qpnp-smb2: add support to configure charge inhibit

Currently charge inhibit feature is enabled by default and the
charge inhibit threshold is not configurable. Add a device tree
parameter "qcom,chg-inhibit-threshold-mv" through which the
charge inhibit threshold can be configured. If the property is
not specified, then charge inhibit feature is kept disabled.

Change-Id: I464d720abc138e8cd9ba8d7f1704cd91f4408bee
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>

3 files changed, 56 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt b/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt
index 82386ba9b082..7090426c68f8 100644
--- a/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt
+++ b/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt
@@ -129,6 +129,15 @@ Charger specific properties:
 		happen but the adapter won't be asked to switch to a higher
 		voltage point.
 
+- qcom,chg-inhibit-threshold-mv
+  Usage:      optional
+  Value type: <u32>
+  Definition: Charge inhibit threshold in milli-volts. Charging will be
+		inhibited when the battery voltage is within this threshold
+		from Vfloat at charger insertion. If this is not specified
+		then charge inhibit will be disabled by default.
+		Allowed values are: 50, 100, 200, 300.
+
 =============================================
 Second Level Nodes - SMB2 Charger Peripherals
 =============================================
diff --git a/drivers/power/qcom-charger/qpnp-smb2.c b/drivers/power/qcom-charger/qpnp-smb2.c
index f9d76c56aa2e..23a85353e4fd 100644
--- a/drivers/power/qcom-charger/qpnp-smb2.c
+++ b/drivers/power/qcom-charger/qpnp-smb2.c
@@ -225,6 +225,7 @@ struct smb_dt_props {
 	s32	step_cc_delta[STEP_CHARGING_MAX_STEPS];
 	struct	device_node *revid_dev_node;
 	int	float_option;
+	int	chg_inhibit_thr_mv;
 	bool	hvdcp_disable;
 };
 
@@ -335,6 +336,14 @@ static int smb2_parse_dt(struct smb2 *chip)
 	chip->dt.hvdcp_disable = of_property_read_bool(node,
 						"qcom,hvdcp-disable");
 
+	of_property_read_u32(node, "qcom,chg-inhibit-threshold-mv",
+				&chip->dt.chg_inhibit_thr_mv);
+	if ((chip->dt.chg_inhibit_thr_mv < 0 ||
+		chip->dt.chg_inhibit_thr_mv > 300)) {
+		pr_err("qcom,chg-inhibit-threshold-mv is incorrect\n");
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -1213,6 +1222,40 @@ static int smb2_init_hw(struct smb2 *chip)
 		return rc;
 	}
 
+	switch (chip->dt.chg_inhibit_thr_mv) {
+	case 50:
+		rc = smblib_masked_write(chg, CHARGE_INHIBIT_THRESHOLD_CFG_REG,
+				CHARGE_INHIBIT_THRESHOLD_MASK,
+				CHARGE_INHIBIT_THRESHOLD_50MV);
+		break;
+	case 100:
+		rc = smblib_masked_write(chg, CHARGE_INHIBIT_THRESHOLD_CFG_REG,
+				CHARGE_INHIBIT_THRESHOLD_MASK,
+				CHARGE_INHIBIT_THRESHOLD_100MV);
+		break;
+	case 200:
+		rc = smblib_masked_write(chg, CHARGE_INHIBIT_THRESHOLD_CFG_REG,
+				CHARGE_INHIBIT_THRESHOLD_MASK,
+				CHARGE_INHIBIT_THRESHOLD_200MV);
+		break;
+	case 300:
+		rc = smblib_masked_write(chg, CHARGE_INHIBIT_THRESHOLD_CFG_REG,
+				CHARGE_INHIBIT_THRESHOLD_MASK,
+				CHARGE_INHIBIT_THRESHOLD_300MV);
+		break;
+	case 0:
+		rc = smblib_masked_write(chg, CHGR_CFG2_REG,
+				CHARGER_INHIBIT_BIT, 0);
+	default:
+		break;
+	}
+
+	if (rc < 0) {
+		dev_err(chg->dev, "Couldn't configure charge inhibit threshold rc=%d\n",
+			rc);
+		return rc;
+	}
+
 	return rc;
 }
 
diff --git a/drivers/power/qcom-charger/smb-reg.h b/drivers/power/qcom-charger/smb-reg.h
index a74fcf730a8c..2aed4cf294a2 100644
--- a/drivers/power/qcom-charger/smb-reg.h
+++ b/drivers/power/qcom-charger/smb-reg.h
@@ -184,6 +184,10 @@ enum {
 
 #define CHARGE_INHIBIT_THRESHOLD_CFG_REG		(CHGR_BASE + 0x72)
 #define CHARGE_INHIBIT_THRESHOLD_MASK			GENMASK(1, 0)
+#define CHARGE_INHIBIT_THRESHOLD_50MV			0
+#define CHARGE_INHIBIT_THRESHOLD_100MV			1
+#define CHARGE_INHIBIT_THRESHOLD_200MV			2
+#define CHARGE_INHIBIT_THRESHOLD_300MV			3
 
 #define RECHARGE_THRESHOLD_CFG_REG			(CHGR_BASE + 0x73)
 #define RECHARGE_THRESHOLD_MASK				GENMASK(1, 0)