Merge branch 'dpll-phase-offset-phase-adjust'

Arkadiusz Kubalewski says:

====================
dpll: add phase-offset and phase-adjust

Improve monitoring and control over dpll devices.
Allow user to receive measurement of phase difference between signals
on pin and dpll (phase-offset).
Allow user to receive and control adjustable value of pin's signal
phase (phase-adjust).

v4->v5:
- rebase series on top of net-next/main, fix conflict - remove redundant
  attribute type definition in subset definition

v3->v4:
- do not increase do version of uAPI header as it is not needed (v3 did
  not have this change)
- fix spelling around commit messages, argument descriptions and docs
- add missing extack errors on failure set callbacks for pin phase
  adjust and frequency
- remove ice check if value is already set, now redundant as checked in
  the dpll subsystem

v2->v3:
- do not increase do version of uAPI header as it is not needed

v1->v2:
- improve handling for error case of requesting the phase adjust set
- align handling for error case of frequency set request with the
approach introduced for phase adjust
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/driver-api/dpll.rst

@@ -173,6 +173,47 @@ in order to configure active input of a MUX-type pin, the user needs to
 request desired pin state of the child pin on the parent pin,
 as described in the ``MUX-type pins`` chapter.
 
+Phase offset measurement and adjustment
+========================================
+
+Device may provide ability to measure a phase difference between signals
+on a pin and its parent dpll device. If pin-dpll phase offset measurement
+is supported, it shall be provided with ``DPLL_A_PIN_PHASE_OFFSET``
+attribute for each parent dpll device.
+
+Device may also provide ability to adjust a signal phase on a pin.
+If pin phase adjustment is supported, minimal and maximal values that pin
+handle shall be provide to the user on ``DPLL_CMD_PIN_GET`` respond
+with ``DPLL_A_PIN_PHASE_ADJUST_MIN`` and ``DPLL_A_PIN_PHASE_ADJUST_MAX``
+attributes. Configured phase adjust value is provided with
+``DPLL_A_PIN_PHASE_ADJUST`` attribute of a pin, and value change can be
+requested with the same attribute with ``DPLL_CMD_PIN_SET`` command.
+
+  =============================== ======================================
+  ``DPLL_A_PIN_ID``               configured pin id
+  ``DPLL_A_PIN_PHASE_ADJUST_MIN`` attr minimum value of phase adjustment
+  ``DPLL_A_PIN_PHASE_ADJUST_MAX`` attr maximum value of phase adjustment
+  ``DPLL_A_PIN_PHASE_ADJUST``     attr configured value of phase
+                                  adjustment on parent dpll device
+  ``DPLL_A_PIN_PARENT_DEVICE``    nested attribute for requesting
+                                  configuration on given parent dpll
+                                  device
+    ``DPLL_A_PIN_PARENT_ID``      parent dpll device id
+    ``DPLL_A_PIN_PHASE_OFFSET``   attr measured phase difference
+                                  between a pin and parent dpll device
+  =============================== ======================================
+
+All phase related values are provided in pico seconds, which represents
+time difference between signals phase. The negative value means that
+phase of signal on pin is earlier in time than dpll's signal. Positive
+value means that phase of signal on pin is later in time than signal of
+a dpll.
+
+Phase adjust (also min and max) values are integers, but measured phase
+offset values are fractional with 3-digit decimal places and shell be
+divided with ``DPLL_PIN_PHASE_OFFSET_DIVIDER`` to get integer part and
+modulo divided to get fractional part.
+
 Configuration commands group
 ============================
 
