regulator: cpr3-regulator: adjust voltage limits based upon aging results

Adjust the floor, ceiling, and open-loop voltages for each corner
of each CPR3 regulator based upon aging measurements.  This
allows the fixed open-loop voltage adjustment to be reduced since
it no longer has to account for the maximum possible aging
adjustment.  This in turn leads to more situations where LDO mode
may be used for the HMSS CPR3 regulators since the LDO must
always operate at the open-loop voltage.

Change-Id: Iaca0ed4b51f258656b5c44dc58f7361814ca3af7
CRs-Fixed: 949622
Signed-off-by: David Collins <collinsd@codeaurora.org>

Documentation/devicetree/bindings/regulator/cpr3-regulator.txt

@@ -517,6 +517,21 @@ Platform independent properties:
 		    regardless of the fuse combination and speed bin found
 		    on a given chip.
 
+- qcom,allow-aging-open-loop-voltage-adjustment
+	Usage:      optional
+	Value type: <prop-encoded-array>
+	Definition: A list of integers which specifies if CPR aging adjustment
+		    should be applied to open-loop voltages for each fuse
+		    combination.  Note that aging adjustment must be allowed via
+		    qcom,allow-aging-voltage-adjustment in order for this
+		    property to have an effect.
+		    Supported per-combo element values:
+			0 - do not perform CPR aging adjustment
+			1 - perform CPR aging adjustment
+
+		    The list must meet the same size requirements as those
+		    specified for qcom,allow-aging-voltage-adjustment above.
+
 - qcom,cpr-aging-max-voltage-adjustment
 	Usage:      required if qcom,allow-aging-voltage-adjustment is specified
 	Value type: <prop-encoded-array>

drivers/regulator/cpr3-regulator.c

@@ -3505,7 +3505,8 @@ cleanup:
 }
 
 /**
- * cpr3_regulator_readjust_quotients() - readjust the target quotients for the
+ * cpr3_regulator_readjust_volt_and_quot() - readjust the target quotients as
+ *		well as the floor, ceiling, and open-loop voltages for the
  *		regulator by removing the old adjustment and adding the new one
  * @vreg:		Pointer to the CPR3 regulator
  * @old_adjust_volt:	Old aging adjustment voltage in microvolts
@@ -3513,12 +3514,14 @@ cleanup:
  *
  * Also reset the cached closed loop voltage (last_volt) to equal the open-loop
  * voltage for each corner.
+ *
+ * Return: None
  */
-static void cpr3_regulator_readjust_quotients(struct cpr3_regulator *vreg,
+static void cpr3_regulator_readjust_volt_and_quot(struct cpr3_regulator *vreg,
 		int old_adjust_volt, int new_adjust_volt)
 {
 	unsigned long long temp;
-	int i, j, old_volt, new_volt;
+	int i, j, old_volt, new_volt, rounded_volt;
 
 	if (!vreg->aging_allowed)
 		return;
@@ -3548,14 +3551,34 @@ static void cpr3_regulator_readjust_quotients(struct cpr3_regulator *vreg,
 						old_volt);
 			}
 		}
+
+		rounded_volt = CPR3_ROUND(new_volt,
+					vreg->thread->ctrl->step_volt);
+
+		if (!vreg->aging_allow_open_loop_adj)
+			rounded_volt = 0;
+
+		vreg->corner[i].ceiling_volt
+			= vreg->corner[i].unaged_ceiling_volt + rounded_volt;
+		vreg->corner[i].ceiling_volt = min(vreg->corner[i].ceiling_volt,
+					      vreg->corner[i].abs_ceiling_volt);
+		vreg->corner[i].floor_volt
+			= vreg->corner[i].unaged_floor_volt + rounded_volt;
+		vreg->corner[i].floor_volt = min(vreg->corner[i].floor_volt,
+						vreg->corner[i].ceiling_volt);
+		vreg->corner[i].open_loop_volt
+			= vreg->corner[i].unaged_open_loop_volt + rounded_volt;
+		vreg->corner[i].open_loop_volt
+			= min(vreg->corner[i].open_loop_volt,
+				vreg->corner[i].ceiling_volt);
+
 		vreg->corner[i].last_volt = vreg->corner[i].open_loop_volt;
 
