diff mbox series

[v2] rtc: rv3028: Improve trickle charger logic

Message ID 20230622071609.4032736-1-andrej.picej@norik.com
State New
Headers
Series [v2] rtc: rv3028: Improve trickle charger logic |

Commit Message

Andrej Picej June 22, 2023, 7:16 a.m. UTC 
  Property "trickle-resistor-ohms" allows us to set trickle charger
resistor. However there is no possibility to disable it afterwards.

From now on, disable trickle charger circuit in case device-tree
property "trickle-resistor-ohms" is set to -1.

Additionally, lets make sure we only update internal EEPROM in case of a
change. This prevents wear due to excessive EEPROM writes on each probe.

Signed-off-by: Andrej Picej <andrej.picej@norik.com>
---
Changes in v2:
- disable trickle charger if device tree property trickle-resistor-ohms
  is set to -1.
---
 drivers/rtc/rtc-rv3028.c | 45 +++++++++++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 12 deletions(-)

Comments

Alexandre Belloni June 22, 2023, 7:34 a.m. UTC | #1 
On 22/06/2023 09:16:09+0200, Andrej Picej wrote:
> Property "trickle-resistor-ohms" allows us to set trickle charger
> resistor. However there is no possibility to disable it afterwards.
> 
> From now on, disable trickle charger circuit in case device-tree
> property "trickle-resistor-ohms" is set to -1.
> 
> Additionally, lets make sure we only update internal EEPROM in case of a
> change. This prevents wear due to excessive EEPROM writes on each probe.
> 
> Signed-off-by: Andrej Picej <andrej.picej@norik.com>
> ---
> Changes in v2:
> - disable trickle charger if device tree property trickle-resistor-ohms
>   is set to -1.

What about using aux-voltage-chargeable which is the generic property
for this?

> ---
>  drivers/rtc/rtc-rv3028.c | 45 +++++++++++++++++++++++++++++-----------
>  1 file changed, 33 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c
> index ec5d7a614e2d..da2ae81fe7c8 100644
> --- a/drivers/rtc/rtc-rv3028.c
> +++ b/drivers/rtc/rtc-rv3028.c
> @@ -859,7 +859,8 @@ static int rv3028_probe(struct i2c_client *client)
>  {
>  	struct rv3028_data *rv3028;
>  	int ret, status;
> -	u32 ohms;
> +	s32 ohms;
> +	int val_old, val;
>  	struct nvmem_config nvmem_cfg = {
>  		.name = "rv3028_nvram",
>  		.word_size = 1,
> @@ -937,22 +938,42 @@ static int rv3028_probe(struct i2c_client *client)
>  	if (ret)
>  		return ret;
>  
> -	/* setup trickle charger */
> -	if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
> -				      &ohms)) {
> -		int i;
> +	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* mask out only trickle charger bits */
> +	val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
>  
> -		for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
> -			if (ohms == rv3028_trickle_resistors[i])
> -				break;
> +	/* setup trickle charger */
> +	if (!of_property_read_s32(client->dev.of_node, "trickle-resistor-ohms",
> +				  &ohms)) {
> +		/* disable trickle charger if trickle-resistor-ohms = <(-1)>; */
> +		if (ohms == -1) {
> +			val = val_old & ~RV3028_BACKUP_TCE;
> +		} else {
> +			int i;
> +
> +			for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
> +				if (ohms == rv3028_trickle_resistors[i])
> +					break;
> +
> +			if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
> +				/* enable trickle charger and its resistor */
> +				val = RV3028_BACKUP_TCE | i;
> +			} else {
> +				dev_warn(&client->dev, "invalid trickle resistor value\n");
> +				/* don't update the trickle charger regs */
> +				val = val_old;
> +			}
> +		}
>  
> -		if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
> +		/* only update EEPROM if changes are necessary */
> +		if (val_old != val) {
>  			ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
> -						 RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i);
> +						RV3028_BACKUP_TCR_MASK, val);
>  			if (ret)
>  				return ret;
> -		} else {
> -			dev_warn(&client->dev, "invalid trickle resistor value\n");
>  		}
>  	}
>  
> -- 
> 2.25.1
>
Andrej Picej June 22, 2023, 8:09 a.m. UTC | #2 
Hi Alexandre,

On 22. 06. 23 09:34, Alexandre Belloni wrote:
> On 22/06/2023 09:16:09+0200, Andrej Picej wrote:
>> Property "trickle-resistor-ohms" allows us to set trickle charger
>> resistor. However there is no possibility to disable it afterwards.
>>
>>  From now on, disable trickle charger circuit in case device-tree
>> property "trickle-resistor-ohms" is set to -1.
>>
>> Additionally, lets make sure we only update internal EEPROM in case of a
>> change. This prevents wear due to excessive EEPROM writes on each probe.
>>
>> Signed-off-by: Andrej Picej <andrej.picej@norik.com>
>> ---
>> Changes in v2:
>> - disable trickle charger if device tree property trickle-resistor-ohms
>>    is set to -1.
> 
> What about using aux-voltage-chargeable which is the generic property
> for this?

