From: Udit Tiwari <quic_utiwari@quicinc.com>

The Qualcomm Crypto Engine (QCE) driver currently lacks support for
runtime power management (PM) and interconnect bandwidth control.
As a result, the hardware remains fully powered and clocks stay
enabled even when the device is idle. Additionally, static
interconnect bandwidth votes are held indefinitely, preventing the
system from reclaiming unused bandwidth.

Address this by enabling runtime PM and dynamic interconnect
bandwidth scaling to allow the system to suspend the device when idle
and scale interconnect usage based on actual demand. Improve overall
system efficiency by reducing power usage and optimizing interconnect
resource allocation.

Make the following changes as part of this integration:

- Add support for pm_runtime APIs to manage device power state
  transitions.
- Implement runtime_suspend() and runtime_resume() callbacks to gate
  clocks and vote for interconnect bandwidth only when needed.
- Replace devm_clk_get_optional_enabled() with devm_pm_clk_create() +
  pm_clk_add() and let the PM core manage device clocks during runtime
  PM and system sleep.
- Register dev_pm_ops with the platform driver to hook into the PM
  framework.

Tested:

- Verify that ICC votes drop to zero after probe and upon request
  completion.
- Confirm that runtime PM usage count increments during active
  requests and decrements afterward.
- Observe that the device correctly enters the suspended state when
  idle.

Signed-off-by: Udit Tiwari <quic_utiwari@quicinc.com>
---
Changes in v3:
- Switch from manual clock management to PM clock helpers
  (devm_pm_clk_create() + pm_clk_add()); no direct clk_* enable/disable
  in runtime callbacks.
- Replace pm_runtime_get_sync() with pm_runtime_resume_and_get(); remove
  pm_runtime_put_noidle() on error.
- Define PM ops using helper macros and reuse runtime callbacks for system
  sleep via pm_runtime_force_suspend()/pm_runtime_force_resume().
- Link to v2: https://lore.kernel.org/lkml/20250826110917.3383061-1-quic_utiwari@quicinc.com/

Changes in v2:
- Extend suspend/resume support to include runtime PM and ICC scaling.
- Register dev_pm_ops and implement runtime_suspend/resume callbacks.
- Link to v1: https://lore.kernel.org/lkml/20250606105808.2119280-1-quic_utiwari@quicinc.com/
---
 drivers/crypto/qce/core.c | 104 +++++++++++++++++++++++++++++++-------
 1 file changed, 87 insertions(+), 17 deletions(-)

diff --git a/drivers/crypto/qce/core.c b/drivers/crypto/qce/core.c
index b966f3365b7d..726c162f6ee7 100644
--- a/drivers/crypto/qce/core.c
+++ b/drivers/crypto/qce/core.c
@@ -12,6 +12,9 @@
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_clock.h>
 #include <linux/types.h>
 #include <crypto/algapi.h>
 #include <crypto/internal/hash.h>
@@ -90,13 +93,17 @@ static int qce_handle_queue(struct qce_device *qce,
 	struct crypto_async_request *async_req, *backlog;
 	int ret = 0, err;
 
+	ret = pm_runtime_resume_and_get(qce->dev);
+	if (ret < 0)
+		return ret;
+
 	scoped_guard(mutex, &qce->lock) {
 		if (req)
 			ret = crypto_enqueue_request(&qce->queue, req);
 
 		/* busy, do not dequeue request */
 		if (qce->req)
-			return ret;
+			goto qce_suspend;
 
 		backlog = crypto_get_backlog(&qce->queue);
 		async_req = crypto_dequeue_request(&qce->queue);
@@ -105,7 +112,7 @@ static int qce_handle_queue(struct qce_device *qce,
 	}
 
 	if (!async_req)
-		return ret;
+		goto qce_suspend;
 
 	if (backlog) {
 		scoped_guard(mutex, &qce->lock)
@@ -118,6 +125,8 @@ static int qce_handle_queue(struct qce_device *qce,
 		schedule_work(&qce->done_work);
 	}
 
+qce_suspend:
+	pm_runtime_put_autosuspend(qce->dev);
 	return ret;
 }
 
@@ -207,37 +216,48 @@ static int qce_crypto_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	qce->core = devm_clk_get_optional_enabled(qce->dev, "core");
-	if (IS_ERR(qce->core))
-		return PTR_ERR(qce->core);
+/* PM clock helpers: register device clocks */
+	ret = devm_pm_clk_create(dev);
+	if (ret)
+		return ret;
 
-	qce->iface = devm_clk_get_optional_enabled(qce->dev, "iface");
-	if (IS_ERR(qce->iface))
-		return PTR_ERR(qce->iface);
+	ret = pm_clk_add(dev, "core");
+	if (ret)
+		return ret;
 
-	qce->bus = devm_clk_get_optional_enabled(qce->dev, "bus");
-	if (IS_ERR(qce->bus))
-		return PTR_ERR(qce->bus);
+	ret = pm_clk_add(dev, "iface");
+	if (ret)
+		return ret;
 
-	qce->mem_path = devm_of_icc_get(qce->dev, "memory");
+	ret = pm_clk_add(dev, "bus");
+	if (ret)
+		return ret;
+
+	qce->mem_path = devm_of_icc_get(dev, "memory");
 	if (IS_ERR(qce->mem_path))
 		return PTR_ERR(qce->mem_path);
 
