[PATCH v2 08/13] power: bq24257: Add charge type setting support

Andreas Dannenberg
2015-09-09T00:12:32Z

The bq2425x devices support charging with a configurable charge current
i_chg or a specific fixed low-current in what's called Low Charge mode.
This patch exposes access to the Low Charge mode through a POWER_
SUPPLY_PROP_CHARGE_TYPE sysfs property value of POWER_SUPPLY_CHARGE_
TYPE_TRICKLE. It also allows to completely disable charging if desired
by setting the property to POWER_SUPPLY_CHARGE_TYPE_NONE. Normal
charging with the configured i_chg current is activated through
POWER_SUPPLY_CHARGE_TYPE_FAST (default).

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
---
drivers/power/bq24257_charger.c | 90 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 90 insertions(+)

diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c
index f0d4307..886040c 100644
--- a/drivers/power/bq24257_charger.c
+++ b/drivers/power/bq24257_charger.c
@@ -265,6 +265,56 @@ enum bq24257_fault {
FAULT_INPUT_LDO_LOW,
};

+static int bq24257_get_charge_type(struct bq24257_device *bq,
+ union power_supply_propval *val)
+{
+ int ret;
+
+ ret = bq24257_field_read(bq, F_CE);
+ if (ret < 0)
+ return ret;
+
+ /* Charge Enable is active-low */
+ if (ret) {
+ val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
+ return 0;
+ }
+
+ /* Low Charge means a fixed low-current is used instead of i_chg */
+ ret = bq24257_field_read(bq, F_LOW_CHG);
+ if (ret < 0)
+ return ret;
+
+ val->intval = ret ? POWER_SUPPLY_CHARGE_TYPE_TRICKLE :
+ POWER_SUPPLY_CHARGE_TYPE_FAST;
+
+ return 0;
+}
+
+static int bq24257_set_charge_type(struct bq24257_device *bq,
+ const union power_supply_propval *val)
+{
+ int ret;
+
+ switch (val->intval) {
+ case POWER_SUPPLY_CHARGE_TYPE_NONE:
+ return bq24257_field_write(bq, F_CE, 1);
+ case POWER_SUPPLY_CHARGE_TYPE_TRICKLE:
+ ret = bq24257_field_write(bq, F_LOW_CHG, 1);
+ break;
+ case POWER_SUPPLY_CHARGE_TYPE_FAST:
+ ret = bq24257_field_write(bq, F_LOW_CHG, 0);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (ret < 0)
+ return ret;
+
+ return bq24257_field_write(bq, F_CE, 0);
+}
+
static int bq24257_power_supply_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
@@ -290,6 +340,10 @@ static int bq24257_power_supply_get_property(struct power_supply *psy,
val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
break;

+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ ret = bq24257_get_charge_type(bq, val);
+ break;
+
case POWER_SUPPLY_PROP_MANUFACTURER:
val->strval = BQ24257_MANUFACTURER;
break;
@@ -358,6 +412,39 @@ static int bq24257_power_supply_get_property(struct power_supply *psy,
return ret;
}

+static int bq24257_power_supply_set_property(struct power_supply *psy,
+ enum power_supply_property prop,
+ const union power_supply_propval *val)
+{
+ struct bq24257_device *bq = power_supply_get_drvdata(psy);
+ int ret;
+
+ mutex_lock(&bq->lock);
+
+ switch (prop) {
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ ret = bq24257_set_charge_type(bq, val);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ mutex_unlock(&bq->lock);
+
+ return ret;
+}
+
+static int bq24257_power_supply_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ return true;
+ default:
+ return false;
+ }
+}
+
static int bq24257_get_chip_state(struct bq24257_device *bq,
struct bq24257_state *state)
{
@@ -683,6 +770,7 @@ static enum power_supply_property bq24257_power_supply_props[] = {
POWER_SUPPLY_PROP_MANUFACTURER,
POWER_SUPPLY_PROP_MODEL_NAME,
POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_CHARGE_TYPE,
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_HEALTH,
POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
@@ -702,6 +790,8 @@ static const struct power_supply_desc bq24257_power_supply_desc = {
.properties = bq24257_power_supply_props,
.num_properties = ARRAY_SIZE(bq24257_power_supply_props),
.get_property = bq24257_power_supply_get_property,
+ .set_property = bq24257_power_supply_set_property,
+ .property_is_writeable = bq24257_power_supply_property_is_writeable
};

static ssize_t bq24257_show_ovp_voltage(struct device *dev,
--
1.9.1