linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: "Jernej Škrabec" <jernej.skrabec@siol.net>
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>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Samuel Holland <samuel@sholland.org>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Samuel Holland <samuel@sholland.org>
Subject: Re: [PATCH 4/5] arm64: dts: allwinner: Add sun4i MMIO timer nodes
Date: Mon, 15 Mar 2021 19:32:20 +0100	[thread overview]
Message-ID: <1897259.uecf0MpyRy@jernej-laptop> (raw)
In-Reply-To: <20210315043250.45095-5-samuel@sholland.org>

Hi!

Dne ponedeljek, 15. marec 2021 ob 05:32:49 CET je Samuel Holland napisal(a):
> 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@sholland.org>
> ---
>  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

This file does not exist yet upstream.

Best regards,
Jernej

> @@ -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";





_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-03-15 18:34 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-15  4:32 [PATCH 0/5] arm64: sunxi: Enable the sun4i timer Samuel Holland
2021-03-15  4:32 ` [PATCH 1/5] dt-bindings: timer: Simplify conditional expressions Samuel Holland
2021-03-15 10:57   ` Maxime Ripard
2021-03-15  4:32 ` [PATCH 2/5] dt-bindings: timer: Add compatibles for sun50i timers Samuel Holland
2021-03-15 11:07   ` Maxime Ripard
2021-03-15  4:32 ` [PATCH 3/5] arm64: dts: allwinner: a64: Sort watchdog node Samuel Holland
2021-03-15  4:32 ` [PATCH 4/5] arm64: dts: allwinner: Add sun4i MMIO timer nodes Samuel Holland
2021-03-15 18:32   ` Jernej Škrabec [this message]
2021-03-16  4:35     ` Samuel Holland
2021-03-15  4:32 ` [PATCH 5/5] arm64: sunxi: Build the sun4i timer driver Samuel Holland

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=1897259.uecf0MpyRy@jernej-laptop \
    --to=jernej.skrabec@siol.net \
    --cc=catalin.marinas@arm.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=devicetree@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mripard@kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=samuel@sholland.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).