linux-kernel - Re: [RFC PATCH v3 6/9] power: supply: Add batinfo functions for OCV to SOC with 0.1% accuracy

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Date:   Fri, 19 Nov 2021 10:11:20 +0200
From:   Matti Vaittinen <mazziesaccount@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
Cc:     Sebastian Reichel <sre@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Lee Jones <lee.jones@...aro.org>, rostokus@...il.com,
        fan.chen@...iatek.com, linux-pm@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-power@...rohmeurope.com
Subject: Re: [RFC PATCH v3 6/9] power: supply: Add batinfo functions for OCV
 to SOC with 0.1% accuracy

On 11/19/21 03:49, Linus Walleij wrote:
> On Tue, Nov 16, 2021 at 1:27 PM Matti Vaittinen
> <matti.vaittinen@...rohmeurope.com> wrote:
> 
>> The battery info functions computing the state-of-charge (SOC) based
>> on open-circuit-voltage (OCV) are returning SOC using units of 1%.
>>
>> Some capacity estimation computations require higher accuracy. Add
>> functions that return SOC using units of 0.1% to reduce rounding error.
>>
>> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
> 
> That sounds useful.
> 
>> +int power_supply_ocv2dcap_simple(struct power_supply_battery_ocv_table *table,
>> +                               int table_len, int ocv)
>> +{
>> +       int i, cap, tmp;
> 
> Why a whole new function? Just rename the original power_supply_ocv2cap_simple()
> to power_supply_ocv2dcap_simple and patch it to return the finegrained value,
> then add a wrapper that use that function but drops it down by one order
> of magnitude.

/me feels slightly stupid.
I wonder ehy you had to explain this to me :) Well, thanks and agreed!

> 
>> +int power_supply_batinfo_ocv2dcap(struct power_supply_battery_info *info,
>> +                                 int ocv, int temp)
> 
> Same with this, saves a lot of code!
> 
> (Also will use my new interpolation routines since you refactor
> on top of that.)

yup. I think this will be _much_ cleaner. I need to revise also the IC 
driver patches because I think I implemented something like your 
interpolation routines there too. So - thanks.

Best Regards
	Matti