This patch allows reading and writing of the input current limit through
the power supply's input_current_limit sysfs property. This allows
userspace to see what charger was detected (if the D+/D- USB signal-
based charger type detection is enabled) and to re-configure the maximum
current drawn from the external supply at runtime based on system-level
knowledge or user input. Note that upon charger disconnection and
re-connection the limit configured through firmware becomes active again
(or the D+/D- USB signal-based charger detection will be run again).
Signed-off-by: Andreas Dannenberg <dannenberg@xxxxxx>
---
drivers/power/bq24257_charger.c | 85 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 79 insertions(+), 6 deletions(-)
diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c
index 2a76009..73fcf89 100644
--- a/drivers/power/bq24257_charger.c
+++ b/drivers/power/bq24257_charger.c
@@ -267,6 +267,47 @@ enum bq24257_fault {
FAULT_INPUT_LDO_LOW,
};
+static int bq24257_get_input_current_limit(struct bq24257_device *bq,
+ union power_supply_propval *val)
+{
+ int ret;
+
+ ret = bq24257_field_read(bq, F_IILIMIT);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * The "External ILIM" and "Production & Test" modes are not exposed
+ * through this driver and not being covered by the lookup table.
+ * Should such a mode have become active let's return an error rather
+ * than exceeding the bounds of the lookup table and returning
+ * garbage.
+ */
+ if (ret >= BQ24257_IILIMIT_MAP_SIZE)
+ return -ENODATA;
+
+ val->intval = bq24257_iilimit_map[ret];
+
+ return 0;
+}
+
+static int bq24257_set_input_current_limit(struct bq24257_device *bq,
+ const union power_supply_propval *val)
+{
+ /*
+ * Address the case where the user manually sets an input current limit
+ * while the charger auto-detection mechanism is is active. In this
+ * case we want to abort and go straight to the user-specified value.
+ */
+ if (bq->iilimit_autoset_enable)
+ cancel_delayed_work_sync(&bq->iilimit_setup_work);
+
+ return bq24257_field_write(bq, F_IILIMIT,
+ bq24257_find_idx(val->intval,
+ bq24257_iilimit_map,
+ BQ24257_IILIMIT_MAP_SIZE));
+}
+
static int bq24257_power_supply_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
@@ -351,6 +392,9 @@ static int bq24257_power_supply_get_property(struct power_supply *psy,
val->intval = bq24257_iterm_map[bq->init_data.iterm];
break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return bq24257_get_input_current_limit(bq, val);
+
default:
return -EINVAL;
}
@@ -358,6 +402,31 @@ static int bq24257_power_supply_get_property(struct power_supply *psy,
return 0;
}
+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);
+
+ switch (prop) {
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return bq24257_set_input_current_limit(bq, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int bq24257_power_supply_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return true;
+ default:
+ return false;
+ }
+}
+
static int bq24257_get_chip_state(struct bq24257_device *bq,
struct bq24257_state *state)
{
@@ -559,13 +628,14 @@ static void bq24257_handle_state_change(struct bq24257_device *bq,
ret = bq24257_field_write(bq, F_DPDM_EN, 1);
if (ret < 0)
goto error;
-
- /* reset input current limit */
- ret = bq24257_field_write(bq, F_IILIMIT,
- bq->init_data.iilimit);
- if (ret < 0)
- goto error;
}
+ /*
+ * When power is removed always return to the default input
+ * current limit as configured during probe.
+ */
+ ret = bq24257_field_write(bq, F_IILIMIT, bq->init_data.iilimit);
+ if (ret < 0)
+ goto error;
} else if (!old_state.power_good) {
dev_dbg(bq->dev, "Power inserted\n");
@@ -682,6 +752,7 @@ static enum power_supply_property bq24257_power_supply_props[] = {
POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
+ POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
};
static char *bq24257_charger_supplied_to[] = {
@@ -694,6 +765,8 @@ 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
--
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