From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f44.google.com (mail-oa1-f44.google.com [209.85.160.44]) (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 683DD1F0985 for ; Tue, 1 Apr 2025 17:02:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743526967; cv=none; b=HtTo6iMkZUIKodkcx0NbO7OSAZurQZh20HLcuKPI6V8GHaCCAafpLXy1mbEsyaSIgW5U12PCI7NTncvutuKWfL6Tv7BDO68BTtwup7I9MOBu7WEjY81030jHvqvfGqcKMZOTVOieMYJ2aM3v//fW4vFcyplWvdDj8knpLEMl3sI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743526967; c=relaxed/simple; bh=+yY04wqEFOM+ZYrFth/D5yZY/advkKXOD7JuGCcg5LM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Cz+NnCVq/t5yb3yNtwg0Wj+XzKjAP7zkBv/usE54zSMy7GSOHZCcz/IJ8lfZavIy/uNQIHaen8h7VnjM5sEgCA04sPEhNZux7oA9RJfMsnLpAi4iUlQx5QJkVlMluw0Dx6mFfuCWlNO/wQYvbCP4bGWQN9SJJD4DA+rvlWSR3G0= 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.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b=KBREUhl5; arc=none smtp.client-ip=209.85.160.44 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.20230601.gappssmtp.com header.i=@baylibre-com.20230601.gappssmtp.com header.b="KBREUhl5" Received: by mail-oa1-f44.google.com with SMTP id 586e51a60fabf-2c2504fa876so1496900fac.0 for ; Tue, 01 Apr 2025 10:02:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20230601.gappssmtp.com; s=20230601; t=1743526963; x=1744131763; 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=NhYpDMqUMYzUiHimtNWCc62ZJOtzgSZhsmk4Mla9PsE=; b=KBREUhl5LAl3P9+FDvqzWoQ1Y3//h14hlYYTWUf/A0i5onADIoTAjGvzILaZywpe3q JQC/V0uBjqpC2nfHtAf4kEcO/QPfCaE+q78PdszU4saGxrXveVbiTrcFefvDwjcLlALj osBel5ebQ4XjtnC/OJBY+UNwfCk3tGFPO7IThVVFhR8eWeld3TMUf58lewTdMi4QCzf/ gCanSIlmg0rK/KQu60Q0VwVkWLBSDU/75WkMpi6RO9NpN0IFpATNzacxBn1DiIMbyMkt skK1K4N4bR6jfgzqY2AqxRVRvkEZ2zc54/9hcBVlnAYejQPn6GrMfA6iGhrlLz2+4Y3u cjfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743526963; x=1744131763; 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=NhYpDMqUMYzUiHimtNWCc62ZJOtzgSZhsmk4Mla9PsE=; b=R7nIidZg/f1WvPpOYfDQtauPYph9Av30npTos2VwlRu4fhRkDSxKH+CEhpGCQ1M7bP Dv6ebtj4ClJ5Bx58iutypB/ZzoIcois/Q2LVQxea7/ZcdTD1JsIFE+hRxpnGxCf9hHPy sep6rZXYQgPCC/SkMsSl2ngPIaznPuriXPEqZET41zv50dYu2i3Rn9TeA2VZYv6U1zp6 AWApiDGVXD+qFrx6uHqoOVY2Z00krh0Crsm/uqRDNv871UNW2fkOUVs9nH7Tn+Hnor0S ayE7RG0Xs5vcXTEFWixs0BKyRMIOu4sECvd/5LLRA6XDri90hOQbKXx6N6h5kctu36dW EASg== X-Forwarded-Encrypted: i=1; AJvYcCUmWSLyjnN62yEyu9itaRWu+TjOymSD/3obEtO9WIRPhc6LfcdvAByMJ+uzz7nZBpEQnbGAVhE7OQuH3LY=@vger.kernel.org X-Gm-Message-State: AOJu0YweYQ1+hbvBvZTrLkAzwmSBLRpniVFYMJ9Rcp7+Dr57b12WpTkj AUj6nP+qdcrWSoib4MSGM6uDKJVETxJftVaiU4e/R+eHUesi5lHu8Rz2P/rQv5c= X-Gm-Gg: ASbGncsmsb6B1XPm+6stz/Gp2E82SVPp/dLgjBlTHgpZj5mVZ1+TJAec9gZUhtchUOE t96LmiOs/uAmwE3+PyX0SP/YCLtCKKX2pi00cjdEaid+1fr9zD1LWSHtNPkSifmu8olHxZR59De QodSbcAmDYXyepipooia5vMM8fCTsTERmZitytwE79B1g8jn6GF81Xc3bHR1GOpcl2AEGYNm+EN AMsqmuM9VQmNmxPT82WODUNHQ33XoyeUcvLidCA9Mth3Rh+122uVOFRZ50twlH2f+oqZbgw1Kbg 9kNMKmnUcH36nj6IG/Hy+b03DQ110O98/8iA2XyqOw/aShjOsRsuab8HJ9BVb5wTyM2Iw+NkReD 7H0S17w== X-Google-Smtp-Source: AGHT+IGTSq0pqqFQI3H0pT8LDtKLGZr8SAjBhx6TdK6GcdGs7Cr91zaRzfary3Xt+Dp2mNKM4qbHyg== X-Received: by 2002:a05:6870:548d:b0:2c1:62ba:cd7c with SMTP id 586e51a60fabf-2cbcf51167fmr7167818fac.15.1743526963436; Tue, 01 Apr 2025 10:02:43 -0700 (PDT) Received: from [192.168.0.113] (ip98-183-112-25.ok.ok.cox.net. [98.183.112.25]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-2c86a4034e3sm2397020fac.9.2025.04.01.10.02.