From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753071AbdKSO6R (ORCPT ); Sun, 19 Nov 2017 09:58:17 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52938 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752932AbdKSOkb (ORCPT ); Sun, 19 Nov 2017 09:40:31 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hans de Goede , Sebastian Reichel , Sasha Levin Subject: [PATCH 4.9 32/72] power: supply: axp288_fuel_gauge: Read 12 bit values 2 registers at a time Date: Sun, 19 Nov 2017 15:38:36 +0100 Message-Id: <20171119143533.693675607@linuxfoundation.org> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171119143532.376035495@linuxfoundation.org> References: <20171119143532.376035495@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hans de Goede [ Upstream commit 248efcf00602f0282587999bcc221a872bd72530 ] In order for the MSB -> LSB latching to work correctly we must read the 2 8 bit registers of a 12 bit value in one consecutive read. This fixes voltage_ocv reporting inconsistent values on my tablet. Signed-off-by: Hans de Goede Signed-off-by: Sebastian Reichel Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/power/supply/axp288_fuel_gauge.c | 40 +++++++++++++++++-------------- 1 file changed, 22 insertions(+), 18 deletions(-) --- a/drivers/power/supply/axp288_fuel_gauge.c +++ b/drivers/power/supply/axp288_fuel_gauge.c @@ -210,6 +210,22 @@ static int fuel_gauge_read_15bit_word(st return ret & FG_15BIT_VAL_MASK; } +static int fuel_gauge_read_12bit_word(struct axp288_fg_info *info, int reg) +{ + unsigned char buf[2]; + int ret; + + ret = regmap_bulk_read(info->regmap, reg, buf, 2); + if (ret < 0) { + dev_err(&info->pdev->dev, "Error reading reg 0x%02x err: %d\n", + reg, ret); + return ret; + } + + /* 12-bit data values have upper 8 bits in buf[0], lower 4 in buf[1] */ + return (buf[0] << 4) | ((buf[1] >> 4) & 0x0f); +} + static int pmic_read_adc_val(const char *name, int *raw_val, struct axp288_fg_info *info) { @@ -270,12 +286,9 @@ static int fuel_gauge_debug_show(struct seq_printf(s, " FG_RDC0[%02x] : %02x\n", AXP288_FG_RDC0_REG, fuel_gauge_reg_readb(info, AXP288_FG_RDC0_REG)); - seq_printf(s, " FG_OCVH[%02x] : %02x\n", + seq_printf(s, " FG_OCV[%02x] : %04x\n", AXP288_FG_OCVH_REG, - fuel_gauge_reg_readb(info, AXP288_FG_OCVH_REG)); - seq_printf(s, " FG_OCVL[%02x] : %02x\n", - AXP288_FG_OCVL_REG, - fuel_gauge_reg_readb(info, AXP288_FG_OCVL_REG)); + fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG)); seq_printf(s, " FG_DES_CAP[%02x] : %04x\n", AXP288_FG_DES_CAP1_REG, fuel_gauge_read_15bit_word(info, AXP288_FG_DES_CAP1_REG)); @@ -532,21 +545,12 @@ temp_read_fail: static int fuel_gauge_get_vocv(struct axp288_fg_info *info, int *vocv) { - int ret, value; - - /* 12-bit data value, upper 8 in OCVH, lower 4 in OCVL */ - ret = fuel_gauge_reg_readb(info, AXP288_FG_OCVH_REG); - if (ret < 0) - goto vocv_read_fail; - value = ret << 4; + int ret; - ret = fuel_gauge_reg_readb(info, AXP288_FG_OCVL_REG); - if (ret < 0) - goto vocv_read_fail; - value |= (ret & 0xf); + ret = fuel_gauge_read_12bit_word(info, AXP288_FG_OCVH_REG); + if (ret >= 0) + *vocv = VOLTAGE_FROM_ADC(ret); - *vocv = VOLTAGE_FROM_ADC(value); -vocv_read_fail: return ret; }