From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754017AbbLXCro (ORCPT ); Wed, 23 Dec 2015 21:47:44 -0500 Received: from arroyo.ext.ti.com ([192.94.94.40]:37239 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353AbbLXCrm (ORCPT ); Wed, 23 Dec 2015 21:47:42 -0500 Subject: Re: [PATCH 1/2] power:bq27xxx: fix reading for bq27000 and bq27010 To: "H. Nikolaus Schaller" , =?UTF-8?Q?Pali_Roh=c3=a1r?= , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse References: CC: , , , From: "Andrew F. Davis" Message-ID: <567B5C93.9090000@ti.com> Date: Wed, 23 Dec 2015 20:46:43 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/17/2015 04:12 AM, H. Nikolaus Schaller wrote: > bug: the driver reports funny capacity values: > > root@letux:/sys/class/power_supply/bq27000-battery# cat uevent > POWER_SUPPLY_NAME=bq27000-battery > POWER_SUPPLY_STATUS=Charging > POWER_SUPPLY_PRESENT=1 > POWER_SUPPLY_VOLTAGE_NOW=3702000 > POWER_SUPPLY_CURRENT_NOW=-464635 > POWER_SUPPLY_CAPACITY=1536 <- over 100% is magic > POWER_SUPPLY_CAPACITY_LEVEL=Normal > POWER_SUPPLY_TEMP=311 > POWER_SUPPLY_TIME_TO_FULL_NOW=10440 > POWER_SUPPLY_TECHNOLOGY=Li-ion > POWER_SUPPLY_CHARGE_FULL=805450 > POWER_SUPPLY_CHARGE_NOW=1068 > POWER_SUPPLY_CHARGE_FULL_DESIGN=8844998 <- battery has just 1200 mAh > POWER_SUPPLY_CYCLE_COUNT=21 > POWER_SUPPLY_ENERGY_NOW=0 > POWER_SUPPLY_POWER_AVG=0 > POWER_SUPPLY_HEALTH=Good > POWER_SUPPLY_MANUFACTURER=Texas Instruments > > reason: the state of charge and the design capacity register are single > byte only. The design capacity returns the higer order byte. > > tested: GTA04 with Openmoko/FIC HF08x battery (using hdq) > > Signed-off-by: H. Nikolaus Schaller > --- > drivers/power/bq27xxx_battery.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/power/bq27xxx_battery.c b/drivers/power/bq27xxx_battery.c > index 880233c..e54a125 100644 > --- a/drivers/power/bq27xxx_battery.c > +++ b/drivers/power/bq27xxx_battery.c > @@ -471,7 +471,10 @@ static int bq27xxx_battery_read_soc(struct bq27xxx_device_info *di) > { > int soc; > > - soc = bq27xxx_read(di, BQ27XXX_REG_SOC, false); > + if (di->chip == BQ27000 || di->chip == BQ27010) > + soc = bq27xxx_read(di, BQ27XXX_REG_SOC, true); > + else > + soc = bq27xxx_read(di, BQ27XXX_REG_SOC, false); > > if (soc < 0) > dev_dbg(di->dev, "error reading State-of-Charge\n"); > @@ -536,7 +539,10 @@ static int bq27xxx_battery_read_dcap(struct bq27xxx_device_info *di) > { > int dcap; > > - dcap = bq27xxx_read(di, BQ27XXX_REG_DCAP, false); > + if (di->chip == BQ27000 || di->chip == BQ27010) > + dcap = bq27xxx_read(di, BQ27XXX_REG_DCAP, true); > + else > + dcap = bq27xxx_read(di, BQ27XXX_REG_DCAP, false); > I'm wondering how the I2C versions will be effected by this change, will we get the right byte when we only read one? Maybe the fix should be to still read 2-bytes but mask out the right bits from the result? The data-sheet doesn't seem clear on this. Well, it is more right than it was before, I'll look for a bq27200 to test and make changes if needed some other time, but for now: Acked-by: Andrew F. Davis > if (dcap < 0) { > dev_dbg(di->dev, "error reading initial last measured discharge\n"); > @@ -544,7 +550,7 @@ static int bq27xxx_battery_read_dcap(struct bq27xxx_device_info *di) > } > > if (di->chip == BQ27000 || di->chip == BQ27010) > - dcap *= BQ27XXX_CURRENT_CONSTANT / BQ27XXX_RS; > + dcap = (dcap << 8) * BQ27XXX_CURRENT_CONSTANT / BQ27XXX_RS; > else > dcap *= 1000; > > -- Andrew F. Davis