1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/dpll/zl3073x/synth.c b/drivers/dpll/zl3073x/synth.c
new file mode 100644
index 000000000000..da839572dab2
--- /dev/null
+++ b/drivers/dpll/zl3073x/synth.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/dev_printk.h>
+#include <linux/string.h>
+#include <linux/string_choices.h>
+#include <linux/types.h>
+
+#include "core.h"
+#include "synth.h"
+
+/**
+ * zl3073x_synth_state_fetch - fetch synth state from hardware
+ * @zldev: pointer to zl3073x_dev structure
+ * @index: synth index to fetch state for
+ *
+ * Function fetches state of the given synthesizer from the hardware and
+ * stores it for later use.
+ *
+ * Return: 0 on success, <0 on error
+ */
+int zl3073x_synth_state_fetch(struct zl3073x_dev *zldev, u8 index)
+{
+	struct zl3073x_synth *synth = &zldev->synth[index];
+	int rc;
+
+	/* Read synth control register */
+	rc = zl3073x_read_u8(zldev, ZL_REG_SYNTH_CTRL(index), &synth->ctrl);
+	if (rc)
+		return rc;
+
+	guard(mutex)(&zldev->multiop_lock);
+
+	/* Read synth configuration */
+	rc = zl3073x_mb_op(zldev, ZL_REG_SYNTH_MB_SEM, ZL_SYNTH_MB_SEM_RD,
+			   ZL_REG_SYNTH_MB_MASK, BIT(index));
+	if (rc)
+		return rc;
+
+	/* The output frequency is determined by the following formula:
+	 * base * multiplier * numerator / denominator
+	 *
+	 * Read registers with these values
+	 */
+	rc = zl3073x_read_u16(zldev, ZL_REG_SYNTH_FREQ_BASE, &synth->freq_base);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_read_u32(zldev, ZL_REG_SYNTH_FREQ_MULT, &synth->freq_mult);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_read_u16(zldev, ZL_REG_SYNTH_FREQ_M, &synth->freq_m);
+	if (rc)
+		return rc;
+
+	rc = zl3073x_read_u16(zldev, ZL_REG_SYNTH_FREQ_N, &synth->freq_n);
+	if (rc)
+		return rc;
+
+	/* Check denominator for zero to avoid div by 0 */
+	if (!synth->freq_n) {
+		dev_err(zldev->dev,
+			"Zero divisor for SYNTH%u retrieved from device\n",
+			index);
+		return -EINVAL;
+	}
+
+	dev_dbg(zldev->dev, "SYNTH%u frequency: %u Hz\n", index,
+		zl3073x_synth_freq_get(synth));
+
+	return rc;
+}
+
+/**
+ * zl3073x_synth_state_get - get current synth state
+ * @zldev: pointer to zl3073x_dev structure
+ * @index: synth index to get state for
+ *
+ * Return: pointer to given synth state
+ */
+const struct zl3073x_synth *zl3073x_synth_state_get(struct zl3073x_dev *zldev,
+						    u8 index)
+{
+	return &zldev->synth[index];
+}