From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) (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 28CFD3D9035 for ; Mon, 2 Mar 2026 13:06:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772456820; cv=none; b=tjouQpLS7ShnhWSJf0U5Go0X5d1uShIKDABj4rN/fgFueHrgaRvg1Dzr2IcFq/OCc0vmljWQXkgu7ESeEyAYaDNHULAZDwHBjcMaX5J8khK/MlXUkuMCiZw8/VyI330r3ermkxXlzACKFwRpgANrLnKcmyUk4bpKKkIOfcdWtVw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772456820; c=relaxed/simple; bh=tJOlEx2YSqymMwX2fM5CB5Sh2YTeZS67ymrbPi2BBeg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZurZ4de08oZ1BVUOR6hC2PLLMK6TxuMVv8vc1Ic7QDbFavpQtopHlMra6r2cDYS9H8CKla9ZdW/7PF+WrfjUssbh3BWCRoI1dhpH3in+G+eSlQQJ3FmirTmOptpP0OoHBhYq5/wpAPTicBTIpHUS9et83CyfFx9wnRNbptAGc5g= 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=I4B59C0q; arc=none smtp.client-ip=209.85.216.51 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="I4B59C0q" Received: by mail-pj1-f51.google.com with SMTP id 98e67ed59e1d1-3585ec417f6so2035384a91.1 for ; Mon, 02 Mar 2026 05:06:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1772456818; x=1773061618; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=2mxbGIf2vs06p+QEYROvnEWXbdM+MByCGD3Xnp5U/wY=; b=I4B59C0qALDlyzRayvHMU9UWZdlGbhute9f1lmCPz3A3O+vhpZSN63g3eW2d3Z/cyk 0hnf8gnYTDZnBMREibP5Pa3oAsFIcP4s05TXgGOqH1xj/MaM5VWBXfSSRn+eriZCPTmw dtXobRfomntWmEIsNNvYLTHjEo/AMVU296QKDha2jWKTEStUOeIN3yUw3yg/Z2wRdRHe 91V/vxdQttZGhpLRxhPX+/+ZdSGb6Skb/l7RCu+irlZIZPryPtfld5CX8M0SYL71L/k9 yzB8o2Xp8b4i1calSGG6lPhLGPeMLuJaaAaZDUzqEpmFzExQUR8wBavvVSiZXDdDAxf0 6LZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772456818; x=1773061618; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=2mxbGIf2vs06p+QEYROvnEWXbdM+MByCGD3Xnp5U/wY=; b=Zjn5p0c2jh26CbCBlisWrjVcZCoQWE6IDJutElYor0Pf335pOiYyv05ZOX5kmaL8lg l+y+2SLtCWLKXszPqNSwO5OTY/KAy+Ci6xxVJdvNLYHNiYrn9dXItlVo4wWwTNjVGEqm GD5rRimTugLIGT/Opo9Bpw0oW+44oQhGuvhYExb3xVEB8EbI9zIZvTPYRuckrrtvxdqy B4dt3FzwD7pkwpTD2T1dxflkP64f30CYw4RjHaHI4lkX42oI7C3gb3KL23xTf47piWon AHo3yv9wOrUt0QAyOCDP7e5N58VlD2ePD1Jx0CXlAv0ZjhQxT71/vG1N/p4dIyXb5mnY 0EPA== X-Forwarded-Encrypted: i=1; AJvYcCWu6s7VJphJppc6Pu3UryQw5FCrha6qOs6L66LPkGC8UiqdMqoADYzMchBdKj079lsql+dy8CxGS9Q=@vger.kernel.org X-Gm-Message-State: AOJu0YxNpUuFohk2xUfgy5naJBH41I/pTofuxOUCemeBJwvAwqcuKr6V Gj6CuaFvhr0TmEaDfFWOMcajsYzhM/e2RaQwPgPovaLsVUmvHx+QmMbb X-Gm-Gg: ATEYQzxZiOUX+AN96L/4zoVPqA2fKosjUOEY08KIZkkcZq5F1j6RB/BonWOXvn5j4GS qGGYC3lWKUwh1jbfWTxCNbLSRBFXXvMtjaYgz2csGfrRJAjTRd+5yaKmyUWXzG4/2CTUozjrtIr 5PcfdgbV5Jwx+LGjkwrtSm/GjY2lq1lSa6p6qZ0QkeEfCqVqektbEdBrP7G1Clu4DxqxmiarfW6 aHP/nsF4DDsn1eLAiVnGR8QFZWj6w2PD+817NUc/LHipNUruBEZs0LPYDH+zSR6m/0TbIKt7DsW UmCVWrjHaGJuiel4OUsFqjbx/L383eNlNQ+OE6zsxm0Njg0rOpn95yoddkQf0obWaPtIHXb8BD4 yJfOiMAKDFYpSQYTA29QrCdMNnIsG901e07wiJ1wdgIevz3uXpgpWB1jdlji8TzjpbOx+E4Tn9R K48AH0Xf5UtB1tJgwjfNBu/FGOJfEvmo0ZuZhm2QGl1Q== X-Received: by 2002:a17:90a:e704:b0:359:8df1:8553 with SMTP id 98e67ed59e1d1-3598df1884emr2375476a91.9.1772456818404; Mon, 02 Mar 2026 05:06:58 -0800 (PST) Received: from debian.ari ([152.58.176.247]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3597b448e38sm7444585a91.5.2026.03.02.05.06.