From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) (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 D7F9237C912; Mon, 6 Jul 2026 02:09:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.135.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783303781; cv=none; b=OUZR/75YLbcjQ3bCe9NwhWNyQtV8uIdS5vDTVdr/LpVyLLbNINVvq92fx0dDL8ljwXdhd7J3V26UIa92c7Vt1NfxV4KORrwZJHnEdOoHh/GR4V8/6dxtNvMkpEV+UCEaJ8kjMsQbnb9fONkVtZzuEjDWF14MyG7EM6AUqYWxaSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783303781; c=relaxed/simple; bh=hky9C2D6iGGEVKf2veReFUr/Y8MLbhh9YrnYkyhMtl0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=cbSK9gdudHm8AzaXR1Z1N87Si14U8w0CvExin6WhRsovKDAQQDhVEwzw3g8UKFpNB6O5WzCR6VbXSLHiqAqJVZq9ontPMOMB7/4FvfldxvRffWEVBAWYu7qN2dtoA8i43UJg3DXqJb/EKNOVwLaiTL3nCqlueU3SJtE0R1Jd+Iw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=analog.com; spf=pass smtp.mailfrom=analog.com; dkim=pass (2048-bit key) header.d=analog.com header.i=@analog.com header.b=xT+248JX; arc=none smtp.client-ip=148.163.135.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=analog.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=analog.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=analog.com header.i=@analog.com header.b="xT+248JX" Received: from pps.filterd (m0516787.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 665M4Kul3211626; Sun, 5 Jul 2026 22:09:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=analog.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=DKIM; bh=ZNJND NAEzdg22PNppNhgGEvDLwkQA8n8edWUkZAztTk=; b=xT+248JXT4pADbmjiaSPe NPx6fsg7dI7yRLLzzcfMki2a4wDNR+U0OKznJUI+kis/a1m1yvirTgJ2d1hRJ+ER LmsfRh2/tlhjOO/xgwzpAmdC/hUObyrx1oPajViaDMfjr8J/I5l7DFccVTUXeUk1 95z4fba4rn44D+ifcDo58dXBjs3sPprVbjsmWJ9ddNlke+v5MtExqnDrqBYeKSjs AtQJGk5f74AijhCnZT9D/eVH5Wc3I/rzuculG5AGvJjUYaVhMePqKqTAUj+QIvzR 507ChzcwEStH9Zh1iH3nQNsGKJt1ViUAeaLhhOq1xWpo1CrGtdrZHshni0oRp3NM w== Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 4f7kgf9uvk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 05 Jul 2026 22:09:17 -0400 (EDT) Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 66629G8D045190 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Sun, 5 Jul 2026 22:09:16 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.37; Sun, 5 Jul 2026 22:09:16 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.2.1748.37 via Frontend Transport; Sun, 5 Jul 2026 22:09:16 -0400 Received: from ATORRENO-L02.ad.analog.com ([10.66.6.191]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 66628o7S015791; Sun, 5 Jul 2026 22:09:11 -0400 From: Alexis Czezar Torreno Date: Mon, 6 Jul 2026 10:08:43 +0800 Subject: [PATCH v2 3/5] hwmon: (pmbus/max20830): add VOUT feedback resistor scaling support Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-ID: <20260706-dev-max20830c-v2-3-37761e89bb5f@analog.com> References: <20260706-dev-max20830c-v2-0-37761e89bb5f@analog.com> In-Reply-To: <20260706-dev-max20830c-v2-0-37761e89bb5f@analog.com> To: Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Corbet , Shuah Khan CC: , , , , Alexis Czezar Torreno X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1783303730; l=3855; i=alexisczezar.torreno@analog.com; s=20250213; h=from:subject:message-id; bh=hky9C2D6iGGEVKf2veReFUr/Y8MLbhh9YrnYkyhMtl0=; b=EDs1LzupOUPEICbA8KJWmERSOUczn9wrcadkRcIZj3zU/t1ot8XxzOS8Vx8xMo27IyMjOqxrm HiAApQH9fYrBXdZioE00Jw68fK2TD9677ZjDgvfwWVGiGiCqExi574x X-Developer-Key: i=alexisczezar.torreno@analog.com; a=ed25519; pk=XpXmJnRjnsKdDil6YpOlj9+44S+XYXVFnxvkbmaZ+10= X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: _YqK6oE8GhAT2meiIhb1mApjW90yMrRp X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzA2MDAxOSBTYWx0ZWRfX8ODDsQPL9id3 eYdt18NyP0qq6+FE+D0kPYSoK8DkWAitvDK5bN7rIB8JAGCDiDR3A7eILY/M7Ri8FtovGLdsH/X 2kkc5PpAqNhxp0W6Uaa0UdYaZDCjiC2ZOn0XcuqJdiZlPGePds4wFXyTz3WayBwDln/xbK3d3oy s0YxLLNWK7gPz5n7PTmw+PFxLzu5EV+4R5yXz7MUfvd0wr/DUFarlGopcAbcyhEgk0S9O5DEL2r 2SNOZ3gIvtH/+Jezg3g2LGSm/zCzRXvyOQwF9TAD1+db3HUYkXjb8YB5Lx/QtZyffEHsb/Lup+P uhyGCBtzKBKAvGponCk/3arvbGWoT5/IEs1SL3RaaGXyMIbVwcD4yulcYqv6qjS6UTSOPfNOL4P Vn1OIxwi0nV0V66vTqZEiTEyPK+PRoja9tbkWBhTSmQwp2WTa6+mq9CosMAz5D17ky8OQ0S7Wf5 