Commit 5534a820 authored by Ivan Vecera's avatar Ivan Vecera Committed by Jakub Kicinski
Browse files

dpll: zl3073x: Cache reference monitor status 



Instead of reading the ZL_REG_REF_MON_STATUS register every time
the reference status is needed, cache this value in the zl3073x_ref
struct.

This is achieved by:
* Adding a mon_status field to struct zl3073x_ref
* Introducing zl3073x_dev_ref_status_update() to read the status for
  all references into this new cache field
* Calling this update function from the periodic work handler
* Adding zl3073x_ref_is_status_ok() and zl3073x_dev_ref_is_status_ok()
  helpers to check the cached value
* Refactoring all callers in dpll.c to use the new
  zl3073x_dev_ref_is_status_ok() helper, removing direct register reads

This change consolidates all status register reads into a single periodic
function and reduces I/O bus traffic in dpll callbacks.

Reviewed-by: default avatarPetr Oros <poros@redhat.com>
Tested-by: default avatarPrathosh Satish <Prathosh.Satish@microchip.com>
Signed-off-by: default avatarIvan Vecera <ivecera@redhat.com>
Link: https://patch.msgid.link/20251113074105.141379-4-ivecera@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 607f2c00

drivers/dpll/zl3073x/core.c

+18 −0
Original line number Diff line number Diff line
@@ -591,6 +591,21 @@ zl3073x_dev_state_fetch(struct zl3073x_dev *zldev) 
	return rc;

}



static void

zl3073x_dev_ref_status_update(struct zl3073x_dev *zldev)

{

	int i, rc;



	for (i = 0; i < ZL3073X_NUM_REFS; i++) {

		rc = zl3073x_read_u8(zldev, ZL_REG_REF_MON_STATUS(i),

				     &zldev->ref[i].mon_status);

		if (rc)

			dev_warn(zldev->dev,

				 "Failed to get REF%u status: %pe\n", i,

				 ERR_PTR(rc));

	}

}



/**

 * zl3073x_ref_phase_offsets_update - update reference phase offsets

 * @zldev: pointer to zl3073x_dev structure
@@ -710,6 +725,9 @@ zl3073x_dev_periodic_work(struct kthread_work *work) 
	struct zl3073x_dpll *zldpll;

	int rc;



	/* Update input references status */

	zl3073x_dev_ref_status_update(zldev);



	/* Update DPLL-to-connected-ref phase offsets registers */

	rc = zl3073x_ref_phase_offsets_update(zldev, -1);

	if (rc)

drivers/dpll/zl3073x/core.h

+15 −0
Original line number Diff line number Diff line
@@ -227,6 +227,21 @@ zl3073x_dev_ref_is_enabled(struct zl3073x_dev *zldev, u8 index) 
	return zl3073x_ref_is_enabled(ref);

}



/*

 * zl3073x_dev_ref_is_status_ok - check the given input reference status

 * @zldev: pointer to zl3073x device

 * @index: input reference index

 *

 * Return: true if the status is ok, false otherwise

 */

static inline bool

zl3073x_dev_ref_is_status_ok(struct zl3073x_dev *zldev, u8 index)

{

	const struct zl3073x_ref *ref = zl3073x_ref_state_get(zldev, index);



	return zl3073x_ref_is_status_ok(ref);

}



/**

 * zl3073x_dev_synth_dpll_get - get DPLL ID the synth is driven by

 * @zldev: pointer to zl3073x device

drivers/dpll/zl3073x/dpll.c

+21 −75
Original line number Diff line number Diff line
@@ -497,19 +497,10 @@ zl3073x_dpll_connected_ref_get(struct zl3073x_dpll *zldpll, u8 *ref) 
	if (rc)

		return rc;



	if (ZL3073X_DPLL_REF_IS_VALID(*ref)) {

		u8 ref_status;



		/* Read the reference monitor status */

		rc = zl3073x_read_u8(zldev, ZL_REG_REF_MON_STATUS(*ref),

				     &ref_status);

		if (rc)

			return rc;



	/* If the monitor indicates an error nothing is connected */

		if (ref_status != ZL_REF_MON_STATUS_OK)

	if (ZL3073X_DPLL_REF_IS_VALID(*ref) &&

	    !zl3073x_dev_ref_is_status_ok(zldev, *ref))

		*ref = ZL3073X_DPLL_REF_NONE;

	}



	return 0;

}
@@ -524,7 +515,7 @@ zl3073x_dpll_input_pin_phase_offset_get(const struct dpll_pin *dpll_pin, 
	struct zl3073x_dpll *zldpll = dpll_priv;

	struct zl3073x_dev *zldev = zldpll->dev;

	struct zl3073x_dpll_pin *pin = pin_priv;

	u8 conn_ref, ref, ref_status;

	u8 conn_ref, ref;

	s64 ref_phase;

	int rc;
@@ -537,21 +528,9 @@ zl3073x_dpll_input_pin_phase_offset_get(const struct dpll_pin *dpll_pin, 
	 * monitor feature is disabled.

