TIMER
Update time：2018-04-13 Views：2818
Introduction
Timer is a programmable timer peripheral. This component is an APB slave device. In RK3399 there are 12 Timers(timer0~timer11), 12 Secure Timers(stimer0~stimer11) in ALIVE and 2 Timers(pmutimer0~pmutimer1) in PMU. We use the Timers(timer0-timer11) clock is 24MHZ and Timer mode selection have free-running and user-defined count
Timer Usage Flow
Timer mode selection
User-defined count mode :Timer loads TIMERn_LOAD_COUNT3 and TIMERn_ LOAD_COUNT2 as initial value. When the timer counts up to the value in TIMERn_LOAD_COUNT1 and TIMERn_LOAD_COUNT0, it will not automatically reload the count register. User need to disable timer firstly and follow the programming sequence to make timer work again.
Free-running mode Timer loads the TIMERn_LOAD_COUNT3 and TIMERn_LOAD_COUNT2 register as initial value. Timer will automatically reload the count register, when timer counts up to the value in TIMERn_LOAD_COUNT1 and TIMERn_LOAD_COUNT0.
Software config
1.Defined the config in the dts file kernel/arch/arm64/boot/dts/rockchip/rk3399.dtsi
rktimer: rktimer@ff850000 {
compatible = "rockchip,rk3399-timer";
reg = <0x0 0xff850000 0x0 0x1000>;
interrupts = <GIC_SPI 81 IRQ_TYPE_LEVEL_HIGH 0>;
clocks = <&cru PCLK_TIMER0>, <&cru SCLK_TIMER00>;
clock-names = "pclk", "timer";
};It is defined the register and Interrupt and clock so on
Other Timer interrupt num can see follow picture
2.The driver file Kernel/drivers/clocksource/rockchip_timer.c
Register and usage
1.Register picture
2.Usage Check the register value
root@rk3399_firefly_box:/ # io -4 0xff85001c //Control Register Value ff85001c: 00000007 root@rk3399_firefly_box:/ # io -4 0xff850000 //Register Count Value ff850000: 0001639f
Control count register
root@rk3399_firefly_box:/ # io -4 -w 0xff85001c 0x06 //Disable Timer
