Merge branch 'dpll-zl3073x-include-current-frequency-in-supported-frequencies-list'

Ivan Vecera says:

====================
dpll: zl3073x: Include current frequency in supported frequencies list

This series ensures that the current operating frequency of a DPLL pin
is always reported in its supported frequencies list.

Problem:
When a ZL3073x DPLL pin is registered, its supported frequencies are
read from the firmware node's "supported-frequencies-hz" property.
However, if the firmware node is missing, or doesn't include the
current operating frequency, the pin reports a frequency that isn't
in its supported list. This inconsistency can confuse userspace tools
that expect the current frequency to be among the supported values.

Solution:
Always include the current pin frequency as the first entry in the
supported frequencies list, followed by any additional frequencies
from the firmware node (with duplicates filtered out).

Patch 1 refactors the output pin frequency calculation into a reusable
helper function zl3073x_dev_output_pin_freq_get(), which mirrors the
existing zl3073x_dev_ref_freq_get() for input pins.

Patch 2 modifies zl3073x_pin_props_get() to obtain the current
frequency early and place it at index 0 of the supported frequencies
array, ensuring it is always present regardless of firmware node
contents.
====================

Link: https://patch.msgid.link/20260205154350.3180465-1-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 69 insertions, 49 deletions

diff --git a/drivers/dpll/zl3073x/core.h b/drivers/dpll/zl3073x/core.h
index 09bca2d0926d..dddfcacea5c0 100644
--- a/drivers/dpll/zl3073x/core.h
+++ b/drivers/dpll/zl3073x/core.h
@@ -302,6 +302,36 @@ u8 zl3073x_dev_out_dpll_get(struct zl3073x_dev *zldev, u8 index)
 }
 
 /**
+ * zl3073x_dev_output_pin_freq_get - get output pin frequency
+ * @zldev: pointer to zl3073x device
+ * @id: output pin id
+ *
+ * Computes the output pin frequency based on the synth frequency, output
+ * divisor, and signal format. For N-div formats, N-pin frequency is
+ * additionally divided by esync_n_period.
+ *
+ * Return: frequency of the given output pin in Hz
+ */
+static inline u32
+zl3073x_dev_output_pin_freq_get(struct zl3073x_dev *zldev, u8 id)
+{
+	const struct zl3073x_synth *synth;
+	const struct zl3073x_out *out;
+	u8 out_id;
+	u32 freq;
+
+	out_id = zl3073x_output_pin_out_get(id);
+	out = zl3073x_out_state_get(zldev, out_id);
+	synth = zl3073x_synth_state_get(zldev, zl3073x_out_synth_get(out));
+	freq = zl3073x_synth_freq_get(synth) / out->div;
+
+	if (zl3073x_out_is_ndiv(out) && zl3073x_is_n_pin(id))
+		freq /= out->esync_n_period;
+
+	return freq;
+}
+
+/**
  * zl3073x_dev_out_is_diff - check if the given output is differential
  * @zldev: pointer to zl3073x device
  * @index: output index
diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index a99d143a7acd..eb94c29af2cf 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c
@@ -916,46 +916,9 @@ zl3073x_dpll_output_pin_frequency_get(const struct dpll_pin *dpll_pin,
 				      struct netlink_ext_ack *extack)
 {
 	struct zl3073x_dpll *zldpll = dpll_priv;
-	struct zl3073x_dev *zldev = zldpll->dev;
 	struct zl3073x_dpll_pin *pin = pin_priv;
-	const struct zl3073x_synth *synth;
-	const struct zl3073x_out *out;
-	u32 synth_freq;
-	u8 out_id;
 
-	out_id = zl3073x_output_pin_out_get(pin->id);
-	out = zl3073x_out_state_get(zldev, out_id);
-
-	/* Get attached synth frequency */
-	synth = zl3073x_synth_state_get(zldev, zl3073x_out_synth_get(out));
-	synth_freq = zl3073x_synth_freq_get(synth);
-
-	switch (zl3073x_out_signal_format_get(out)) {
-	case ZL_OUTPUT_MODE_SIGNAL_FORMAT_2_NDIV:
-	case ZL_OUTPUT_MODE_SIGNAL_FORMAT_2_NDIV_INV:
-		/* In case of divided format we have to distiguish between
-		 * given output pin type.
-		 *
-		 * For P-pin the resulting frequency is computed as simple
-		 * division of synth frequency and output divisor.
-		 *
-		 * For N-pin we have to divide additionally by divisor stored
-		 * in esync_n_period output mailbox register that is used as
-		 * N-pin divisor for these modes.
-		 */
-		*frequency = synth_freq / out->div;
-
-		if (!zl3073x_dpll_is_p_pin(pin))
-			*frequency = (u32)*frequency / out->esync_n_period;
-
-		break;
-	default:
-		/* In other modes the resulting frequency is computed as
-		 * division of synth frequency and output divisor.
-		 */
-		*frequency = synth_freq / out->div;
-		break;
-	}
+	*frequency = zl3073x_dev_output_pin_freq_get(zldpll->dev, pin->id);
 
 	return 0;
 }
diff --git a/drivers/dpll/zl3073x/out.h b/drivers/dpll/zl3073x/out.h
index e8ea7a0e0f07..318f9bb8da3a 100644
--- a/drivers/dpll/zl3073x/out.h
+++ b/drivers/dpll/zl3073x/out.h
@@ -80,6 +80,23 @@ static inline bool zl3073x_out_is_enabled(const struct zl3073x_out *out)
 }
 
