From patchwork Fri Mar 3 09:14:49 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Carlo Caione X-Patchwork-Id: 9602371 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CAD9D60453 for ; Fri, 3 Mar 2017 09:12:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE4102818E for ; Fri, 3 Mar 2017 09:12:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B0EB4285D8; Fri, 3 Mar 2017 09:12:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5BBFE2818E for ; Fri, 3 Mar 2017 09:12:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751262AbdCCJMS (ORCPT ); Fri, 3 Mar 2017 04:12:18 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:34232 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751463AbdCCJMO (ORCPT ); Fri, 3 Mar 2017 04:12:14 -0500 Received: by mail-wm0-f65.google.com with SMTP id m70so2085508wma.1 for ; Fri, 03 Mar 2017 01:11:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=0H3EQhf4QFsS5XWFJiAAk8XeqT5lV0KYQUW+K+GTcO0=; b=RZzJRek0QGk62RwnJsvgW79WrMKxeqSFI+FDHp5aA9tFs5heg+AQJkboANZ9cljsJw Ceugt+oYxhnGTmlhoNsPBTjYefbg2aJcEZY6NTsBK+ZOrTvEqYJYF+qaXYjlxtmqjXRO rjLwQbBCUsOAFxsqximV1mVusbMwFzASdS+2xDndzP3l8puh/5jt6RQvHR49UUcQPBuy pQ7U1kmXIyoQ2RJSYmBbwuakRduMXwK0aRuYCDkayg+BRGFK/+CL/SqZrpkrPQaCecOh D7a2R9C666Et1T4ufouZH524GlPKkKwmNKwz1aZnX1IKEytne+ax3HNl9jUcsQM/Myai 57mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=0H3EQhf4QFsS5XWFJiAAk8XeqT5lV0KYQUW+K+GTcO0=; b=laS39n5wPB3t+4dXwtwvh4qXYec2CFMDt5socSHmbCCXap2GYzeTekN9IXG8Q2Rlzc U6m4/GcWBEzqDvZMStLjh1h70fE01cgNgWQcb5w14Ob8wzBRokclg5bqkjuPFsGxJBhv i1VYa+odp6EVYmq5LAKqd4OPnAmjhFz/7UItfiiy71ICY8MNvZ1qrLVGtJEoZ/pIgbjL 4g2B2aso0zSqo19B9BiHXqam3nIrGxJ77aGKlFuom6CnH10PzGHLENqrmTicilV87uY4 MC5Wzt0NGAioUGhzIzRTFFRZWq4O5roavA/o1z7c/wN7oDkiNrzi8gCkpljfeCs5fN4k FyPg== X-Gm-Message-State: AMke39mCBiEYorxz1Fvte+9OmUVivDt/pmDjoiZRpYMOm2XsY+/OAn1xVhUU+KRaalCL5w== X-Received: by 10.28.111.136 with SMTP id c8mr1604186wmi.128.1488531907363; Fri, 03 Mar 2017 01:05:07 -0800 (PST) Received: from satan.homestation.setup ([151.45.79.45]) by smtp.gmail.com with ESMTPSA id z198sm2189747wmz.24.2017.03.03.01.05.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 03 Mar 2017 01:05:06 -0800 (PST) From: Carlo Caione To: jdelvare@suse.com, linux@roeck-us.net, linux-hwmon@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux@endlessm.com, punit.agrawal@arm.com, sudeep.holla@arm.com, robh+dt@kernel.org Cc: Carlo Caione Subject: [PATCH v2 2/2] hwmon: (scpi) Fix the scale of SCP sensor readings Date: Fri, 3 Mar 2017 10:14:49 +0100 Message-Id: <20170303091449.3512-3-carlo@caione.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170303091449.3512-1-carlo@caione.org> References: <20170303091449.3512-1-carlo@caione.org> Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Carlo Caione The implementation details for SCPI seems to suggest that the sensor readings must be reported by SCP using a well defined scale (millidegree Celsius for temperature, millivolts for voltage, milliamperes for current, microwatts for power and microjoules for energy). This is also important for the interaction with other subsystems: for example both the thermal sub-system and the hwmon sysfs interface expect the temperature expressed in millidegree Celsius. Unfortunately since this behaviour is dependent on the firmware implementation there are cases where the sensor readings are reported using a different scale. For example in the Amlogic SoCs the temperature is reported in degree and not millidegree Celsius. To take into account this discrepancy and fixup the values reported by SCP a new DT property `scpi,sensors-scale' is introduced and used in this patch by the scpi-hwmon driver to convert the sensor readings to the expected scale. Signed-off-by: Carlo Caione Acked-by: Punit Agrawal --- drivers/hwmon/scpi-hwmon.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c index 094f948f99ff..b64fe7d10742 100644 --- a/drivers/hwmon/scpi-hwmon.c +++ b/drivers/hwmon/scpi-hwmon.c @@ -23,6 +23,7 @@ #include struct sensor_data { + unsigned int scale; struct scpi_sensor_info info; struct device_attribute dev_attr_input; struct device_attribute dev_attr_label; @@ -44,6 +45,22 @@ struct scpi_sensors { const struct attribute_group *groups[2]; }; +static const u32 scpi_scale[] = { + [TEMPERATURE] = 1000, /* (millicelsius) */ + [VOLTAGE] = 1000, /* (millivolts) */ + [CURRENT] = 1000, /* (milliamperes) */ + [POWER] = 1000000, /* (microwatts) */ + [ENERGY] = 1000000, /* (microjoules) */ +}; + +void scpi_scale_reading(u64 *value, struct sensor_data *sensor) +{ + if (scpi_scale[sensor->info.class] != sensor->scale) { + *value *= scpi_scale[sensor->info.class]; + do_div(*value, sensor->scale); + } +} + static int scpi_read_temp(void *dev, int *temp) { struct scpi_thermal_zone *zone = dev; @@ -57,6 +74,8 @@ static int scpi_read_temp(void *dev, int *temp) if (ret) return ret; + scpi_scale_reading(&value, sensor); + *temp = value; return 0; } @@ -77,6 +96,8 @@ scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf) if (ret) return ret; + scpi_scale_reading(&value, sensor); + return sprintf(buf, "%llu\n", value); } @@ -97,6 +118,7 @@ static struct thermal_zone_of_device_ops scpi_sensor_ops = { static int scpi_hwmon_probe(struct platform_device *pdev) { u16 nr_sensors, i; + u32 scale[] = { 1000, 1000, 1000, 1000000, 1000000 }; int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0; int num_energy = 0; struct scpi_ops *scpi_ops; @@ -131,6 +153,16 @@ static int scpi_hwmon_probe(struct platform_device *pdev) scpi_sensors->scpi_ops = scpi_ops; + of_property_read_u32_array(dev->of_node, "scpi,sensors-scale", + scale, ARRAY_SIZE(scale)); + + for (i = 0; i < ARRAY_SIZE(scale); i++) { + if (!scale[i]) { + dev_err(dev, "%s: scale cannot be zero (%d)\n", __func__, i); + return -EINVAL; + } + } + for (i = 0, idx = 0; i < nr_sensors; i++) { struct sensor_data *sensor = &scpi_sensors->data[idx]; @@ -178,6 +210,8 @@ static int scpi_hwmon_probe(struct platform_device *pdev) continue; } + sensor->scale = scale[sensor->info.class]; + sensor->dev_attr_input.attr.mode = S_IRUGO; sensor->dev_attr_input.show = scpi_show_sensor; sensor->dev_attr_input.attr.name = sensor->input;