[PATCH net-next v11 11/14] dpll: zl3073x: Add support to get/set priority on input pins

[Ivan Vecera <ivecera@redhat.com>]

Add support for getting and setting input pin priority. Implement
required callbacks and set appropriate capability for input pins.
Although the pin priority make sense only if the DPLL is running in
automatic mode we have to expose this capability unconditionally because
input pins (references) are shared between all DPLLs where one of them
can run in automatic mode while the other one not.

Co-developed-by: Prathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: Prathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/dpll/zl3073x/dpll.c | 88 +++++++++++++++++++++++++++++++++++++
 drivers/dpll/zl3073x/prop.c |  1 +
 2 files changed, 89 insertions(+)

diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index 89da2c34609eb..e67ef37479910 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c
@@ -287,6 +287,56 @@ zl3073x_dpll_ref_prio_get(struct zl3073x_dpll_pin *pin, u8 *prio)
 	return rc;
 }
 
+/**
+ * zl3073x_dpll_ref_prio_set - set priority for given input pin
+ * @pin: pointer to pin
+ * @prio: place to store priority
+ *
+ * Sets priority for the given input pin.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int
+zl3073x_dpll_ref_prio_set(struct zl3073x_dpll_pin *pin, u8 prio)
+{
+	struct zl3073x_dpll *zldpll = pin->dpll;
+	struct zl3073x_dev *zldev = zldpll->dev;
+	u8 ref, ref_prio;
+	int rc;
+
+	guard(mutex)(&zldev->multiop_lock);
+
+	/* Read DPLL configuration into mailbox */
+	rc = zl3073x_mb_op(zldev, ZL_REG_DPLL_MB_SEM, ZL_DPLL_MB_SEM_RD,
+			   ZL_REG_DPLL_MB_MASK, BIT(zldpll->id));
+	if (rc)
+		return rc;
+
+	/* Read reference priority - one value shared between P&N pins */
+	ref = zl3073x_input_pin_ref_get(pin->id);
+	rc = zl3073x_read_u8(zldev, ZL_REG_DPLL_REF_PRIO(ref / 2), &ref_prio);
+	if (rc)
+		return rc;
+
+	/* Update nibble according pin type */
+	if (zl3073x_dpll_is_p_pin(pin)) {
+		ref_prio &= ~ZL_DPLL_REF_PRIO_REF_P;
+		ref_prio |= FIELD_PREP(ZL_DPLL_REF_PRIO_REF_P, prio);
+	} else {
+		ref_prio &= ~ZL_DPLL_REF_PRIO_REF_N;
+		ref_prio |= FIELD_PREP(ZL_DPLL_REF_PRIO_REF_N, prio);
+	}
+
+	/* Update reference priority */
+	rc = zl3073x_write_u8(zldev, ZL_REG_DPLL_REF_PRIO(ref / 2), ref_prio);
+	if (rc)
+		return rc;
+
+	/* Commit configuration */
+	return zl3073x_mb_op(zldev, ZL_REG_DPLL_MB_SEM, ZL_DPLL_MB_SEM_WR,
+			     ZL_REG_DPLL_MB_MASK, BIT(zldpll->id));
+}
+
 /**
  * zl3073x_dpll_ref_state_get - get status for given input pin
  * @pin: pointer to pin
@@ -400,6 +450,42 @@ zl3073x_dpll_input_pin_state_on_dpll_set(const struct dpll_pin *dpll_pin,
 	return rc;
 }
 
+static int
+zl3073x_dpll_input_pin_prio_get(const struct dpll_pin *dpll_pin, void *pin_priv,
+				const struct dpll_device *dpll, void *dpll_priv,
+				u32 *prio, struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll_pin *pin = pin_priv;
+
+	*prio = pin->prio;
+
+	return 0;
+}
+
+static int
+zl3073x_dpll_input_pin_prio_set(const struct dpll_pin *dpll_pin, void *pin_priv,
+				const struct dpll_device *dpll, void *dpll_priv,
+				u32 prio, struct netlink_ext_ack *extack)
+{
+	struct zl3073x_dpll_pin *pin = pin_priv;
+	int rc;
+
+	if (prio > ZL_DPLL_REF_PRIO_MAX)
+		return -EINVAL;
+
+	/* If the pin is selectable then update HW registers */
+	if (pin->selectable) {
+		rc = zl3073x_dpll_ref_prio_set(pin, prio);
+		if (rc)
+			return rc;
+	}
+
+	/* Save priority */
+	pin->prio = prio;
+
+	return 0;
+}
+
 static int
 zl3073x_dpll_output_pin_state_on_dpll_get(const struct dpll_pin *dpll_pin,
 					  void *pin_priv,
@@ -474,6 +560,8 @@ zl3073x_dpll_mode_get(const struct dpll_device *dpll, void *dpll_priv,
 
 static const struct dpll_pin_ops zl3073x_dpll_input_pin_ops = {
 	.direction_get = zl3073x_dpll_pin_direction_get,
+	.prio_get = zl3073x_dpll_input_pin_prio_get,
+	.prio_set = zl3073x_dpll_input_pin_prio_set,
 	.state_on_dpll_get = zl3073x_dpll_input_pin_state_on_dpll_get,
 	.state_on_dpll_set = zl3073x_dpll_input_pin_state_on_dpll_set,
 };
diff --git a/drivers/dpll/zl3073x/prop.c b/drivers/dpll/zl3073x/prop.c
index c3224e78cbf01..4cf7e8aefcb37 100644
--- a/drivers/dpll/zl3073x/prop.c
+++ b/drivers/dpll/zl3073x/prop.c
@@ -205,6 +205,7 @@ struct zl3073x_pin_props *zl3073x_pin_props_get(struct zl3073x_dev *zldev,
 	if (dir == DPLL_PIN_DIRECTION_INPUT) {
 		props->dpll_props.type = DPLL_PIN_TYPE_EXT;
 		props->dpll_props.capabilities =
+			DPLL_PIN_CAPABILITIES_PRIORITY_CAN_CHANGE |
 			DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
 	} else {
 		props->dpll_props.type = DPLL_PIN_TYPE_GNSS;
-- 
2.49.0