Commit c371d449 authored by Hans de Goede's avatar Hans de Goede Committed by Sebastian Reichel
Browse files

power: supply: axp288_fuel_gauge: Only read PWR_OP_MODE, FG_LOW_CAP_REG regs once 



Accessing registers on the AXP288 is quite expensive, so we should avoid
doing unnecessary accesses.

The FG_LOW_CAP_REG never changes underneath us, so we only need to read
it once. Devices with an AXP288 do not have user-replace (let alone
hot-swappable) batteries and the only bit we care about in the
PWR_OP_MODE register is the CHRG_STAT_BAT_PRESENT bit, so we can get
away with only reading the PWR_OP_MODE register once too.

Note that the FG_LOW_CAP_REG is not marked volatile in the regmap, so we
were effectively already reading it once. This change makes this explicit,
this is done as preparation of a further patch which moves all remaining
register accesses in fuel_gauge_get_property() out of that function.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent 7eef3e66

drivers/power/supply/axp288_fuel_gauge.c

+21 −16
Original line number Diff line number Diff line
@@ -111,6 +111,8 @@ struct axp288_fg_info { 
	struct mutex lock;

	int status;

	int max_volt;

	int pwr_op;

	int low_cap;

	struct dentry *debug_file;

};
@@ -336,11 +338,7 @@ static int fuel_gauge_get_property(struct power_supply *ps, 
		val->intval = PROP_CURR(value);

		break;

	case POWER_SUPPLY_PROP_PRESENT:

		ret = fuel_gauge_reg_readb(info, AXP20X_PWR_OP_MODE);

		if (ret < 0)

			goto fuel_gauge_read_err;



		if (ret & CHRG_STAT_BAT_PRESENT)

		if (info->pwr_op & CHRG_STAT_BAT_PRESENT)

			val->intval = 1;

		else

			val->intval = 0;
@@ -355,10 +353,7 @@ static int fuel_gauge_get_property(struct power_supply *ps, 
		val->intval = (ret & FG_REP_CAP_VAL_MASK);

		break;

	case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:

		ret = fuel_gauge_reg_readb(info, AXP288_FG_LOW_CAP_REG);

		if (ret < 0)

			goto fuel_gauge_read_err;

		val->intval = (ret & 0x0f);

		val->intval = (info->low_cap & 0x0f);

		break;

	case POWER_SUPPLY_PROP_TECHNOLOGY:

		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
@@ -398,7 +393,7 @@ static int fuel_gauge_set_property(struct power_supply *ps, 
		const union power_supply_propval *val)

{

	struct axp288_fg_info *info = power_supply_get_drvdata(ps);

	int ret = 0;

	int new_low_cap, ret = 0;



	mutex_lock(&info->lock);

	switch (prop) {
@@ -407,12 +402,12 @@ static int fuel_gauge_set_property(struct power_supply *ps, 
			ret = -EINVAL;

			break;

		}

		ret = fuel_gauge_reg_readb(info, AXP288_FG_LOW_CAP_REG);

		if (ret < 0)

			break;

		ret &= 0xf0;

		ret |= (val->intval & 0xf);

		ret = fuel_gauge_reg_writeb(info, AXP288_FG_LOW_CAP_REG, ret);

		new_low_cap = info->low_cap;

		new_low_cap &= 0xf0;

		new_low_cap |= (val->intval & 0xf);

		ret = fuel_gauge_reg_writeb(info, AXP288_FG_LOW_CAP_REG, new_low_cap);

		if (ret == 0)

			info->low_cap = new_low_cap;

		break;

	default:

		ret = -EINVAL;
@@ -695,6 +690,16 @@ static int axp288_fuel_gauge_probe(struct platform_device *pdev) 
		break;

	}



	ret = fuel_gauge_reg_readb(info, AXP20X_PWR_OP_MODE);

	if (ret < 0)

		goto out_free_iio_chan;

	info->pwr_op = ret;



	ret = fuel_gauge_reg_readb(info, AXP288_FG_LOW_CAP_REG);

	if (ret < 0)

		goto out_free_iio_chan;

	info->low_cap = ret;



	psy_cfg.drv_data = info;

	info->bat = power_supply_register(&pdev->dev, &fuel_gauge_desc, &psy_cfg);

	if (IS_ERR(info->bat)) {