[PATCH 3/3] power: max17042: allow battery to returncharge/voltage to use -- RESEND

[Philip Rakity]

Resend

On Aug 29, 2011, at 10:04 AM, Philip Rakity wrote:

> 
> implement the properties
> POWER_SUPPLY_PROP_CHARGE_TO_USE
> POWER_SUPPLY_PROP_VOLTAGE_TO_USE
> 
> these properties return to the caller the voltage and current
> to use to charge the battery.  The calculation is handled
> by board specific functions otherwise 0 voltage/current is returned.
> 
> In our implementation the intersil charger is told it is supplying
> power to the max17042 using the supplied_to field.  The intersil
> driver will ask the battery what power and charge to use.
> 
> Similarly the max8925 is told it is supplying power to the intersil
> driver using the supplied_to field.  The intersil driver implements
> the external_power_changed callback to know if you should ask
> the battery what charge to supply.
> 
> Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
> ---
> drivers/power/max17042_battery.c       |   88 +++++++++++++++++++++++++++----
> include/linux/power/max17042_battery.h |    4 ++
> 2 files changed, 80 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
> index 9a85f90..ab69849 100644
> --- a/drivers/power/max17042_battery.c
> +++ b/drivers/power/max17042_battery.c
> @@ -75,10 +75,74 @@ static enum power_supply_property max17042_battery_props[] = {
> 	POWER_SUPPLY_PROP_CAPACITY,
> 	POWER_SUPPLY_PROP_CHARGE_FULL,
> 	POWER_SUPPLY_PROP_TEMP,
> +	POWER_SUPPLY_PROP_CHARGE_TO_USE,
> +	POWER_SUPPLY_PROP_VOLTAGE_TO_USE,
> 	POWER_SUPPLY_PROP_CURRENT_NOW,
> 	POWER_SUPPLY_PROP_CURRENT_AVG,
> };
> 
> +static int max17042_get_voltage(struct max17042_chip *chip)
> +{
> +	int temp;
> +
> +	temp = max17042_read_reg(chip->client,
> +			MAX17042_VCELL) * 625 / 8; /* mV */
> +	return temp;
> +}
> +
> +static int max17042_get_temperature(struct max17042_chip *chip)
> +{
> +	int temp;
> +
> +	temp = max17042_read_reg(chip->client,
> +			MAX17042_TEMP);
> +	/* The value is signed. */
> +	if (temp & 0x8000) {
> +		temp = (0x7fff & ~temp) + 1;
> +		temp *= -1;
> +	}
> +	/* The value is converted into deci-centigrade scale */
> +	/* Units of LSB = 1 / 256 degree Celsius */
> +	temp = temp * 10 / 256;
> +	pr_debug("%s: temperature = %d\n", __func__, temp);
> +	return temp;
> +}
> +
> +static int max17042_get_charge_to_use(struct max17042_chip *chip)
> +{
> +	int voltage;
> +	int charge;
> +
> +	if (max17042_get_temperature(chip) >
> +			chip->pdata->max_temperature) {
> +		charge = 0;	/* no charge - temp too high */
> +		pr_debug("%s: Temp too high to charge\n", __func__);
> +	} else {
> +		voltage = max17042_get_voltage(chip);
> +		if (chip->pdata->charge_to_use)
> +			charge = chip->pdata->charge_to_use(voltage);
> +		else
> +			charge = 0;
> +	}
> +	pr_debug("%s: charge_to_use = %d\n", __func__, charge);
> +	return charge;
> +}
> +
> +static int max17042_get_voltage_to_use(struct max17042_chip *chip)
> +{
> +	int voltage;
> +	int charge;
> +
> +	charge = max17042_get_charge_to_use(chip);
> +	if (chip->pdata->voltage_to_use)
> +		voltage = chip->pdata->voltage_to_use(charge);
> +	else
> +		voltage = 0;
> +
> +	pr_debug("%s: voltage_to_use = %d\n", __func__, voltage);
> +	return voltage;
> +}
> +
> static int max17042_get_property(struct power_supply *psy,
> 			    enum power_supply_property psp,
> 			    union power_supply_propval *val)
> @@ -112,8 +176,7 @@ static int max17042_get_property(struct power_supply *psy,
> 		val->intval *= 10000; /* Units of LSB = 10mV */
> 		break;
> 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> -		val->intval = max17042_read_reg(chip->client, MAX17042_VCELL)
> -			    * 625 / 8;
> +		val->intval = max17042_get_voltage(chip);
> 		break;
> 	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
> 		val->intval = max17042_read_reg(chip->client, MAX17042_AvgVCELL)
> @@ -132,16 +195,7 @@ static int max17042_get_property(struct power_supply *psy,
> 			val->intval = 0;
> 		break;
> 	case POWER_SUPPLY_PROP_TEMP:
> -		val->intval = max17042_read_reg(chip->client,
> -				MAX17042_TEMP);
> -		/* The value is signed. */
> -		if (val->intval & 0x8000) {
> -			val->intval = (0x7fff & ~val->intval) + 1;
> -			val->intval *= -1;
> -		}
> -		/* The value is converted into deci-centigrade scale */
> -		/* Units of LSB = 1 / 256 degree Celsius */
> -		val->intval = val->intval * 10 / 256;
> +		val->intval = max17042_get_temperature(chip);
> 		break;
> 	case POWER_SUPPLY_PROP_CURRENT_NOW:
> 		if (chip->pdata->enable_current_sense) {
> @@ -173,6 +227,13 @@ static int max17042_get_property(struct power_supply *psy,
> 			return -EINVAL;
> 		}
> 		break;
> +
> +	case POWER_SUPPLY_PROP_CHARGE_TO_USE:
> +		val->intval = max17042_get_charge_to_use(chip);
> +		break;
> +	case POWER_SUPPLY_PROP_VOLTAGE_TO_USE:
> +		val->intval =  max17042_get_voltage_to_use(chip);
> +		break;
> 	default:
> 		return -EINVAL;
> 	}
> @@ -212,6 +273,9 @@ static int __devinit max17042_probe(struct i2c_client *client,
> 	if (chip->pdata->r_sns == 0)
> 		chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
> 
> +	if (chip->pdata->max_temperature == 0)
> +		chip->pdata->max_temperature = MAX17042_MAX_TEMP_NO_CHARGE;
> +
> 	ret = power_supply_register(&client->dev, &chip->battery);
> 	if (ret) {
> 		dev_err(&client->dev, "failed: power supply register\n");
> diff --git a/include/linux/power/max17042_battery.h b/include/linux/power/max17042_battery.h
> index fe99211..e924363 100644
> --- a/include/linux/power/max17042_battery.h
> +++ b/include/linux/power/max17042_battery.h
> @@ -26,6 +26,7 @@
> #define MAX17042_STATUS_BattAbsent	(1 << 3)
> #define MAX17042_BATTERY_FULL	(100)
> #define MAX17042_DEFAULT_SNS_RESISTOR	(10000)
> +#define MAX17042_MAX_TEMP_NO_CHARGE	(450)  /* 45 C */
> 
> enum max17042_register {
> 	MAX17042_STATUS		= 0x00,
> @@ -116,6 +117,9 @@ struct max17042_platform_data {
> 	 * the datasheet although it can be changed by board designers.
> 	 */
> 	unsigned int r_sns;
> +	unsigned int max_temperature;  /* do not charge above this */
> +	int (*charge_to_use) (int voltage);
> +	int (*voltage_to_use)(int charge);
> };
> 
> #endif /* __MAX17042_BATTERY_H_ */
> -- 
> 1.7.6
> 
> 

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