Existing userspace (in particular, upower) disables charge control by
setting the start threshold to 0 and the stop threshold to 100.

Handle that by actually setting the enable bit to 0 when a start
threshold of 0 was requested.

Fixes: cc3e883a0625 ("power: supply: qcom_battmgr: Add charge control support")
Signed-off-by: Val Packett <val@packett.cool>
---
 drivers/power/supply/qcom_battmgr.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/qcom_battmgr.c b/drivers/power/supply/qcom_battmgr.c
index c8028606bba0..e6f01e0122e1 100644
--- a/drivers/power/supply/qcom_battmgr.c
+++ b/drivers/power/supply/qcom_battmgr.c
@@ -257,6 +257,7 @@ struct qcom_battmgr_info {
 	unsigned int capacity_warning;
 	unsigned int cycle_count;
 	unsigned int charge_count;
+	bool charge_ctrl_enable;
 	unsigned int charge_ctrl_start;
 	unsigned int charge_ctrl_end;
 	char model_number[BATTMGR_STRING_LEN];
@@ -659,13 +660,13 @@ static int qcom_battmgr_bat_get_property(struct power_supply *psy,
 }
 
 static int qcom_battmgr_set_charge_control(struct qcom_battmgr *battmgr,
-					   u32 target_soc, u32 delta_soc)
+					   bool enable, u32 target_soc, u32 delta_soc)
 {
 	struct qcom_battmgr_charge_ctrl_request request = {
 		.hdr.owner = cpu_to_le32(PMIC_GLINK_OWNER_BATTMGR),
 		.hdr.type = cpu_to_le32(PMIC_GLINK_REQ_RESP),
 		.hdr.opcode = cpu_to_le32(BATTMGR_CHG_CTRL_LIMIT_EN),
-		.enable = cpu_to_le32(1),
+		.enable = cpu_to_le32(enable),
 		.target_soc = cpu_to_le32(target_soc),
 		.delta_soc = cpu_to_le32(delta_soc),
 	};
@@ -677,6 +678,7 @@ static int qcom_battmgr_set_charge_start_threshold(struct qcom_battmgr *battmgr,
 {
 	u32 target_soc, delta_soc;
 	int ret;
+	bool enable = start_soc != 0;
 
 	start_soc = clamp(start_soc, CHARGE_CTRL_START_THR_MIN, CHARGE_CTRL_START_THR_MAX);
 
@@ -696,9 +698,10 @@ static int qcom_battmgr_set_charge_start_threshold(struct qcom_battmgr *battmgr,
 	}
 
 	mutex_lock(&battmgr->lock);
-	ret = qcom_battmgr_set_charge_control(battmgr, target_soc, delta_soc);
+	ret = qcom_battmgr_set_charge_control(battmgr, enable, target_soc, delta_soc);
 	mutex_unlock(&battmgr->lock);
 	if (!ret) {
+		battmgr->info.charge_ctrl_enable = enable;
 		battmgr->info.charge_ctrl_start = start_soc;
 		battmgr->info.charge_ctrl_end = target_soc;
 	}
@@ -710,6 +713,7 @@ static int qcom_battmgr_set_charge_end_threshold(struct qcom_battmgr *battmgr, i
 {
 	u32 delta_soc = CHARGE_CTRL_DELTA_SOC;
 	int ret;
+	bool enable = battmgr->info.charge_ctrl_enable;
 
 	end_soc = clamp(end_soc, CHARGE_CTRL_END_THR_MIN, CHARGE_CTRL_END_THR_MAX);
 
@@ -717,7 +721,7 @@ static int qcom_battmgr_set_charge_end_threshold(struct qcom_battmgr *battmgr, i
 		delta_soc = end_soc - battmgr->info.charge_ctrl_start;
 
 	mutex_lock(&battmgr->lock);
-	ret = qcom_battmgr_set_charge_control(battmgr, end_soc, delta_soc);
+	ret = qcom_battmgr_set_charge_control(battmgr, enable, end_soc, delta_soc);
 	mutex_unlock(&battmgr->lock);
 	if (!ret) {
 		battmgr->info.charge_ctrl_start = end_soc - delta_soc;
-- 
2.51.0

