From patchwork Thu Jan 26 22:32:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cormier X-Patchwork-Id: 48941 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp521696wrn; Thu, 26 Jan 2023 14:36:12 -0800 (PST) X-Google-Smtp-Source: AMrXdXv5dcPdQmWAS/B2i4rUHKzmd/G/Utcsc56gbIGRt0uJqJc/ufBKB/4e37mtwVyN2f7YIVjw X-Received: by 2002:a17:90b:3b4a:b0:22a:3756:542c with SMTP id ot10-20020a17090b3b4a00b0022a3756542cmr26820626pjb.39.1674772572232; Thu, 26 Jan 2023 14:36:12 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674772572; cv=none; d=google.com; s=arc-20160816; b=eIsEHDUNGR8X44YH9ahtYw5WCCzsVhcIjW1X0uC9tt2WWpF41sEuLO9fxpXzbuwi+z +sJf2XGtHeZT7xIktIBz0rd961BygrXIdWrql9AcnewxX5+AYA1AOvCUE3XQAIGyUoxR /Kc4RqS0ff8GOsdtdu07prJq3kBk13B0S0gTtpNlN7BkdnQnhN77CZEVnGkeCQa7Dk+T MpDVJy7grUF0Ky/sVgHGQrzzxd04SlhWYW/PS8z8B22le3AVaOq52kL3YpJXzQB9YoL+ EzBjo6zWg7Iod/nnLMf09B4iwZ3TVDMMjyxIAo+wq+LbOpr7V8EfsGCTZoORhpIo5ee0 chCg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:in-reply-to:references:message-id :content-transfer-encoding:mime-version:subject:date:from :dkim-signature; bh=SCHr8u8LkHFJIdDqjoshO09JHhBWtvWwNk0DDadovgI=; b=dsV8ZBGhMPUvEM5x/aD4dyhzJlgOAByBgjXGMQKSTBvchGOKb7iq6dydKRu11+nXnz N1dsf+v0c8jLfr7gEoYUFo8wgUSw+Zphk2dKQ3qjEZB3uyiqyP+xhfFXU0lP8G0Fl9ma cgx1082C5sORQSSZfG2XRn5PwpuN2B2wYikqddDASJrObX4Ge93y2bRDmQ/FjsHBUK3f Z1xehGkCkXtCf9nicBsZrMqfYfPG5uQFSc9uUX061j2yiLTGwNgxrOa0q8jaVq0nwPlM cxQQOHPsPcKvz7FEiyQ/Gx8idiIe5kc6V7XQVVe4uHJRWKiCqJK24Opo/uAn20qKkKRo sxJQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@criticallink.com header.s=google header.b=TFi70dSx; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=criticallink.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id n11-20020a17090b0d0b00b00228ff7707a9si2809411pjz.34.2023.01.26.14.35.59; Thu, 26 Jan 2023 14:36:12 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@criticallink.com header.s=google header.b=TFi70dSx; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=criticallink.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233290AbjAZWde (ORCPT + 99 others); Thu, 26 Jan 2023 17:33:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232576AbjAZWcw (ORCPT ); Thu, 26 Jan 2023 17:32:52 -0500 Received: from mail-qv1-xf35.google.com (mail-qv1-xf35.google.com [IPv6:2607:f8b0:4864:20::f35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D504645F5E for ; Thu, 26 Jan 2023 14:32:32 -0800 (PST) Received: by mail-qv1-xf35.google.com with SMTP id h10so2588298qvq.7 for ; Thu, 26 Jan 2023 14:32:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=criticallink.com; s=google; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=SCHr8u8LkHFJIdDqjoshO09JHhBWtvWwNk0DDadovgI=; b=TFi70dSxljUji9Q8+lRwOqeik36CcxykG1bkL7Zmf4w+0tfOzcN5b85Yn9/0xi8/Gj sj/I4tMTUr/52yQrbPTK5aruYP4IuMdcqDjtELTU9Bf4/KgwDKbe9h9Vo4ZXVZF1fkBC ZI/cth4gdK1SQ8awl1oUTlgXWExLx1Iyt0cZBEQiw+aQBxRIMMFHr4lcRSk+Zvg4f+y8 ae8jKPwB/UtSxPp0xbI40WchEDa4Ka7ikNQfK500slNPN7y0Mv86dv7Q7k6oDFli0wzw kZtYjh57Gw/V9vHYOmcRAjXA70S8lBR8GrW8AfphZyRzyfF6ehRilbsgdCg4mIg6TTpu 1QWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=SCHr8u8LkHFJIdDqjoshO09JHhBWtvWwNk0DDadovgI=; b=zub5W+BKemSgzckjfbAYWHwFNVCU6lUcn07jkdP4Mwj9qQobJxC+WlpW+vlWTsaiLG Qu/jSaRRgp3Q6v2xbnQxKbBup/VA1CeflngfY0rwFu6uLWMWcNsX7oqDF5Y4sd2wcuOP orcXGAokgFfWmv5UMwYperPIZJhXulPzRg9D0kFzt3qYXWypLqgCDZre9B3WmRYx6X0W 2WtmSS/y7vOVyK7tjG//g30KAhsCfkniVLKSCEemdk6qgEPmMb4hsvGMc807wIL7btpl 5m8D0mslnzeWtJwjtfCqDXzhwU7qiwzFG8zubIzI/W2eMxbaBJVrLXtbpUj7WIhtqeTT 4lSw== X-Gm-Message-State: AO0yUKWYrcDtyZYi+q6Y1S5oc2UfNhrgZK+YcEGpGeYDiUYu6Si8Kl1R zF7TPuJsIGLpTJxS4XCbSy1HON9HTA6Cs+5K9Ps= X-Received: by 2002:a0c:f812:0:b0:537:8125:b533 with SMTP id r18-20020a0cf812000000b005378125b533mr4687943qvn.34.1674772351923; Thu, 26 Jan 2023 14:32:31 -0800 (PST) Received: from [127.0.1.1] (static-72-90-70-109.syrcny.fios.verizon.net. [72.90.70.109]) by smtp.gmail.com with ESMTPSA id m7-20020a05620a220700b006ff8a122a1asm1723091qkh.78.2023.01.26.14.32.