[PATCH v3] counter: intel-qep: Replace manual mutex logic with lock guards

[Joao Paulo Menezes Linaris <jplinaris@usp.br>]

Use guard() for handling mutex lock instead of locking and unlocking
mutex explicitly. This improves readability by eliminating the need for
gotos and by clearly indicating mutex will be locked only when
execution is in guard scope.

Signed-off-by: Joao Paulo Menezes Linaris <jplinaris@usp.br>
Co-developed-by: Guilherme Dias <guilhermeabreu200105@usp.br>
Signed-off-by: Guilherme Dias <guilhermeabreu200105@usp.br>
---
v2 -> v3:
 - add blank line between guard(mutex)() and other code

 drivers/counter/intel-qep.c | 50 +++++++++++++------------------------
 1 file changed, 18 insertions(+), 32 deletions(-)

diff --git a/drivers/counter/intel-qep.c b/drivers/counter/intel-qep.c
index c49c17805..9c6536f75 100644
--- a/drivers/counter/intel-qep.c
+++ b/drivers/counter/intel-qep.c
@@ -188,25 +188,21 @@ static int intel_qep_ceiling_write(struct counter_device *counter,
 				   struct counter_count *count, u64 max)
 {
 	struct intel_qep *qep = counter_priv(counter);
-	int ret = 0;
 
 	/* Intel QEP ceiling configuration only supports 32-bit values */
 	if (max != (u32)max)
 		return -ERANGE;
 
-	mutex_lock(&qep->lock);
-	if (qep->enabled) {
-		ret = -EBUSY;
-		goto out;
-	}
+	guard(mutex)(&qep->lock);
+
+	if (qep->enabled)
+		return -EBUSY;
 
 	pm_runtime_get_sync(qep->dev);
 	intel_qep_writel(qep, INTEL_QEPMAX, max);
 	pm_runtime_put(qep->dev);
 
-out:
-	mutex_unlock(&qep->lock);
-	return ret;
+	return 0;
 }
 
 static int intel_qep_enable_read(struct counter_device *counter,
@@ -226,10 +222,11 @@ static int intel_qep_enable_write(struct counter_device *counter,
 	u32 reg;
 	bool changed;
 
-	mutex_lock(&qep->lock);
+	guard(mutex)(&qep->lock);
+
 	changed = val ^ qep->enabled;
 	if (!changed)
-		goto out;
+		return 0;
 
 	pm_runtime_get_sync(qep->dev);
 	reg = intel_qep_readl(qep, INTEL_QEPCON);
@@ -246,8 +243,6 @@ static int intel_qep_enable_write(struct counter_device *counter,
 	pm_runtime_put(qep->dev);
 	qep->enabled = val;
 
-out:
-	mutex_unlock(&qep->lock);
 	return 0;
 }
 
@@ -279,7 +274,6 @@ static int intel_qep_spike_filter_ns_write(struct counter_device *counter,
 	struct intel_qep *qep = counter_priv(counter);
 	u32 reg;
 	bool enable;
-	int ret = 0;
 
 	/*
 	 * Spike filter length is (MAX_COUNT + 2) clock periods.
@@ -300,11 +294,10 @@ static int intel_qep_spike_filter_ns_write(struct counter_device *counter,
 	if (length > INTEL_QEPFLT_MAX_COUNT(length))
 		return -ERANGE;
 
-	mutex_lock(&qep->lock);
-	if (qep->enabled) {
-		ret = -EBUSY;
-		goto out;
-	}
+	guard(mutex)(&qep->lock);
+
+	if (qep->enabled)
+		return -EBUSY;
 
 	pm_runtime_get_sync(qep->dev);
 	reg = intel_qep_readl(qep, INTEL_QEPCON);
@@ -316,9 +309,7 @@ static int intel_qep_spike_filter_ns_write(struct counter_device *counter,
 	intel_qep_writel(qep, INTEL_QEPCON, reg);
 	pm_runtime_put(qep->dev);
 
-out:
-	mutex_unlock(&qep->lock);
-	return ret;
+	return 0;
 }
 
 static int intel_qep_preset_enable_read(struct counter_device *counter,
@@ -342,13 +333,11 @@ static int intel_qep_preset_enable_write(struct counter_device *counter,
 {
 	struct intel_qep *qep = counter_priv(counter);
 	u32 reg;
-	int ret = 0;
 
-	mutex_lock(&qep->lock);
-	if (qep->enabled) {
-		ret = -EBUSY;
-		goto out;
-	}
+	guard(mutex)(&qep->lock);
+
+	if (qep->enabled)
+		return -EBUSY;
 
 	pm_runtime_get_sync(qep->dev);
 	reg = intel_qep_readl(qep, INTEL_QEPCON);
@@ -360,10 +349,7 @@ static int intel_qep_preset_enable_write(struct counter_device *counter,
 	intel_qep_writel(qep, INTEL_QEPCON, reg);
 	pm_runtime_put(qep->dev);
 
-out:
-	mutex_unlock(&qep->lock);
-
-	return ret;
+	return 0;
 }
 
 static struct counter_comp intel_qep_count_ext[] = {
-- 
2.34.1