From: Samuel Holland <samuel@sholland.org>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Rob Herring <robh+dt@kernel.org>,
Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org,
Samuel Holland <samuel@sholland.org>
Subject: [PATCH v2 4/5] arm64: dts: allwinner: Add sun4i MMIO timer nodes
Date: Sun, 21 Mar 2021 23:47:06 -0500 [thread overview]
Message-ID: <20210322044707.19479-5-samuel@sholland.org> (raw)
In-Reply-To: <20210322044707.19479-1-samuel@sholland.org>
For a CPU to enter an idle state, some timer must be available to
trigger an IRQ and wake it back up. The local ARM architectural timer is
not sufficient, because that timer stops when the CPU is powered down.
The ARM architectural timer from some other CPU can be used, but doing
so prevents that other CPU from entering an idle state. For all CPUs to
power down at the same time, Linux needs a timer which is not tied to
any CPU.
Hook up the "sun4i" timer so it can be used for this purpose. It runs at
24 MHz, which balances resolution and power consumption.
Signed-off-by: Samuel Holland <samuel@sholland.org>
---
arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 9 +++++++++
arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi | 9 +++++++++
2 files changed, 18 insertions(+)
diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
index 9cac88576975..c89032dfb316 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
@@ -798,6 +798,15 @@ 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 49e979794094..01884b32390d 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
@@ -271,6 +271,15 @@ 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";
--
2.26.2
next prev parent reply other threads:[~2021-03-22 4:47 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 4:47 [PATCH v2 0/5] arm64: sunxi: Enable the sun4i timer Samuel Holland
2021-03-22 4:47 ` [PATCH v2 1/5] dt-bindings: timer: Simplify conditional expressions Samuel Holland
2021-03-27 16:44 ` Rob Herring
2021-03-22 4:47 ` [PATCH v2 2/5] dt-bindings: timer: Add compatibles for sun50i timers Samuel Holland
2021-03-27 16:46 ` Rob Herring
2021-03-22 4:47 ` [PATCH v2 3/5] arm64: dts: allwinner: a64: Sort watchdog node Samuel Holland
2021-03-22 4:47 ` Samuel Holland [this message]
2021-03-22 4:47 ` [PATCH v2 5/5] arm64: sunxi: Build the sun4i timer driver Samuel Holland
2021-03-22 14:18 ` [PATCH v2 0/5] arm64: sunxi: Enable the sun4i timer Daniel Lezcano
2021-03-24 3:51 ` Samuel Holland
2021-03-24 9:33 ` Daniel Lezcano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210322044707.19479-5-samuel@sholland.org \
--to=samuel@sholland.org \
--cc=catalin.marinas@arm.com \
--cc=daniel.lezcano@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=jernej.skrabec@siol.net \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sunxi@lists.linux.dev \
--cc=mripard@kernel.org \
--cc=robh+dt@kernel.org \
--cc=tglx@linutronix.de \
--cc=wens@csie.org \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).