[PATCH v12 7/9] power: bq27xxx_battery: Add power_supply_battery_info support

[Liam Breck <liam@networkimprov.net>]

From: Liam Breck <kernel@networkimprov.net>

Previously there was no way to configure these chips in the event that the
defaults didn't match the battery in question.

We now call power_supply_get_battery_info(), check its values, and write
battery data to chip data memory (flash/RAM/NVM).

Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Liam Breck <kernel@networkimprov.net>
---
 drivers/power/supply/bq27xxx_battery.c | 105 ++++++++++++++++++++++++++++++++-
 1 file changed, 104 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
index ad152cc..d845ade 100644
--- a/drivers/power/supply/bq27xxx_battery.c
+++ b/drivers/power/supply/bq27xxx_battery.c
@@ -1210,6 +1210,98 @@ static int bq27xxx_battery_write_dm_block(struct bq27xxx_device_info *di,
 	return ret;
 }
 
+static void bq27xxx_battery_set_config(struct bq27xxx_device_info *di,
+				       struct power_supply_battery_info *info)
+{
+	struct bq27xxx_dm_buf bd = BQ27XXX_DM_BUF(di, BQ27XXX_DM_DESIGN_CAPACITY);
+	struct bq27xxx_dm_buf bt = BQ27XXX_DM_BUF(di, BQ27XXX_DM_TERMINATE_VOLTAGE);
+
+	if (bq27xxx_battery_unseal(di) < 0)
+		return;
+
+	if (info->charge_full_design_uah != -EINVAL &&
+	    info->energy_full_design_uwh != -EINVAL) {
+		bq27xxx_battery_read_dm_block(di, &bd);
+		/* assume design energy & capacity are in same block */
+		bq27xxx_battery_update_dm_block(di, &bd,
+					BQ27XXX_DM_DESIGN_CAPACITY,
+					info->charge_full_design_uah / 1000);
+		bq27xxx_battery_update_dm_block(di, &bd,
+					BQ27XXX_DM_DESIGN_ENERGY,
+					info->energy_full_design_uwh / 1000);
+	}
+
+	if (info->voltage_min_design_uv != -EINVAL) {
+		bool same = bd.class == bt.class && bd.block == bt.block;
+		if (!same)
+			bq27xxx_battery_read_dm_block(di, &bt);
+		bq27xxx_battery_update_dm_block(di, same ? &bd : &bt,
+					BQ27XXX_DM_TERMINATE_VOLTAGE,
+					info->voltage_min_design_uv / 1000);
+	}
+
+	bq27xxx_battery_write_dm_block(di, &bd);
+	bq27xxx_battery_write_dm_block(di, &bt);
+
+	bq27xxx_battery_seal(di);
+
+	if (di->chip != BQ27421) { /* not a cfgupdate chip, so reset */
+		bq27xxx_write(di, BQ27XXX_REG_CTRL, BQ27XXX_RESET, false);
+		BQ27XXX_MSLEEP(300); /* reset time is not documented */
+	}
+	/* assume bq27xxx_battery_update() is called hereafter */
+}
+
+void bq27xxx_battery_settings(struct bq27xxx_device_info *di)
+{
+	struct power_supply_battery_info info = {};
+	unsigned int min, max;
+
+	if (!di->dm_regs)
+		return;
+
+	if (power_supply_get_battery_info(di->bat, &info) < 0)
+		return;
+
+	if (info.energy_full_design_uwh != info.charge_full_design_uah) {
+		if (info.energy_full_design_uwh == -EINVAL)
+			dev_warn(di->dev, "missing battery:energy-full-design-microwatt-hours\n");
+		else if (info.charge_full_design_uah == -EINVAL)
+			dev_warn(di->dev, "missing battery:charge-full-design-microamp-hours\n");
+	}
+
+	/* assume min == 0 */
+	max = di->dm_regs[BQ27XXX_DM_DESIGN_ENERGY].max;
+	if (info.energy_full_design_uwh > max * 1000) {
+		dev_err(di->dev, "invalid battery:energy-full-design-microwatt-hours %d\n",
+			info.energy_full_design_uwh);
+		info.energy_full_design_uwh = -EINVAL;
+	}
+
+	/* assume min == 0 */
+	max = di->dm_regs[BQ27XXX_DM_DESIGN_CAPACITY].max;
+	if (info.charge_full_design_uah > max * 1000) {
+		dev_err(di->dev, "invalid battery:charge-full-design-microamp-hours %d\n",
+			info.charge_full_design_uah);
+		info.charge_full_design_uah = -EINVAL;
+	}
+
+	min = di->dm_regs[BQ27XXX_DM_TERMINATE_VOLTAGE].min;
+	max = di->dm_regs[BQ27XXX_DM_TERMINATE_VOLTAGE].max;
+	if ((info.voltage_min_design_uv < min * 1000 ||
+	     info.voltage_min_design_uv > max * 1000) &&
+	     info.voltage_min_design_uv != -EINVAL) {
+		dev_err(di->dev, "invalid battery:voltage-min-design-microvolt %d\n",
+			info.voltage_min_design_uv);
+		info.voltage_min_design_uv = -EINVAL;
+	}
+
+	if ((info.energy_full_design_uwh != -EINVAL &&
+	     info.charge_full_design_uah != -EINVAL) ||
+	     info.voltage_min_design_uv  != -EINVAL)
+		bq27xxx_battery_set_config(di, &info);
+}
+
 /*
  * Return the battery State-of-Charge
  * Or < 0 if something fails.
@@ -1727,6 +1819,13 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 		ret = bq27xxx_simple_value(di->charge_design_full, val);
 		break;
+	/*
+	 * TODO: Implement these to make registers set from
+	 * power_supply_battery_info visible in sysfs.
+	 */
+	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		return -EINVAL;
 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
 		ret = bq27xxx_simple_value(di->cache.cycle_count, val);
 		break;
@@ -1760,7 +1859,10 @@ static void bq27xxx_external_power_changed(struct power_supply *psy)
 int bq27xxx_battery_setup(struct bq27xxx_device_info *di)
 {
 	struct power_supply_desc *psy_desc;
-	struct power_supply_config psy_cfg = { .drv_data = di, };
+	struct power_supply_config psy_cfg = {
+		.of_node = di->dev->of_node,
+		.drv_data = di,
+	};
 
 	INIT_DELAYED_WORK(&di->work, bq27xxx_battery_poll);
 	mutex_init(&di->lock);
@@ -1785,6 +1887,7 @@ int bq27xxx_battery_setup(struct bq27xxx_device_info *di)
 
 	dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 
+	bq27xxx_battery_settings(di);
 	bq27xxx_battery_update(di);
 
 	mutex_lock(&bq27xxx_list_lock);
-- 
2.9.3