@@ -263,15 +304,23 @@ according to attribute purpose.
                                        frequencies
       ``DPLL_A_PIN_ANY_FREQUENCY_MIN`` attr minimum value of frequency
       ``DPLL_A_PIN_ANY_FREQUENCY_MAX`` attr maximum value of frequency
+    ``DPLL_A_PIN_PHASE_ADJUST_MIN``    attr minimum value of phase
+                                       adjustment
+    ``DPLL_A_PIN_PHASE_ADJUST_MAX``    attr maximum value of phase
+                                       adjustment
+    ``DPLL_A_PIN_PHASE_ADJUST``        attr configured value of phase
+                                       adjustment on parent device
     ``DPLL_A_PIN_PARENT_DEVICE``       nested attr for each parent device
                                        the pin is connected with
       ``DPLL_A_PIN_PARENT_ID``         attr parent dpll device id
       ``DPLL_A_PIN_PRIO``              attr priority of pin on the
                                        dpll device
       ``DPLL_A_PIN_STATE``             attr state of pin on the parent
                                        dpll device
-     ``DPLL_A_PIN_DIRECTION``          attr direction of a pin on the
+      ``DPLL_A_PIN_DIRECTION``         attr direction of a pin on the
                                        parent dpll device
+      ``DPLL_A_PIN_PHASE_OFFSET``      attr measured phase difference
+                                       between a pin and parent dpll
     ``DPLL_A_PIN_PARENT_PIN``          nested attr for each parent pin
                                        the pin is connected with
       ``DPLL_A_PIN_PARENT_ID``         attr parent pin id
@@ -284,6 +333,8 @@ according to attribute purpose.
   ``DPLL_CMD_PIN_SET``                 command to set pins configuration
     ``DPLL_A_PIN_ID``                  attr unique a pin ID
     ``DPLL_A_PIN_FREQUENCY``           attr requested frequency of a pin
+    ``DPLL_A_PIN_PHASE_ADJUST``        attr requested value of phase
+                                       adjustment on parent device
     ``DPLL_A_PIN_PARENT_DEVICE``       nested attr for each parent dpll
                                        device configuration request
       ``DPLL_A_PIN_PARENT_ID``         attr parent dpll device id

Documentation/netlink/specs/dpll.yaml

@@ -164,6 +164,18 @@ definitions:
       -
         name: state-can-change
         doc: pin state can be changed
+  -
+    type: const
+    name: phase-offset-divider
+    value: 1000
+    doc: |
+      phase offset divider allows userspace to calculate a value of
+      measured signal phase difference between a pin and dpll device
+      as a fractional value with three digit decimal precision.
+      Value of (DPLL_A_PHASE_OFFSET / DPLL_PHASE_OFFSET_DIVIDER) is an
+      integer part of a measured phase offset value.
+      Value of (DPLL_A_PHASE_OFFSET % DPLL_PHASE_OFFSET_DIVIDER) is a
+      fractional part of a measured phase offset value.
 
 attribute-sets:
   -
@@ -272,6 +284,18 @@ attribute-sets:
         type: nest
         multi-attr: true
         nested-attributes: pin-parent-pin
+      -
+        name: phase-adjust-min
+        type: s32
+      -
+        name: phase-adjust-max
+        type: s32
+      -
+        name: phase-adjust
+        type: s32
+      -
+        name: phase-offset
+        type: s64
   -
     name: pin-parent-device
     subset-of: pin
@@ -284,6 +308,8 @@ attribute-sets:
         name: prio
       -
         name: state
+      -
+        name: phase-offset
   -
     name: pin-parent-pin
     subset-of: pin
@@ -431,6 +457,9 @@ operations:
             - capabilities
             - parent-device
             - parent-pin
+            - phase-adjust-min
+            - phase-adjust-max
+            - phase-adjust
 
       dump:
         pre: dpll-lock-dumpit
@@ -458,6 +487,7 @@ operations:
             - state
             - parent-device
             - parent-pin
+            - phase-adjust
     -
       name: pin-create-ntf
       doc: Notification about pin appearing

drivers/dpll/dpll_netlink.c

@@ -212,6 +212,53 @@ dpll_msg_add_pin_direction(struct sk_buff *msg, struct dpll_pin *pin,
 	return 0;
 }
 