ICyCFGKBkfWWN8ggY/Q== X-Authority-Analysis: v=2.4 cv=SebHsPRu c=1 sm=1 tr=0 ts=6a4b0e4d cx=c_pps a=3WNzaoukacrqR9RwcOSAdA==:117 a=3WNzaoukacrqR9RwcOSAdA==:17 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=0sLvza09kfJOxVLZPwjg:22 a=OmVn7CZJonkx5R5zMQLL:22 a=gAnH3GRIAAAA:8 a=_8IsL081WaPWLXqRiQAA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzA2MDAxOSBTYWx0ZWRfX4ymVSLOObUv5 RMrtPRF7qoUjHR4+7nkK8PiH9xGSCnPJsJ/Ramj2ZouEwAsw9JVC5iOa6MmBDurtOcssOsAQ+2G BX5CKrNBFJDIqqlopoQUmhQ5RumTt+XVpMwZpTSZaVRuZ+o07v/w X-Proofpoint-ORIG-GUID: _YqK6oE8GhAT2meiIhb1mApjW90yMrRp X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-07-05_02,2026-07-03_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 impostorscore=0 lowpriorityscore=0 bulkscore=0 adultscore=0 clxscore=1015 phishscore=0 priorityscore=1501 spamscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607060019 Implement support for external voltage divider scaling using the adi,vout-rfb1-ohms and adi,vout-rfb2-ohms device tree properties. When the desired output voltage exceeds VREF, a resistor divider (RFB1 and RFB2) is used to scale down the feedback voltage. The driver reads these resistor values from device tree and applies the scaling formula: VOUT_actual = VOUT_measured × (1 + RFB1/RFB2) The properties are optional. If not specified, the driver assumes no voltage divider is present and reports the raw VOUT reading. Signed-off-by: Alexis Czezar Torreno --- drivers/hwmon/pmbus/max20830.c | 54 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 53 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/pmbus/max20830.c b/drivers/hwmon/pmbus/max20830.c index cb2c23672166d641852199ca07eb716924f4f286..5aad4448054fc55bb0a87920d89f96bc28fda072 100644 --- a/drivers/hwmon/pmbus/max20830.c +++ b/drivers/hwmon/pmbus/max20830.c @@ -7,6 +7,7 @@ #include #include +#include #include #include #include @@ -14,6 +15,45 @@ #define MAX20830_IC_DEVICE_ID_LENGTH 9 +struct max20830_data { + struct pmbus_driver_info info; + u32 vout_rfb1; + u32 vout_rfb2; +}; + +/* + * Driver currently only supports READ_VOUT for monitoring that needs scaling to + * convert from feedback voltage to actual output voltage. + * + * vout_actual = vout_fb × (1 + RFB1/RFB2) + * + * VOUT_COMMAND and VOUT_MAX are currently not in use, but work with feedback + * voltage. If regulator support is added, VOUT_COMMAND values would need + * to be adjusted accordingly. + */ +static int max20830_read_word_data(struct i2c_client *client, int page, + int phase, int reg) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + const struct max20830_data *data = container_of(info, struct max20830_data, info); + int ret; + + switch (reg) { + case PMBUS_READ_VOUT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + + /* Apply voltage divider scaling if resistors are non-zero */ + if (data->vout_rfb1 && data->vout_rfb2) + ret = DIV_ROUND_CLOSEST_ULL((u64)ret * (data->vout_rfb1 + + data->vout_rfb2), data->vout_rfb2); + return ret; + default: + return -ENODATA; + } +} + static struct pmbus_driver_info max20830_info = { .pages = 1, .format[PSC_VOLTAGE_IN] = linear, @@ -24,13 +64,25 @@ static struct pmbus_driver_info max20830_info = { PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP, + .read_word_data = max20830_read_word_data, }; static int max20830_probe(struct i2c_client *client) { u8 buf[I2C_SMBUS_BLOCK_MAX + 1] = {}; + struct max20830_data *data; int ret; + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->info = max20830_info; + + /* Read optional voltage divider resistor values */ + device_property_read_u32(&client->dev, "adi,vout-rfb1-ohms", &data->vout_rfb1); + device_property_read_u32(&client->dev, "adi,vout-rfb2-ohms", &data->vout_rfb2); + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BLOCK_DATA) && !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) return -ENODEV; @@ -78,7 +130,7 @@ static int max20830_probe(struct i2c_client *client) return dev_err_probe(&client->dev, -ENODEV, "Unsupported device: '%s'\n", buf); - return pmbus_do_probe(client, &max20830_info); + return pmbus_do_probe(client, &data->info); } static const struct i2c_device_id max20830_id[] = { -- 2.34.1