From patchwork Sun Oct 4 03:14:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chu Lin X-Patchwork-Id: 11815477 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2448A6CB for ; Sun, 4 Oct 2020 03:14:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A621206B8 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 S1726499AbgJDDO4 (ORCPT ); Sat, 3 Oct 2020 23:14:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726497AbgJDDOz (ORCPT ); Sat, 3 Oct 2020 23:14:55 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25A31C0613E7 for ; Sat, 3 Oct 2020 20:14:55 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id b13so638151pgr.4 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=UmnxxVy68TtkYCJQxKXahBngDvyLNwjMmRW1sBivhGIF+i+fjTZziVpxZApio37Nb2 Nfim8MPVyn4WwzwMnyFvMaQa4XkOUf1eJJ/7EgjxsapYCxDHuPjrRdr9iYTksnaqQn2v 5tbxT8otjdOhJlAMEEKhq/N4WhhW7Y/7xWUoz1r1VwEsomKr0Llh3DjZtOMz+oy93b4K W3/FyxLvJP2mGoTlp8Us8srPquHWh2AQBeaN0/QQqJ41cirj9Qw1tNFYadihyBpPUZyJ WkNWf6f/9QW01UWo8w2DmBLQSOVwU190DXJfY9/GkyTiz0EyZXzskOJZP9Y1kb0gm22D cPKg== X-Gm-Message-State: AOAM531MjDt/MIJgPY1jBIrAC929g2Xgy3osDmEqJ6rcJ8nU2SBQZKqo 8x/XBoSrPKrWAbf6fGfk1OnrpRWY4dWDQ94T 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 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@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 Reviewed-by: Guenter Roeck --- 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)