+static int
+dpll_msg_add_pin_phase_adjust(struct sk_buff *msg, struct dpll_pin *pin,
+			      struct dpll_pin_ref *ref,
+			      struct netlink_ext_ack *extack)
+{
+	const struct dpll_pin_ops *ops = dpll_pin_ops(ref);
+	struct dpll_device *dpll = ref->dpll;
+	s32 phase_adjust;
+	int ret;
+
+	if (!ops->phase_adjust_get)
+		return 0;
+	ret = ops->phase_adjust_get(pin, dpll_pin_on_dpll_priv(dpll, pin),
+				    dpll, dpll_priv(dpll),
+				    &phase_adjust, extack);
+	if (ret)
+		return ret;
+	if (nla_put_s32(msg, DPLL_A_PIN_PHASE_ADJUST, phase_adjust))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int
+dpll_msg_add_phase_offset(struct sk_buff *msg, struct dpll_pin *pin,
+			  struct dpll_pin_ref *ref,
+			  struct netlink_ext_ack *extack)
+{
+	const struct dpll_pin_ops *ops = dpll_pin_ops(ref);
+	struct dpll_device *dpll = ref->dpll;
+	s64 phase_offset;
+	int ret;
+
+	if (!ops->phase_offset_get)
+		return 0;
+	ret = ops->phase_offset_get(pin, dpll_pin_on_dpll_priv(dpll, pin),
+				    dpll, dpll_priv(dpll), &phase_offset,
+				    extack);
+	if (ret)
+		return ret;
+	if (nla_put_64bit(msg, DPLL_A_PIN_PHASE_OFFSET, sizeof(phase_offset),
+			  &phase_offset, DPLL_A_PIN_PAD))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int
 dpll_msg_add_pin_freq(struct sk_buff *msg, struct dpll_pin *pin,
 		      struct dpll_pin_ref *ref, struct netlink_ext_ack *extack)
@@ -330,6 +377,9 @@ dpll_msg_add_pin_dplls(struct sk_buff *msg, struct dpll_pin *pin,
 		if (ret)
 			goto nest_cancel;
 		ret = dpll_msg_add_pin_direction(msg, pin, ref, extack);
+		if (ret)
+			goto nest_cancel;
+		ret = dpll_msg_add_phase_offset(msg, pin, ref, extack);
 		if (ret)
 			goto nest_cancel;
 		nla_nest_end(msg, attr);
@@ -377,6 +427,15 @@ dpll_cmd_pin_get_one(struct sk_buff *msg, struct dpll_pin *pin,
 	if (nla_put_u32(msg, DPLL_A_PIN_CAPABILITIES, prop->capabilities))
 		return -EMSGSIZE;
 	ret = dpll_msg_add_pin_freq(msg, pin, ref, extack);
+	if (ret)
+		return ret;
+	if (nla_put_s32(msg, DPLL_A_PIN_PHASE_ADJUST_MIN,
+			prop->phase_range.min))
+		return -EMSGSIZE;
+	if (nla_put_s32(msg, DPLL_A_PIN_PHASE_ADJUST_MAX,
+			prop->phase_range.max))
+		return -EMSGSIZE;
+	ret = dpll_msg_add_pin_phase_adjust(msg, pin, ref, extack);
 	if (ret)
 		return ret;
 	if (xa_empty(&pin->parent_refs))
@@ -416,7 +475,7 @@ dpll_device_get_one(struct dpll_device *dpll, struct sk_buff *msg,
 	if (nla_put_u32(msg, DPLL_A_TYPE, dpll->type))
 		return -EMSGSIZE;
 
-	return ret;
+	return 0;
 }
 
 static int
@@ -556,8 +615,10 @@ static int
 dpll_pin_freq_set(struct dpll_pin *pin, struct nlattr *a,
 		  struct netlink_ext_ack *extack)
 {
-	u64 freq = nla_get_u64(a);
-	struct dpll_pin_ref *ref;
+	u64 freq = nla_get_u64(a), old_freq;
+	struct dpll_pin_ref *ref, *failed;
+	const struct dpll_pin_ops *ops;
+	struct dpll_device *dpll;
 	unsigned long i;
 	int ret;
 
@@ -567,19 +628,51 @@ dpll_pin_freq_set(struct dpll_pin *pin, struct nlattr *a,
 	}
 
 	xa_for_each(&pin->dpll_refs, i, ref) {
-		const struct dpll_pin_ops *ops = dpll_pin_ops(ref);
-		struct dpll_device *dpll = ref->dpll;
-
-		if (!ops->frequency_set)
+		ops = dpll_pin_ops(ref);
+		if (!ops->frequency_set || !ops->frequency_get) {
+			NL_SET_ERR_MSG(extack, "frequency set not supported by the device");
 			return -EOPNOTSUPP;
+		}
+	}
+	ref = dpll_xa_ref_dpll_first(&pin->dpll_refs);
+	ops = dpll_pin_ops(ref);
+	dpll = ref->dpll;
+	ret = ops->frequency_get(pin, dpll_pin_on_dpll_priv(dpll, pin), dpll,
+				 dpll_priv(dpll), &old_freq, extack);
+	if (ret) {
+		NL_SET_ERR_MSG(extack, "unable to get old frequency value");
+		return ret;
+	}
+	if (freq == old_freq)
+		return 0;
+
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		ops = dpll_pin_ops(ref);
+		dpll = ref->dpll;
 		ret = ops->frequency_set(pin, dpll_pin_on_dpll_priv(dpll, pin),
 					 dpll, dpll_priv(dpll), freq, extack);
-		if (ret)
-			return ret;
+		if (ret) {
+			failed = ref;
+			NL_SET_ERR_MSG_FMT(extack, "frequency set failed for dpll_id:%u",
+					   dpll->id);
+			goto rollback;
+		}
 	}
 	__dpll_pin_change_ntf(pin);
 
