From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 43CAB2DCF73; Wed, 3 Sep 2025 20:39:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756931971; cv=none; b=uMzsi2bTM+ieHpQJwXYDFEW84yHBz+g2ODARwR3ke47XXkFHUkfNXPu5LFL5FEZ013P/CbKwRwMwRBWinKaBmygtHBSXtebwLmIV3gKdMP29GtQkKxR9z71j225qJbwdT+gFlFMBJkVVh/otwbnR7LxECpHUcT9fewCs9wvhbwg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756931971; c=relaxed/simple; bh=rGJu4bA2Dfozpo/XJl1d3k02MLlU4X3HlyiWNj2hz7Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QvG53nj8SartNCoJkaWNNIrE8TepKXCff3wFLsc7Fiak994ezSyfYcVYO1GLLxlCS/4MTyPvpQkuJe5uKR5qtxODC35fxn95Bc7WvMSEOWkGPdXnK6LNWQnN1a5cf4Q3JgSIysIxN+iISyoxpYWEBvh2X54nTpG83Fe8IHEe02E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cBFgbaBb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cBFgbaBb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89CDEC4CEE7; Wed, 3 Sep 2025 20:39:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756931970; bh=rGJu4bA2Dfozpo/XJl1d3k02MLlU4X3HlyiWNj2hz7Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cBFgbaBbRRf9/BKzJBltT+NKCqzs2h3Tr03Fao6fxNyrvzoMtjOiwXr2HuFUnAcai /+qq4Ly7XvMdrnE32UZZvEp4hiAXx/qjEFQ80ss5b94dlMuECVfF6FuNyn5nK6uQqj MduW05aokCBN33sngZ3ZIikHGO3+/sHxsIxMpsJiRCLWid/JXCivjgAyWaVlc8R7Ra WrWAqRfkpG2jgVTtri/4IIW0QVr7NtD9ZKWho5da9ZQRqg9lJYx+7sMuZNQoNQL8N8 Q/A0iRVlTMjZ/WdiYqgCb+7Hlk8UYakgmCTYZetK3EHLgqtIsRyAFtj9RVqdlynGRf KW9OkJ0JdwBVg== Date: Wed, 3 Sep 2025 15:39:28 -0500 From: Rob Herring To: Sarthak Garg Cc: Ulf Hansson , Krzysztof Kozlowski , Conor Dooley , Bjorn Andersson , Konrad Dybcio , Adrian Hunter , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, quic_nguyenb@quicinc.com, quic_rampraka@quicinc.com, quic_pragalla@quicinc.com, quic_sayalil@quicinc.com, quic_nitirawa@quicinc.com, quic_bhaskarv@quicinc.com, kernel@oss.qualcomm.com Subject: Re: [PATCH V5 2/4] dt-bindings: mmc: controller: Add max-sd-hs-frequency property Message-ID: <20250903203928.GA2663015-robh@kernel.org> References: <20250903080404.3260135-1-quic_sartgarg@quicinc.com> <20250903080404.3260135-3-quic_sartgarg@quicinc.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250903080404.3260135-3-quic_sartgarg@quicinc.com> On Wed, Sep 03, 2025 at 01:34:02PM +0530, Sarthak Garg wrote: > Some platforms may require limiting the maximum frequency used in SD > High-Speed (HS) mode due to board-level hardware constraints. For > example, certain boards may include level shifters or other components > that cannot reliably operate at the default 50 MHz HS frequency. > > Introduce a new optional device tree property max-sd-hs-frequency to > limit the maximum frequency (in Hz) used for SD cards operating in > High-Speed (HS) mode. > > Signed-off-by: Sarthak Garg > --- > .../devicetree/bindings/mmc/mmc-controller-common.yaml | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml > index 9a7235439759..d6b785cb2bd9 100644 > --- a/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml > +++ b/Documentation/devicetree/bindings/mmc/mmc-controller-common.yaml > @@ -93,6 +93,14 @@ properties: > minimum: 400000 > maximum: 384000000 > > + max-sd-hs-hz: > + description: | > + Maximum frequency (in Hz) to be used for SD cards operating in > + High-Speed (HS) mode. This is useful for board-specific limitations, > + such as level shifters or others where the card cannot reliably > + operate at the default 50 MHz HS frequency. > + default: 50000000 Why doesn't max-frequency work for you? I would think frequency limits wouldn't really depend on the mode. > + > disable-wp: > $ref: /schemas/types.yaml#/definitions/flag > description: > -- > 2.34.1 >