[PATCH] mfd: wcd934x: Unroll regmap and irqchip on removal

[Bjorn Andersson]

When the slimbus-up event is handled a new regmap is created, an IRQ
chip is registered on this regmap and then the MFD devices are added.

But the regmap is left dangling if either any of those operations are
failing or if the slimbus-down event ever comes. Which manifest itself
as an error print from debugfs once the next slimbus-up event happens.

Likewise, if for some reason a slimbus-down event would be followed by
a slimbus-up event without the MFD being torn down by the slimbus
controller inbetween, we're going to have a dangling irq_chip.

Add cleanup of the registered resources on failure and on removal.

Fixes: 6ac7e4d7ad70 ("mfd: wcd934x: Add support to wcd9340/wcd9341 codec")
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxxxx>
---
 drivers/mfd/wcd934x.c | 49 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 11 deletions(-)

diff --git a/drivers/mfd/wcd934x.c b/drivers/mfd/wcd934x.c
index 3c3080e8c8cf7ecaaa62e255c7e01a850e65e9ad..b03cc91cc3a6a114a34efdb278420ae3dfa016eb 100644
--- a/drivers/mfd/wcd934x.c
+++ b/drivers/mfd/wcd934x.c
@@ -170,29 +170,56 @@ static int wcd934x_slim_status_up(struct slim_device *sdev)
 	ret = wcd934x_bring_up(ddata);
 	if (ret) {
 		dev_err(dev, "Failed to bring up WCD934X: err = %d\n", ret);
-		return ret;
+		goto err_regmap_exit;
 	}
 
-	ret = devm_regmap_add_irq_chip(dev, ddata->regmap, ddata->irq,
-				       IRQF_TRIGGER_HIGH, 0,
-				       &wcd934x_regmap_irq_chip,
-				       &ddata->irq_data);
+	ret = regmap_add_irq_chip(ddata->regmap, ddata->irq,
+				  IRQF_TRIGGER_HIGH, 0,
+				  &wcd934x_regmap_irq_chip,
+				  &ddata->irq_data);
 	if (ret) {
 		dev_err(dev, "Failed to add IRQ chip: err = %d\n", ret);
-		return ret;
+		goto err_regmap_exit;
 	}
 
 	ret = mfd_add_devices(dev, PLATFORM_DEVID_AUTO, wcd934x_devices,
 			      ARRAY_SIZE(wcd934x_devices), NULL, 0, NULL);
 	if (ret) {
-		dev_err(dev, "Failed to add child devices: err = %d\n",
-			ret);
-		return ret;
+		dev_err(dev, "Failed to add child devices: err = %d\n", ret);
+		goto err_del_irq_chip;
 	}
 
+	return 0;
+
+err_del_irq_chip:
+	regmap_del_irq_chip(ddata->irq, ddata->irq_data);
+	ddata->irq_data = NULL;
+err_regmap_exit:
+	regmap_exit(ddata->regmap);
+	ddata->regmap = NULL;
 	return ret;
 }
 
+static void wcd934x_slim_status_down(struct slim_device *sdev)
+{
+	struct device *dev = &sdev->dev;
+	struct wcd934x_ddata *ddata;
+
+	ddata = dev_get_drvdata(dev);
+
+	mfd_remove_devices(&sdev->dev);
+
+	if (ddata->irq_data) {
+		regmap_del_irq_chip(ddata->irq, ddata->irq_data);
+		ddata->irq_data = NULL;
+	}
+
+	if (ddata->regmap) {
+		regmap_exit(ddata->regmap);
+		ddata->regmap = NULL;
+	}
+}
+
 static int wcd934x_slim_status(struct slim_device *sdev,
 			       enum slim_device_status status)
 {
@@ -200,7 +227,7 @@ static int wcd934x_slim_status(struct slim_device *sdev,
 	case SLIM_DEVICE_STATUS_UP:
 		return wcd934x_slim_status_up(sdev);
 	case SLIM_DEVICE_STATUS_DOWN:
-		mfd_remove_devices(&sdev->dev);
+		wcd934x_slim_status_down(sdev);
 		break;
 	default:
 		return -EINVAL;
@@ -276,7 +303,7 @@ static void wcd934x_slim_remove(struct slim_device *sdev)
 	struct wcd934x_ddata *ddata = dev_get_drvdata(&sdev->dev);
 
 	regulator_bulk_disable(WCD934X_MAX_SUPPLY, ddata->supplies);
-	mfd_remove_devices(&sdev->dev);
+	wcd934x_slim_status_down(sdev);
 }
 
 static const struct slim_device_id wcd934x_slim_id[] = {

---
base-commit: a0ae2a256046c0c5d3778d1a194ff2e171f16e5f
change-id: 20260309-wcd934x-unroll-regmap-f9e08834f9d7

Best regards,
-- 
Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxxxx>