Hi, all: ATCPIT100 is often used on the Andes architecture, This timer provide 4 PIT channels. Each PIT channel is a multi-function timer, can be configured as 32,16,8 bit timers or PWM as well.
For system timer it will set channel 1 32-bit timer0 as clock source and count downwards until underflow and restart again. It also set channel 0 32-bit timer0 as clock event and count downwards until condition match. It will generate an interrupt for handling periodically. Changes in v7: - Fix atcpit100_clkevt_next_event(), before set reload register, clock source timer shall disable. And re-enable it after the setting. Without this modification, the test case 'clock_nanosleep02' of ltp_20170929 will fail. Changes in v6: - To select TIMER_OF in drivers/clocksource/Kconfig instead of arch/nds32/Kconfig - Refine Kconfig - Update license format to SPDX-License-Identifier Rick Chen (3): clocksource/drivers/atcpit100: Add andestech atcpit100 timer clocksource/drivers/atcpit100: VDSO support dt-bindings: timer: Add andestech atcpit100 timer binding doc .../bindings/timer/andestech,atcpit100-timer.txt | 33 +++ drivers/clocksource/Kconfig | 9 + drivers/clocksource/Makefile | 1 + drivers/clocksource/timer-atcpit100.c | 266 +++++++++++++++++++++ 4 files changed, 309 insertions(+) create mode 100644 Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt create mode 100644 drivers/clocksource/timer-atcpit100.c -- 2.16.1
