From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AC58C35296 for ; Fri, 13 May 2022 13:50:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229741AbiEMNt6 (ORCPT ); Fri, 13 May 2022 09:49:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378060AbiEMNkQ (ORCPT ); Fri, 13 May 2022 09:40:16 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8922B13FAB; Fri, 13 May 2022 06:40:14 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: shreeya) with ESMTPSA id 20E7E1F4608A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1652449212; bh=X8gPJfUaPvojokUrQ1VToFmt1LKmH1dH4HkLO7C9KHE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=CyYDwTVi4ueHyg/u7jL4r3bByMb9muNVhf6HiSrmSxIDn3/qh1ZgF4hKY0Ve7GJTq NC1TSrTlB0lJuLsY2sFbzJpb7CwAoZBX0oqpF+p+IoGrcmuxmm/RBCHxEvQNnRllOO f5yX2BHYZ/IrsOovE3YL32ovPyEW6ZlcM3IPTwl/kLyR35Qe59iDQHoDp8A/LKH2iD nR8JyJJTEq6MZdtGHIqxLN1c9ppxEPIWfe9YXO6NTCvN0WhWiOJsb4BvRTwE0KkAou aCv0jmHfaxIHZ/tqMfw2g1XqFG0zSiWl/Nthk3dmXLdzOxl1e91/cGnjMnjWHQQMP9 7GELqEiEDvEzQ== Message-ID: <88b33ada-e997-05e9-f555-b9c1ed369fb7@collabora.com> Date: Fri, 13 May 2022 19:10:05 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v4 3/3] iio: light: Add support for ltrf216a sensor Content-Language: en-US To: Dmitry Osipenko , jic23@kernel.org, lars@metafoo.de, robh+dt@kernel.org, Zhigang.Shi@liteon.com, krisman@collabora.com Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@collabora.com, alvaro.soliverez@collabora.com References: <20220511094024.175994-1-shreeya.patel@collabora.com> <20220511094024.175994-4-shreeya.patel@collabora.com> From: Shreeya Patel In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 13/05/22 05:24, Dmitry Osipenko wrote: Hi Dmitry, > 11.05.2022 12:40, Shreeya Patel пишет: >> +static int ltrf216a_init(struct iio_dev *indio_dev) >> +{ >> + int ret; >> + struct ltrf216a_data *data = iio_priv(indio_dev); >> + >> + ret = i2c_smbus_read_byte_data(data->client, LTRF216A_MAIN_CTRL); >> + if (ret < 0) { >> + dev_err(&data->client->dev, "Error reading LTRF216A_MAIN_CTRL\n"); >> + return ret; >> + } >> + >> + /* enable sensor */ >> + ret |= FIELD_PREP(LTRF216A_ALS_ENABLE_MASK, 1); >> + ret = i2c_smbus_write_byte_data(data->client, LTRF216A_MAIN_CTRL, ret); >> + if (ret < 0) { >> + dev_err(&data->client->dev, "Error writing LTRF216A_MAIN_CTRL\n"); >> + return ret; >> + } > Couldn't you write "1" directly without reading? > > What about doing SW reset? I think we are doing a read here just to make sure device registers are ready and accessible without any issues. Also, why would we want to do a SW reset here? In the datasheet, I could see the following steps to enable the sensor Supply VDD to Sensor (Sensor in Standby Mode) ---> Wait 100 ms (min) - initial startup time ---> I2C Command (Write) To enable sensor to Active Mode Thanks, Shreeya Patel >