[PATCH v2 09/13] power: bq24257: Allow input current limit sysfs access

Andreas Dannenberg
2015-09-09T00:14:03Z

This patch allows reading (and writing, if the D+/D- USB signal-based
charger type detection is disabled) of the input current limit through
the POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT sysfs property. This allows
userspace to see what charger was detected and to re-configure the
maximum current drawn from the external supply at runtime based on
system-level knowledge or user input.

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
---
drivers/power/bq24257_charger.c | 44 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c
index 886040c..f0602b3 100644
--- a/drivers/power/bq24257_charger.c
+++ b/drivers/power/bq24257_charger.c
@@ -315,6 +315,41 @@ static int bq24257_set_charge_type(struct bq24257_device *bq,
return bq24257_field_write(bq, F_CE, 0);
}

+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)
+{
+ if (!bq->in_ilimit_autoset_disable)
+ return -EPERM;
+
+ 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)
@@ -403,6 +438,10 @@ 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:
+ ret = bq24257_get_input_current_limit(bq, val);
+ break;
+
default:
ret = -EINVAL;
}
@@ -425,6 +464,9 @@ static int bq24257_power_supply_set_property(struct power_supply *psy,
case POWER_SUPPLY_PROP_CHARGE_TYPE:
ret = bq24257_set_charge_type(bq, val);
break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ ret = bq24257_set_input_current_limit(bq, val);
+ break;
default:
ret = -EINVAL;
}
@@ -439,6 +481,7 @@ static int bq24257_power_supply_property_is_writeable(struct power_supply *psy,
{
switch (psp) {
case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
return true;
default:
return false;
@@ -778,6 +821,7 @@ 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[] = {
--
1.9.1