-		cpr3_debug(vreg, "corner %d: applying %d uV closed-loop voltage margin adjustment\n",
-			i, new_volt);
+		cpr3_debug(vreg, "corner %d: applying %d uV closed-loop and %d uV open-loop voltage margin adjustment\n",
+			i, new_volt, rounded_volt);
 	}
 }
 
-
 /**
  * cpr3_regulator_set_aging_ref_adjustment() - adjust target quotients for the
  *		regulators managed by this CPR controller to account for aging
@@ -3574,7 +3597,7 @@ static void cpr3_regulator_set_aging_ref_adjustment(
 
 	for (i = 0; i < ctrl->thread_count; i++) {
 		for (j = 0; j < ctrl->thread[i].vreg_count; j++) {
-			cpr3_regulator_readjust_quotients(
+			cpr3_regulator_readjust_volt_and_quot(
 				&ctrl->thread[i].vreg[j],
 				ctrl->aging_ref_adjust_volt,
 				ref_adjust_volt);
@@ -5586,10 +5609,13 @@ static int cpr3_regulator_init_ctrl_data(struct cpr3_controller *ctrl)
 static int cpr3_regulator_init_vreg_data(struct cpr3_regulator *vreg)
 {
 	int i, j;
+	bool init_aging;
 
 	vreg->current_corner = CPR3_REGULATOR_CORNER_INVALID;
 	vreg->last_closed_loop_corner = CPR3_REGULATOR_CORNER_INVALID;
 
+	init_aging = vreg->aging_allowed && vreg->thread->ctrl->aging_required;
+
 	for (i = 0; i < vreg->corner_count; i++) {
 		vreg->corner[i].last_volt = vreg->corner[i].open_loop_volt;
 		vreg->corner[i].irq_en = CPR3_IRQ_UP | CPR3_IRQ_DOWN;
@@ -5599,6 +5625,33 @@ static int cpr3_regulator_init_vreg_data(struct cpr3_regulator *vreg)
 			if (vreg->corner[i].target_quot[j] == 0)
 				vreg->corner[i].ro_mask |= BIT(j);
 		}
+
+		if (init_aging) {
+			vreg->corner[i].unaged_floor_volt
+				= vreg->corner[i].floor_volt;
+			vreg->corner[i].unaged_ceiling_volt
+				= vreg->corner[i].ceiling_volt;
+			vreg->corner[i].unaged_open_loop_volt
+				= vreg->corner[i].open_loop_volt;
+		}
+
+		if (vreg->aging_allowed) {
+			if (vreg->corner[i].unaged_floor_volt <= 0) {
+				cpr3_err(vreg, "invalid unaged_floor_volt[%d] = %d\n",
+					i, vreg->corner[i].unaged_floor_volt);
+				return -EINVAL;
+			}
+			if (vreg->corner[i].unaged_ceiling_volt <= 0) {
+				cpr3_err(vreg, "invalid unaged_ceiling_volt[%d] = %d\n",
+					i, vreg->corner[i].unaged_ceiling_volt);
+				return -EINVAL;
+			}
+			if (vreg->corner[i].unaged_open_loop_volt <= 0) {
+				cpr3_err(vreg, "invalid unaged_open_loop_volt[%d] = %d\n",
+				      i, vreg->corner[i].unaged_open_loop_volt);
+				return -EINVAL;
+			}
+		}
 	}
 