 /**
+ * zl3073x_out_is_ndiv - check if the given output is in N-div mode
+ * @out: pointer to out state
+ *
+ * Return: true if output is in N-div mode, false otherwise
+ */
+static inline bool zl3073x_out_is_ndiv(const struct zl3073x_out *out)
+{
+	switch (zl3073x_out_signal_format_get(out)) {
+	case ZL_OUTPUT_MODE_SIGNAL_FORMAT_2_NDIV:
+	case ZL_OUTPUT_MODE_SIGNAL_FORMAT_2_NDIV_INV:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/**
  * zl3073x_out_synth_get - get synth connected to given output
  * @out: pointer to out state
  *
diff --git a/drivers/dpll/zl3073x/prop.c b/drivers/dpll/zl3073x/prop.c
index ad1f099cbe2b..8523dc8c226e 100644
--- a/drivers/dpll/zl3073x/prop.c
+++ b/drivers/dpll/zl3073x/prop.c
@@ -193,9 +193,10 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 {
 	struct dpll_pin_frequency *ranges;
 	struct zl3073x_pin_props *props;
-	int i, j, num_freqs, rc;
+	int i, j, num_freqs = 0, rc;
+	u64 *freqs = NULL;
 	const char *type;
-	u64 *freqs;
+	u32 curr_freq;
 
 	props = kzalloc(sizeof(*props), GFP_KERNEL);
 	if (!props)
@@ -207,6 +208,7 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 		props->dpll_props.capabilities =
 			DPLL_PIN_CAPABILITIES_PRIORITY_CAN_CHANGE |
 			DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
+		curr_freq = zl3073x_dev_ref_freq_get(zldev, index);
 	} else {
 		u8 out, synth;
 		u32 f;
@@ -220,6 +222,7 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 		synth = zl3073x_dev_out_synth_get(zldev, out);
 		f = 2 * zl3073x_dev_synth_freq_get(zldev, synth);
 		props->dpll_props.phase_gran = f ? div_u64(PSEC_PER_SEC, f) : 1;
+		curr_freq = zl3073x_dev_output_pin_freq_get(zldev, index);
 	}
 
 	props->dpll_props.phase_range.min = S32_MIN;
@@ -230,7 +233,7 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 	/* Get firmware node for the given pin */
 	rc = zl3073x_prop_pin_fwnode_get(zldev, props, dir, index);
 	if (rc)
-		return props; /* Return if it does not exist */
+		goto skip_fwnode_props;
 
 	/* Look for label property and store the value as board label */
 	fwnode_property_read_string(props->fwnode, "label",
@@ -264,9 +267,10 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 	/* Read supported frequencies property if it is specified */
 	num_freqs = fwnode_property_count_u64(props->fwnode,
 					      "supported-frequencies-hz");
-	if (num_freqs <= 0)
-		/* Return if the property does not exist or number is 0 */
-		return props;
+	if (num_freqs <= 0) {
+		num_freqs = 0;
+		goto skip_fwnode_props;
+	}
 
 	/* The firmware node specifies list of supported frequencies while
 	 * DPLL core pin properties requires list of frequency ranges.
@@ -283,19 +287,25 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 				       "supported-frequencies-hz", freqs,
 				       num_freqs);
 
-	/* Allocate frequency ranges list and fill it */
-	ranges = kcalloc(num_freqs, sizeof(*ranges), GFP_KERNEL);
+skip_fwnode_props:
+	/* Allocate frequency ranges list - extra slot for current frequency */
+	ranges = kcalloc(num_freqs + 1, sizeof(*ranges), GFP_KERNEL);
 	if (!ranges) {
 		rc = -ENOMEM;
 		goto err_alloc_ranges;
 	}
 
-	/* Convert list of frequencies to list of frequency ranges but
-	 * filter-out frequencies that are not representable by device
+	/* Start with current frequency at index 0 */
+	ranges[0] = (struct dpll_pin_frequency)DPLL_PIN_FREQUENCY(curr_freq);
+
+	/* Add frequencies from firmware node, skipping current frequency
+	 * and filtering out frequencies not representable by device
 	 */
-	for (i = 0, j = 0; i < num_freqs; i++) {
+	for (i = 0, j = 1; i < num_freqs; i++) {
 		struct dpll_pin_frequency freq = DPLL_PIN_FREQUENCY(freqs[i]);
 
+		if (freqs[i] == curr_freq)
+			continue;
 		if (zl3073x_pin_check_freq(zldev, dir, index, freqs[i])) {
 			ranges[j] = freq;
 			j++;