coresight: Refactor runtime PM

The validation for driver data pointers and clock pointers are redundant
in the runtime PM callbacks.  After a driver's probing, its driver data
and clocks have been initialized successfully, this ensures it is safe
to access driver data and clocks in the runtime PM callbacks.  A corner
case is a clock pointer is NULL, in this case, the clock core layer can
handle it properly.  So remove these redundant checking.

In runtime resume, respect values returned from clock function and add
error handling.

Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250731-arm_cs_fix_clock_v4-v6-10-1dfe10bb3f6f@arm.com

8 files changed, 53 insertions, 60 deletions

diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c
index 3edfb5d3d020..5f21366406aa 100644
--- a/drivers/hwtracing/coresight/coresight-cpu-debug.c
+++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c
@@ -731,8 +731,8 @@ static int debug_runtime_suspend(struct device *dev)
 {
 	struct debug_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_disable_unprepare(drvdata->pclk);
+	clk_disable_unprepare(drvdata->pclk);
+
 	return 0;
 }
 
@@ -740,9 +740,7 @@ static int debug_runtime_resume(struct device *dev)
 {
 	struct debug_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_prepare_enable(drvdata->pclk);
-	return 0;
+	return clk_prepare_enable(drvdata->pclk);
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c
index 75b5114ef652..c586495e9a08 100644
--- a/drivers/hwtracing/coresight/coresight-ctcu-core.c
+++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c
@@ -278,8 +278,7 @@ static int ctcu_runtime_suspend(struct device *dev)
 {
 	struct ctcu_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->apb_clk))
-		clk_disable_unprepare(drvdata->apb_clk);
+	clk_disable_unprepare(drvdata->apb_clk);
 
 	return 0;
 }
@@ -288,10 +287,7 @@ static int ctcu_runtime_resume(struct device *dev)
 {
 	struct ctcu_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->apb_clk))
-		clk_prepare_enable(drvdata->apb_clk);
-
-	return 0;
+	return clk_prepare_enable(drvdata->apb_clk);
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 8e81b41eb222..35db1b6093d1 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -809,8 +809,7 @@ static int etb_runtime_suspend(struct device *dev)
 {
 	struct etb_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->atclk);
 
 	return 0;
 }
@@ -819,10 +818,7 @@ static int etb_runtime_resume(struct device *dev)
 {
 	struct etb_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_prepare_enable(drvdata->atclk);
-
-	return 0;
+	return clk_prepare_enable(drvdata->atclk);
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index baba2245b1df..45630a1cd32f 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -925,8 +925,7 @@ static int etm_runtime_suspend(struct device *dev)
 {
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->atclk);
 
 	return 0;
 }
@@ -935,10 +934,7 @@ static int etm_runtime_resume(struct device *dev)
 {
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_prepare_enable(drvdata->atclk);
-
-	return 0;
+	return clk_prepare_enable(drvdata->atclk);
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 9dcfc5ce8845..3b248e54471a 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -284,11 +284,8 @@ static int funnel_runtime_suspend(struct device *dev)
 {
 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
-
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_disable_unprepare(drvdata->pclk);
+	clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->pclk);
 
 	return 0;
 }
@@ -296,13 +293,17 @@ static int funnel_runtime_suspend(struct device *dev)
 static int funnel_runtime_resume(struct device *dev)
 {
 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(drvdata->pclk);
+	if (ret)
+		return ret;
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_prepare_enable(drvdata->pclk);
+	ret = clk_prepare_enable(drvdata->atclk);
+	if (ret)
+		clk_disable_unprepare(drvdata->pclk);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_prepare_enable(drvdata->atclk);
-	return 0;
+	return ret;
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index e53095603b0c..e6472658235d 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -323,24 +323,26 @@ static int replicator_runtime_suspend(struct device *dev)
 {
 	struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->pclk);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_disable_unprepare(drvdata->pclk);
 	return 0;
 }
 
 static int replicator_runtime_resume(struct device *dev)
 {
 	struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
+	int ret;
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_prepare_enable(drvdata->pclk);
+	ret = clk_prepare_enable(drvdata->pclk);
+	if (ret)
+		return ret;
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_prepare_enable(drvdata->atclk);
-	return 0;
+	ret = clk_prepare_enable(drvdata->atclk);
+	if (ret)
+		clk_disable_unprepare(drvdata->pclk);
+
+	return ret;
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index 7b1e289f17ab..e68529bf89c9 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -957,24 +957,26 @@ static int stm_runtime_suspend(struct device *dev)
 {
 	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->pclk);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_disable_unprepare(drvdata->pclk);
 	return 0;
 }
 
 static int stm_runtime_resume(struct device *dev)
 {
 	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
+	int ret;
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_prepare_enable(drvdata->pclk);
+	ret = clk_prepare_enable(drvdata->pclk);
+	if (ret)
+		return ret;
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_prepare_enable(drvdata->atclk);
-	return 0;
+	ret = clk_prepare_enable(drvdata->atclk);
+	if (ret)
+		clk_disable_unprepare(drvdata->pclk);
+
+	return ret;
 }
 #endif
 
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index 1c5c2a829714..9463afdbda8a 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -206,24 +206,26 @@ static int tpiu_runtime_suspend(struct device *dev)
 {
 	struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->atclk);
+	clk_disable_unprepare(drvdata->pclk);
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_disable_unprepare(drvdata->pclk);
 	return 0;
 }
 
 static int tpiu_runtime_resume(struct device *dev)
 {
 	struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);
+	int ret;
 
-	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
-		clk_prepare_enable(drvdata->pclk);
+	ret = clk_prepare_enable(drvdata->pclk);
+	if (ret)
+		return ret;
 
-	if (drvdata && !IS_ERR(drvdata->atclk))
-		clk_prepare_enable(drvdata->atclk);
-	return 0;
+	ret = clk_prepare_enable(drvdata->atclk);
+	if (ret)
+		clk_disable_unprepare(drvdata->pclk);
+
+	return ret;
 }
 #endif