[PATCH 1/3] thermal/drivers/qcom/tsens: Release parent resources on probe failure

[Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>]

On legacy MSM8960/APQ8064 device trees without a separate TSENS child
node, the Global Clock Controller (GCC) driver creates a qcom-tsens
platform device without an OF node. TSENS consequently uses the parent
device for firmware lookups and managed resource allocations.

If probing fails, including calibration returning -EPROBE_DEFER, the
driver core releases only the child device's managed resources.
Allocations attached to the parent remain, accumulating across repeated
probe attempts.

Wrap the parent-bound allocations in a devres group and register a
cleanup action on the TSENS child. This releases the resources on probe
failure and unbind while preserving legacy firmware lookups. Keep the
group handling in a probe wrapper so the existing initialization path
remains self-contained.

Fixes: 9066073c6c27 ("thermal: qcom: tsens: Add a skeletal TSENS drivers")
Closes: https://sashiko.dev/#/bug/linux-7dc6dad0-c471-47ca-b493-8402752cf13a
Signed-off-by: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>
Cc: Rajendra Nayak <rajendra.nayak@oss.qualcomm.com>
---
 drivers/thermal/qcom/tsens.c | 37 +++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
index b5ec70201e2f..4f69ce4976d9 100644
--- a/drivers/thermal/qcom/tsens.c
+++ b/drivers/thermal/qcom/tsens.c
@@ -1374,7 +1374,7 @@ static int tsens_register(struct tsens_priv *priv)
 	return ret;
 }
 
-static int tsens_probe(struct platform_device *pdev)
+static int tsens_probe_common(struct platform_device *pdev)
 {
 	int ret, i;
 	struct device *dev;
@@ -1452,6 +1452,41 @@ static int tsens_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static void tsens_release_resources(void *data)
+{
+	struct device *dev = data;
+
+	devres_release_group(dev->parent, dev);
+}
+
+static int tsens_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	/*
+	 * DT-backed devices own their managed resources directly. Legacy devices
+	 * created by the Global Clock Controller (GCC) driver have no OF node and
+	 * use the parent's firmware data and managed resources instead. Group
+	 * those resources so the child releases them on probe failure or unbind.
+	 */
+	if (dev->of_node)
+		return tsens_probe_common(pdev);
+
+	/* Tie resources allocated on the parent to the TSENS lifetime. */
+	if (!devres_open_group(dev->parent, dev, GFP_KERNEL))
+		return -ENOMEM;
+
+	ret = devm_add_action_or_reset(dev, tsens_release_resources, dev);
+	if (ret)
+		return ret;
+
+	ret = tsens_probe_common(pdev);
+	devres_close_group(dev->parent, dev);
+
+	return ret;
+}
+
 static void tsens_remove(struct platform_device *pdev)
 {
 	struct tsens_priv *priv = platform_get_drvdata(pdev);
-- 
2.43.0