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Mar 2026 05:06:57 -0800 (PST) From: Archit Anant To: jic23@kernel.org, lars@metafoo.de, Michael.Hennerich@analog.com Cc: dlechner@baylibre.com, nuno.sa@analog.com, andy@kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Archit Anant Subject: [PATCH v3 2/4] iio: adc: ad799x: cache regulator voltages during probe Date: Mon, 2 Mar 2026 18:36:30 +0530 Message-Id: <20260302130632.29144-3-architanant5@gmail.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20260302130632.29144-1-architanant5@gmail.com> References: <20260302130632.29144-1-architanant5@gmail.com> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Reading the regulator voltage via regulator_get_voltage() can be a slow operation. Since the reference voltages for this ADC are not expected to change at runtime, it is inefficient to query the regulator API every time userspace reads the IIO_CHAN_INFO_SCALE attribute. Cache the VCC and VREF voltages in the state structure during probe(). This improves the performance of ad799x_read_raw() and removes the dependency on the regulator pointers during fast-path reads. Suggested-by: Jonathan Cameron Signed-off-by: Archit Anant --- drivers/iio/adc/ad799x.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c index 7775be874081..35e0589428d0 100644 --- a/drivers/iio/adc/ad799x.c +++ b/drivers/iio/adc/ad799x.c @@ -135,6 +135,10 @@ struct ad799x_state { u16 config; unsigned int transfer_size; + + int vcc_uv; + int vref_uv; + IIO_DECLARE_DMA_BUFFER_WITH_TS(__be16, rx_buf, AD799X_MAX_CHANNELS); }; @@ -303,9 +307,9 @@ static int ad799x_read_raw(struct iio_dev *indio_dev, return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: if (st->vref) - ret = regulator_get_voltage(st->vref); + ret = st->vref_uv; else - ret = regulator_get_voltage(st->reg); + ret = st->vcc_uv; if (ret < 0) return ret; @@ -809,6 +813,10 @@ static int ad799x_probe(struct i2c_client *client) ret = regulator_enable(st->reg); if (ret) return ret; + ret = regulator_get_voltage(st->reg); + if (ret < 0) + goto error_disable_reg; + st->vcc_uv = ret; /* check if an external reference is supplied */ if (chip_info->has_vref) { @@ -827,6 +835,11 @@ static int ad799x_probe(struct i2c_client *client) ret = regulator_enable(st->vref); if (ret) goto error_disable_reg; + + ret = regulator_get_voltage(st->vref); + if (ret < 0) + goto error_disable_vref; + st->vref_uv = ret; } } -- 2.39.5