From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 465FB1C5D77 for ; Mon, 13 Jan 2025 16:09:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736784586; cv=none; b=rqrXACTI9KP4/nT2tD7m91h+Ka9AHXdF/Trohc8x94BjLHMAkE27QxGWZOE6S7gjQHzWZNLe/ECib+L8u4V2R2h0EQYCMMiXdLYN1zP30j0wxgv/PKOekjz4f+FXy0E/ljZVEwq60YPPOJd7Kv5h8nA5b7CdgZ3/QPkydkq+Fx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736784586; c=relaxed/simple; bh=Pm+KD02tcADamsCS0wc/Gp4EUipnsdSbq3MH4JwZ0Zk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=S/0/MpNoRYY2BE4lRTVcZ4MSKwiaeDs/rxZpHCH6FhwQUovQivYY2R6TjXf2LvNsTHon6BS+a4GhZrvvyp2hyNGiYnC9/Wi1xfp1zstt6nMlfTmzy+AiMrb9Eb7QqxFl43wgrCmCOZcTV2PC7eSOt5mQNwSCuMiFIs8LC7S7i8o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1tXN0C-0007mJ-8O; Mon, 13 Jan 2025 17:09:20 +0100 Message-ID: <45bbdacc-6683-43df-b7ff-d3bd09842f65@pengutronix.de> Date: Mon, 13 Jan 2025 17:09:19 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/6] dt-bindings: clock: imx8m: document nominal/overdrive properties To: Frank Li Cc: Abel Vesa , Peng Fan , Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Abel Vesa , Marek Vasut , linux-clk@vger.kernel.org, imx@lists.linux.dev, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20250113-imx8m-clk-v3-0-0d6e9bdeaa4e@pengutronix.de> <20250113-imx8m-clk-v3-1-0d6e9bdeaa4e@pengutronix.de> Content-Language: en-US From: Ahmad Fatoum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org On 13.01.25 16:58, Frank Li wrote: > On Mon, Jan 13, 2025 at 02:42:51PM +0100, Ahmad Fatoum wrote: >> The imx8m-clock.yaml binding covers the clock controller inside all >> of the i.MX8M Q/M/N/P SoCs. All of them have in common that they >> support two operating modes: nominal and overdrive mode. >> >> While the overdrive mode allows for higher frequencies for many IPs, >> the nominal mode needs a lower SoC voltage, thereby reducing >> heat generation and power usage. >> >> As increasing clock rates beyond the maximum permitted by the supplied >> SoC voltage can lead to difficult to debug issues, device tree consumers >> would benefit from knowing what mode is active to enforce the clock rate >> limits that come with it. >> >> To facilitate this, extend the clock controller bindings with an >> optional fsl,operating-mode property. This intentionally allows the >> absence of the property, because there is no default suitable for all >> boards: >> >> For i.MX8M Mini and Nano, the kernel SoC DTSIs has assigned-clock-rates >> that are all achievable in nominal mode. For i.MX8MP, there are some >> rates only validated for overdrive mode. >> >> But even for the i.MX8M Mini/Nano boards, we don't know what rates they >> may configure at runtime, so it has not been possible so far to infer from >> just the device tree what the mode is. >> >> Signed-off-by: Ahmad Fatoum >> --- >> Documentation/devicetree/bindings/clock/imx8m-clock.yaml | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml >> index c643d4a814786a1fc7e559140fe58911990f71bb..b03672255cae9462013a8a4e7a2adaff440f1420 100644 >> --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml >> +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml >> @@ -43,6 +43,16 @@ properties: >> ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8m-clock.h >> for the full list of i.MX8M clock IDs. >> >> + fsl,operating-mode: >> + $ref: /schemas/types.yaml#/definitions/string >> + description: >> + The operating mode of the SoC. This affects the maximum clock rates that >> + can safely be configured by the clock controller. >> + oneOf: >> + - enum: >> + - nominal >> + - overdrive > > I remember > > fsl,operating-mode: > enum: [nominal, overdrive] > > should work without oneOf Yes, you're right. This is a left-over from the example I copy-pasted from. Thanks, will fix for v4. Feel free to leave some Reviewed-by on the other patches though in the mean-time. :-) Cheers, Ahmad > > Frank > > >> + >> required: >> - compatible >> - reg >> @@ -109,6 +119,7 @@ examples: >> <&clk_ext3>, <&clk_ext4>; >> clock-names = "osc_32k", "osc_24m", "clk_ext1", "clk_ext2", >> "clk_ext3", "clk_ext4"; >> + fsl,operating-mode = "nominal"; >> }; >> >> - | >> >> -- >> 2.39.5 >> > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |