From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f176.google.com (mail-dy1-f176.google.com [74.125.82.176]) (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 624884218AA for ; Sat, 10 Oct 2026 06:53:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791615228; cv=none; b=hQE0lM6yJy2798dGTNb8Agx8NP/9MI2VxrIFEhOPyr1G/dPWondY9FNAJB0BqgfxYKSXE8dEmKPeH0Ko0EEPmFE9RqV0ntMnmf1fW/XlHJuw/SI5MmkXNEuQqr2VQ0CAlOGvL8Lvc+xgiDmk3PsHLoTcdAVqA1SWOjYiEHnry5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791615228; c=relaxed/simple; bh=dIjt8nwdTss/bhvR/VsQb/EXL6ivNKMpYRbB1ZzbmXo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Ych3k/5cSwA5vG3WyiJAZoUVqhQR7jv8zTuI5SDONe22VQFlfLo4WzZCWQ7dEYVb/F5oXSRIrcQzbSLZwBLVze4KS8WImX4rUpsFv3k0qhQBIi6CpazwBPRaVt+8eZI4vhVlO7oldyDq66EAm/aqJl8GB1n+A0KE1kkh8n/h3uI= 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=h0IPla3L; arc=none smtp.client-ip=74.125.82.176 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="h0IPla3L" Received: by mail-dy1-f176.google.com with SMTP id 5a478bee46e88-3115c4451c8so353991eec.1 for ; Fri, 09 Oct 2026 23:53:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791615226; x=1792220026; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=KntCeUOH3O9JYy7Y7gr5oB4PSucBlpkuinakVxuUlIQ=; b=h0IPla3LhjguxLaXqe2+yzbhCpqJfxKF3nkVoCyOPdsbuqDvy9EjcMcxVBZewhbA7h d4zS3DUVC16JbWBx6lbMYiVLJPrwozCUx6sX9nz+ZYNccLMebIIrAZuQNm0rPhITrg9x bLUw6xj/FcnILfz+9YnR5kmwU4f+sVIgIdMHTxomvapkkIu6urbW+jxm9Gnx83h58LKt 26tL53ilV0AU35+RjBLu31vdw57SS38+bj8Jk+eYvC+Dw2YVwY6XWmawrB+wbKtfDPS8 6kEMkIlufbvUNHx7OSTeL3v+Fw6R6TGoI3jnJWtZAfIg97gf4dyhdXInouebA7Pc+r8y 9pyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791615226; x=1792220026; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=KntCeUOH3O9JYy7Y7gr5oB4PSucBlpkuinakVxuUlIQ=; b=1DhmJS1lw+6VElu7SlwOJb/DzDlAcvUCE1bM5dKTEEf2GJf8v0BqKNu1EgEfbs+Eu6 D1TypMwo3Q1ahhrhrPxi8ar7MZyEbcVZKDp8RCCya7IL/F+6lkZON1JiY6IQ6OxxekE9 mkYx79Ji3KlTIuFITJRF8W62WHzeERlnZxM1lCkrG55D5sKPHCk/VWlyKcJDivL1CGrY Yn5mp6mXfylEloPdQRrgvgelB+hZOjPrlQXB7z3YghOVYOY6iiSPsXR6Zv4Caepv3s/8 k40eNOwxyWYfqFbvSBjj+uGk62MHhPOWuclsvqyAqjQBvjm1stJ4/8mMUhPs5Xlr5LWq H2jQ== X-Forwarded-Encrypted: i=1; AKwUvBxWEIEkCvxnsq4ru2blKUfLkReR4h+RqKXxnxrKfnSmmtw1dj7CHrIk1RkAEFQRxu/FPL63Z69Oi4Xc@vger.kernel.org X-Gm-Message-State: AFq9FYLN73dRhBL+4vriSlN6N3x3+YH1rX8PN6RLeQ5J7ZMWuuwTmfDn dXd/ugpDIrzD+eXaZZNAgE74pXkU1GGrlkBF97HCDbUFYA10rFvIC5Re X-Gm-Gg: AYBFou3dM6OnKlYcymyXzfr5/GS0zxvBmE9hulJe+gPTeOCBoy58ozfc0Of1IE1puuO FWPph3AUTiMVsbjvEE8BnuWhXRBeklRpx291Ih4gLm+ZkEL+lXMf95EgHDcRTJxwxCCgK8R5Ewi 4HZKFCKkZ/tNw62VwhPoqTyj8XGh3/+OlIXO83TjY7xpD7c56ecuBamPnWm0NpJ3BK2amRyBBS9 pXREsr3W+Loj3ltCadjER6C24U8i0KvMpG8re5e1IbJMXX8A0Pbw1dUiLO1PnYTSyiGqxpRep4z QeI+McYZonneVxQjZSO4Uq60JGMIcf4WyTKQsUvIIgXlRkUZHX7g7Q3NX6h4Y+RZUODTGcVwakJ lcL7I4ufkXdskFiHs5zDPnvQ+wRrTSV9gUDZr0E3dvwlX4rEMwneSbCr66j9OuwJ8icYDdlC6Zc p0uDcCpHt2x+FsyJxPqmKTgIZmX4mlieA2b/Mxv8U5LfxnPcGN9aNrx4cF9thRSv0EuQp4gKJxz TTSNy363fjqLp3WoWVw1iMphjuyy7xiAPKRfR4= X-Received: by 2002:a05:693c:8112:b0:358:6d16:44e2 with SMTP id 5a478bee46e88-3586d16487fmr1250091eec.22.1791615226276; Fri, 09 Oct 2026 23:53:46 -0700 (PDT) Received: from [192.168.100.70] (host-200-61-172-117.iplanisp.com.ar. [200.61.172.117]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-3537cacb5e9sm13009650eec.20.2026.10.09.23.53.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2026 23:53:45 -0700 (PDT) From: Kurt Borja Date: Sat, 10 Oct 2026 03:52:45 -0300 Subject: [PATCH v5 06/10] iio: adc: ti-ads1262: support input chopping Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261010-ads126x-v5-6-49e331cb2fed@gmail.com> References: <20261010-ads126x-v5-0-49e331cb2fed@gmail.com> In-Reply-To: <20261010-ads126x-v5-0-49e331cb2fed@gmail.com> To: Kurt Borja , Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , David Lechner Cc: =?utf-8?q?Nuno_S=C3=A1?