regulator: axp20x: Add support for the (external) drivebus regulator

The axp20x pmics have 2 power inputs, one called ACIN which is intended
for to be supplied via a powerbarrel on the board and one called VBUS
which is intended to be supplied via an otg connector.

In the VBUS case the pmic needs to know if the board is supplying power
to the otg connector, because then it should not take any power from
its VBUS pin. The axp209 pmic has a N_VBUSEN input pin via which the
board can signal to the pmic whether the board is supplying power to the
otg connector or not.

On the axp221/axp223 this pin can alternatively be used as an output
which controls an external regulator which (optionally) supplies
power to the otg connector from the board. When the pin is used as
output it is called DRIVEVBUS in the datasheet.

This commit adds support for the DRIVEVBUS pin as an extra pmic
controlled regulator. Since this is optional a new x-powers,drivebus dt
property is added. When this is present the misc-control register is
written to change the N_VBUSEN input pin to DRIVEVBUS output pin mode and
the extra drivebus regulator is registered with the regulator subsystem.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
index 728be64e817a..6d9ac76a772f 100644
--- a/drivers/regulator/axp20x-regulator.c
+++ b/drivers/regulator/axp20x-regulator.c
@@ -36,6 +36,8 @@
 
 #define AXP20X_FREQ_DCDC_MASK		0x0f
 
+#define AXP22X_MISC_N_VBUSEN_FUNC	BIT(4)
+
 #define AXP_DESC_IO(_family, _id, _match, _supply, _min, _max, _step, _vreg,	\
 		    _vmask, _ereg, _emask, _enable_val, _disable_val)		\
 	[_family##_##_id] = {							\
@@ -230,6 +232,18 @@ static const struct regulator_desc axp22x_regulators[] = {
 	AXP_DESC_FIXED(AXP22X, RTC_LDO, "rtc_ldo", "ips", 3000),
 };
 
+static const struct regulator_desc axp22x_drivevbus_regulator = {
+	.name		= "drivevbus",
+	.supply_name	= "drivevbus",
+	.of_match	= of_match_ptr("drivevbus"),
+	.regulators_node = of_match_ptr("regulators"),
+	.type		= REGULATOR_VOLTAGE,
+	.owner		= THIS_MODULE,
+	.enable_reg	= AXP20X_VBUS_IPSOUT_MGMT,
+	.enable_mask	= BIT(2),
+	.ops		= &axp20x_ops_sw,
+};
+
 static const struct regulator_linear_range axp809_dcdc4_ranges[] = {
 	REGULATOR_LINEAR_RANGE(600000, 0x0, 0x2f, 20000),
 	REGULATOR_LINEAR_RANGE(1800000, 0x30, 0x38, 100000),
@@ -411,6 +425,7 @@ static int axp20x_regulator_probe(struct platform_device *pdev)
 	u32 workmode;
 	const char *dcdc1_name = axp22x_regulators[AXP22X_DCDC1].name;
 	const char *dcdc5_name = axp22x_regulators[AXP22X_DCDC5].name;
+	bool drivevbus = false;
 
 	switch (axp20x->variant) {
 	case AXP202_ID:
@@ -422,6 +437,8 @@ static int axp20x_regulator_probe(struct platform_device *pdev)
 	case AXP223_ID:
 		regulators = axp22x_regulators;
 		nregulators = AXP22X_REG_ID_MAX;
+		drivevbus = of_property_read_bool(pdev->dev.parent->of_node,
+						  "x-powers,drive-vbus-en");
 		break;
 	case AXP809_ID:
 		regulators = axp809_regulators;
@@ -500,6 +517,19 @@ static int axp20x_regulator_probe(struct platform_device *pdev)
 						&dcdc5_name);
 	}
 
+	if (drivevbus) {
+		/* Change N_VBUSEN sense pin to DRIVEVBUS output pin */
+		regmap_update_bits(axp20x->regmap, AXP20X_OVER_TMP,
+				   AXP22X_MISC_N_VBUSEN_FUNC, 0);
+		rdev = devm_regulator_register(&pdev->dev,
+					       &axp22x_drivevbus_regulator,
+					       &config);
+		if (IS_ERR(rdev)) {
+			dev_err(&pdev->dev, "Failed to register drivevbus\n");
+			return PTR_ERR(rdev);
+		}
+	}
+
 	return 0;
 }