dts/hpet.dtsi | 7 ++ drivers/timer/Kconfig | 9 +++ drivers/timer/Makefile | 1 + drivers/timer/hpet_timer.c | 179 +++++++++++++++++++++++++++++++++++++++++++++ drivers/timer/tsc_timer.c | 8 ++ 7 files changed, 226 insertions(+), 1 deletion(-) create mode 100644 arch/x86/dts/hpet.dtsi create mode 100644 drivers/timer/hpet_timer.c
[..]
diff --git a/drivers/timer/tsc_timer.c b/drivers/timer/tsc_timer.c index 9296de6..bd0e75c 100644 --- a/drivers/timer/tsc_timer.c +++ b/drivers/timer/tsc_timer.c @@ -277,6 +277,8 @@ success: return delta / 1000; }
+#ifdef CONFIG_X86_EARLY_TIMER_TSC
Why do we surround the following APIs with CONFIG_X86_EARLY_TIMER_TSC? These APIs are generic U-Boot timer APIs. If we select CONFIG_X86_EARLY_TIMER_HPET, these APIs are not available and will cause build error.
Simon, do you think we should fix such in the timer uclass driver?
We should not have arch-specific code in the uclass, or in any generic driver.
Regards, Simon