[PATCH] power: supply: bq25890: Add support for setting IINLIM

[Marek Vasut <marex@denx.de>]

Let user set input current limit via sysfs. This is useful in case there
are multiple chargers connected to the device, each of which with its own
arbitrary maximum current which it can provide, some of which may provide
more than the default 500mA. In that case, userspace can listen for plug
events generated by each charger and adjust the current limit accordingly,
e.g. to permit battery to charge faster.

Note that the IINLIM is reset every time the bq25890 is disconnected from
a charger, so the userspace must adjust the limit repeatly on every plug
event.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
To: linux-pm@vger.kernel.org
---
 drivers/power/supply/bq25890_charger.c | 30 ++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/power/supply/bq25890_charger.c b/drivers/power/supply/bq25890_charger.c
index 131ec7d882fe9..e412bcf90b40c 100644
--- a/drivers/power/supply/bq25890_charger.c
+++ b/drivers/power/supply/bq25890_charger.c
@@ -613,6 +613,34 @@ static int bq25890_power_supply_get_property(struct power_supply *psy,
 	return 0;
 }
 
+static int bq25890_power_supply_set_property(struct power_supply *psy,
+					     enum power_supply_property psp,
+					     const union power_supply_propval *val)
+{
+	struct bq25890_device *bq = power_supply_get_drvdata(psy);
+	u32 lval;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		lval = clamp(val->intval, 100000, 3250000);
+		lval = DIV_ROUND_UP(lval - 100000, 50000);
+		return bq25890_field_write(bq, F_IINLIM, lval);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bq25890_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 bq25890_get_chip_state(struct bq25890_device *bq,
 				  struct bq25890_state *state)
 {
@@ -837,6 +865,8 @@ static const struct power_supply_desc bq25890_power_supply_desc = {
 	.properties = bq25890_power_supply_props,
 	.num_properties = ARRAY_SIZE(bq25890_power_supply_props),
 	.get_property = bq25890_power_supply_get_property,
+	.set_property = bq25890_power_supply_set_property,
+	.property_is_writeable = bq25890_power_supply_property_is_writeable,
 };
 
 static int bq25890_power_supply_init(struct bq25890_device *bq)
-- 
2.35.1