regulator: qpnp-lcdb: Add headroom voltage for boost

Increase the boost headroom to 200mV. Also add a device tree
property to make the headroom configurable.

Change-Id: Ibc932f191e64824ba948153a7ae80f109ffcdff9
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>

1 files changed, 53 insertions, 31 deletions

diff --git a/drivers/regulator/qpnp-lcdb-regulator.c b/drivers/regulator/qpnp-lcdb-regulator.c
index 724e8a4c00da..27f2d9851c2a 100644
--- a/drivers/regulator/qpnp-lcdb-regulator.c
+++ b/drivers/regulator/qpnp-lcdb-regulator.c
@@ -147,6 +147,8 @@
 #define MIN_SOFT_START_US		0
 #define MAX_SOFT_START_US		2000
 
+#define BST_HEADROOM_DEFAULT_MV		200
+
 struct ldo_regulator {
 	struct regulator_desc		rdesc;
 	struct regulator_dev		*rdev;
@@ -187,6 +189,7 @@ struct bst_params {
 	int				soft_start_us;
 	int				vreg_ok_dbc_us;
 	int				voltage_mv;
+	u16				headroom_mv;
 };
 
 struct qpnp_lcdb {
@@ -853,28 +856,40 @@ irq_handled:
 #define VOLTAGE_STEP_50_MV			50
 #define VOLTAGE_STEP_50MV_OFFSET		0xA
 static int qpnp_lcdb_set_bst_voltage(struct qpnp_lcdb *lcdb,
-					int voltage_mv)
+					int voltage_mv, u8 type)
 {
 	int rc = 0;
 	u8 val = 0;
+	int bst_voltage_mv;
+	struct ldo_regulator *ldo = &lcdb->ldo;
+	struct ncp_regulator *ncp = &lcdb->ncp;
+	struct bst_params *bst = &lcdb->bst;
+
+	/* Vout_Boost = headroom_mv + max( Vout_LDO, abs (Vout_NCP)) */
+	bst_voltage_mv = max(voltage_mv, max(ldo->voltage_mv, ncp->voltage_mv));
+	bst_voltage_mv += bst->headroom_mv;
+
+	if (bst_voltage_mv < MIN_BST_VOLTAGE_MV)
+		bst_voltage_mv = MIN_BST_VOLTAGE_MV;
+	else if (bst_voltage_mv > MAX_BST_VOLTAGE_MV)
+		bst_voltage_mv = MAX_BST_VOLTAGE_MV;
+
+	if (bst_voltage_mv != bst->voltage_mv) {
+		val = DIV_ROUND_UP(bst_voltage_mv - MIN_BST_VOLTAGE_MV,
+						VOLTAGE_STEP_50_MV);
 
-	if (voltage_mv < MIN_BST_VOLTAGE_MV)
-		voltage_mv = MIN_BST_VOLTAGE_MV;
-	else if (voltage_mv > MAX_BST_VOLTAGE_MV)
-		voltage_mv = MAX_BST_VOLTAGE_MV;
-
-	val = DIV_ROUND_UP(voltage_mv - MIN_BST_VOLTAGE_MV,
-					VOLTAGE_STEP_50_MV);
-
-	rc = qpnp_lcdb_masked_write(lcdb, lcdb->base +
-				LCDB_BST_OUTPUT_VOLTAGE_REG,
-				SET_OUTPUT_VOLTAGE_MASK, val);
-	if (rc < 0)
-		pr_err("Failed to set boost voltage %d mv rc=%d\n",
-			voltage_mv, rc);
-	else
-		pr_debug("Boost voltage set = %d mv (0x%02x = 0x%02x)\n",
-			voltage_mv, LCDB_BST_OUTPUT_VOLTAGE_REG, val);
+		rc = qpnp_lcdb_masked_write(lcdb, lcdb->base +
+					LCDB_BST_OUTPUT_VOLTAGE_REG,
+					SET_OUTPUT_VOLTAGE_MASK, val);
+		if (rc < 0) {
+			pr_err("Failed to set boost voltage %d mv rc=%d\n",
+				bst_voltage_mv, rc);
+		} else {
+			pr_debug("Boost voltage set = %d mv (0x%02x = 0x%02x)\n",
+			      bst_voltage_mv, LCDB_BST_OUTPUT_VOLTAGE_REG, val);
+			bst->voltage_mv = bst_voltage_mv;
+		}
+	}
 
 	return rc;
 }
@@ -905,25 +920,16 @@ static int qpnp_lcdb_set_voltage(struct qpnp_lcdb *lcdb,
 	u16 offset = LCDB_LDO_OUTPUT_VOLTAGE_REG;
 	u8 val = 0;
 