 	if (vreg->aging_allowed && vreg->corner[vreg->aging_corner].ceiling_volt

drivers/regulator/cpr3-regulator.h

@@ -100,6 +100,16 @@ struct cpr4_sdelta {
  *			microvolts
  * @last_volt:		Last known settled CPR closed-loop voltage which is used
  *			when switching to a new corner
+ * @abs_ceiling_volt:	The absolute CPR closed-loop ceiling voltage in
+ *			microvolts.  This is used to limit the ceiling_volt
+ *			value when it is increased as a result of aging
+ *			adjustment.
+ * @unaged_floor_volt:	The CPR closed-loop floor voltage in microvolts before
+ *			any aging adjustment is performed
+ * @unaged_ceiling_volt: The CPR closed-loop ceiling voltage in microvolts
+ *			before any aging adjustment is performed
+ * @unaged_open_loop_volt: The CPR open-loop voltage (i.e. initial voltage) in
+ *			microvolts before any aging adjusment is performed
  * @system_volt:	The system-supply voltage in microvolts or corners or
  *			levels
  * @mem_acc_volt:	The mem-acc-supply voltage in corners
@@ -136,7 +146,11 @@ struct cpr4_sdelta {
  *
  * The value of last_volt is initialized inside of the cpr3_regulator_register()
  * call with the open_loop_volt value.  It can later be updated to the settled
- * VDD supply voltage.
+ * VDD supply voltage.  The values for unaged_floor_volt, unaged_ceiling_volt,
+ * and unaged_open_loop_volt are initialized inside of cpr3_regulator_register()
+ * if ctrl->aging_required == true.  These three values must be pre-initialized
+ * if cpr3_regulator_register() is called with ctrl->aging_required == false and
+ * ctrl->aging_succeeded == true.
  *
  * The values of ro_mask and irq_en are initialized inside of the
  * cpr3_regulator_register() call.
@@ -146,6 +160,10 @@ struct cpr3_corner {
 	int			ceiling_volt;
 	int			open_loop_volt;
 	int			last_volt;
+	int			abs_ceiling_volt;
+	int			unaged_floor_volt;
+	int			unaged_ceiling_volt;
+	int			unaged_open_loop_volt;
 	int			system_volt;
 	int			mem_acc_volt;
 	u32			proc_freq;
@@ -277,6 +295,13 @@ struct cprh_corner_band {
  * @aging_allowed:	Boolean defining if CPR aging adjustments are allowed
  *			for this CPR3 regulator given the fuse combo of the
  *			device
+ * @aging_allow_open_loop_adj: Boolean defining if the open-loop voltage of each
+ *			corner of this regulator should be adjusted as a result
+ *			of an aging measurement.  This flag can be set to false
+ *			when the open-loop voltage adjustments have been
+ *			specified such that they include the maximum possible
+ *			aging adjustment.  This flag is only used if
+ *			aging_allowed == true.
  * @aging_corner:	The corner that should be configured for this regulator
  *			when an aging measurement is performed.
  * @aging_max_adjust_volt: The maximum aging voltage margin in microvolts that
@@ -342,6 +367,7 @@ struct cpr3_regulator {
 	bool			vreg_enabled;
 
 	bool			aging_allowed;
+	bool			aging_allow_open_loop_adj;
 	int			aging_corner;
 	int			aging_max_adjust_volt;
 

drivers/regulator/cpr3-util.c

@@ -695,9 +695,11 @@ int cpr3_parse_common_corner_data(struct cpr3_regulator *vreg)
 			1, temp);
 	if (rc)
 		goto free_temp;
-	for (i = 0; i < vreg->corner_count; i++)
+	for (i = 0; i < vreg->corner_count; i++) {
 		vreg->corner[i].ceiling_volt
 			= CPR3_ROUND(temp[i], ctrl->step_volt);
+		vreg->corner[i].abs_ceiling_volt = vreg->corner[i].ceiling_volt;
+	}
 
 	rc = cpr3_parse_corner_array_property(vreg, "qcom,cpr-voltage-floor",
 			1, temp);
@@ -807,6 +809,17 @@ int cpr3_parse_common_corner_data(struct cpr3_regulator *vreg)
 		vreg->aging_allowed = aging_allowed;
 	}
 
+	if (of_find_property(vreg->of_node,
+		       "qcom,allow-aging-open-loop-voltage-adjustment", NULL)) {
+		rc = cpr3_parse_array_property(vreg,
+			"qcom,allow-aging-open-loop-voltage-adjustment",
+			1, &aging_allowed);
+		if (rc)
+			goto free_temp;
+
+		vreg->aging_allow_open_loop_adj = aging_allowed;
+	}
+
 	if (vreg->aging_allowed) {
 		if (ctrl->aging_ref_volt <= 0) {
 			cpr3_err(ctrl, "qcom,cpr-aging-ref-voltage must be specified\n");