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 X-Spam-Level: X-Spam-Status: No, score=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05FB5C4727E for ; Sun, 4 Oct 2020 03:14:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5EC2206B8 for ; Sun, 4 Oct 2020 03:14:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bAzh9QPy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726526AbgJDDO5 (ORCPT ); Sat, 3 Oct 2020 23:14:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726516AbgJDDO4 (ORCPT ); Sat, 3 Oct 2020 23:14:56 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3286AC0613E8 for ; Sat, 3 Oct 2020 20:14:55 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id a27so3866441pfl.17 for ; Sat, 03 Oct 2020 20:14:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to; bh=LhQBM6coR58Co/ZAPA0BFc3M4Mk5vH1MxVZJV9ls2vA=; b=bAzh9QPy/8+oA04boCqNdkX9voAP/+Gg756k4vP8HjMlDBZ2nMYJSINilK52c1NBez q31UZmbwzvjug2Q0mmo/iOB0pErHbhLKpnX7RpVvOUjq+adQfQHjzgPFvaNwzE8USvMZ Guh8IPPr51x8M9+F6QYQjsbzHNOjGopcZaSZaur+vqIN53nJWpTlwkj73EXl9dcvbrTG eqquSXE5F0qaVh8hIOxHPuOP7hhHirFxcXaWA7ovnvMdC3D1O8KhQUoLKFZhasL2iKtC 0WBHitfyKkreWL0ePFIGykj+vZuGJRaN8kvVoh3CneyY8Puw69/q9TcplQdVm9mMAqEa InTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to; bh=LhQBM6coR58Co/ZAPA0BFc3M4Mk5vH1MxVZJV9ls2vA=; b=RxqKuuu4VkwuFYW1ov2o8p71QtkSiH4lVdnqQpoqS90L751gnGumCtBv9dNX25wPKd dOxA3bpIUqOJ2Vica6e7AGWAUQdp2e5L8QAMvcds4UoboF8pa+ncmF9zZRDciss1FdZ5 BeBsp2GsOKYqy0AOCulxYNAVUyMi9wFl7AxrHAE+UmZSlEXL1TTUagSjRux7khg8xgVF vNfDlAI2yt8sv+3iueX15ExixVE7BrfsX9Qk0kaqmgrJBEM9C/2303gOfMtCiRDYQ5dy JX0IgJULhTRhr10odY30RshnmZsdTkCLYC35QOlUSuAhLr4LRKpkwJ2YIHzTfddE5Dgl 1NOQ== X-Gm-Message-State: AOAM5321U4xwoYa0LCwaDFdm9HMPFblpA6PtYVWTGwNu92YRPHqA6W3u DZOTw0HXw94WXTpQt2+dRAeVst5HagaWb+sx X-Google-Smtp-Source: ABdhPJwzzMxNDTk6r9V6wNabUs9CJ15rB1Am55ZHxJYf8iqp+g/GkSnAUj9Ajd4XZxCWHO/XflZpBBlIIstATRSz Sender: "linchuyuan via sendgmr" X-Received: from chu-dev.c.googlers.com ([fda3:e722:ac3:10:24:72f4:c0a8:3cfb]) (user=linchuyuan job=sendgmr) by 2002:a17:90a:990c:: with SMTP id b12mr233850pjp.0.1601781294305; Sat, 03 Oct 2020 20:14:54 -0700 (PDT) Date: Sun, 4 Oct 2020 03:14:45 +0000 In-Reply-To: <20201004031445.2321090-1-linchuyuan@google.com> Message-Id: <20201004031445.2321090-3-linchuyuan@google.com> Mime-Version: 1.0 References: <20201004031445.2321090-1-linchuyuan@google.com> X-Mailer: git-send-email 2.28.0.806.g8561365e88-goog Subject: [PATCH v4 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider From: Chu Lin To: linchuyuan@google.com, jdelvare@suse.com, linux@roeck-us.net, robh+dt@kernel.org, linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Problem: We use voltage dividers so that the voltage presented at the voltage sense pins is confusing. We might need to convert these readings to more meaningful readings given the voltage divider. Solution: Read the voltage divider resistance from dts and convert the voltage reading to a more meaningful reading. Testing: max20730 with voltage divider Signed-off-by: Chu Lin --- ChangeLog v1 -> v2 hwmon: pmbus: max20730: - Don't do anything to the ret if an error is returned from pmbus_read_word - avoid overflow when doing multiplication ChangeLog v2 -> v3 dt-bindings: hwmon: max20730: - Provide the binding documentation in yaml format hwmon: pmbus: max20730: - No change ChangeLog v3 -> v4 dt-bindings: hwmon: max20730: - Fix highefficiency to high efficiency in description - Fix presents to present in vout-voltage-divider - Add additionalProperties: false hwmon: pmbus: max20730: - No change drivers/hwmon/pmbus/max20730.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c index a151a2b588a5..fbf2f1e6c969 100644 --- a/drivers/hwmon/pmbus/max20730.c +++ b/drivers/hwmon/pmbus/max20730.c @@ -31,6 +31,7 @@ struct max20730_data { struct pmbus_driver_info info; struct mutex lock; /* Used to protect against parallel writes */ u16 mfr_devset1; + u32 vout_voltage_divider[2]; }; #define to_max20730_data(x) container_of(x, struct max20730_data, info) @@ -114,6 +115,14 @@ static int max20730_read_word_data(struct i2c_client *client, int page, max_c = max_current[data->id][(data->mfr_devset1 >> 5) & 0x3]; ret = val_to_direct(max_c, PSC_CURRENT_OUT, info); break; + case PMBUS_READ_VOUT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret > 0 && data->vout_voltage_divider[0] && data->vout_voltage_divider[1]) { + u64 temp = DIV_ROUND_CLOSEST_ULL((u64)ret * data->vout_voltage_divider[1], + data->vout_voltage_divider[0]); + ret = clamp_val(temp, 0, 0xffff); + } + break; default: ret = -ENODATA; break; @@ -364,6 +373,15 @@ static int max20730_probe(struct i2c_client *client, data->id = chip_id; mutex_init(&data->lock); memcpy(&data->info, &max20730_info[chip_id], sizeof(data->info)); + if (of_property_read_u32_array(client->dev.of_node, "vout-voltage-divider", + data->vout_voltage_divider, + ARRAY_SIZE(data->vout_voltage_divider)) != 0) + memset(data->vout_voltage_divider, 0, sizeof(data->vout_voltage_divider)); + if (data->vout_voltage_divider[1] < data->vout_voltage_divider[0]) { + dev_err(dev, + "The total resistance of voltage divider is less than output resistance\n"); + return -ENODEV; + } ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET1); if (ret < 0) -- 2.28.0.806.g8561365e88-goog