On 10/13/2025 7:32 AM, Val Packett wrote:
> Existing userspace (in particular, upower) disables charge control by
> setting the start threshold to 0 and the stop threshold to 100.
>
> Handle that by actually setting the enable bit to 0 when a start
> threshold of 0 was requested.
>
> Fixes: cc3e883a0625 ("power: supply: qcom_battmgr: Add charge control support")
> Signed-off-by: Val Packett <val@packett.cool>
> ---
>   drivers/power/supply/qcom_battmgr.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/power/supply/qcom_battmgr.c b/drivers/power/supply/qcom_battmgr.c
> index c8028606bba0..e6f01e0122e1 100644
> --- a/drivers/power/supply/qcom_battmgr.c
> +++ b/drivers/power/supply/qcom_battmgr.c
> @@ -257,6 +257,7 @@ struct qcom_battmgr_info {
>   	unsigned int capacity_warning;
>   	unsigned int cycle_count;
>   	unsigned int charge_count;
> +	bool charge_ctrl_enable;
>   	unsigned int charge_ctrl_start;
>   	unsigned int charge_ctrl_end;
>   	char model_number[BATTMGR_STRING_LEN];
> @@ -659,13 +660,13 @@ static int qcom_battmgr_bat_get_property(struct power_supply *psy,
>   }
>   
>   static int qcom_battmgr_set_charge_control(struct qcom_battmgr *battmgr,
> -					   u32 target_soc, u32 delta_soc)
> +					   bool enable, u32 target_soc, u32 delta_soc)
>   {
>   	struct qcom_battmgr_charge_ctrl_request request = {
>   		.hdr.owner = cpu_to_le32(PMIC_GLINK_OWNER_BATTMGR),
>   		.hdr.type = cpu_to_le32(PMIC_GLINK_REQ_RESP),
>   		.hdr.opcode = cpu_to_le32(BATTMGR_CHG_CTRL_LIMIT_EN),
> -		.enable = cpu_to_le32(1),
> +		.enable = cpu_to_le32(enable),
>   		.target_soc = cpu_to_le32(target_soc),
>   		.delta_soc = cpu_to_le32(delta_soc),
>   	};
> @@ -677,6 +678,7 @@ static int qcom_battmgr_set_charge_start_threshold(struct qcom_battmgr *battmgr,
>   {
>   	u32 target_soc, delta_soc;
>   	int ret;
> +	bool enable = start_soc != 0;
>   
>   	start_soc = clamp(start_soc, CHARGE_CTRL_START_THR_MIN, CHARGE_CTRL_START_THR_MAX);
>   
> @@ -696,9 +698,10 @@ static int qcom_battmgr_set_charge_start_threshold(struct qcom_battmgr *battmgr,
>   	}
>   
>   	mutex_lock(&battmgr->lock);
> -	ret = qcom_battmgr_set_charge_control(battmgr, target_soc, delta_soc);
> +	ret = qcom_battmgr_set_charge_control(battmgr, enable, target_soc, delta_soc);
>   	mutex_unlock(&battmgr->lock);
>   	if (!ret) {
> +		battmgr->info.charge_ctrl_enable = enable;
>   		battmgr->info.charge_ctrl_start = start_soc;
>   		battmgr->info.charge_ctrl_end = target_soc;
>   	}
> @@ -710,6 +713,7 @@ static int qcom_battmgr_set_charge_end_threshold(struct qcom_battmgr *battmgr, i
>   {
>   	u32 delta_soc = CHARGE_CTRL_DELTA_SOC;
>   	int ret;
> +	bool enable = battmgr->info.charge_ctrl_enable;
Can you initialize "battmgr->info.charge_ctrl_enable" in 
"qcom_battmgr_charge_control_thresholds_init()" based on the value 
reading from the nvmem cell? Otherwise, it would have a false value by 
default and a single write to the end threshold would result disabling 
the charging control instead.
>   
>   	end_soc = clamp(end_soc, CHARGE_CTRL_END_THR_MIN, CHARGE_CTRL_END_THR_MAX);
>   
> @@ -717,7 +721,7 @@ static int qcom_battmgr_set_charge_end_threshold(struct qcom_battmgr *battmgr, i
>   		delta_soc = end_soc - battmgr->info.charge_ctrl_start;
>   
>   	mutex_lock(&battmgr->lock);
> -	ret = qcom_battmgr_set_charge_control(battmgr, end_soc, delta_soc);
> +	ret = qcom_battmgr_set_charge_control(battmgr, enable, end_soc, delta_soc);
>   	mutex_unlock(&battmgr->lock);
>   	if (!ret) {
>   		battmgr->info.charge_ctrl_start = end_soc - delta_soc;