= , Andy Shevchenko , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3240; i=kuurtb@gmail.com; h=from:subject:message-id; bh=dIjt8nwdTss/bhvR/VsQb/EXL6ivNKMpYRbB1ZzbmXo=; b=kA0DAAoWFmBDOPSf1GYByyZiAGrJ4Oait7mMTMA4MGTYlatrqswcZ8sCDSkSGJidd6JLjCXPO 4h1BAAWCgAdFiEEh2Ci9uJabu1OwFXfFmBDOPSf1GYFAmrJ4OYACgkQFmBDOPSf1GbfVAEA8NJZ 5Rd7VzJasMWFIupSIwiW4kHbh1uIQZWNeR+X96oBALDwvFEDzxYdnuQSn3OtTp4iHTzlIXHwwLc P9Ly1VlQC X-Developer-Key: i=kuurtb@gmail.com; a=openpgp; fpr=54D3BE170AEF777983C3C63B57E3B6585920A69A Enable per-channel input chopping via the "input-chopping" property. As the device withholds the first conversion in chop mode, single reads are taken in CONTINUOUS run mode with a brief start/stop pulse, as recommended by the datasheet (Section 9.4.1.2). Reviewed-by: David Lechner Signed-off-by: Kurt Borja --- drivers/iio/adc/ti-ads1262.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/ti-ads1262.c b/drivers/iio/adc/ti-ads1262.c index 98d147f120c4..938e26075302 100644 --- a/drivers/iio/adc/ti-ads1262.c +++ b/drivers/iio/adc/ti-ads1262.c @@ -205,6 +205,7 @@ struct ads1262_channel { u8 ref_n; bool ref_reversal; bool is_resistance; + bool input_chop; size_t num_scales; int scales[ADS1262_GAIN_COUNT][2]; }; @@ -456,7 +457,7 @@ static int ads1262_dev_stop(struct ads1262 *st) return ret; } -static int ads1262_dev_start_one(struct ads1262 *st) +static int ads1262_dev_start_one(struct ads1262 *st, u8 runmode) { int ret; @@ -464,7 +465,7 @@ static int ads1262_dev_start_one(struct ads1262 *st) if (ret) return ret; - if (st->start_gpiod) { + if (runmode == ADS1262_RUNMODE_CONTINUOUS || st->start_gpiod) { /* * The START pulse timing requirement is 4 clock cycles, at the * minimum clock rate this is 4 microseconds. @@ -512,7 +513,9 @@ static int ads1262_channel_enable(struct ads1262 *st, guard(mutex)(&st->chan_lock); ret = regmap_update_bits(st->regmap, ADS1262_MODE0_REG, + ADS1262_MODE0_INPUT_CHOP_MASK | ADS1262_MODE0_REFREV_MASK, + FIELD_PREP(ADS1262_MODE0_INPUT_CHOP_MASK, chan->input_chop) | FIELD_PREP(ADS1262_MODE0_REFREV_MASK, chan->ref_reversal)); if (ret) return ret; @@ -553,13 +556,26 @@ static int ads1262_channel_read(struct iio_dev *indio_dev, const struct iio_chan_spec *spec, __be32 *val) { struct ads1262 *st = iio_priv(indio_dev); + struct ads1262_channel *chan = &st->channels[spec->scan_index]; + u8 runmode; int ret; IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim); if (IIO_DEV_ACQUIRE_FAILED(claim)) return -EBUSY; - ret = ads1262_set_runmode(st, ADS1262_RUNMODE_PULSE); + /* + * When a channel has chop mode or IDAC rotation mode, the first + * conversion is always withheld so the datasheet suggests using the + * CONTINUOUS mode and briefly starting and stopping conversions to + * achieve the same effect (Section 9.4.1.2). + */ + if (chan->input_chop) + runmode = ADS1262_RUNMODE_CONTINUOUS; + else + runmode = ADS1262_RUNMODE_PULSE; + + ret = ads1262_set_runmode(st, runmode); if (ret) return ret; @@ -569,7 +585,7 @@ static int ads1262_channel_read(struct iio_dev *indio_dev, reinit_completion(&st->drdy); - ret = ads1262_dev_start_one(st); + ret = ads1262_dev_start_one(st, runmode); if (ret) return ret; @@ -1316,6 +1332,7 @@ static int ads1262_parse_channel_node(struct ads1262 *st, } } + chan->input_chop = fwnode_property_read_bool(node, "input-chopping"); chan->ref_reversal = fwnode_property_read_bool(node, "ti,reference-reversal"); return 0; -- 2.55.0