Re: [PATCH] power: supply: bq24190: Fix NTC status decoding for BQ24193

[Sebastian Reichel <sebastian.reichel@collabora.com>]

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Hi,

On Mon, Oct 26, 2026 at 07:25:05AM +0100, Patrick Fischer via B4 Relay wrote:
> From: Patrick Fischer <admin@tsv-stahl-riesa.de>
> 
> The BQ24193 has a single thermistor input and applies the JEITA
> temperature profile. Its NTC_FAULT field in REG09 is encoded
> differently from the BQ24190, which has two TS inputs:
> 
>   NTC_FAULT  BQ24190    BQ24193
>   000        Normal     Normal
>   010        TS1 Hot    Warm
>   011        TS2 Cold   Cool
>   101        Both Cold  Cold
>   110        Both Hot   Hot
> 
> (BQ24190/2/2I datasheet SLUSAW5B, table 17; BQ24193 datasheet
> SLUSBG7A, table 16.)
> 
> Warm (45-60 C at the TS pin) and Cool (0-10 C) are not faults. The
> charger keeps charging at a reduced charge voltage or charge current.
> The BQ24193 uses bq24190_charger_get_ntc_status() though, so a warm
> battery is reported as POWER_SUPPLY_HEALTH_OVERHEAT and a cool one as
> POWER_SUPPLY_HEALTH_COLD.
> 
> Add a BQ24193 decoder that reports POWER_SUPPLY_HEALTH_WARM and
> POWER_SUPPLY_HEALTH_COOL for these states. Cold and Hot are unchanged.
> 
> On an NVIDIA Tegra Note 7 (P1640) REG09 reads 0x02 after a few minutes
> on USB power. The battery keeps charging, but the charger reports
> health "Overheat". With this patch it reports "Warm" in that state and
> "Good" while REG09 reads 0x00.
> 
> Fixes: afe5301bfbaa ("power: bq24190: Add BQ24193 support")
> Signed-off-by: Patrick Fischer <admin@tsv-stahl-riesa.de>
> ---
> I kept this a pure decoding fix. Two things stay as they are and could
> be follow-ups if you want them:
> 
> - The interrupt handler still logs a change to Warm or Cool as
>   "Fault: ... ntc 1", as it does for every change of REG09.
> - bq24190_charger_get_health() checks the NTC bits first, so while the
>   battery is warm or cool the charger health hides a charge fault or
>   battery over-voltage.
> 
> Tool use (see Documentation/process/generated-content.rst): this patch,
> its changelog and this note were prepared with an LLM coding assistant
> (Claude Code). It compared the driver with both datasheets and wrote the
> code change and the texts from my register dumps and instructions. I
> reviewed the change and ran the test on the device.
> ---

Looks like bq24190_charger_get_ntc_status can just be updated to
handle a single temperature sensor as warm/cool and dual-sensor as
overheat/cold?

Greetings,

-- Sebastian

>  drivers/power/supply/bq24190_charger.c | 26 +++++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/power/supply/bq24190_charger.c b/drivers/power/supply/bq24190_charger.c
> index 4bea6fd83c36..350cf79a0744 100644
> --- a/drivers/power/supply/bq24190_charger.c
> +++ b/drivers/power/supply/bq24190_charger.c
> @@ -999,6 +999,30 @@ static int bq24190_charger_get_ntc_status(u8 value)
>  	return health;
>  }
>  
> +static int bq24193_charger_get_ntc_status(u8 value)
> +{
> +	int health;
> +
> +	switch (value >> BQ24190_REG_F_NTC_FAULT_SHIFT & 0x7) {
> +	case 0x2: /* Warm */
> +		health = POWER_SUPPLY_HEALTH_WARM;
> +		break;
> +	case 0x3: /* Cool */
> +		health = POWER_SUPPLY_HEALTH_COOL;
> +		break;
> +	case 0x5: /* Cold */
> +		health = POWER_SUPPLY_HEALTH_COLD;
> +		break;
> +	case 0x6: /* Hot */
> +		health = POWER_SUPPLY_HEALTH_OVERHEAT;
> +		break;
> +	default:
> +		health = POWER_SUPPLY_HEALTH_UNKNOWN;
> +	}
> +
> +	return health;
> +}
> +
>  static int bq24296_charger_get_ntc_status(u8 value)
>  {
>  	int health;
> @@ -2013,7 +2037,7 @@ static const struct bq24190_chip_info bq24190_chip_info_tbl[] = {
>  		.check_chip = bq24190_check_chip,
>  		.set_chg_config = bq24190_battery_set_chg_config,
>  		.ntc_fault_mask = BQ24190_REG_F_NTC_FAULT_MASK,
> -		.get_ntc_status = bq24190_charger_get_ntc_status,
> +		.get_ntc_status = bq24193_charger_get_ntc_status,
>  		.set_otg_vbus = bq24190_set_otg_vbus,
>  	},
>  	[BQ24196] = {
> 
> ---
> base-commit: 734bef548a96e8774d6eef5dfa2026c6edc4e80b
> change-id: 20261023-upstream-bq24190-ntc-f35ec3323449
> 
> Best regards,
> --  
> Patrick Fischer <admin@tsv-stahl-riesa.de>
> 
> 

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