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 01 Apr 2025 10:02:41 -0700 (PDT) Message-ID: Date: Tue, 1 Apr 2025 12:02:40 -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 v4 14/17] iio: adc: ad7768-1: add support for Synchronization over SPI To: Jonathan Santos , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org Cc: lars@metafoo.de, Michael.Hennerich@analog.com, marcelo.schmitt@analog.com, jic23@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, linus.walleij@linaro.org, brgl@bgdev.pl, lgirdwood@gmail.com, broonie@kernel.org, marcelo.schmitt1@gmail.com, jonath4nns@gmail.com References: <65bc11611c40d66858fb2ce5c1bbaf7e790a9f8f.1741268122.git.Jonathan.Santos@analog.com> Content-Language: en-US From: David Lechner In-Reply-To: <65bc11611c40d66858fb2ce5c1bbaf7e790a9f8f.1741268122.git.Jonathan.Santos@analog.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/6/25 3:03 PM, Jonathan Santos wrote: > The synchronization method using GPIO requires the generated pulse to be > truly synchronous with the base MCLK signal. When it is not possible to > do that in hardware, the datasheet recommends using synchronization over > SPI, where the generated pulse is already synchronous with MCLK. This > requires the SYNC_OUT pin to be connected to SYNC_IN pin. > > Use trigger-sources property to enable device synchronization over SPI. > > Signed-off-by: Jonathan Santos > --- ... > +static int ad7768_setup_spi_sync(struct device *dev, struct ad7768_state *st) > +{ > + struct fwnode_reference_args args; > + int ret; > + > + ret = fwnode_property_get_reference_args(dev_fwnode(dev), > + "trigger-sources", > + "#trigger-source-cells", > + 0, 0, &args); As in the DT binding patch, we may need to allow an arg here to be able to tell the difference between /SYNC_OUT and /DRDY triggers. Also, in reviews on previous versions of this series, Jonathan and Conor both mentioned that it would be sensible to allow omitting the trigger-sources property when /SYNC_OUT is connected to /SYNC_IN if you want to consider that. > + if (ret) > + return dev_err_probe(dev, ret, "Failed to get trigger-sources reference\n"); > + > + /* > + * Currently, the driver supports SPI-based synchronization only for > + * single-device setups, where the device's own SYNC_OUT is looped back > + * to its SYNC_IN. Only enable this feature if the trigger-sources > + * references the current device. > + */ > + st->en_spi_sync = args.fwnode->dev == dev; > + fwnode_handle_put(args.fwnode); > + > + return st->en_spi_sync ? 0 : -EOPNOTSUPP; > +}