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Jan 2023 14:32:31 -0800 (PST) From: Jonathan Cormier Date: Thu, 26 Jan 2023 17:32:26 -0500 Subject: [PATCH v4 4/5] hwmon: ltc2945: Allow setting shunt resistor MIME-Version: 1.0 Message-Id: <20230126-b4-ltc2945_shunt_resistor-v4-4-bb913470d8da@criticallink.com> References: <20230126-b4-ltc2945_shunt_resistor-v4-0-bb913470d8da@criticallink.com> In-Reply-To: <20230126-b4-ltc2945_shunt_resistor-v4-0-bb913470d8da@criticallink.com> To: Jean Delvare , Guenter Roeck , Rob Herring , Krzysztof Kozlowski Cc: linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Bob Duke , John Pruitt , Jonathan Cormier X-Mailer: b4 0.12.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=9001; i=jcormier@criticallink.com; h=from:subject:message-id; bh=kCSpCo/P+JFRfq9IZAl6ayWTbbT5LfJiwbvQxfe6g3w=; b=owEBbQKS/ZANAwAKAdzX/S4LNuuqAcsmYgBj0v96zFJJWKGHqQesz69ayOn6UqiOCCZzjw53eNx4 YdJI+omJAjMEAAEKAB0WIQT/MozqCeZtYxNnVN/c1/0uCzbrqgUCY9L/egAKCRDc1/0uCzbrqkb+EA CCTTrUKXIvVjU0LpKAJFLD/5sUp+4Tg8mMk/H4dslTDJWDfBMPsCYZMxyFzxPgV4leYqaGWZjG6vns UWkFvuveqvD1kESxVbY0NiLZjuCmYe4ZP/0Rl9ycRUrFHmSMIhvpaOhBCkiPY028+bGuFc54bakurO 4txYNTh20oylXaYxx0woWD9K+cdT2zJ3p3F7e2Gbb77HM4rX98HpFC1RvMN03P42ImbaXWGgO+F0h8 5ihdlmfMMAqGiWNiVmv4++1eldYEYl+c8LrjrwSDbZewxCX6OD/y0xF9atczAWBzILF8H5wo3VQRBU VJCCyGWyZxoAeKrVAsovjs+2IO2O2A4BDCu0Mn0hxnYfodlvUYNDl1Rxc45PKFPzVDPTEQRzFfqhLv JFp29d2SdlYNesKPDoSrliGql1cOvhLBSd7pW6kVYLN0q3Y0RXt0nW0Rsjzh9oqaf0ZluhY5LadAHo UgsZNMVLMNZUAMPomN/sDwROHbspJvCYWqv84PgEHG1dwX54rCPI6Ln/FsBNk35DdNStMsh+Pjnscl JQYmNIAchqr6Xf6xniLxWNKZaFL38j4nWBYe+HygM7efrVxwe6IMImIEoTwuLEV/zxH2CjZfHB6ZeN wp90D1H0WnxpxuaUYYXXqDJ5YCRig4NyaboWviqrNd0Aj+tVRJ4E3oXOFVsw== X-Developer-Key: i=jcormier@criticallink.com; a=openpgp; fpr=FF328CEA09E66D63136754DFDCD7FD2E0B36EBAA X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756126325090835794?= X-GMAIL-MSGID: =?utf-8?q?1756126325090835794?= From: John Pruitt Add the ability to specify the value of the shunt resistor in the device tree instead of assuming it is 1 milliOhm. The value in the device tree has the name shunt-resistor-micro-ohms and the default value is 1000 micro-ohms in order to preserve the current behavior. Signed-off-by: Jonathan Cormier Signed-off-by: John Pruitt --- drivers/hwmon/ltc2945.c | 117 +++++++++++++++++++++++++++++++----------------- 1 file changed, 75 insertions(+), 42 deletions(-) diff --git a/drivers/hwmon/ltc2945.c b/drivers/hwmon/ltc2945.c index ac15298a6558..0b5e448b4f12 100644 --- a/drivers/hwmon/ltc2945.c +++ b/drivers/hwmon/ltc2945.c @@ -64,6 +64,16 @@ static const struct of_device_id __maybe_unused ltc2945_of_match[] = { }; MODULE_DEVICE_TABLE(of, ltc2945_of_match); +/** + * struct ltc2945_data - LTC2945 device data + * @regmap: regmap device + * @shunt_resistor: shunt resistor value in micro ohms (1000 by default) + */ +struct ltc2945_data { + struct regmap *regmap; + u32 shunt_resistor; +}; + static inline bool is_power_reg(u8 reg) { return reg < LTC2945_SENSE_H; @@ -72,7 +82,9 @@ static