From fe96617b875d6d0d52be41133ae46222e4e85f61 Mon Sep 17 00:00:00 2001
From: Harry Yang <harryy@codeaurora.org>
Date: Fri, 26 Feb 2016 10:08:13 -0800
Subject: [PATCH] power: qpnp-smbcharger: return UNKNOWN in case of no charger
 present

POWER_SUPPLY_TYPE_USB_DCP type is returned in read_usb_type() if no
charger is connected, which might cause APSD to unnecessarily rerun.
To fix it, POWER_SUPPLY_TYPE_UNKNOWN should be returned instead.

A bug is also fixed by returning right after IDEV_STS register
read error in this function .

CRs-fixed: 963745
Change-Id: Ia399e05fe8d0ad13c2f1f272c6737e8798177174
Signed-off-by: Harry Yang <harryy@codeaurora.org>
---
 drivers/power/qpnp-smbcharger.c | 34 ++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/power/qpnp-smbcharger.c b/drivers/power/qpnp-smbcharger.c
index 500838dadaa3..fbb163908c03 100644
--- a/drivers/power/qpnp-smbcharger.c
+++ b/drivers/power/qpnp-smbcharger.c
@@ -845,17 +845,38 @@ static inline enum power_supply_type get_usb_supply_type(int type)
 	return usb_type_enum[type];
 }
 
+static bool is_src_detect_high(struct smbchg_chip *chip)
+{
+	int rc;
+	u8 reg;
+
+	rc = smbchg_read(chip, &reg, chip->usb_chgpth_base + RT_STS, 1);
+	if (rc < 0) {
+		dev_err(chip->dev, "Couldn't read usb rt status rc = %d\n", rc);
+		return false;
+	}
+	return reg &= USBIN_SRC_DET_BIT;
+}
+
 static void read_usb_type(struct smbchg_chip *chip, char **usb_type_name,
 				enum power_supply_type *usb_supply_type)
 {
 	int rc, type;
 	u8 reg;
 
+	if (!is_src_detect_high(chip)) {
+		pr_smb(PR_MISC, "src det low\n");
+		*usb_type_name = "Absent";
+		*usb_supply_type = POWER_SUPPLY_TYPE_UNKNOWN;
+		return;
+	}
+
 	rc = smbchg_read(chip, &reg, chip->misc_base + IDEV_STS, 1);
 	if (rc < 0) {
 		dev_err(chip->dev, "Couldn't read status 5 rc = %d\n", rc);
 		*usb_type_name = "Other";
 		*usb_supply_type = POWER_SUPPLY_TYPE_UNKNOWN;
+		return;
 	}
 	type = get_type(reg);
 	*usb_type_name = get_usb_type_name(type);
@@ -4552,19 +4573,6 @@ static void handle_usb_removal(struct smbchg_chip *chip)
 		restore_from_hvdcp_detection(chip);
 }
 
-static bool is_src_detect_high(struct smbchg_chip *chip)
-{
-	int rc;
-	u8 reg;
-
-	rc = smbchg_read(chip, &reg, chip->usb_chgpth_base + RT_STS, 1);
-	if (rc < 0) {
-		dev_err(chip->dev, "Couldn't read usb rt status rc = %d\n", rc);
-		return false;
-	}
-	return reg &= USBIN_SRC_DET_BIT;
-}
-
 static bool is_usbin_uv_high(struct smbchg_chip *chip)
 {
 	int rc;