From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f48.google.com (mail-oa1-f48.google.com [209.85.160.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C857F4519A4 for ; Wed, 12 Aug 2026 13:40:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786542024; cv=none; b=XYIemb2GxADjVp+i/uolKv5T89U7g6JAbEUZy+F11+H+YYi4AlTbjdDfE5Eiu0Kcrzc6P4OobuKxNYcDDRL0aTAL9ugq95CccKjKztzKLdJ5RIRJJklSi6uPcH4jLNfSXX18YJiWXUyZF7P9trZRn16TZ1tlMIX65hZmlJkpMa8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786542024; c=relaxed/simple; bh=Yp2oRgRlHLK5S6oFnlyMQg7hEjEr5DC8Y6ykHGauOQI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=av8sjbx3DwAilWO3zrxRutBZklRzGEON0JmMP7lPLfziyiFW2BMgkJPsA4Xt5JwbDoFCytes84vAGbwj01HRxA87OnAHwhixDX4iS1GH7kOKkhIWQ5LTr68Oz8g/NDz1iVeg1TKlYILdyeYTAQDErAvhngMJ0zvHxfp9ggu/S3U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre.com header.i=@baylibre.com header.b=KuYoRDzE; arc=none smtp.client-ip=209.85.160.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre.com header.i=@baylibre.com header.b="KuYoRDzE" Received: by mail-oa1-f48.google.com with SMTP id 586e51a60fabf-43ccd4f6f6eso589430fac.0 for ; Wed, 12 Aug 2026 06:40:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre.com; s=google; t=1786542017; x=1787146817; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=3m/mAJLnKMaOtoiImwSaVIw0nteRIaUTkKOvX93AqPM=; b=KuYoRDzEwL4PLALIl5YDeM+Ss0GYokunxQqXZlzOz6dGYO3Fy1YgftesXLbaMqjZ2g kZmWap+0y/mjsGUlq+JP3iJiFxdjwXHYqZTFovc+Z1clywebjWCs/zB3IG/S32ro6qmw LEb3/1ieoLnuz7H9tbF0FjJMDgKbtb1CWUQz+jXOLuGEVgETKeedrlczKQTtU/Z6+0KQ Z/3g7/qirYN8G1DGnEqgDCEUigohrfD0p6SmRWR/j71trki9+iMm8RTpPAiH65M1yRz/ YnBmt0dvMbAqEBWfq+qpbxYc/LD7a7wUuRj89w7y0SSjK0upk3tJVypAWE2/GcDDzgyA 8zbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786542017; x=1787146817; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=3m/mAJLnKMaOtoiImwSaVIw0nteRIaUTkKOvX93AqPM=; b=LoogWpr6Fh9tbx4w33Te5bfGCvxHrbrQ7YlVaFmIvCxgbmppeLye/hWOZa31EOQQnd I+UR/nZUN8lpctsxLXo+gXPRTofq8rMDw1uunairNqP6mPhzk9IoIG9qDTPnyK+TpDin ssicb7smmuW9AQCyoWU/sEHifwUYNhgV+otD3yNs/fELiqRjNNa3HHPUpbw4ACfh7TvN BS9+ocSSNSCy8WWch+daQ3zPmQocZ/TSJFq21lZ2KvN/w/LM82gbK//K2FiyLpg5nXsA /50lCzmrX9w3DK0D8D/Bt/eB4pfD+VB7ce6s6nOjpR1ZpUVlbLFDgmdknFBStDr2w9Jz P2hA== X-Forwarded-Encrypted: i=1; AHgh+Rp66b4j10RAenftTw4nDIbYIBO7i6wkCCusFr+94W1FmPmBrxlPHbiIbXF1FC4PYbKphBjX0vtnaytZq3c=@vger.kernel.org X-Gm-Message-State: AOJu0YzL+C86g3TjZBYFVgzUUnzDIAJkyRDuhDrZj7OIBtsWETbk+163 0Tl4R0mJFBs9VBHO+lxCujrCtyPaOUsw5HsC0WPT4dMpd4ilrU0WIZfCyZaQuudMlKQ= X-Gm-Gg: AR+sD10Qgat/sBvgEGGXj3Orwo7DKlFvvbuCgZhAN1TfBIzUCbn8Mv8g0z4wR5rcXsT uBITVRaog6VVNd+c1Ez41M8CA1bFaNgbXWJKGNBnn/ebuaxOk76kkHFqS9Lz/H/E06C8Ue0mD5B oMfaIZPgB4SUsAtiw/EzyvGMHNhSxG0rNVeJfMWJ2qcbCBpAP3tf/2a5+YmqsdNEeanUcd/52po ECJUODB69psuNPWoTeh2NBh2pNXD/T/qYbML3oHw/qX8GQXntXygGf0IFEHFG4a2os6iqjWpczA