Refactor DPLL initialization and move DPLL (de)registration, monitoring
control, fetching device invariant parameters and phase offset
measurement block setup to separate functions.

Use these new functions during device probe and teardown functions and
during changes to the clock_id devlink parameter.

These functions will also be used in the next patch implementing devlink
flash, where this functionality is likewise required.

Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/core.c    | 207 +++++++++++++++++++++------------
 drivers/dpll/zl3073x/core.h    |   3 +
 drivers/dpll/zl3073x/devlink.c |  18 +--
 3 files changed, 142 insertions(+), 86 deletions(-)

diff --git a/drivers/dpll/zl3073x/core.c b/drivers/dpll/zl3073x/core.c
index 86c26edc90462..b3015173d9f63 100644
--- a/drivers/dpll/zl3073x/core.c
+++ b/drivers/dpll/zl3073x/core.c
@@ -956,21 +956,142 @@ zl3073x_dev_periodic_work(struct kthread_work *work)
 				   msecs_to_jiffies(500));
 }
 
+/**
+ * zl3073x_dev_phase_meas_setup - setup phase offset measurement
+ * @zldev: pointer to zl3073x_dev structure
+ *
+ * Enable phase offset measurement block, set measurement averaging factor
+ * and enable DPLL-to-its-ref phase measurement for all DPLLs.
+ *
+ * Returns: 0 on success, <0 on error
+ */
+static int
+zl3073x_dev_phase_meas_setup(struct zl3073x_dev *zldev)
+{
+	struct zl3073x_dpll *zldpll;
+	u8 dpll_meas_ctrl, mask;
+	int rc;
+
+	/* Read DPLL phase measurement control register */
+	rc = zl3073x_read_u8(zldev, ZL_REG_DPLL_MEAS_CTRL, &dpll_meas_ctrl);
+	if (rc)
+		return rc;
+
+	/* Setup phase measurement averaging factor */
+	dpll_meas_ctrl &= ~ZL_DPLL_MEAS_CTRL_AVG_FACTOR;
+	dpll_meas_ctrl |= FIELD_PREP(ZL_DPLL_MEAS_CTRL_AVG_FACTOR, 3);
+
+	/* Enable DPLL measurement block */
+	dpll_meas_ctrl |= ZL_DPLL_MEAS_CTRL_EN;
+
+	/* Update phase measurement control register */
+	rc = zl3073x_write_u8(zldev, ZL_REG_DPLL_MEAS_CTRL, dpll_meas_ctrl);
+	if (rc)
+		return rc;
+
+	/* Enable DPLL-to-connected-ref measurement for each channel */
+	list_for_each_entry(zldpll, &zldev->dplls, list)
+		mask |= BIT(zldpll->id);
+
+	return zl3073x_write_u8(zldev, ZL_REG_DPLL_PHASE_ERR_READ_MASK, mask);
+}
+
+/**
+ * zl3073x_dev_start - Start normal operation
+ * @zldev: zl3073x device pointer
+ * @full: perform full initialization
+ *
+ * The function starts normal operation, which means registering all DPLLs and
+ * their pins, and starting monitoring. If full initialization is requested,
+ * the function additionally initializes the phase offset measurement block and
+ * fetches hardware-invariant parameters.
+ *
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_dev_start(struct zl3073x_dev *zldev, bool full)
+{
+	struct zl3073x_dpll *zldpll;
+	int rc;
+
+	if (full) {
+		/* Fetch device state */
+		rc = zl3073x_dev_state_fetch(zldev);
+		if (rc)
+			return rc;
+
+		/* Setup phase offset measurement block */
+		rc = zl3073x_dev_phase_meas_setup(zldev);
+		if (rc) {
+			dev_err(zldev->dev,
+				"Failed to setup phase measurement\n");
+			return rc;
+		}
+	}
+
+	/* Register all DPLLs */
+	list_for_each_entry(zldpll, &zldev->dplls, list) {
+		rc = zl3073x_dpll_register(zldpll);
+		if (rc) {
+			dev_err_probe(zldev->dev, rc,
+				      "Failed to register DPLL%u\n",
+				      zldpll->id);
+			return rc;
+		}
+	}
+
+	/* Perform initial firmware fine phase correction */
+	rc = zl3073x_dpll_init_fine_phase_adjust(zldev);
+	if (rc) {
+		dev_err_probe(zldev->dev, rc,
+			      "Failed to init fine phase correction\n");
+		return rc;
+	}
+
+	/* Start monitoring */
+	kthread_queue_delayed_work(zldev->kworker, &zldev->work, 0);
+
+	return 0;
+}
+
+/**
+ * zl3073x_dev_stop - Stop normal operation
+ * @zldev: zl3073x device pointer
+ *
+ * The function stops the normal operation that mean deregistration of all
+ * DPLLs and their pins and stop monitoring.
+ *
+ * Return: 0 on success, <0 on error
+ */
+void zl3073x_dev_stop(struct zl3073x_dev *zldev)
+{
+	struct zl3073x_dpll *zldpll;
+
+	/* Stop monitoring */
+	kthread_cancel_delayed_work_sync(&zldev->work);
+
+	/* Unregister all DPLLs */
+	list_for_each_entry(zldpll, &zldev->dplls, list) {
+		if (zldpll->dpll_dev)
+			zl3073x_dpll_unregister(zldpll);
+	}
+}
+
 static void zl3073x_dev_dpll_fini(void *ptr)
 {
 	struct zl3073x_dpll *zldpll, *next;
 	struct zl3073x_dev *zldev = ptr;
 
