regulator: cpr3-regulator: add support for corners above max fuse corner

Add support for fuse corner to corner mappings in which the
highest fuse corner is mapped to a corner lower than the
highest corner.  This can be used to define a corner which has
a constant voltage offset above the highest fuse corner but which
does not impact interpolation for the lower corners.

Change-Id: Ie41522cb06ca81898f58458694067a567f608df0
CRs-Fixed: 981475
Signed-off-by: David Collins <collinsd@codeaurora.org>

3 files changed, 54 insertions, 34 deletions

diff --git a/drivers/regulator/cpr3-hmss-regulator.c b/drivers/regulator/cpr3-hmss-regulator.c
index f907a71d4a95..73a0529b3dc6 100644
--- a/drivers/regulator/cpr3-hmss-regulator.c
+++ b/drivers/regulator/cpr3-hmss-regulator.c
@@ -690,19 +690,8 @@ static int cpr3_msm8996_hmss_calculate_open_loop_voltages(
 		goto done;
 	}
 
-	/* Determine highest corner mapped to each fuse corner */
-	j = vreg->fuse_corner_count - 1;
-	for (i = vreg->corner_count - 1; i >= 0; i--) {
-		if (vreg->corner[i].cpr_fuse_corner == j) {
-			fmax_corner[j] = i;
-			j--;
-		}
-	}
-	if (j >= 0) {
-		cpr3_err(vreg, "invalid fuse corner mapping\n");
-		rc = -EINVAL;
-		goto done;
-	}
+	for (i = 0; i < vreg->fuse_corner_count; i++)
+		fmax_corner[i] = vreg->fuse_corner_map[i];
 
 	/*
 	 * Interpolation is not possible for corners mapped to the lowest fuse
@@ -712,6 +701,14 @@ static int cpr3_msm8996_hmss_calculate_open_loop_voltages(
 		vreg->corner[i].open_loop_volt = fuse_volt[0];
 
 	/*
+	 * Interpolation is not possible for corners mapped above the highest
+	 * fuse corner so use the fuse corner value directly.
+	 */
+	j = vreg->fuse_corner_count - 1;
+	for (i = fmax_corner[j] + 1; i < vreg->corner_count; i++)
+		vreg->corner[i].open_loop_volt = fuse_volt[j];
+
+	/*
 	 * Corner LowSVS should be skipped for voltage interpolation
 	 * since no fuse exists for it.  Instead, the lowest interpolation
 	 * should be between MinSVS and SVS.
@@ -871,19 +868,8 @@ static int cpr3_msm8996_hmss_calculate_target_quotients(
 				volt_adjust, volt_adjust_fuse, ro_scale);
 	}
 
-	/* Determine highest corner mapped to each fuse corner */
-	j = vreg->fuse_corner_count - 1;
-	for (i = vreg->corner_count - 1; i >= 0; i--) {
-		if (vreg->corner[i].cpr_fuse_corner == j) {
-			fmax_corner[j] = i;
-			j--;
-		}
-	}
-	if (j >= 0) {
-		cpr3_err(vreg, "invalid fuse corner mapping\n");
-		rc = -EINVAL;
-		goto done;
-	}
+	for (i = 0; i < vreg->fuse_corner_count; i++)
+		fmax_corner[i] = vreg->fuse_corner_map[i];
 
 	/*
 	 * Interpolation is not possible for corners mapped to the lowest fuse
@@ -901,6 +887,17 @@ static int cpr3_msm8996_hmss_calculate_target_quotients(
 		vreg->corner[i].target_quot[ro] = quot;
 
