From nobody Mon Apr 6 19:59:40 2026 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 A76FE3806C7 for ; Wed, 18 Mar 2026 10:51:34 +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=1773831096; cv=none; b=hYnTEUeynkvlx5fMhA9vDKhvG5Za5Gst6cZ1j/WAhHTQgdZltsUCzROl9XiENtcvPGJgzHYv64q6R1SH8HmYK89NngBS5zgVMgKRt2etAxg7mNWJPa3D+98qAWuXzZwhMWxNrccOtaIyRva0IJ2vwxO5lGfNNDR0p2HDo0aMAnA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773831096; c=relaxed/simple; bh=thnm6PEYhA6tWFCd44xDPHzccXm1OIwwLMjKMACRj+0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qrJayRUTfzXb/d9cgANQ6TI3HOP+vuO6ZAghY28uyp+zAIdoeaOK77FZFJNiTKvuRqocIUxlMdRWyqHDe1SMl1kf14P7i+lDjVO6ZUW9QdAxzmWauDIWESK6bjL51BR8nyAqeUfMzXtm9uQnycfbZlp79pG9igyDWA8fg3vW1Hk= 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 drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1w2oUn-0001WK-F0; Wed, 18 Mar 2026 11:51:25 +0100 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac] helo=dude04) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1w2oUn-000tSO-06; Wed, 18 Mar 2026 11:51:25 +0100 Received: from ore by dude04 with local (Exim 4.98.2) (envelope-from ) id 1w2oUm-00000003RIS-41UW; Wed, 18 Mar 2026 11:51:24 +0100 From: Oleksij Rempel To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue Cc: David Jander , stable@vger.kernel.org, Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH v1 2/7] ARM: dts: stm32: stm32mp15x-mecio1-io: Fix ADC sampling times Date: Wed, 18 Mar 2026 11:51:18 +0100 Message-ID: <20260318105123.819807-3-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260318105123.819807-1-o.rempel@pengutronix.de> References: <20260318105123.819807-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@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 Content-Type: text/plain; charset="utf-8" From: David Jander Increase the minimum ADC sample times for all configured channels on ADC1 and ADC2 to ensure measurement accuracy meets specifications. The default 5us sample time is insufficient for the internal sampling capacitor to fully charge. Increase the default time to 20us to relax the input impedance requirements. Additionally, the phint0_ain and phint1_ain channels require a much longer sampling period due to their specific circuit design. Increase their sample times to 200us. Remove stale comments regarding clock cycles that no longer match the updated timings. Fixes: 8267753c891c ("ARM: dts: stm32: Add MECIO1 and MECT1S board variants= ") Cc: Signed-off-by: David Jander Co-developed-by: Oleksij Rempel Signed-off-by: Oleksij Rempel --- .../arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi | 32 +++++++++---------- 1 file changed, 15 insertions(+), 17 deletions(-) diff --git a/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi b/arch/arm/boot= /dts/st/stm32mp15x-mecio1-io.dtsi index 1ce01bac9814..1b1299770ca0 100644 --- a/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi +++ b/arch/arm/boot/dts/st/stm32mp15x-mecio1-io.dtsi @@ -104,80 +104,79 @@ &adc1 { =20 channel@0 { reg =3D <0>; - /* 16.5 ck_cycles sampling time */ - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "p24v_stp"; }; =20 channel@1 { reg =3D <1>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "p24v_hpdcm"; }; =20 channel@2 { reg =3D <2>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "ain0"; }; =20 channel@3 { reg =3D <3>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "hpdcm1_i2"; }; =20 channel@5 { reg =3D <5>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "hpout1_i"; }; =20 channel@6 { reg =3D <6>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "ain1"; }; =20 channel@9 { reg =3D <9>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "hpout0_i"; }; =20 channel@10 { reg =3D <10>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <200000>; label =3D "phint0_ain"; }; =20 channel@13 { reg =3D <13>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <200000>; label =3D "phint1_ain"; }; =20 channel@15 { reg =3D <15>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "hpdcm0_i1"; }; =20 channel@16 { reg =3D <16>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "lsin"; }; =20 channel@18 { reg =3D <18>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "hpdcm0_i2"; }; =20 channel@19 { reg =3D <19>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "hpdcm1_i1"; }; }; @@ -187,14 +186,13 @@ &adc2 { =20 channel@2 { reg =3D <2>; - /* 16.5 ck_cycles sampling time */ - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "ain2"; }; =20 channel@6 { reg =3D <6>; - st,min-sample-time-ns =3D <5000>; + st,min-sample-time-ns =3D <20000>; label =3D "ain3"; }; }; --=20 2.47.3