-	/* Stop monitoring thread */
+	/* Stop monitoring and unregister DPLLs */
+	zl3073x_dev_stop(zldev);
+
+	/* Destroy monitoring thread */
 	if (zldev->kworker) {
-		kthread_cancel_delayed_work_sync(&zldev->work);
 		kthread_destroy_worker(zldev->kworker);
 		zldev->kworker = NULL;
 	}
 
-	/* Release DPLLs */
+	/* Free all DPLLs */
 	list_for_each_entry_safe(zldpll, next, &zldev->dplls, list) {
-		zl3073x_dpll_unregister(zldpll);
 		list_del(&zldpll->list);
 		zl3073x_dpll_free(zldpll);
 	}
@@ -986,7 +1107,7 @@ zl3073x_devm_dpll_init(struct zl3073x_dev *zldev, u8 num_dplls)
 
 	INIT_LIST_HEAD(&zldev->dplls);
 
-	/* Initialize all DPLLs */
+	/* Allocate all DPLLs */
 	for (i = 0; i < num_dplls; i++) {
 		zldpll = zl3073x_dpll_alloc(zldev, i);
 		if (IS_ERR(zldpll)) {
@@ -996,25 +1117,9 @@ zl3073x_devm_dpll_init(struct zl3073x_dev *zldev, u8 num_dplls)
 			goto error;
 		}
 
-		rc = zl3073x_dpll_register(zldpll);
-		if (rc) {
-			dev_err_probe(zldev->dev, rc,
-				      "Failed to register DPLL%u\n", i);
-			zl3073x_dpll_free(zldpll);
-			goto error;
-		}
-
 		list_add_tail(&zldpll->list, &zldev->dplls);
 	}
 
-	/* Perform initial firmware fine phase correction */
-	rc = zl3073x_dpll_init_fine_phase_adjust(zldev);
-	if (rc) {
-		dev_err_probe(zldev->dev, rc,
-			      "Failed to init fine phase correction\n");
-		goto error;
-	}
-
 	/* Initialize monitoring thread */
 	kthread_init_delayed_work(&zldev->work, zl3073x_dev_periodic_work);
 	kworker = kthread_run_worker(0, "zl3073x-%s", dev_name(zldev->dev));
@@ -1022,9 +1127,14 @@ zl3073x_devm_dpll_init(struct zl3073x_dev *zldev, u8 num_dplls)
 		rc = PTR_ERR(kworker);
 		goto error;
 	}
-
 	zldev->kworker = kworker;
-	kthread_queue_delayed_work(zldev->kworker, &zldev->work, 0);
+
+	/* Start normal operation */
+	rc = zl3073x_dev_start(zldev, true);
+	if (rc) {
+		dev_err_probe(zldev->dev, rc, "Failed to start device\n");
+		goto error;
+	}
 
 	/* Add devres action to release DPLL related resources */
 	rc = devm_add_action_or_reset(zldev->dev, zl3073x_dev_dpll_fini, zldev);
@@ -1039,46 +1149,6 @@ zl3073x_devm_dpll_init(struct zl3073x_dev *zldev, u8 num_dplls)
 	return rc;
 }
 