 	/*
+	 * Interpolation is not possible for corners mapped above the highest
+	 * fuse corner so use the fuse corner value directly.
+	 */
+	j = vreg->fuse_corner_count - 1;
+	quot_adjust = cpr3_quot_adjustment(ro_scale[j], volt_adjust_fuse[j]);
+	quot = fuse->target_quot[j] + quot_adjust;
+	ro = fuse->ro_sel[j];
+	for (i = fmax_corner[j] + 1; i < vreg->corner_count; i++)
+		vreg->corner[i].target_quot[ro] = quot;
+
+	/*
 	 * The LowSVS target quotient is defined as:
 	 *	(SVS target quotient) - (the unpacked SVS quotient offset)
 	 * MinSVS, LowSVS, and SVS fuse corners all share the same RO so it is
diff --git a/drivers/regulator/cpr3-regulator.h b/drivers/regulator/cpr3-regulator.h
index 150104c11fc1..919034cfb0fd 100644
--- a/drivers/regulator/cpr3-regulator.h
+++ b/drivers/regulator/cpr3-regulator.h
@@ -140,6 +140,14 @@ struct cpr3_corner {
  * @fuse_combos_supported: The number of fuse combinations supported by the
  *			device tree configuration for this CPR3 regulator
  * @fuse_corner_count:	Number of corners defined by fuse parameters
+ * @fuse_corner_map:	Array of length fuse_corner_count which specifies the
+ *			highest corner associated with each fuse corner.  Note
+ *			that each element must correspond to a valid corner
+ *			and that element values must be strictly increasing.
+ *			Also, it is acceptable for the lowest fuse corner to map
+ *			to a corner other than the lowest.  Likewise, it is
+ *			acceptable for the highest fuse corner to map to a
+ *			corner other than the highest.
  * @fuse_combo_corner_sum: The sum of the corner counts across all fuse combos
  * @fuse_combo_offset:	The device tree property array offset for the selected
  *			fuse combo
@@ -219,6 +227,7 @@ struct cpr3_regulator {
 	int			fuse_combo;
 	int			fuse_combos_supported;
 	int			fuse_corner_count;
+	int			*fuse_corner_map;
 	int			fuse_combo_corner_sum;
 	int			fuse_combo_offset;
 	int			speed_bin_corner_sum;
diff --git a/drivers/regulator/cpr3-util.c b/drivers/regulator/cpr3-util.c
index fcd876e823d0..390436faf91d 100644
--- a/drivers/regulator/cpr3-util.c
+++ b/drivers/regulator/cpr3-util.c
@@ -445,9 +445,9 @@ int cpr3_parse_corner_array_property(struct cpr3_regulator *vreg,
  * and qcom,cpr-corner-fmax-map.
  *
  * It initializes these CPR3 regulator elements: corner, corner_count,
- * fuse_combos_supported, and speed_bins_supported.  It initializes these
- * elements for each corner: ceiling_volt, floor_volt, proc_freq, and
- * cpr_fuse_corner.
+ * fuse_combos_supported, fuse_corner_map, and speed_bins_supported.  It
+ * initializes these elements for each corner: ceiling_volt, floor_volt,
+ * proc_freq, and cpr_fuse_corner.
  *
  * It requires that the following CPR3 regulator elements be initialized before
  * being called: fuse_corner_count, fuse_combo, and speed_bin_fuse.
@@ -658,11 +658,19 @@ int cpr3_parse_common_corner_data(struct cpr3_regulator *vreg)
 		}
 	}
 
+	vreg->fuse_corner_map = devm_kcalloc(ctrl->dev, vreg->fuse_corner_count,
+				    sizeof(*vreg->fuse_corner_map), GFP_KERNEL);
+	if (!vreg->fuse_corner_map) {
+		rc = -ENOMEM;
+		goto free_temp;
+	}
+
 	rc = cpr3_parse_array_property(vreg, "qcom,cpr-corner-fmax-map",
 		vreg->fuse_corner_count, temp);
 	if (rc)
 		goto free_temp;
 	for (i = 0; i < vreg->fuse_corner_count; i++) {
+		vreg->fuse_corner_map[i] = temp[i] - CPR3_CORNER_OFFSET;
 		if (temp[i] < CPR3_CORNER_OFFSET
 		    || temp[i] > vreg->corner_count + CPR3_CORNER_OFFSET) {
 			cpr3_err(vreg, "invalid corner value specified in qcom,cpr-corner-fmax-map: %u\n",
@@ -676,13 +684,11 @@ int cpr3_parse_common_corner_data(struct cpr3_regulator *vreg)
 			goto free_temp;
 		}
 	}
-	if (temp[vreg->fuse_corner_count - 1] != vreg->corner_count) {
-		cpr3_err(vreg, "highest Fmax corner %u in qcom,cpr-corner-fmax-map does not match highest supported corner %d\n",
+	if (temp[vreg->fuse_corner_count - 1] != vreg->corner_count)
+		cpr3_debug(vreg, "Note: highest Fmax corner %u in qcom,cpr-corner-fmax-map does not match highest supported corner %d\n",
 			temp[vreg->fuse_corner_count - 1],
 			vreg->corner_count);
-		rc = -EINVAL;
-		goto free_temp;
-	}
+
 	for (i = 0; i < vreg->corner_count; i++) {
 		for (j = 0; j < vreg->fuse_corner_count; j++) {
 			if (i + CPR3_CORNER_OFFSET <= temp[j]) {
@@ -690,6 +696,14 @@ int cpr3_parse_common_corner_data(struct cpr3_regulator *vreg)
 				break;
 			}
 		}
+		if (j == vreg->fuse_corner_count) {
+			/*
+			 * Handle the case where the highest fuse corner maps
+			 * to a corner below the highest corner.
+			 */
+			vreg->corner[i].cpr_fuse_corner
+				= vreg->fuse_corner_count - 1;
+		}
 	}
 
 	if (of_find_property(vreg->of_node,