From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04B6B24B23A; Sat, 11 Jan 2025 12:56:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736600192; cv=none; b=FPG0jUJCJ7m7Sq89R0WUsf8vhyp2rcNNLUizH09qdUwJ4KbTmQCG2j1clSVH890sL673iC3zdWnLBwk4dkTXW8gEuRiLFFQId69kL/zkNqqOyBvO0UIHr44xIZm/NhL/SfLWuo3WNsTR7yRQrKOXxOglf8Zio2DfwE7orVM5DPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736600192; c=relaxed/simple; bh=LhZdJ42sMqFKGDmGiTMv1PLug74O089BpN8CgVbPYBk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nrOf2RKHAB6WyJH+li+/m7oV4vh0ap8EPhoWXDzQY78/GzeATcrYc7Fx22IbQWib8vGBNfrim1PqkY8+OFmhDu1lrIdv4igXrz97tYDrvYeYSya9hzBjV9zti1HKUwpWq8O3wDbO4APkevxsWz8jnJfW4HwfOD9BHlq1VbKhKDs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lkWo5q6n; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lkWo5q6n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BF68C4CED2; Sat, 11 Jan 2025 12:56:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736600191; bh=LhZdJ42sMqFKGDmGiTMv1PLug74O089BpN8CgVbPYBk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lkWo5q6nB1BMYay3bfUHadpZckebW9PR1fQLv5VW4ytwZYsWPFBkYDklHf3zOGJdH /53bPXtalkRP5EcE4ev8NVijCBucSpJ9SyWU/mv3TFZ3i5nWQq2v000ku8fn7NnORO aHLpbO4T2gaZK7ehC8mt/O24TFRFsyHkTmVGIpyUnOuYw/xa8Nk9fdQD8qlP6RKS8o uhZ16J0PIUIJEeR5eIs64Y0TN4KyRq6RH+9b9bv/LpCeHfIEMc5bgnaipTJx31o6s1 KkcITkxKuSltO2aJ3l6VkOxX3YpS1nGpK35v5z8DzMmM5+IRt70DM1bqDgnmFgzC3P UWrsBTRPm6W/A== Date: Sat, 11 Jan 2025 12:56:16 +0000 From: Jonathan Cameron To: Yu-Hsian Yang Cc: marcelo.schmitt@analog.com, olivier.moysan@foss.st.com, avifishman70@gmail.com, tmaimon77@gmail.com, tali.perry1@gmail.com, venture@google.com, yuenn@google.com, benjaminfair@google.com, lars@metafoo.de, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, nuno.sa@analog.com, dlechner@baylibre.com, javier.carrasco.cruz@gmail.com, andriy.shevchenko@linux.intel.com, mitrutzceclan@gmail.com, tgamblin@baylibre.com, matteomartelli3@gmail.com, alisadariana@gmail.com, gstols@baylibre.com, thomas.bonnefille@bootlin.com, herve.codina@bootlin.com, chanh@os.amperecomputing.com, KWLIU@nuvoton.com, yhyang2@nuvoton.com, openbmc@lists.ozlabs.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] iio: adc: add Nuvoton NCT7201 ADC driver Message-ID: <20250111125616.2b12f03e@jic23-huawei> In-Reply-To: References: <20241226055313.2841977-1-j2anfernee@gmail.com> <20241226055313.2841977-3-j2anfernee@gmail.com> <20241228133531.5e98357e@jic23-huawei> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit > > > + > > > + /* > > > + * After about 25 msecs, the device should be ready and then > > > + * the Power Up bit will be set to 1. If not, wait for it. > > > + */ > > > + mdelay(25); > > > + err = regmap_read(chip->regmap, NCT7201_REG_BUSY_STATUS, &value); > > > + if (err < 0) > > > + return err; > > > + if (!(value & NCT7201_BIT_PWR_UP)) > > > + return dev_err_probe(&chip->client->dev, -EIO, "failed to power up after reset\n"); > > > + > > > + /* Enable Channel */ > > > + guard(mutex)(&chip->access_lock); > > > + regmap_write(chip->regmap, NCT7201_REG_CHANNEL_ENABLE_1, > > > + NCT7201_REG_CHANNEL_ENABLE_1_MASK); > > > > Check return value. This is over an I2C bus, not the most reliable of > > transports! > > > > Consider doing this differently and using a bulk write for the larger > > case. > > > > if (chip->num_vin_channels <= 8) > > ret = regmap_write(); > > else > > ret = regmap_bulk_write(); > > > > However as you read ENABLE_2 unconditionally below, can you instead just > > always use a bulk write here? > > > > We can't use regmap_bulk_write() due to the chip's limit. > regmap_bulk_write(chip->regmap, ..., ..., 2) , > the first byte is well written, but the second byte don't changed. Find out why. You may well need to set a few more parameters for the configuration of the regmap to ensure the correct form of bulk write. > > > > > + if (chip->num_vin_channels == 12) > > > + regmap_write(chip->regmap, NCT7201_REG_CHANNEL_ENABLE_2, > > > + NCT7201_REG_CHANNEL_ENABLE_2_MASK); > > > + Jonathan