inline bool is_power_reg(u8 reg) /* Return the value from the given register in uW, mV, or mA */ static long long ltc2945_reg_to_val(struct device *dev, u8 reg) { - struct regmap *regmap = dev_get_drvdata(dev); + struct ltc2945_data *data = dev_get_drvdata(dev); + struct regmap *regmap = data->regmap; + u32 shunt_resistor = data->shunt_resistor; unsigned int control; u8 buf[3]; long long val; @@ -84,10 +96,10 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg) return ret; if (is_power_reg(reg)) { - /* power */ + /* 24-bit power */ val = (buf[0] << 16) + (buf[1] << 8) + buf[2]; } else { - /* current, voltage */ + /* 12-bit current, voltage */ val = (buf[0] << 4) + (buf[1] >> 4); } @@ -98,9 +110,7 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg) case LTC2945_MAX_POWER_THRES_H: case LTC2945_MIN_POWER_THRES_H: /* - * Convert to uW by assuming current is measured with - * an 1mOhm sense resistor, similar to current - * measurements. + * Convert to uW * Control register bit 0 selects if voltage at SENSE+/VDD * or voltage at ADIN is used to measure power. */ @@ -114,6 +124,14 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg) /* 0.5 mV * 25 uV = 0.0125 uV resolution. */ val = (val * 25LL) >> 1; } + val *= 1000; + /* Overflow check: Assuming max 24-bit power, val is at most 53 bits right now. */ + val = DIV_ROUND_CLOSEST_ULL(val, shunt_resistor); + /* + * Overflow check: After division, depending on shunt resistor, + * val can still be > 32 bits so returning long long makes sense + */ + break; case LTC2945_VIN_H: case LTC2945_MAX_VIN_H: @@ -136,14 +154,11 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg) case LTC2945_MIN_SENSE_H: case LTC2945_MAX_SENSE_THRES_H: case LTC2945_MIN_SENSE_THRES_H: - /* - * 25 uV resolution. Convert to current as measured with - * an 1 mOhm sense resistor, in mA. If a different sense - * resistor is installed, calculate the actual current by - * dividing the reported current by the sense resistor value - * in mOhm. - */ - val *= 25; + /* 25 uV resolution. Convert to mA. */ + val *= 25 * 1000; + /* Overflow check: Assuming max 12-bit sense, val is at most 27 bits right now */ + val = DIV_ROUND_CLOSEST_ULL(val, shunt_resistor); + /* Overflow check: After division, <= 27 bits */ break; default: return -EINVAL; @@ -151,13 +166,18 @@ static long long ltc2945_reg_to_val(struct device *dev, u8 reg) return val; } -static int ltc2945_val_to_reg(struct device *dev, u8 reg, - unsigned long val) +static long long ltc2945_val_to_reg(struct device *dev, u8 reg, + unsigned long long val) { - struct regmap *regmap = dev_get_drvdata(dev); + struct ltc2945_data *data = dev_get_drvdata(dev); + struct regmap *regmap = data->regmap; + u32 shunt_resistor = data->shunt_resistor; unsigned int control; int ret; + /* Ensure we don't overflow */ + val = clamp_val(val, 0, U32_MAX); + switch (reg) { case LTC2945_POWER_H: case LTC2945_MAX_POWER_H: @@ -165,9 +185,6 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg, case LTC2945_MAX_POWER_THRES_H: case LTC2945_MIN_POWER_THRES_H: /* - * Convert to register value by assuming current is measured - * with an 1mOhm sense resistor, similar to current - * measurements. * Control register bit 0 selects if voltage at SENSE+/VDD * or voltage at ADIN is used to measure power, which in turn * determines register calculations. @@ -177,14 +194,16 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg, return ret; if (control & CONTROL_MULT_SELECT) { /* 25 mV * 25 uV = 0.625 uV