From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f45.google.com (mail-lf1-f45.google.com [209.85.167.45]) (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 F122F26A1A8; Fri, 8 Aug 2025 09:01:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754643670; cv=none; b=OpNn8DWSS8lAeR+Ge/VkQBv8vuKb5Tqoy8LPlteYl0tQGCv/8bR9KulL7pMy1BSAaUYA/GLpKmiplAYijvQZLvxXy8bSo65WZ33LaKj4LEtXqMK6sRW44IN97++/kZcLG1KrWI7QPb6ysMDdA6HA3NBX0yWAIyy/PlgiFhWmvnU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754643670; c=relaxed/simple; bh=1LbQYxv+uEmEfmk9w/U9/tOmLfA8HuJ+dBFmopJiVm8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=I/UgPFUl3zeAbO6gPZysGq+Aiv/GORv8FepMkmv4liIkldF/9xQCmrOpmFWrGHZlSGUMDvwYo5j4am3gARJrlOYeYImOKDreA2BBG4d+kVveSJ/exzu7mELKvYXefXeKf0l54C5Qjvi9rhXLuANgKl9403souU/HyRwHLcMXBOA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=QLDiFpz0; arc=none smtp.client-ip=209.85.167.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QLDiFpz0" Received: by mail-lf1-f45.google.com with SMTP id 2adb3069b0e04-54b10594812so2139475e87.1; Fri, 08 Aug 2025 02:01:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1754643664; x=1755248464; darn=vger.kernel.org; h=content-transfer-encoding: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; bh=P6MavA5nJNsvMG9xx0PcTftiCh+5uHKFSh91f+LoJBo=; b=QLDiFpz0Bts1xQNqvLOBjWBprMuZNNYjaBJh+sQBRfRTBYEjyDE3x36FHzfOiDzF+F xYb3ov+ZIWSJeuXhnLB9Z9OA9/t1GOhtZoJX08p8rcARKozxAFPFqhijHoTv9tOtPvnM /J4BjLGT/wVCfDdJoDH+UxkPlatnLiuVjGdb11mDjd3h4AgDKUSp7T7Dz67wz3DpRTRk rqsxpnBa4zR3xcrmVgzaQ99SH9Op84gCa6XNV8gnOEi9j0DuZtApmC7TC5lv1YM7Pz7B dLnFKgHRPolfz8I4sQ1SLYCwhKoueOGTv4UWcu5asSXGhoQGeAMVLL3Qo16qujQF1U5o vllA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754643664; x=1755248464; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=P6MavA5nJNsvMG9xx0PcTftiCh+5uHKFSh91f+LoJBo=; b=YnR0nsW7z6e10nzhXakly6Bz/krovEVshsHy8tUWHeOWPL/z2aQMfz2YuHvzXg+zCq rVdsEFn/21Sh6WBAKIDDEdEPk6MXe+CTf115T399sD0vjW8RkephP5cQrpzwdXtvFale w+MQqEVtacxAeo3VjQZ7Ur+I4oA6N8BIFlv+tKxBU4scTAq5mVqEyfVOniG6PUn1fN94 sk4xjCvEWnIVrG13DkG0K9iaZ7sDDGQwD2nEnX4AGOTo294brPC+fimZg2ohzRmP2nMD i6mWgIOWeYauewN+bKIFQhSKSXYbkRbLs/kOI/QYvAZ6jvAxJduhx+mSXe6n/uXBZxfi ccug== X-Forwarded-Encrypted: i=1; AJvYcCVzuFEmzT5+KXBlAvsePbNQiZZSYlMUHNjl9lmMG3MpZUJ/MSiExoLmyVtLg2f1/AGvemk1u/hjQEU8@vger.kernel.org, AJvYcCWyAtDfxB5MfKaubetOitaLMIwtHentQWRnh1hzU7JV4820lw+10EzGjr2PmVZhqwQe2u5SusheZb3O@vger.kernel.org, AJvYcCXeiyOEEb3f2bt1kLFWzL40NFcZSAliN2Sm67et9f1pifxSBcoY6G8si1tyD+1qlyB99vPoZfM2XEZndszS@vger.kernel.org X-Gm-Message-State: AOJu0YyT22T/VY0ad/knWHX1Yc6oO/15oUfCEXx8GNNDznDc5Yn3sc6a GhLJjVt8E7/L07jtoTlCPTsEEof69rtojmFS+S9fLNqfX2S3ZTFA+k+I1+dA9g== X-Gm-Gg: ASbGncuWQjYwNLxill0BD9eDO92o2lZ60LjkJo3awYVSrFylQTl4knX0+xGXYZaIL6a WP8wgwVuPhi6ZZoWUduegfOSg7lZ/3QM3K0csCruip+0/RYOy/2KdcVXH86mT8JDGcG4I/6OC7V N78Dtp9L3I2bqMd5Zpu+5DM5cIuycgPv7zUHvpYno9eDNHeTzK1BpY/4LH4BLxu7/fb71z+9Xt3 Q+RuUMXYIlNrThPFYMHo9cdbMZy9lmjKMzDvkJUnTFfqk6i29WIFvnq2eK372IUOVgGJutNLEcc IiZsTxmJr96IkJCrVhcmkXL1KrqXC/mpOnXwW/rwon11/imUVXubVrOKF9INVd/TsmVOBwcelUz aTWlAz0JdYtbvADmvXB9oiJzG6OJh0MXwQkMBW/33SXyRfysX/xMXKGe6aHm1Y2NRBrlnnAfknx ahm2E= X-Google-Smtp-Source: AGHT+IHcEHzRarzPfv8ooyQNRcZ0b2FcqnAOFrZrk3dR1dxtp259FGDfRs0RExwr3uvGwIf6Za73ag== X-Received: by 2002:a05:6512:1586:b0:55b:840c:5636 with SMTP id 2adb3069b0e04-55cc012c8camr559935e87.50.1754643663843; Fri, 08 Aug 2025 02:01:03 -0700 (PDT) Received: from ?IPV6:2a10:a5c0:800d:dd00:8fdf:935a:2c85:d703? ([2a10:a5c0:800d:dd00:8fdf:935a:2c85:d703]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-55b889ac4dbsm2948790e87.63.2025.08.08.02.01.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 08 Aug 2025 02:01:03 -0700 (PDT) Message-ID: <1348e677-d8ea-40db-831b-2f75a7ff6d79@gmail.com> Date: Fri, 8 Aug 2025 12:01:02 +0300 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 v2 09/10] iio: adc: ad7476: Support ROHM BD79105 To: =?UTF-8?Q?Nuno_S=C3=A1?= Cc: Matti Vaittinen , Lars-Peter Clausen , Michael Hennerich , Jonathan Cameron , David Lechner , =?UTF-8?Q?Nuno_S=C3=A1?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Liam Girdwood , Mark Brown , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <2a678156-8e0b-4fa9-a940-f368cfac8f7a@gmail.com> <5w6ryx7dvu5fuxfyz3hwqbncwwh573a6nou3w3ebspbm4e4p7k@ne637fm22n5i> Content-Language: en-US, en-AU, en-GB, en-BW From: Matti Vaittinen In-Reply-To: <5w6ryx7dvu5fuxfyz3hwqbncwwh573a6nou3w3ebspbm4e4p7k@ne637fm22n5i> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 08/08/2025 11:54, Nuno Sá wrote: > On Fri, Aug 08, 2025 at 09:11:03AM +0300, Matti Vaittinen wrote: >> On 07/08/2025 16:01, Nuno Sá wrote: >>> On Thu, Aug 07, 2025 at 12:35:25PM +0300, Matti Vaittinen wrote: >>>> The ROHM BD79105 is a simple 16-bit ADC accessible via SPI*. >>>> >>>> The BD79105 has a CONVSTART pin, which must be set high to start the ADC >>>> conversion. Unlike with the ad7091 and ad7091r which also have a >>>> CONVSTART pin, the BD79105 requires that the pin must remain high also >>>> for the duration of the SPI access. >>>> >>>> (*) Couple of words about the SPI. The BD79105 has pins named as >>>> CONVSTART, SCLK, DIN and DOUT. For the curious reader, DIN is not SPI >>>> ISO. >>>> >>>> DIN is a signal which can be used as a chip-select. When DIN is pulled >>>> low, the ADC will output the completed measurement via DOUT as SCLK is >>>> clocked. According to the data-sheet, the DIN can also be used for >>>> daisy-chaining multiple ADCs. Furthermore, DOUT can be used also for a >>>> 'data-ready' -IRQ. These modes aren't supported by this driver. >>>> >>>> Support reading ADC scale and data from the BD79105 using SPI, when DIN >>>> is used as a chip-select. >>>> >>>> Signed-off-by: Matti Vaittinen >>>> --- >>>> Revision history: >>>> v1 => v2: >>>> - Fix the conversion delay for the BD79105 >>>> - Drop unnecessary GPIO check from the convstart disable >>>> - Drop unintended whitespace change >>>> - Fix spelling >>>> --- >>> ... >> >> ...I see two other options. One is adding the check in probe as you suggest. > > I do think this is the right approach. We should make sure no one tries > to probe this device without any gpio because it will be pretty much > useless so better to fail probe in the first place. I Agree. > I'm also not sure > it's that complicated. Maybe just a chip_info flag like > 'convgpio_mandatory' (likelly a bad name) and act accordingly when > checking the return value. Just sent v3 couple of minutes ago, and this was exactly what I did. (although with another name for the flag). Thanks! :) Yours, -- Matti