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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 A8E75C433FF for ; Tue, 13 Aug 2019 14:43:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ABCC20651 for ; Tue, 13 Aug 2019 14:43:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729603AbfHMOnT (ORCPT ); Tue, 13 Aug 2019 10:43:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:11186 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729600AbfHMOnT (ORCPT ); Tue, 13 Aug 2019 10:43:19 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Aug 2019 07:43:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,381,1559545200"; d="scan'208";a="183888495" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.145]) by FMSMGA003.fm.intel.com with ESMTP; 13 Aug 2019 07:43:17 -0700 Received: from andy by smile with local (Exim 4.92.1) (envelope-from ) id 1hxY15-0007QA-OZ; Tue, 13 Aug 2019 17:43:15 +0300 Date: Tue, 13 Aug 2019 17:43:15 +0300 From: Andy Shevchenko To: Jonathan Cameron Cc: linux-iio@vger.kernel.org, Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler Subject: Re: [PATCH v1] iio: hid-sensor-attributes: Convert to use int_pow() Message-ID: <20190813144315.GH30120@smile.fi.intel.com> References: <20190619140702.18506-1-andriy.shevchenko@linux.intel.com> <20190622100642.7a8fb0ff@archlinux> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190622100642.7a8fb0ff@archlinux> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Sat, Jun 22, 2019 at 10:06:42AM +0100, Jonathan Cameron wrote: > On Wed, 19 Jun 2019 17:07:02 +0300 > Andy Shevchenko wrote: > > > Instead of linear approach to calculate power of 10, use generic int_pow() > > which does it better. > > > > Signed-off-by: Andy Shevchenko > Hi Andy, > > Looks good to me, but I would like Srinivas to take a look and > preferably test this a bit just to check we aren't all missing something > subtle! > > +CC Srinivas Srinivas, do you have any comments on this? > > Thanks, > > Jonathan > > --- > > .../hid-sensors/hid-sensor-attributes.c | 53 ++++++++----------- > > 1 file changed, 22 insertions(+), 31 deletions(-) > > > > diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c > > index a8a3fe428d8d..b9dd19b34267 100644 > > --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c > > +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c > > @@ -8,6 +8,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -68,16 +69,6 @@ static struct { > > {HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0}, > > }; > > > > -static int pow_10(unsigned power) > > -{ > > - int i; > > - int ret = 1; > > - for (i = 0; i < power; ++i) > > - ret = ret * 10; > > - > > - return ret; > > -} > > - > > static void simple_div(int dividend, int divisor, int *whole, > > int *micro_frac) > > { > > @@ -96,14 +87,14 @@ static void simple_div(int dividend, int divisor, int *whole, > > rem *= 10; > > exp++; > > } > > - *micro_frac = (rem / divisor) * pow_10(6-exp); > > + *micro_frac = (rem / divisor) * int_pow(10, 6 - exp); > > } > > } > > > > static void split_micro_fraction(unsigned int no, int exp, int *val1, int *val2) > > { > > - *val1 = no/pow_10(exp); > > - *val2 = no%pow_10(exp) * pow_10(6-exp); > > + *val1 = no / int_pow(10, exp); > > + *val2 = no % int_pow(10, exp) * int_pow(10, 6 - exp); > > } > > > > /* > > @@ -125,7 +116,7 @@ static void convert_from_vtf_format(u32 value, int size, int exp, > > } > > exp = hid_sensor_convert_exponent(exp); > > if (exp >= 0) { > > - *val1 = sign * value * pow_10(exp); > > + *val1 = sign * value * int_pow(10, exp); > > *val2 = 0; > > } else { > > split_micro_fraction(value, -exp, val1, val2); > > @@ -145,10 +136,10 @@ static u32 convert_to_vtf_format(int size, int exp, int val1, int val2) > > sign = -1; > > exp = hid_sensor_convert_exponent(exp); > > if (exp < 0) { > > - value = abs(val1) * pow_10(-exp); > > - value += abs(val2) / pow_10(6+exp); > > + value = abs(val1) * int_pow(10, -exp); > > + value += abs(val2) / int_pow(10, 6 + exp); > > } else > > - value = abs(val1) / pow_10(exp); > > + value = abs(val1) / int_pow(10, exp); > > if (sign < 0) > > value = ((1LL << (size * 8)) - value); > > > > @@ -211,12 +202,12 @@ int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st, > > if (val1 < 0 || val2 < 0) > > return -EINVAL; > > > > - value = val1 * pow_10(6) + val2; > > + value = val1 * int_pow(10, 6) + val2; > > if (value) { > > if (st->poll.units == HID_USAGE_SENSOR_UNITS_MILLISECOND) > > - value = pow_10(9)/value; > > + value = int_pow(10, 9) / value; > > else if (st->poll.units == HID_USAGE_SENSOR_UNITS_SECOND) > > - value = pow_10(6)/value; > > + value = int_pow(10, 6) / value; > > else > > value = 0; > > } > > @@ -311,34 +302,34 @@ static void adjust_exponent_nano(int *val0, int *val1, int scale0, > > int rem; > > > > if (exp > 0) { > > - *val0 = scale0 * pow_10(exp); > > + *val0 = scale0 * int_pow(10, exp); > > res = 0; > > if (exp > 9) { > > *val1 = 0; > > return; > > } > > for (i = 0; i < exp; ++i) { > > - x = scale1 / pow_10(8 - i); > > - res += (pow_10(exp - 1 - i) * x); > > - scale1 = scale1 % pow_10(8 - i); > > + x = scale1 / int_pow(10, 8 - i); > > + res += int_pow(10, exp - 1 - i) * x; > > + scale1 = scale1 % int_pow(10, 8 - i); > > } > > *val0 += res; > > - *val1 = scale1 * pow_10(exp); > > + *val1 = scale1 * int_pow(10, exp); > > } else if (exp < 0) { > > exp = abs(exp); > > if (exp > 9) { > > *val0 = *val1 = 0; > > return; > > } > > - *val0 = scale0 / pow_10(exp); > > - rem = scale0 % pow_10(exp); > > + *val0 = scale0 / int_pow(10, exp); > > + rem = scale0 % int_pow(10, exp); > > res = 0; > > for (i = 0; i < (9 - exp); ++i) { > > - x = scale1 / pow_10(8 - i); > > - res += (pow_10(8 - exp - i) * x); > > - scale1 = scale1 % pow_10(8 - i); > > + x = scale1 / int_pow(10, 8 - i); > > + res += int_pow(10, 8 - exp - i) * x; > > + scale1 = scale1 % int_pow(10, 8 - i); > > } > > - *val1 = rem * pow_10(9 - exp) + res; > > + *val1 = rem * int_pow(10, 9 - exp) + res; > > } else { > > *val0 = scale0; > > *val1 = scale1; > -- With Best Regards, Andy Shevchenko