resolution. */ - val = DIV_ROUND_CLOSEST(val, 625); + val *= shunt_resistor; + /* Overflow check: Assuming 32-bit val and shunt resistor, val <= 64bits */ + val = DIV_ROUND_CLOSEST_ULL(val, 625 * 1000); + /* Overflow check: val is now <= 44 bits */ } else { - /* - * 0.5 mV * 25 uV = 0.0125 uV resolution. - * Divide first to avoid overflow; - * accept loss of accuracy. - */ - val = DIV_ROUND_CLOSEST(val, 25) * 2; + /* 0.5 mV * 25 uV = 0.0125 uV resolution. */ + val *= shunt_resistor; + /* Overflow check: Assuming 32-bit val and shunt resistor, val <= 64bits */ + val = DIV_ROUND_CLOSEST_ULL(val, 25 * 1000) * 2; + /* Overflow check: val is now <= 51 bits */ } break; case LTC2945_VIN_H: @@ -208,14 +227,11 @@ static int ltc2945_val_to_reg(struct device *dev, u8 reg, case LTC2945_MIN_SENSE_H: case LTC2945_MAX_SENSE_THRES_H: case LTC2945_MIN_SENSE_THRES_H: - /* - * 25 uV resolution. Convert to current as measured with - * an 1 mOhm sense resistor, in mA. If a different sense - * resistor is installed, calculate the actual current by - * dividing the reported current by the sense resistor value - * in mOhm. - */ - val = DIV_ROUND_CLOSEST(val, 25); + /* 25 uV resolution. Convert to mA. */ + val *= shunt_resistor; + /* Overflow check: Assuming 32-bit val and 32-bit shunt resistor, val is 64bits */ + val = DIV_ROUND_CLOSEST_ULL(val, 25 * 1000); + /* Overflow check: val is now <= 50 bits */ break; default: return -EINVAL; @@ -240,15 +256,16 @@ static ssize_t ltc2945_value_store(struct device *dev, const char *buf, size_t count) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); - struct regmap *regmap = dev_get_drvdata(dev); + struct ltc2945_data *data = dev_get_drvdata(dev); + struct regmap *regmap = data->regmap; u8 reg = attr->index; - unsigned long val; + unsigned int val; u8 regbuf[3]; int num_regs; - int regval; + long long regval; int ret; - ret = kstrtoul(buf, 10, &val); + ret = kstrtouint(buf, 10, &val); if (ret) return ret; @@ -277,7 +294,8 @@ static ssize_t ltc2945_history_store(struct device *dev, const char *buf, size_t count) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); - struct regmap *regmap = dev_get_drvdata(dev); + struct ltc2945_data *data = dev_get_drvdata(dev); + struct regmap *regmap = data->regmap; u8 reg = attr->index; int num_regs = is_power_reg(reg) ? 3 : 2; u8 buf_min[3] = { 0xff, 0xff, 0xff }; @@ -329,7 +347,8 @@ static ssize_t ltc2945_bool_show(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); - struct regmap *regmap = dev_get_drvdata(dev); + struct ltc2945_data *data = dev_get_drvdata(dev); + struct regmap *regmap = data->regmap; unsigned int fault; int ret; @@ -458,6 +477,12 @@ static int ltc2945_probe(struct i2c_client *client) struct device *dev = &client->dev; struct device *hwmon_dev; struct regmap *regmap; + struct ltc2945_data *data; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + dev_set_drvdata(dev, data); regmap = devm_regmap_init_i2c(client, <c2945_regmap_config); if (IS_ERR(regmap)) { @@ -465,11 +490,19 @@ static int ltc2945_probe(struct i2c_client *client) return PTR_ERR(regmap); } + data->regmap = regmap; + if (device_property_read_u32(dev, "shunt-resistor-micro-ohms", + &data->shunt_resistor)) + data->shunt_resistor = 1000; + + if (data->shunt_resistor == 0) + return -EINVAL; + /* Clear faults */ regmap_write(regmap, LTC2945_FAULT, 0x00); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, - regmap, + data, ltc2945_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }