For a CPU to enter an idle state, there must be some timer which can
trigger an IRQ to wake it back up. The local ARM architectural timer is
not sufficient, because that timer stops when the CPU is powered down.
Some other CPU's ARM architectural timer can be used, but this prevents
that other CPU from entering an idle state. So to allow all CPUs to
enter an idle state at the same time, some MMIO timer must be available
that is not tied to any CPU.
The basic "sun4i" timer seems most appropriate for this purpose due to
its moderate rate, balancing precision and power consumption.
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---
arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 9 +++++++++
arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi | 9 +++++++++
arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi | 9 +++++++++
3 files changed, 27 insertions(+)
diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
index 33df866f6ea9..64e8b4a372cc 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
@@ -905,6 +905,15 @@ uart4_rts_cts_pins: uart4-rts-cts-pins {
};
};
+ timer@1c20c00 {
+ compatible = "allwinner,sun50i-a64-timer",
+ "allwinner,sun8i-a23-timer";
+ reg = <0x01c20c00 0xa0>;
+ interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 19 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&osc24M>;
+ };
+
wdt0: watchdog@1c20ca0 {
compatible = "allwinner,sun50i-a64-wdt",
"allwinner,sun6i-a31-wdt";
diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
index 62334054c710..9ba3b30e11fa 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
@@ -332,6 +332,15 @@ cpu_speed_grade: cpu-speed-grade@1c {
};
};
+ timer@3009000 {
+ compatible = "allwinner,sun50i-h6-timer",
+ "allwinner,sun8i-a23-timer";
+ reg = <0x03009000 0xa0>;
+ interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&osc24M>;
+ };
+
watchdog: watchdog@30090a0 {
compatible = "allwinner,sun50i-h6-wdt",
"allwinner,sun6i-a31-wdt";
diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi
index c277b53f94ea..ff55712ce96e 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi
@@ -128,6 +128,15 @@ ccu: clock@3001000 {
#reset-cells = <1>;
};
+ timer@3009000 {
+ compatible = "allwinner,sun50i-h616-timer",
+ "allwinner,sun8i-a23-timer";
+ reg = <0x03009000 0xa0>;
+ interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&osc24M>;
+ };
+
watchdog: watchdog@30090a0 {
compatible = "allwinner,sun50i-h616-wdt",
"allwinner,sun6i-a31-wdt";
--
2.26.2