 	return 0;
+
+rollback:
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		if (ref == failed)
+			break;
+		ops = dpll_pin_ops(ref);
+		dpll = ref->dpll;
+		if (ops->frequency_set(pin, dpll_pin_on_dpll_priv(dpll, pin),
+				       dpll, dpll_priv(dpll), old_freq, extack))
+			NL_SET_ERR_MSG(extack, "set frequency rollback failed");
+	}
+	return ret;
 }
 
 static int
@@ -705,6 +798,78 @@ dpll_pin_direction_set(struct dpll_pin *pin, struct dpll_device *dpll,
 	return 0;
 }
 
+static int
+dpll_pin_phase_adj_set(struct dpll_pin *pin, struct nlattr *phase_adj_attr,
+		       struct netlink_ext_ack *extack)
+{
+	struct dpll_pin_ref *ref, *failed;
+	const struct dpll_pin_ops *ops;
+	s32 phase_adj, old_phase_adj;
+	struct dpll_device *dpll;
+	unsigned long i;
+	int ret;
+
+	phase_adj = nla_get_s32(phase_adj_attr);
+	if (phase_adj > pin->prop->phase_range.max ||
+	    phase_adj < pin->prop->phase_range.min) {
+		NL_SET_ERR_MSG_ATTR(extack, phase_adj_attr,
+				    "phase adjust value not supported");
+		return -EINVAL;
+	}
+
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		ops = dpll_pin_ops(ref);
+		if (!ops->phase_adjust_set || !ops->phase_adjust_get) {
+			NL_SET_ERR_MSG(extack, "phase adjust not supported");
+			return -EOPNOTSUPP;
+		}
+	}
+	ref = dpll_xa_ref_dpll_first(&pin->dpll_refs);
+	ops = dpll_pin_ops(ref);
+	dpll = ref->dpll;
+	ret = ops->phase_adjust_get(pin, dpll_pin_on_dpll_priv(dpll, pin),
+				    dpll, dpll_priv(dpll), &old_phase_adj,
+				    extack);
+	if (ret) {
+		NL_SET_ERR_MSG(extack, "unable to get old phase adjust value");
+		return ret;
+	}
+	if (phase_adj == old_phase_adj)
+		return 0;
+
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		ops = dpll_pin_ops(ref);
+		dpll = ref->dpll;
+		ret = ops->phase_adjust_set(pin,
+					    dpll_pin_on_dpll_priv(dpll, pin),
+					    dpll, dpll_priv(dpll), phase_adj,
+					    extack);
+		if (ret) {
+			failed = ref;
+			NL_SET_ERR_MSG_FMT(extack,
+					   "phase adjust set failed for dpll_id:%u",
+					   dpll->id);
+			goto rollback;
+		}
+	}
+	__dpll_pin_change_ntf(pin);
+
+	return 0;
+
+rollback:
+	xa_for_each(&pin->dpll_refs, i, ref) {
+		if (ref == failed)
+			break;
+		ops = dpll_pin_ops(ref);
+		dpll = ref->dpll;
+		if (ops->phase_adjust_set(pin, dpll_pin_on_dpll_priv(dpll, pin),
+					  dpll, dpll_priv(dpll), old_phase_adj,
+					  extack))
+			NL_SET_ERR_MSG(extack, "set phase adjust rollback failed");
+	}
+	return ret;
+}
+
 static int
 dpll_pin_parent_device_set(struct dpll_pin *pin, struct nlattr *parent_nest,
 			   struct netlink_ext_ack *extack)
@@ -793,6 +958,11 @@ dpll_pin_set_from_nlattr(struct dpll_pin *pin, struct genl_info *info)
 			if (ret)
 				return ret;
 			break;
+		case DPLL_A_PIN_PHASE_ADJUST:
+			ret = dpll_pin_phase_adj_set(pin, a, info->extack);
+			if (ret)
+				return ret;
+			break;
 		case DPLL_A_PIN_PARENT_DEVICE:
 			ret = dpll_pin_parent_device_set(pin, a, info->extack);
 			if (ret)