lmsWLWRGtH8a0dm9kEZC00NYzEQdbFFR3K43w6CTAyF+J77rBFRHweQOc5pp7Rl1+6XWLlvHqku NgY3J5BfmNV3nla3ZIuLS0zjgId6CNddjlkx97Ncbs46k+Qr6l9VHKHyOzY1CQxn/GVaqom4ezv L/5dXXtA1qZojXyOu264jenrzETkHvn4+wRs1wvs8pTz5smJpneixUGslhyZWg1s9ZNnFvMAx0+ aNAQx86s+qyXxKAmIJs4zzd+iUeJjJRM/a3J+U= X-Received: by 2002:a05:6870:c267:b0:456:4c3f:7e03 with SMTP id 586e51a60fabf-45e3ea95283mr4055401fac.18.1786542017417; Wed, 12 Aug 2026 06:40:17 -0700 (PDT) Received: from ?IPV6:2600:8803:e7e4:500:76d8:83ff:449f:8518? ([2600:8803:e7e4:500:76d8:83ff:449f:8518]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-45e35173939sm1812914fac.8.2026.08.12.06.40.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Aug 2026 06:40:16 -0700 (PDT) Message-ID: Date: Wed, 12 Aug 2026 08:40:16 -0500 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 2/9] iio: adc: add the ti-ads1262 driver To: Kurt Borja , Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Linus Walleij , Bartosz Golaszewski Cc: =?UTF-8?Q?Nuno_S=C3=A1?= , Andy Shevchenko , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org References: <20260807-ads126x-v3-0-f89925d72792@gmail.com> <20260807-ads126x-v3-2-f89925d72792@gmail.com> <7a42a318-780d-4bd0-baf1-55d030b39233@baylibre.com> Content-Language: en-US From: David Lechner In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/11/26 3:28 PM, Kurt Borja wrote: > On Mon Aug 10, 2026 at 11:42 AM -05, David Lechner wrote: >> On 8/9/26 3:26 AM, Kurt Borja wrote: >>> On Sat Aug 8, 2026 at 1:39 PM -05, David Lechner wrote: >>>> On 8/7/26 10:58 PM, Kurt Borja wrote: >>>>> Add the ti-ads1262 driver with initial support for the primary ADC >>>>> (ADC1). The ADS1263 auxiliary ADC (ADC2) is handled by a separate driver >>>>> and interoperability considerations were taken into account. >>>> >> >> ... >> >>>>> +static int ads1262_dev_reset(struct ads1262 *st) >>>>> +{ >>>>> + int ret; >>>>> + >>>>> + if (st->reset_gpiod) { >>>>> + ret = gpiod_set_value_cansleep(st->reset_gpiod, 1); >>>>> + if (ret) >>>>> + return ret; >>>>> + >>>>> + /* >>>>> + * The RESET pulse timing requirement is 4 clock cycles, at the >>>>> + * minimum clock rate this is 4 microseconds. >>>>> + */ >>>>> + fsleep(4); >>>> >>>> How long do we have to hold reset before the chip powers down? >>> >>> For power down 65536 clk cycles. Less than that is simple reset. >> >> How long is 65536 clk cycles in microseconds at the fasted clock rate? >> Hopefully won't accidentally shut down the chip here even if fsleep() >> goes significantly longer than requested. > > That would be 8192 microseconds. Do you think there is a risk we end up > turning off the device? > Linux is not a realtime system, so yes technically it is possible. It would probably be hard to do in practice though. So hopefully not something we have to worry about. If it did get put to sleep here, how does it get turned back on?