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 D99BA13775E for ; Mon, 6 Jan 2025 19:55:23 +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=1736193325; cv=none; b=npzLy6uMHXVDyW3X3CnABRpu2m5frgvNygZSv5S+QpXkIZ6VDU8mQWWbL4zsAvJnoIpz3fre6kCxEN0AQ3VOD1WW7S5vdEPVUzHiWPQHzDo1zkpYuTZZOS+/aUlPGhDq6qd996X8xUBzzSSTQfTftWca3eTCLsAVufRbKagNafs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736193325; c=relaxed/simple; bh=SeUo7BaIcxWwemHIfO+p/enNO4psUpQ5xmhe155trQw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=c8xg20ZrCeV8Y8D7J+g5JPe3pv+IaFXbxz1CkSFSYSQ3cPfXyZjYJ66jPPcsFofTkJrvullY3IzuHL66ErBBo0S/Addy087L4zXBh0PvQAaXtiJ/rNW8HBV83O3jLsMJHEwd5PuOlk0ZXlgts6cN8L1guTRlE3L4lcVLYVUg6wY= 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 1tUtBt-00069T-Pa; Mon, 06 Jan 2025 20:55:09 +0100 Message-ID: <6fddfd9a-8a8c-4dae-9f74-e8019b7ed404@pengutronix.de> Date: Mon, 6 Jan 2025 20:55:08 +0100 Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/6] dt-bindings: clock: imx8m: document nominal/overdrive properties To: Frank Li , Conor Dooley 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, Conor Dooley References: <20250106-imx8m-clk-v2-0-6aaeadac65fe@pengutronix.de> <20250106-imx8m-clk-v2-1-6aaeadac65fe@pengutronix.de> <957ad153-17f3-4cb8-8878-73093a9a2724@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: imx@lists.linux.dev Hello Frank, On 06.01.25 20:42, Frank Li wrote: > On Mon, Jan 06, 2025 at 08:25:38PM +0100, Ahmad Fatoum wrote: >> On 06.01.25 17:41, Frank Li wrote: >>> On Mon, Jan 06, 2025 at 03:21:42PM +0100, Ahmad Fatoum wrote: >>>> Allowing for absence of both properties is >>>> needed, 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. >> >> [snip] >> >>>> + fsl,nominal-mode: >>>> + description: Set if SoC is operated in nominal mode >>>> + $ref: /schemas/types.yaml#/definitions/flag >>>> + >>>> + fsl,overdrive-mode: >>>> + description: Set if SoC is operated in overdrive mode >>>> + $ref: /schemas/types.yaml#/definitions/flag >>>> + >>> >>> why need two flags? suppose "not set fsl,overdrive-mode" is equal to >>> fsl,nominal-mode >> >> Conor had the same question on v1[1] and I have addressed this in the commit >> message of v2, see above. >> >> In short, there is unfortunately no universally applicable default. >> >> [1]: https://lore.kernel.org/all/4e2250b3-5170-4e88-aa0a-dd796b81e78b@pengutronix.de/ >> > > But there are problem if use dts overlay because dts overlay can't support > delete property. > > If one dts file use "fsl,overdrive-mode", dts overlay file can't delete > this property. "mutually exclusive optional properties" was not preferred. > > mode = ["normal" | "overdrive"] I don't see myself setting this via overlay, but if you say it's useful, we can adjust the binding. I am not sure what's the preference is though, should we have fsl,operating-mode = "normal" / "overdrive" or fsl,operating-mode = / Any idea? Conor? Cheers, Ahmad > > Frank > >> Thanks, >> Ahmad >> >> >>> >>> Frank >>> >>>> required: >>>> - compatible >>>> - reg >>>> @@ -95,6 +103,12 @@ allOf: >>>> - const: clk_ext2 >>>> - const: clk_ext3 >>>> - const: clk_ext4 >>>> + - if: >>>> + required: >>>> + - fsl,overdrive-mode >>>> + then: >>>> + properties: >>>> + fsl,nominal-mode: false >>>> >>>> additionalProperties: false >>>> >>>> >>>> -- >>>> 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 | > -- 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 |