[PATCH 13/15] power: supply: ab8500_charger: Recover inactive AB8505 charger

[Linus Walleij <linusw@kernel.org>]

UsbChCtrl1.UsbChEna can remain set while UsbChStatus1.UsbChOn is
clear. The existing recovery only checks the control bit, so it considers
the charger enabled and leaves charging stopped.

The Samsung-GT-S7710-Skomer, Samsung-SGH-I407-Kyle, and
Samsung-SGH-T599-Codina-TMO product trees are reference points for
checking both bits and cycling the charger when they disagree.

Extend the USB charger check to detect this AB8505 state and enable the
check in the charging algorithm for AB8505. Only cycle the charger when
VBUS is debounced and no charger-not-OK, thermal, overvoltage, or
watchdog fault accounts for the inactive hardware.

Fixes: 4dcdf57773fd ("ab8500-bm: Quick re-attach charging behaviour")
Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 drivers/power/supply/ab8500_chargalg.c |  9 ++----
 drivers/power/supply/ab8500_charger.c  | 51 +++++++++++++++++++++++++++++++++-
 2 files changed, 53 insertions(+), 7 deletions(-)

diff --git a/drivers/power/supply/ab8500_chargalg.c b/drivers/power/supply/ab8500_chargalg.c
index d2b9880b0770..71d82c6c193e 100644
--- a/drivers/power/supply/ab8500_chargalg.c
+++ b/drivers/power/supply/ab8500_chargalg.c
@@ -1241,12 +1241,9 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di)
 
 	charger_status = ab8500_chargalg_check_charger_connection(di);
 
-	if (is_ab8500(di->parent)) {
-		ret = ab8500_chargalg_check_charger_enable(di);
-		if (ret < 0)
-			dev_err(di->dev, "Checking charger is enabled error"
-					": Returned Value %d\n", ret);
-	}
+	ret = ab8500_chargalg_check_charger_enable(di);
+	if (ret < 0)
+		dev_err(di->dev, "Checking charger enable failed: %d\n", ret);
 
 	/*
 	 * First check if we have a charger connected.
diff --git a/drivers/power/supply/ab8500_charger.c b/drivers/power/supply/ab8500_charger.c
index 8430bc247df7..19cc56624ee4 100644
--- a/drivers/power/supply/ab8500_charger.c
+++ b/drivers/power/supply/ab8500_charger.c
@@ -52,6 +52,7 @@
 #define MAIN_CH_DET			0x01
 #define MAIN_CH_CV_ON			0x04
 #define USB_CH_CV_ON			0x08
+#define USB_CH_ON			0x04
 #define VBUS_DET_DBNC_LONG		0x02
 #define VBUS_DET_DBNC1			0x01
 #define OTP_ENABLE_WD			0x01
@@ -1877,6 +1878,9 @@ static int ab8500_charger_usb_check_enable(struct ux500_charger *charger,
 	int vset_uv, int iset_ua)
 {
 	u8 usbch_ctrl1 = 0;
+	u8 usbch_status1;
+	u8 usbch_status2;
+	bool reenable;
 	int ret = 0;
 
 	struct ab8500_charger *di = to_ab8500_charger_usb_device_info(charger);
@@ -1892,7 +1896,52 @@ static int ab8500_charger_usb_check_enable(struct ux500_charger *charger,
 	}
 	dev_dbg(di->dev, "USB charger ctrl: 0x%02x\n", usbch_ctrl1);
 
-	if (!(usbch_ctrl1 & USB_CH_ENA)) {
+	reenable = !(usbch_ctrl1 & USB_CH_ENA);
+	if (is_ab8505(di->parent)) {
+		ret = abx500_get_register_interruptible(di->dev,
+							AB8500_CHARGER,
+							AB8500_CH_USBCH_STAT1_REG,
+							&usbch_status1);
+		if (ret < 0) {
+			dev_err(di->dev, "USB charger status read failed\n");
+			return ret;
+		}
+
+		if (!reenable && (usbch_status1 & USB_CH_ON))
+			return 0;
+
+		if (!(usbch_status1 & VBUS_DET_DBNC_LONG))
+			return 0;
+
+		ret = abx500_get_register_interruptible(di->dev,
+							AB8500_CHARGER,
+							AB8500_CH_USBCH_STAT2_REG,
+							&usbch_status2);
+		if (ret < 0) {
+			dev_err(di->dev, "USB charger fault status read failed\n");
+			return ret;
+		}
+
+		if ((usbch_status2 &
+		     (VBUS_CH_NOK | USB_CH_TH_PROT | VBUS_OVV_TH)) ||
+		    di->flags.usbchargernotok || di->flags.usb_thermal_prot ||
+		    di->flags.vbus_ovv || di->usb.wd_expired)
+			return 0;
+
+		if (!reenable) {
+			dev_info(di->dev,
+				 "USB charger enabled but inactive, cycling it\n");
+			ret = abx500_mask_and_set_register_interruptible(di->dev,
+									 AB8500_CHARGER,
+									 AB8500_USBCH_CTRL1_REG,
+									 USB_CH_ENA, 0);
+			if (ret < 0)
+				return ret;
+			reenable = true;
+		}
+	}
+
+	if (reenable) {
 		dev_info(di->dev, "Charging has been disabled abnormally and will be re-enabled\n");
 
 		ret = abx500_mask_and_set_register_interruptible(di->dev,

-- 
2.55.0