linux-kernel - Re: [PATCH v2 04/20] power: supply: bq25890: Reduce reported CONSTANT_CHARGE_CURRENT

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Date:   Tue, 16 Nov 2021 10:43:10 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Mark Gross <markgross@...nel.org>,
        Andy Shevchenko <andy@...radead.org>,
        Wolfram Sang <wsa@...-dreams.de>,
        Sebastian Reichel <sre@...nel.org>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Ard Biesheuvel <ardb@...nel.org>
Cc:     Len Brown <lenb@...nel.org>, linux-acpi@...r.kernel.org,
        Yauhen Kharuzhy <jekhor@...il.com>,
        Tsuchiya Yuto <kitakar@...il.com>,
        platform-driver-x86@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-efi@...r.kernel.org
Subject: Re: [PATCH v2 04/20] power: supply: bq25890: Reduce reported
 CONSTANT_CHARGE_CURRENT_MAX for low temperatures

Hi,

On 11/14/21 18:03, Hans de Goede wrote:
> From: Yauhen Kharuzhy <jekhor@...il.com>
> 
> Take into account possible current reduction due to low-temperature when
> reading POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX. As described in
> the datasheet in cool (0-20° Celcius) conditions the current limit is
> decreased to 20% or 50% of ICHG field value depended on JEITA_ISET field.
> 
> Also add NTC_FAULT field value to the debug message in
> bq25890_get_chip_state().
> 
> Changed by Hans de Goede:
> - Fix reading F_CHG_FAULT instead of F_NTC_FIELD for state->ntc_fault
> - Only read JEITA_ISET field if necessary
> - Tweak commit message a bit
> 
> Signed-off-by: Yauhen Kharuzhy <jekhor@...il.com>
> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> ---
>  drivers/power/supply/bq25890_charger.c | 33 +++++++++++++++++++++++---
>  1 file changed, 30 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/power/supply/bq25890_charger.c b/drivers/power/supply/bq25890_charger.c
> index b208cc2193b8..617a653221ab 100644
> --- a/drivers/power/supply/bq25890_charger.c
> +++ b/drivers/power/supply/bq25890_charger.c
> @@ -94,6 +94,7 @@ struct bq25890_state {
>  	u8 vsys_status;
>  	u8 boost_fault;
>  	u8 bat_fault;
> +	u8 ntc_fault;
>  };
>  
>  struct bq25890_device {
> @@ -383,6 +384,14 @@ enum bq25890_chrg_fault {
>  	CHRG_FAULT_TIMER_EXPIRED,
>  };
>  
> +enum bq25890_ntc_fault {
> +	NTC_FAULT_NORMAL = 0,
> +	NTC_FAULT_WARM = 2,
> +	NTC_FAULT_COOL = 3,
> +	NTC_FAULT_COLD = 5,
> +	NTC_FAULT_HOT = 6,
> +};
> +
>  static bool bq25890_is_adc_property(enum power_supply_property psp)
>  {
>  	switch (psp) {
> @@ -474,6 +483,18 @@ static int bq25890_power_supply_get_property(struct power_supply *psy,
>  
>  	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
>  		val->intval = bq25890_find_val(bq->init_data.ichg, TBL_ICHG);
> +
> +		/* When temperature is too low, charge current is decreased */
> +		if (bq->state.ntc_fault == NTC_FAULT_COOL) {
> +			ret = bq25890_field_read(bq, F_JEITA_ISET);
> +			if (ret < 0)
> +				return ret;
> +
> +			if (ret)
> +				val->intval /= 5;
> +			else
> +				val->intval /= 2;
> +		}
>  		break;
>  
>  	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> @@ -486,6 +507,10 @@ static int bq25890_power_supply_get_property(struct power_supply *psy,
>  		if (ret < 0)
>  			return ret;
>  
> +		ret = bq25890_field_read(bq, F_JEITA_VSET);
> +		if (ret < 0)
> +			return ret;
> +
>  		/* converted_val = 2.304V + ADC_val * 20mV (table 10.3.15) */
>  		val->intval = 2304000 + ret * 20000;
>  		break;

Ugh, this should not be here. I guess this is a leftover from an attempt to
also apply temperature correction to the POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE
prop.

I'll drop this for v3 of the series. Note I'll first wait a week or so for
other feedback.

Regards,

Hans




> @@ -549,7 +574,8 @@ static int bq25890_get_chip_state(struct bq25890_device *bq,
>  		{F_VSYS_STAT,	&state->vsys_status},
>  		{F_BOOST_FAULT, &state->boost_fault},
>  		{F_BAT_FAULT,	&state->bat_fault},
> -		{F_CHG_FAULT,	&state->chrg_fault}
> +		{F_CHG_FAULT,	&state->chrg_fault},
> +		{F_NTC_FAULT,	&state->ntc_fault}
>  	};
>  
>  	for (i = 0; i < ARRAY_SIZE(state_fields); i++) {
> @@ -560,9 +586,10 @@ static int bq25890_get_chip_state(struct bq25890_device *bq,
>  		*state_fields[i].data = ret;
>  	}
>  
> -	dev_dbg(bq->dev, "S:CHG/PG/VSYS=%d/%d/%d, F:CHG/BOOST/BAT=%d/%d/%d\n",
> +	dev_dbg(bq->dev, "S:CHG/PG/VSYS=%d/%d/%d, F:CHG/BOOST/BAT/NTC=%d/%d/%d/%d\n",
>  		state->chrg_status, state->online, state->vsys_status,
> -		state->chrg_fault, state->boost_fault, state->bat_fault);
> +		state->chrg_fault, state->boost_fault, state->bat_fault,
> +		state->ntc_fault);
>  
>  	return 0;
>  }
>