	 */

	ref = zl3073x_input_pin_ref_get(pin->id);

	if (!zldpll->phase_monitor && ref != conn_ref) {

		*phase_offset = 0;



		return 0;

	}



	/* Get this pin monitor status */

	rc = zl3073x_read_u8(zldev, ZL_REG_REF_MON_STATUS(ref), &ref_status);

	if (rc)

		return rc;



	/* Report phase offset only if the input pin signal is present */

	if (ref_status != ZL_REF_MON_STATUS_OK) {

	if ((!zldpll->phase_monitor && ref != conn_ref) ||

	    !zl3073x_dev_ref_is_status_ok(zldev, ref)) {

		*phase_offset = 0;



		return 0;

	}
@@ -777,7 +756,7 @@ zl3073x_dpll_ref_state_get(struct zl3073x_dpll_pin *pin, 
{

	struct zl3073x_dpll *zldpll = pin->dpll;

	struct zl3073x_dev *zldev = zldpll->dev;

	u8 ref, ref_conn, status;

	u8 ref, ref_conn;

	int rc;



	ref = zl3073x_input_pin_ref_get(pin->id);
@@ -797,21 +776,10 @@ zl3073x_dpll_ref_state_get(struct zl3073x_dpll_pin *pin, 
	 * pin as selectable.

	 */

	if (zldpll->refsel_mode == ZL_DPLL_MODE_REFSEL_MODE_AUTO &&

	    pin->selectable) {

		/* Read reference monitor status */

		rc = zl3073x_read_u8(zldev, ZL_REG_REF_MON_STATUS(ref),

				     &status);

		if (rc)

			return rc;



		/* If the monitor indicates errors report the reference

		 * as disconnected

		 */

		if (status == ZL_REF_MON_STATUS_OK) {

	    zl3073x_dev_ref_is_status_ok(zldev, ref) && pin->selectable) {

		*state = DPLL_PIN_STATE_SELECTABLE;

		return 0;

	}

	}



	/* Otherwise report the pin as disconnected */

	*state = DPLL_PIN_STATE_DISCONNECTED;
@@ -2036,37 +2004,23 @@ zl3073x_dpll_pin_phase_offset_check(struct zl3073x_dpll_pin *pin) 


	ref = zl3073x_input_pin_ref_get(pin->id);



	/* No phase offset if the ref monitor reports signal errors */

	if (!zl3073x_dev_ref_is_status_ok(zldev, ref))

		return false;



	/* Select register to read phase offset value depending on pin and

	 * phase monitor state:

	 * 1) For connected pin use dpll_phase_err_data register

	 * 2) For other pins use appropriate ref_phase register if the phase

	 *    monitor feature is enabled and reference monitor does not

	 *    report signal errors for given input pin

	 *    monitor feature is enabled.

	 */

	if (pin->pin_state == DPLL_PIN_STATE_CONNECTED) {

	if (pin->pin_state == DPLL_PIN_STATE_CONNECTED)

		reg = ZL_REG_DPLL_PHASE_ERR_DATA(zldpll->id);

	} else if (zldpll->phase_monitor) {

		u8 status;



		/* Get reference monitor status */

		rc = zl3073x_read_u8(zldev, ZL_REG_REF_MON_STATUS(ref),

				     &status);

		if (rc) {

			dev_err(zldev->dev,

				"Failed to read %s refmon status: %pe\n",

				pin->label, ERR_PTR(rc));



			return false;

		}



		if (status != ZL_REF_MON_STATUS_OK)

			return false;



	else if (zldpll->phase_monitor)

		reg = ZL_REG_REF_PHASE(ref);

	} else {

	else

		/* The pin is not connected or phase monitor disabled */

		return false;

	}



	/* Read measured phase offset value */

	rc = zl3073x_read_u48(zldev, reg, &phase_offset);
@@ -2105,22 +2059,14 @@ zl3073x_dpll_pin_ffo_check(struct zl3073x_dpll_pin *pin) 
{

	struct zl3073x_dpll *zldpll = pin->dpll;

	struct zl3073x_dev *zldev = zldpll->dev;

	u8 ref, status;

	s64 ffo;

	int rc;

	u8 ref;



	/* Get reference monitor status */

	ref = zl3073x_input_pin_ref_get(pin->id);

	rc = zl3073x_read_u8(zldev, ZL_REG_REF_MON_STATUS(ref), &status);

	if (rc) {

		dev_err(zldev->dev, "Failed to read %s refmon status: %pe\n",

			pin->label, ERR_PTR(rc));



		return false;

	}



	/* Do not report ffo changes if the reference monitor report errors */

	if (status != ZL_REF_MON_STATUS_OK)

	if (!zl3073x_dev_ref_is_status_ok(zldev, ref))

		return false;



	/* Get the latest measured ref's ffo */

drivers/dpll/zl3073x/ref.h

+14 −0
Original line number Diff line number Diff line
@@ -14,10 +14,12 @@ struct zl3073x_dev; 
 * struct zl3073x_ref - input reference state

 * @ffo: current fractional frequency offset

 * @config: reference config

 * @mon_status: reference monitor status

 */

struct zl3073x_ref {

	s64	ffo;

	u8	config;

	u8	mon_status;

};



int zl3073x_ref_state_fetch(struct zl3073x_dev *zldev, u8 index);
@@ -63,4 +65,16 @@ zl3073x_ref_is_enabled(const struct zl3073x_ref *ref) 
	return !!FIELD_GET(ZL_REF_CONFIG_ENABLE, ref->config);

}



/**

 * zl3073x_ref_is_status_ok - check the given input reference status

 * @ref: pointer to ref state

 *

 * Return: true if the status is ok, false otherwise

 */

static inline bool

zl3073x_ref_is_status_ok(const struct zl3073x_ref *ref)

{

	return ref->mon_status == ZL_REF_MON_STATUS_OK;

}



#endif /* _ZL3073X_REF_H */