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=-6.7 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS autolearn=ham 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 56EFBC004C9 for ; Tue, 7 May 2019 23:41:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10D61205ED for ; Tue, 7 May 2019 23:41:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GjZeETvJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726313AbfEGXl6 (ORCPT ); Tue, 7 May 2019 19:41:58 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:34616 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726091AbfEGXl6 (ORCPT ); Tue, 7 May 2019 19:41:58 -0400 Received: by mail-pl1-f194.google.com with SMTP id ck18so8948606plb.1; Tue, 07 May 2019 16:41:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=6S43puIWlKpo3l0ctTYo9CwnfuvXVXnPWjkU3LnYrYE=; b=GjZeETvJT+eTWZ1uhPcJw7Bco8Ytbnq5Ktg3NTxlpUZBqTga93GcdN2/9ngvD/6dcR wSdJarS82zLEtv+15PpZwSzBaLZNI5NgBVmRGnYwfukvjjO+sPldzkBKeHcZl1499w8y FUxjc27cnAM2BwgvaxkDFedwHnI9x91/xkIfk2jgFMp48c9c95ZrVGtTRRdUsDRe0as/ EiVWzqVG1BXnHnI1xyQhCDkeBV650Esz+Em4N2UsfBTuv9qku+0E2m3gCLfyTQFGZpIU gTUArMIb28nXA5QKC2GfnyXDKGNSqjtdqDRQwinPl51JXDJrc7BncgukshFwUma73Knj n1/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:to:cc:references:from:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=6S43puIWlKpo3l0ctTYo9CwnfuvXVXnPWjkU3LnYrYE=; b=Dcqhy/OP0DM+hL2fM2yabWDLgUK7tVyKGgs0yaujYP3cSaCvGStHE69ZbHd5w2DpzG rN2zGVbm4BvANB3VyMzbsrCNw0MUVLha+3XhSYZ1ojiT8lzFEzCwo0ycnQqHBxP7APjA c1OzMkJtb7Hb+3RWD+pOj/mn8IExqUSzJ4SaN0lyFUbpuhoHE1bKEwl1geln4dzIqU4E 7wAATPXoKF8PuiJW445KQuy5sYVDBxIFyGgsNPj4gNQpnXJ23ncaUhfZbSDA+b91EY8t RLaA2o7pn9MtJLnmsDB5bHKzyGnDrizH3tulClx579NcpPZ613o2EQ1jf8XDIRuEgwiD +Y4w== X-Gm-Message-State: APjAAAXYbltNC2b3t1m0O/0FlurYC2B4pBsozI69eDPlv3L5jHTrc/lR 3T/a4w4ybetxeWtRGg+fR9KR2gkG X-Google-Smtp-Source: APXvYqxccXn8zrgvQZyT7s/F9BOzQU9Kx3XQQw3HZ0E/XS1FVv/mBe9nJlyrYN/apNwFQfaXSQNwUA== X-Received: by 2002:a17:902:bc83:: with SMTP id bb3mr41252727plb.303.1557272517350; Tue, 07 May 2019 16:41:57 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id h189sm24700224pfc.125.2019.05.07.16.41.55 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 May 2019 16:41:55 -0700 (PDT) Subject: Re: [PATCH v3 2/2] hwmon: scmi: Scale values to target desired HWMON units To: Florian Fainelli , linux-kernel@vger.kernel.org Cc: bcm-kernel-feedback-list@broadcom.com, Sudeep Holla , Jean Delvare , linux-arm-kernel@lists.infradead.org, "open list:HARDWARE MONITORING" References: <20190507230917.21659-1-f.fainelli@gmail.com> <20190507230917.21659-3-f.fainelli@gmail.com> From: Guenter Roeck Message-ID: <690aff21-d68c-7d62-071f-ba1c9502e5ac@roeck-us.net> Date: Tue, 7 May 2019 16:41:54 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190507230917.21659-3-f.fainelli@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On 5/7/19 4:09 PM, Florian Fainelli wrote: > If the SCMI firmware implementation is reporting values in a scale that > is different from the HWMON units, we need to scale up or down the value > according to how far appart they are. > > Signed-off-by: Florian Fainelli > --- > drivers/hwmon/scmi-hwmon.c | 43 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 42 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c > index a80183a488c5..7820854e5954 100644 > --- a/drivers/hwmon/scmi-hwmon.c > +++ b/drivers/hwmon/scmi-hwmon.c > @@ -18,6 +18,47 @@ struct scmi_sensors { > const struct scmi_sensor_info **info[hwmon_max]; > }; > > +static inline u64 __pow10(u8 x) > +{ > + u64 r = 1; > + > + if (unlikely(x > 18)) > + return r; > + Strictly speaking that would be 19 (10^19=0x8AC7230489E80000), and I am not sure if returning 1 in that case is such a good idea. If you really want to handle over/underflow situations, it should be in the calling code. Thanks, Guenter > + while (x--) > + r *= 10; > + > + return r; > +} > + > +static u64 scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 value) > +{ > + s8 scale = sensor->scale; > + u64 f; > + > + switch (sensor->type) { > + case TEMPERATURE_C: > + case VOLTAGE: > + case CURRENT: > + scale += 3; > + break; > + case POWER: > + case ENERGY: > + scale += 6; > + break; > + default: > + break; > + } > + > + f = __pow10(abs(scale)); > + if (scale > 0) > + value *= f; > + else > + value = div64_u64(value, f); > + > + return value; > +} > + > static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, > u32 attr, int channel, long *val) > { > @@ -30,7 +71,7 @@ static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, > sensor = *(scmi_sensors->info[type] + channel); > ret = h->sensor_ops->reading_get(h, sensor->id, false, &value); > if (!ret) > - *val = value; > + *val = scmi_hwmon_scale(sensor, value); > > return ret; > } >