-	ret = icc_set_bw(qce->mem_path, QCE_DEFAULT_MEM_BANDWIDTH, QCE_DEFAULT_MEM_BANDWIDTH);
+	/* Enable runtime PM after clocks and ICC are acquired */
+
+	ret = devm_pm_runtime_enable(dev);
 	if (ret)
 		return ret;
 
-	ret = devm_qce_dma_request(qce->dev, &qce->dma);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret)
 		return ret;
 
+	ret = devm_qce_dma_request(qce->dev, &qce->dma);
+	if (ret)
+		goto err_pm;
+
 	ret = qce_check_version(qce);
 	if (ret)
-		return ret;
+		goto err_pm;
 
 	ret = devm_mutex_init(qce->dev, &qce->lock);
 	if (ret)
-		return ret;
+		goto err_pm;
 
 	INIT_WORK(&qce->done_work, qce_req_done_work);
 	crypto_init_queue(&qce->queue, QCE_QUEUE_LENGTH);
@@ -245,9 +265,58 @@ static int qce_crypto_probe(struct platform_device *pdev)
 	qce->async_req_enqueue = qce_async_request_enqueue;
 	qce->async_req_done = qce_async_request_done;
 
-	return devm_qce_register_algs(qce);
+	ret = devm_qce_register_algs(qce);
+	if (ret)
+		goto err_pm;
+
+	/* Configure autosuspend after successful init */
+	pm_runtime_set_autosuspend_delay(dev, 100);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
+
+err_pm:
+	pm_runtime_put(dev);
+
+	return ret;
 }
 
+static int qce_runtime_suspend(struct device *dev)
+{
+	struct qce_device *qce = dev_get_drvdata(dev);
+
+	icc_disable(qce->mem_path);
+
+	return 0;
+}
+
+static int qce_runtime_resume(struct device *dev)
+{
+	struct qce_device *qce = dev_get_drvdata(dev);
+	int ret = 0;
+
+	ret = icc_enable(qce->mem_path);
+	if (ret)
+		return ret;
+
+	ret = icc_set_bw(qce->mem_path, QCE_DEFAULT_MEM_BANDWIDTH, QCE_DEFAULT_MEM_BANDWIDTH);
+	if (ret)
+		goto err_icc;
+
+	return 0;
+
+err_icc:
+	icc_disable(qce->mem_path);
+	return ret;
+}
+
+static const struct dev_pm_ops qce_crypto_pm_ops = {
+	SET_RUNTIME_PM_OPS(qce_runtime_suspend, qce_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
+};
+
 static const struct of_device_id qce_crypto_of_match[] = {
 	{ .compatible = "qcom,crypto-v5.1", },
 	{ .compatible = "qcom,crypto-v5.4", },
@@ -261,6 +330,7 @@ static struct platform_driver qce_crypto_driver = {
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.of_match_table = qce_crypto_of_match,
+		.pm = &qce_crypto_pm_ops,
 	},
 };
 module_platform_driver(qce_crypto_driver);
-- 
2.34.1

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on herbert-cryptodev-2.6/master]
[also build test WARNING on herbert-crypto-2.6/master linus/master v6.18-rc5 next-20251114]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/quic_utiwari-quicinc-com/crypto-qce-Add-runtime-PM-and-interconnect-bandwidth-scaling-support/20251115-165032
base:   https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master
patch link:    https://lore.kernel.org/r/20251115084851.2750446-1-quic_utiwari%40quicinc.com
patch subject: [PATCH v3] crypto: qce - Add runtime PM and interconnect bandwidth scaling support
config: openrisc-allyesconfig (https://download.01.org/0day-ci/archive/20251116/202511160711.Q6ytYvlG-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251116/202511160711.Q6ytYvlG-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511160711.Q6ytYvlG-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/crypto/qce/core.c:295:12: warning: 'qce_runtime_resume' defined but not used [-Wunused-function]
     295 | static int qce_runtime_resume(struct device *dev)
         |            ^~~~~~~~~~~~~~~~~~
>> drivers/crypto/qce/core.c:286:12: warning: 'qce_runtime_suspend' defined but not used [-Wunused-function]
     286 | static int qce_runtime_suspend(struct device *dev)
         |            ^~~~~~~~~~~~~~~~~~~


vim +/qce_runtime_resume +295 drivers/crypto/qce/core.c

   285	
 > 286	static int qce_runtime_suspend(struct device *dev)
   287	{
   288		struct qce_device *qce = dev_get_drvdata(dev);
   289	
   290		icc_disable(qce->mem_path);
   291	
   292		return 0;
   293	}
   294	
 > 295	static int qce_runtime_resume(struct device *dev)
   296	{
   297		struct qce_device *qce = dev_get_drvdata(dev);
   298		int ret = 0;
   299	
   300		ret = icc_enable(qce->mem_path);
   301		if (ret)
   302			return ret;
   303	
   304		ret = icc_set_bw(qce->mem_path, QCE_DEFAULT_MEM_BANDWIDTH, QCE_DEFAULT_MEM_BANDWIDTH);
   305		if (ret)
   306			goto err_icc;
   307	
   308		return 0;
   309	
   310	err_icc:
   311		icc_disable(qce->mem_path);
   312		return ret;
   313	}
   314	

-- 
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https://github.com/intel/lkp-tests/wiki