-/**
- * zl3073x_dev_phase_meas_setup - setup phase offset measurement
- * @zldev: pointer to zl3073x_dev structure
- * @num_channels: number of DPLL channels
- *
- * Enable phase offset measurement block, set measurement averaging factor
- * and enable DPLL-to-its-ref phase measurement for all DPLLs.
- *
- * Returns: 0 on success, <0 on error
- */
-static int
-zl3073x_dev_phase_meas_setup(struct zl3073x_dev *zldev, int num_channels)
-{
-	u8 dpll_meas_ctrl, mask;
-	int i, rc;
-
-	/* Read DPLL phase measurement control register */
-	rc = zl3073x_read_u8(zldev, ZL_REG_DPLL_MEAS_CTRL, &dpll_meas_ctrl);
-	if (rc)
-		return rc;
-
-	/* Setup phase measurement averaging factor */
-	dpll_meas_ctrl &= ~ZL_DPLL_MEAS_CTRL_AVG_FACTOR;
-	dpll_meas_ctrl |= FIELD_PREP(ZL_DPLL_MEAS_CTRL_AVG_FACTOR, 3);
-
-	/* Enable DPLL measurement block */
-	dpll_meas_ctrl |= ZL_DPLL_MEAS_CTRL_EN;
-
-	/* Update phase measurement control register */
-	rc = zl3073x_write_u8(zldev, ZL_REG_DPLL_MEAS_CTRL, dpll_meas_ctrl);
-	if (rc)
-		return rc;
-
-	/* Enable DPLL-to-connected-ref measurement for each channel */
-	for (i = 0, mask = 0; i < num_channels; i++)
-		mask |= BIT(i);
-
-	return zl3073x_write_u8(zldev, ZL_REG_DPLL_PHASE_ERR_READ_MASK, mask);
-}
-
 /**
  * zl3073x_dev_probe - initialize zl3073x device
  * @zldev: pointer to zl3073x device
@@ -1146,17 +1216,6 @@ int zl3073x_dev_probe(struct zl3073x_dev *zldev,
 		return dev_err_probe(zldev->dev, rc,
 				     "Failed to initialize mutex\n");
 
-	/* Fetch device state */
-	rc = zl3073x_dev_state_fetch(zldev);
-	if (rc)
-		return rc;
-
-	/* Setup phase offset measurement block */
-	rc = zl3073x_dev_phase_meas_setup(zldev, chip_info->num_channels);
-	if (rc)
-		return dev_err_probe(zldev->dev, rc,
-				     "Failed to setup phase measurement\n");
-
 	/* Register DPLL channels */
 	rc = zl3073x_devm_dpll_init(zldev, chip_info->num_channels);
 	if (rc)
diff --git a/drivers/dpll/zl3073x/core.h b/drivers/dpll/zl3073x/core.h
index a9c098dd6d5a2..f4a6cecbbba7e 100644
--- a/drivers/dpll/zl3073x/core.h
+++ b/drivers/dpll/zl3073x/core.h
@@ -111,6 +111,9 @@ struct zl3073x_dev *zl3073x_devm_alloc(struct device *dev);
 int zl3073x_dev_probe(struct zl3073x_dev *zldev,
 		      const struct zl3073x_chip_info *chip_info);
 
+int zl3073x_dev_start(struct zl3073x_dev *zldev, bool full);
+void zl3073x_dev_stop(struct zl3073x_dev *zldev);
+
 /**********************
  * Registers operations
  **********************/
diff --git a/drivers/dpll/zl3073x/devlink.c b/drivers/dpll/zl3073x/devlink.c
index f3ca973a4d416..d0f6d9cd4a68e 100644
--- a/drivers/dpll/zl3073x/devlink.c
+++ b/drivers/dpll/zl3073x/devlink.c
@@ -86,14 +86,12 @@ zl3073x_devlink_reload_down(struct devlink *devlink, bool netns_change,
 			    struct netlink_ext_ack *extack)
 {
 	struct zl3073x_dev *zldev = devlink_priv(devlink);
-	struct zl3073x_dpll *zldpll;
 
 	if (action != DEVLINK_RELOAD_ACTION_DRIVER_REINIT)
 		return -EOPNOTSUPP;
 
