[PATCH net-next 2/2] dpll: zl3073x: Initialize clock ID from device property

[Ivan Vecera <ivecera@redhat.com>]

The clock ID value can be specified by the platform via 'clock-id'
property. Use this property value to initialize clock ID and if it
is not specified generate random one as fallback.

Tested-by: Prathosh Satish <prathosh.satish@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/core.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/dpll/zl3073x/core.c b/drivers/dpll/zl3073x/core.c
index 7ebcfc5ec1f09..f5245225f1d3b 100644
--- a/drivers/dpll/zl3073x/core.c
+++ b/drivers/dpll/zl3073x/core.c
@@ -9,6 +9,8 @@
 #include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/netlink.h>
+#include <linux/property.h>
+#include <linux/random.h>
 #include <linux/regmap.h>
 #include <linux/sprintf.h>
 #include <linux/string_choices.h>
@@ -932,6 +934,29 @@ zl3073x_dev_phase_meas_setup(struct zl3073x_dev *zldev, int num_channels)
 	return zl3073x_write_u8(zldev, ZL_REG_DPLL_PHASE_ERR_READ_MASK, mask);
 }
 
+/**
+ * zl3073x_dev_clock_id_init - initialize clock ID
+ * @zldev: pointer to zl3073x device
+ *
+ * Initializes clock ID using device property if it is provided or
+ * generates random one.
+ */
+static void
+zl3073x_dev_clock_id_init(struct zl3073x_dev *zldev)
+{
+	u64 clock_id;
+	int rc;
+
+	/* Try to read clock ID from device property */
+	rc = device_property_read_u64(zldev->dev, "clock-id", &clock_id);
+
+	/* Generate random id if the property does not exist or value is zero */
+	if (rc || !clock_id)
+		clock_id = get_random_u64();
+
+	zldev->clock_id = clock_id;
+}
+
 /**
  * zl3073x_dev_probe - initialize zl3073x device
  * @zldev: pointer to zl3073x device
@@ -985,11 +1010,8 @@ int zl3073x_dev_probe(struct zl3073x_dev *zldev,
 		FIELD_GET(GENMASK(15, 8), cfg_ver),
 		FIELD_GET(GENMASK(7, 0), cfg_ver));
 
-	/* Generate random clock ID as the device has not such property that
-	 * could be used for this purpose. A user can later change this value
-	 * using devlink.
-	 */
-	zldev->clock_id = get_random_u64();
+	/* Initialize clock ID */
+	zl3073x_dev_clock_id_init(zldev);
 
 	/* Initialize mutex for operations where multiple reads, writes
 	 * and/or polls are required to be done atomically.
-- 
2.49.1