-	if (type == BST)
-		return qpnp_lcdb_set_bst_voltage(lcdb, voltage_mv);
-
-	if (type == NCP)
-		offset = LCDB_NCP_OUTPUT_VOLTAGE_REG;
-
 	if (!is_between(voltage_mv, MIN_VOLTAGE_MV, MAX_VOLTAGE_MV)) {
 		pr_err("Invalid voltage %dmv (min=%d max=%d)\n",
 			voltage_mv, MIN_VOLTAGE_MV, MAX_VOLTAGE_MV);
 		return -EINVAL;
 	}
 
-	/* Change the BST voltage to LDO + 100mV */
-	if (type == LDO) {
-		rc = qpnp_lcdb_set_bst_voltage(lcdb, voltage_mv + 100);
-		if (rc < 0) {
-			pr_err("Failed to set boost voltage rc=%d\n", rc);
-			return rc;
-		}
+	rc = qpnp_lcdb_set_bst_voltage(lcdb, voltage_mv, type);
+	if (rc < 0) {
+		pr_err("Failed to set boost voltage rc=%d\n", rc);
+		return rc;
 	}
 
 	/* Below logic is only valid for LDO and NCP type */
@@ -936,6 +942,9 @@ static int qpnp_lcdb_set_voltage(struct qpnp_lcdb *lcdb,
 		val += VOLTAGE_STEP_50MV_OFFSET;
 	}
 
+	if (type == NCP)
+		offset = LCDB_NCP_OUTPUT_VOLTAGE_REG;
+
 	rc = qpnp_lcdb_masked_write(lcdb, lcdb->base + offset,
 				SET_OUTPUT_VOLTAGE_MASK, val);
 	if (rc < 0)
@@ -1058,6 +1067,8 @@ static int qpnp_lcdb_ldo_regulator_set_voltage(struct regulator_dev *rdev,
 	rc = qpnp_lcdb_set_voltage(lcdb, min_uV / 1000, LDO);
 	if (rc < 0)
 		pr_err("Failed to set LDO voltage rc=%c\n", rc);
+	else
+		lcdb->ldo.voltage_mv = min_uV / 1000;
 
 	return rc;
 }
@@ -1129,6 +1140,8 @@ static int qpnp_lcdb_ncp_regulator_set_voltage(struct regulator_dev *rdev,
 	rc = qpnp_lcdb_set_voltage(lcdb, min_uV / 1000, NCP);
 	if (rc < 0)
 		pr_err("Failed to set LDO voltage rc=%c\n", rc);
+	else
+		lcdb->ncp.voltage_mv = min_uV / 1000;
 
 	return rc;
 }
@@ -1389,6 +1402,12 @@ static int qpnp_lcdb_bst_dt_init(struct qpnp_lcdb *lcdb)
 		return -EINVAL;
 	}
 
+	/* Boost head room configuration */
+	of_property_read_u16(node, "qcom,bst-headroom-mv",
+					&lcdb->bst.headroom_mv);
+	if (lcdb->bst.headroom_mv < BST_HEADROOM_DEFAULT_MV)
+		lcdb->bst.headroom_mv = BST_HEADROOM_DEFAULT_MV;
+
 	return 0;
 }
 
@@ -1695,6 +1714,9 @@ static int qpnp_lcdb_init_bst(struct qpnp_lcdb *lcdb)
 	}
 	lcdb->bst.soft_start_us = (val & SOFT_START_MASK) * 200	+ 200;
 
+	if (!lcdb->bst.headroom_mv)
+		lcdb->bst.headroom_mv = BST_HEADROOM_DEFAULT_MV;
+
 	return 0;
 }