From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753319AbbALNrc (ORCPT ); Mon, 12 Jan 2015 08:47:32 -0500 Received: from mail-wi0-f170.google.com ([209.85.212.170]:52999 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753219AbbALNrb (ORCPT ); Mon, 12 Jan 2015 08:47:31 -0500 From: Bartosz Golaszewski To: Guenter Roeck Cc: LKML , Benoit Cousson , Patrick Titiano , LM Sensors , Bartosz Golaszewski Subject: [PATCH 2/2] hwmon: (ina2xx) use DIV_ROUND_CLOSEST() to avoid rounding errors Date: Mon, 12 Jan 2015 14:47:22 +0100 Message-Id: <1421070442-9635-3-git-send-email-bgolaszewski@baylibre.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1421070442-9635-1-git-send-email-bgolaszewski@baylibre.com> References: <1421070442-9635-1-git-send-email-bgolaszewski@baylibre.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use DIV_ROUND_CLOSEST() when dealing with the calibration values to make the calculations less error prone. Signed-off-by: Bartosz Golaszewski --- drivers/hwmon/ina2xx.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c index ae110c5..611ec4e 100644 --- a/drivers/hwmon/ina2xx.c +++ b/drivers/hwmon/ina2xx.c @@ -186,8 +186,11 @@ static void ina226_set_update_interval(struct ina2xx_data *data) static int ina2xx_calibrate(struct ina2xx_data *data) { - return i2c_smbus_write_word_swapped(data->client, INA2XX_CALIBRATION, - data->config->calibration_factor / data->rshunt); + u16 val = DIV_ROUND_CLOSEST(data->config->calibration_factor, + data->rshunt); + + return i2c_smbus_write_word_swapped(data->client, + INA2XX_CALIBRATION, val); } /* @@ -307,7 +310,8 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg) val = (s16)data->regs[reg]; break; case INA2XX_CALIBRATION: - val = data->config->calibration_factor / data->regs[reg]; + val = DIV_ROUND_CLOSEST(data->config->calibration_factor, + data->regs[reg]); break; default: /* programmer goofed */ -- 2.1.3