-	/* Unregister all DPLLs */
-	list_for_each_entry(zldpll, &zldev->dplls, list)
-		zl3073x_dpll_unregister(zldpll);
+	/* Stop normal operation */
+	zl3073x_dev_stop(zldev);
 
 	return 0;
 }
@@ -107,7 +105,6 @@ zl3073x_devlink_reload_up(struct devlink *devlink,
 {
 	struct zl3073x_dev *zldev = devlink_priv(devlink);
 	union devlink_param_value val;
-	struct zl3073x_dpll *zldpll;
 	int rc;
 
 	if (action != DEVLINK_RELOAD_ACTION_DRIVER_REINIT)
@@ -125,13 +122,10 @@ zl3073x_devlink_reload_up(struct devlink *devlink,
 		zldev->clock_id = val.vu64;
 	}
 
-	/* Re-register all DPLLs */
-	list_for_each_entry(zldpll, &zldev->dplls, list) {
-		rc = zl3073x_dpll_register(zldpll);
-		if (rc)
-			dev_warn(zldev->dev,
-				 "Failed to re-register DPLL%u\n", zldpll->id);
-	}
+	/* Restart normal operation */
+	rc = zl3073x_dev_start(zldev, false);
+	if (rc)
+		dev_warn(zldev->dev, "Failed to re-start normal operation\n");
 
 	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
 
-- 
2.49.1

Hi Ivan,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Ivan-Vecera/dpll-zl3073x-Add-functions-to-access-hardware-registers/20250725-234600
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250725154136.1008132-5-ivecera%40redhat.com
patch subject: [PATCH net-next 4/5] dpll: zl3073x: Refactor DPLL initialization
config: i386-randconfig-001-20250726 (https://download.01.org/0day-ci/archive/20250726/202507261812.7458edBX-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250726/202507261812.7458edBX-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/202507261812.7458edBX-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/dpll/zl3073x/core.c:994:3: warning: variable 'mask' is uninitialized when used here [-Wuninitialized]
     994 |                 mask |= BIT(zldpll->id);
         |                 ^~~~
   drivers/dpll/zl3073x/core.c:972:25: note: initialize the variable 'mask' to silence this warning
     972 |         u8 dpll_meas_ctrl, mask;
         |                                ^
         |                                 = '\0'
   1 warning generated.


vim +/mask +994 drivers/dpll/zl3073x/core.c

   958	
   959	/**
   960	 * zl3073x_dev_phase_meas_setup - setup phase offset measurement
   961	 * @zldev: pointer to zl3073x_dev structure
   962	 *
   963	 * Enable phase offset measurement block, set measurement averaging factor
   964	 * and enable DPLL-to-its-ref phase measurement for all DPLLs.
   965	 *
   966	 * Returns: 0 on success, <0 on error
   967	 */
   968	static int
   969	zl3073x_dev_phase_meas_setup(struct zl3073x_dev *zldev)
   970	{
   971		struct zl3073x_dpll *zldpll;
   972		u8 dpll_meas_ctrl, mask;
   973		int rc;
   974	
   975		/* Read DPLL phase measurement control register */
   976		rc = zl3073x_read_u8(zldev, ZL_REG_DPLL_MEAS_CTRL, &dpll_meas_ctrl);
   977		if (rc)
   978			return rc;
   979	
   980		/* Setup phase measurement averaging factor */
   981		dpll_meas_ctrl &= ~ZL_DPLL_MEAS_CTRL_AVG_FACTOR;
   982		dpll_meas_ctrl |= FIELD_PREP(ZL_DPLL_MEAS_CTRL_AVG_FACTOR, 3);
   983	
   984		/* Enable DPLL measurement block */
   985		dpll_meas_ctrl |= ZL_DPLL_MEAS_CTRL_EN;
   986	
   987		/* Update phase measurement control register */
   988		rc = zl3073x_write_u8(zldev, ZL_REG_DPLL_MEAS_CTRL, dpll_meas_ctrl);
   989		if (rc)
   990			return rc;
   991	
   992		/* Enable DPLL-to-connected-ref measurement for each channel */
   993		list_for_each_entry(zldpll, &zldev->dplls, list)
 > 994			mask |= BIT(zldpll->id);
   995	
   996		return zl3073x_write_u8(zldev, ZL_REG_DPLL_PHASE_ERR_READ_MASK, mask);
   997	}
   998	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki