qcom-charger: software fix for OTG soft-start

OTG devices with high capacitance could cause a system UVLO
due to a large amount of in-rush current drawn from battery.
Fix this by regulating the OTG boost start and altering PFM
threshold in software.

CRs-Fixed: 1048244
Change-Id: I08838d81eb99a424a3fd396582c56b120cbb46cb
Signed-off-by: Harry Yang <harryy@codeaurora.org>

5 files changed, 100 insertions, 4 deletions

diff --git a/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt b/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt
index 21404dfc4b7b..12ac75a8608c 100644
--- a/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt
+++ b/Documentation/devicetree/bindings/power/qcom-charger/qpnp-smb2.txt
@@ -53,6 +53,12 @@ Charger specific properties:
   Definition: Specifies the USB input current limit in micro-amps.
 		 If the value is not present, 1.5Amps is used as default.
 
+- qcom,usb-ocl-ua
+  Usage:      optional
+  Value type: <u32>
+  Definition: Specifies the OTG output current limit in micro-amps.
+		If the value is not present, 1.5Amps is used as default
+
 - qcom,dc-icl-ua
   Usage:      optional
   Value type: <u32>
diff --git a/drivers/power/qcom-charger/qpnp-smb2.c b/drivers/power/qcom-charger/qpnp-smb2.c
index 1b63f51088ee..ee576d300054 100644
--- a/drivers/power/qcom-charger/qpnp-smb2.c
+++ b/drivers/power/qcom-charger/qpnp-smb2.c
@@ -58,6 +58,13 @@ static struct smb_params v1_params = {
 		.max_u	= 4800000,
 		.step_u	= 25000,
 	},
+	.otg_cl			= {
+		.name	= "usb otg current limit",
+		.reg	= OTG_CURRENT_LIMIT_CFG_REG,
+		.min_u	= 250000,
+		.max_u	= 2000000,
+		.step_u	= 250000,
+	},
 	.dc_icl			= {
 		.name	= "dc input current limit",
 		.reg	= DCIN_CURRENT_LIMIT_CFG_REG,
@@ -202,6 +209,7 @@ struct smb_dt_props {
 	bool	no_battery;
 	int	fcc_ua;
 	int	usb_icl_ua;
+	int	otg_cl_ua;
 	int	dc_icl_ua;
 	int	fv_uv;
 	int	wipower_max_uw;
@@ -226,6 +234,7 @@ module_param_named(
 	pl_master_percent, __pl_master_percent, int, S_IRUSR | S_IWUSR
 );
 
+#define MICRO_1P5A	1500000
 static int smb2_parse_dt(struct smb2 *chip)
 {
 	struct smb_charger *chg = &chip->chg;
@@ -278,6 +287,11 @@ static int smb2_parse_dt(struct smb2 *chip)
 		chip->dt.usb_icl_ua = -EINVAL;
 
 	rc = of_property_read_u32(node,
+				"qcom,otg-cl-ua", &chip->dt.otg_cl_ua);
+	if (rc < 0)
+		chip->dt.otg_cl_ua = MICRO_1P5A;
+
+	rc = of_property_read_u32(node,
 				"qcom,dc-icl-ua", &chip->dt.dc_icl_ua);
 	if (rc < 0)
 		chip->dt.dc_icl_ua = -EINVAL;
@@ -981,6 +995,8 @@ static int smb2_init_hw(struct smb2 *chip)
 		smblib_get_charge_param(chg, &chg->param.dc_icl,
 					&chip->dt.dc_icl_ua);
 
+	chg->otg_cl_ua = chip->dt.otg_cl_ua;
+
 	/* votes must be cast before configuring software control */
 	vote(chg->pl_disable_votable,
 		PL_INDIRECT_VOTER, true, 0);
diff --git a/drivers/power/qcom-charger/smb-lib.c b/drivers/power/qcom-charger/smb-lib.c
index e9c189ae17e7..0067ec5c2ca2 100644
--- a/drivers/power/qcom-charger/smb-lib.c
+++ b/drivers/power/qcom-charger/smb-lib.c
@@ -12,6 +12,7 @@
 
 #include <linux/device.h>
 #include <linux/regmap.h>
+#include <linux/delay.h>
 #include <linux/iio/consumer.h>
 #include <linux/power_supply.h>
 #include <linux/regulator/driver.h>
@@ -642,6 +643,31 @@ suspend:
 	return rc;
 }
 
+#define MICRO_250MA	250000
+static int smblib_otg_cl_config(struct smb_charger *chg, int otg_cl_ua)
+{
+	int rc = 0;
+
+	rc = smblib_set_charge_param(chg, &chg->param.otg_cl, otg_cl_ua);
+	if (rc < 0) {
+		dev_err(chg->dev, "Couldn't set otg current limit rc=%d\n",
+			rc);
+		return rc;
+	}
+
+	/* configure PFM/PWM mode for OTG regulator */
+	rc = smblib_masked_write(chg, DC_ENG_SSUPPLY_CFG3_REG,
+				 ENG_SSUPPLY_CFG_SKIP_TH_V0P2_BIT,
+				 otg_cl_ua > MICRO_250MA ? 1 : 0);
+	if (rc < 0) {
+		dev_err(chg->dev,
+			"Couldn't write DC_ENG_SSUPPLY_CFG3_REG rc=%d\n", rc);
+		return rc;
+	}
+
+	return rc;
+}
+
 static int smblib_dc_icl_vote_callback(struct votable *votable, void *data,
 			int icl_ua, const char *client)
 {
@@ -746,14 +772,36 @@ static int smblib_pl_enable_indirect_vote_callback(struct votable *votable,
  * OTG REGULATOR *
  *****************/
 
+#define OTG_SOFT_START_DELAY_MS	20
 int smblib_vbus_regulator_enable(struct regulator_dev *rdev)
 {
 	struct smb_charger *chg = rdev_get_drvdata(rdev);
+	u8 stat;
 	int rc = 0;
 
-	rc = regmap_write(chg->regmap, CMD_OTG_REG, OTG_EN_BIT);
-	if (rc < 0)
+	rc = smblib_masked_write(chg, OTG_ENG_OTG_CFG_REG,
+				 ENG_BUCKBOOST_HALT1_8_MODE_BIT,
+				 ENG_BUCKBOOST_HALT1_8_MODE_BIT);
+	if (rc < 0) {
+		dev_err(chg->dev, "Couldn't set OTG_ENG_OTG_CFG_REG rc=%d\n",
+			rc);
+		return rc;
+	}
+
+	rc = smblib_write(chg, CMD_OTG_REG, OTG_EN_BIT);
+	if (rc < 0) {
 		dev_err(chg->dev, "Couldn't enable OTG regulator rc=%d\n", rc);
+		return rc;
+	}
+
+	msleep(OTG_SOFT_START_DELAY_MS);
+	rc = smblib_read(chg, OTG_STATUS_REG, &stat);
+	if (rc < 0) {
+		dev_err(chg->dev, "Couldn't read OTG_STATUS_REG rc=%d\n", rc);
+		return rc;
+	}
+	if (stat & BOOST_SOFTSTART_DONE_BIT)
+		smblib_otg_cl_config(chg, chg->otg_cl_ua);
 
 	return rc;
 }
@@ -763,9 +811,22 @@ int smblib_vbus_regulator_disable(struct regulator_dev *rdev)
 	struct smb_charger *chg = rdev_get_drvdata(rdev);
 	int rc = 0;
 
-	rc = regmap_write(chg->regmap, CMD_OTG_REG, 0);
-	if (rc < 0)
+	rc = smblib_write(chg, CMD_OTG_REG, 0);
+	if (rc < 0) {
 		dev_err(chg->dev, "Couldn't disable OTG regulator rc=%d\n", rc);
+		return rc;
+	}
+
+	smblib_otg_cl_config(chg, MICRO_250MA);
+
+	rc = smblib_masked_write(chg, OTG_ENG_OTG_CFG_REG,
+				 ENG_BUCKBOOST_HALT1_8_MODE_BIT, 0);
+	if (rc < 0) {
+		dev_err(chg->dev, "Couldn't set OTG_ENG_OTG_CFG_REG rc=%d\n",
+			rc);
+		return rc;
+	}
+
 
 	return rc;
 }
diff --git a/drivers/power/qcom-charger/smb-lib.h b/drivers/power/qcom-charger/smb-lib.h
index c9732c25dfcd..5b4c2016adc8 100644
--- a/drivers/power/qcom-charger/smb-lib.h
+++ b/drivers/power/qcom-charger/smb-lib.h
@@ -77,6 +77,7 @@ struct smb_params {
 	struct smb_chg_param	fv;
 	struct smb_chg_param	usb_icl;
 	struct smb_chg_param	icl_stat;
+	struct smb_chg_param	otg_cl;
 	struct smb_chg_param	dc_icl;
 	struct smb_chg_param	dc_icl_pt_lv;
 	struct smb_chg_param	dc_icl_pt_hv;
@@ -167,6 +168,8 @@ struct smb_charger {
 	int			thermal_levels;
 	int			*thermal_mitigation;
 
+	int			otg_cl_ua;
+
 	int			fake_capacity;
 
 	bool			step_chg_enabled;
diff --git a/drivers/power/qcom-charger/smb-reg.h b/drivers/power/qcom-charger/smb-reg.h
index c4ad72e254f9..8a49a8fb38ba 100644
--- a/drivers/power/qcom-charger/smb-reg.h
+++ b/drivers/power/qcom-charger/smb-reg.h
@@ -366,6 +366,9 @@ enum {
 #define OTG_EN_SRC_CFG_BIT		BIT(1)
 #define CONCURRENT_MODE_CFG_BIT		BIT(0)
 
+#define OTG_ENG_OTG_CFG_REG		(OTG_BASE + 0xC0)
+#define ENG_BUCKBOOST_HALT1_8_MODE_BIT	BIT(0)
+
 /* BATIF Peripheral Registers */
 /* BATIF Interrupt Bits */
 #define BAT_7_RT_STS_BIT			BIT(7)
@@ -766,6 +769,13 @@ enum {
 	ZIN_ICL_HV_MAX_MV = 11000,
 };
 
+#define DC_ENG_SSUPPLY_CFG3_REG			(DCIN_BASE + 0xC2)
+#define ENG_SSUPPLY_HI_CAP_BIT			BIT(6)
+#define ENG_SSUPPLY_HI_RES_BIT			BIT(5)
+#define ENG_SSUPPLY_CFG_SKIP_TH_V0P2_BIT	BIT(3)
+#define ENG_SSUPPLY_CFG_SYSOV_TH_4P8_BIT	BIT(2)
+#define ENG_SSUPPLY_5V_OV_OPT_BIT		BIT(0)
+
 /* MISC Peripheral Registers */
 #define REVISION1_REG				(MISC_BASE + 0x00)
 #define DIG_MINOR_MASK				GENMASK(7, 0)