[PATCH 1/2] Input: drv260x: Make vbat supply optional

[Maurizio Casciano <mauriziocasciano7@gmail.com>]

The Lenovo Yoga Book YB1-X91L firmware instantiates two DRV2604
ACPI devices, but does not describe a software-controllable vbat supply
for either device. The generic regulator lookup therefore creates a
dummy supply.

Use the optional regulator lookup and skip regulator operations when no
supply is described. Systems which provide vbat retain the existing
enable, managed-disable, suspend, resume, and error-unwind behavior.

Signed-off-by: Maurizio Casciano <mauriziocasciano7@gmail.com>
Assisted-by: Codex:gpt-5.6-sol sparse
---
 drivers/input/misc/drv260x.c | 57 +++++++++++++++++++++---------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/drivers/input/misc/drv260x.c b/drivers/input/misc/drv260x.c
index 6c5c4c53753b..c4fbb10b254e 100644
--- a/drivers/input/misc/drv260x.c
+++ b/drivers/input/misc/drv260x.c
@@ -499,22 +499,26 @@ static int drv260x_probe(struct i2c_client *client)
 	haptics->overdrive_voltage = error ? DRV260X_DEF_OD_CLAMP_VOLT :
 					     drv260x_calculate_voltage(voltage);
 
-	haptics->regulator = devm_regulator_get(dev, "vbat");
+	haptics->regulator = devm_regulator_get_optional(dev, "vbat");
 	if (IS_ERR(haptics->regulator)) {
-		error = PTR_ERR(haptics->regulator);
-		dev_err(dev, "unable to get regulator, error: %d\n", error);
-		return error;
+		if (PTR_ERR(haptics->regulator) == -ENODEV) {
+			haptics->regulator = NULL;
+			dev_dbg(dev, "No vbat regulator found\n");
+		} else {
+			error = PTR_ERR(haptics->regulator);
+			return dev_err_probe(dev, error, "Unable to get vbat regulator\n");
+		}
 	}
 
-	error = regulator_enable(haptics->regulator);
-	if (error) {
-		dev_err(dev, "Failed to enable regulator: %d\n", error);
-		return error;
-	}
+	if (haptics->regulator) {
+		error = regulator_enable(haptics->regulator);
+		if (error)
+			return dev_err_probe(dev, error, "Failed to enable regulator\n");
 
-	error = devm_add_action_or_reset(dev, drv260x_power_off, haptics);
-	if (error)
-		return error;
+		error = devm_add_action_or_reset(dev, drv260x_power_off, haptics);
+		if (error)
+			return error;
+	}
 
 	haptics->enable_gpio = devm_gpiod_get_optional(dev, "enable",
 						       GPIOD_OUT_HIGH);
@@ -585,13 +589,15 @@ static int drv260x_suspend(struct device *dev)
 
 		gpiod_set_value(haptics->enable_gpio, 0);
 
-		error = regulator_disable(haptics->regulator);
-		if (error) {
-			dev_err(dev, "Failed to disable regulator\n");
-			regmap_update_bits(haptics->regmap,
-					   DRV260X_MODE,
-					   DRV260X_STANDBY_MASK, 0);
-			return error;
+		if (haptics->regulator) {
+			error = regulator_disable(haptics->regulator);
+			if (error) {
+				dev_err(dev, "Failed to disable regulator\n");
+				regmap_update_bits(haptics->regmap,
+						   DRV260X_MODE,
+						   DRV260X_STANDBY_MASK, 0);
+				return error;
+			}
 		}
 	}
 
@@ -606,10 +612,12 @@ static int drv260x_resume(struct device *dev)
 	guard(mutex)(&haptics->input_dev->mutex);
 
 	if (input_device_enabled(haptics->input_dev)) {
-		error = regulator_enable(haptics->regulator);
-		if (error) {
-			dev_err(dev, "Failed to enable regulator\n");
-			return error;
+		if (haptics->regulator) {
+			error = regulator_enable(haptics->regulator);
+			if (error) {
+				dev_err(dev, "Failed to enable regulator\n");
+				return error;
+			}
 		}
 
 		error = regmap_update_bits(haptics->regmap,
@@ -617,7 +625,8 @@ static int drv260x_resume(struct device *dev)
 					   DRV260X_STANDBY_MASK, 0);
 		if (error) {
 			dev_err(dev, "Failed to unset standby mode\n");
-			regulator_disable(haptics->regulator);
+			if (haptics->regulator)
+				regulator_disable(haptics->regulator);
 			return error;
 		}
 
-- 
2.53.0