I thought that this is more of a property for specifying if connected 
battery/supercap has charging capabilities. I guess at the end it would 
be the same thing as knowingly disabling the trickle charger even if 
battery/supercap can be charged.
Do you want that I change and use "aux-voltage-chargeable"?

BR,
Andrej

> 
>> ---
>>   drivers/rtc/rtc-rv3028.c | 45 +++++++++++++++++++++++++++++-----------
>>   1 file changed, 33 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c
>> index ec5d7a614e2d..da2ae81fe7c8 100644
>> --- a/drivers/rtc/rtc-rv3028.c
>> +++ b/drivers/rtc/rtc-rv3028.c
>> @@ -859,7 +859,8 @@ static int rv3028_probe(struct i2c_client *client)
>>   {
>>   	struct rv3028_data *rv3028;
>>   	int ret, status;
>> -	u32 ohms;
>> +	s32 ohms;
>> +	int val_old, val;
>>   	struct nvmem_config nvmem_cfg = {
>>   		.name = "rv3028_nvram",
>>   		.word_size = 1,
>> @@ -937,22 +938,42 @@ static int rv3028_probe(struct i2c_client *client)
>>   	if (ret)
>>   		return ret;
>>   
>> -	/* setup trickle charger */
>> -	if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
>> -				      &ohms)) {
>> -		int i;
>> +	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	/* mask out only trickle charger bits */
>> +	val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
>>   
>> -		for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
>> -			if (ohms == rv3028_trickle_resistors[i])
>> -				break;
>> +	/* setup trickle charger */
>> +	if (!of_property_read_s32(client->dev.of_node, "trickle-resistor-ohms",
>> +				  &ohms)) {
>> +		/* disable trickle charger if trickle-resistor-ohms = <(-1)>; */
>> +		if (ohms == -1) {
>> +			val = val_old & ~RV3028_BACKUP_TCE;
>> +		} else {
>> +			int i;
>> +
>> +			for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
>> +				if (ohms == rv3028_trickle_resistors[i])
>> +					break;
>> +
>> +			if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
>> +				/* enable trickle charger and its resistor */
>> +				val = RV3028_BACKUP_TCE | i;
>> +			} else {
>> +				dev_warn(&client->dev, "invalid trickle resistor value\n");
>> +				/* don't update the trickle charger regs */
>> +				val = val_old;
>> +			}
>> +		}
>>   
>> -		if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
>> +		/* only update EEPROM if changes are necessary */
>> +		if (val_old != val) {
>>   			ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
>> -						 RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i);
>> +						RV3028_BACKUP_TCR_MASK, val);
>>   			if (ret)
>>   				return ret;
>> -		} else {
>> -			dev_warn(&client->dev, "invalid trickle resistor value\n");
>>   		}
>>   	}
>>   
>> -- 
>> 2.25.1
>>
>
diff mbox series

Patch

diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c
index ec5d7a614e2d..da2ae81fe7c8 100644
--- a/drivers/rtc/rtc-rv3028.c
+++ b/drivers/rtc/rtc-rv3028.c
@@ -859,7 +859,8 @@  static int rv3028_probe(struct i2c_client *client)
 {
 	struct rv3028_data *rv3028;
 	int ret, status;
-	u32 ohms;
+	s32 ohms;
+	int val_old, val;
 	struct nvmem_config nvmem_cfg = {
 		.name = "rv3028_nvram",
 		.word_size = 1,
@@ -937,22 +938,42 @@  static int rv3028_probe(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	/* setup trickle charger */
-	if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
-				      &ohms)) {
-		int i;
+	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
+	if (ret < 0)
+		return ret;
+
+	/* mask out only trickle charger bits */
+	val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
 
-		for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
-			if (ohms == rv3028_trickle_resistors[i])
-				break;
+	/* setup trickle charger */
+	if (!of_property_read_s32(client->dev.of_node, "trickle-resistor-ohms",
+				  &ohms)) {
+		/* disable trickle charger if trickle-resistor-ohms = <(-1)>; */
+		if (ohms == -1) {
+			val = val_old & ~RV3028_BACKUP_TCE;
+		} else {
+			int i;
+
+			for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
+				if (ohms == rv3028_trickle_resistors[i])
+					break;
+
+			if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
+				/* enable trickle charger and its resistor */
+				val = RV3028_BACKUP_TCE | i;
+			} else {
+				dev_warn(&client->dev, "invalid trickle resistor value\n");
+				/* don't update the trickle charger regs */
+				val = val_old;
+			}
+		}
 
-		if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
+		/* only update EEPROM if changes are necessary */
+		if (val_old != val) {
 			ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
-						 RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i);
+						RV3028_BACKUP_TCR_MASK, val);
 			if (ret)
 				return ret;
-		} else {
-			dev_warn(&client->dev, "invalid trickle resistor value\n");
 		}
 	}