linux-kernel - [PATCH v5 06/15] USB: typec: Clear dead battery flag

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Message-Id: <20230917152639.21443-7-alkuor@gmail.com>
Date:   Sun, 17 Sep 2023 11:26:30 -0400
From:   Abdel Alkuor <alkuor@...il.com>
To:     heikki.krogerus@...ux.intel.com, krzysztof.kozlowski+dt@...aro.org,
        bryan.odonoghue@...aro.org
Cc:     gregkh@...uxfoundation.org, robh+dt@...nel.org,
        linux-usb@...r.kernel.org, devicetree@...r.kernel.org,
        conor+dt@...nel.org, linux-kernel@...r.kernel.org,
        abdelalkuor@...tab.com
Subject: [PATCH v5 06/15] USB: typec: Clear dead battery flag

From: Abdel Alkuor <abdelalkuor@...tab.com>

Dead battery flag must be cleared after switching tps25750 to APP mode
so the PD controller becomes fully functional.

Signed-off-by: Abdel Alkuor <abdelalkuor@...tab.com>
---
 drivers/usb/typec/tipd/core.c     | 16 ++++++++++++++++
 drivers/usb/typec/tipd/tps6598x.h |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index b3d4b2b5bf5f..3ad8112c78b6 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -933,6 +933,22 @@ static int tps25750_apply_patch(struct tps6598x *tps)
 
 	} while (mode != TPS_MODE_APP);
 
+	/*
+	 * The dead battery flag may be triggered when the controller
+	 * port is connected to a device that can source power and
+	 * attempts to power up both the controller and the board it is on.
+	 * To restore controller functionality, it is necessary to clear
+	 * this flag
+	 */
+	if (status & TPS_BOOT_STATUS_DEAD_BATTERY_FLAG) {
+		ret = tps6598x_exec_cmd(tps, "DBfg", 0, NULL, 0, NULL, 1000, 0);
+		if (ret) {
+			dev_err(tps->dev,
+				"failed to clear dead battery %d\n", ret);
+			return ret;
+		}
+	}
+
 	dev_info(tps->dev, "controller switched to \"APP\" mode\n");
 
 	return 0;
diff --git a/drivers/usb/typec/tipd/tps6598x.h b/drivers/usb/typec/tipd/tps6598x.h
index 5e942c089c27..362e1eca53ad 100644
--- a/drivers/usb/typec/tipd/tps6598x.h
+++ b/drivers/usb/typec/tipd/tps6598x.h
@@ -200,6 +200,7 @@
 #define TPS_DATA_STATUS_DP_SPEC_PIN_ASSIGNMENT_B    (BIT(2) | BIT(1))
 
 /* BOOT STATUS REG*/
+#define TPS_BOOT_STATUS_DEAD_BATTERY_FLAG	BIT(2)
 #define TPS25750_BOOT_STATUS_I2C_EEPROM_PRESENT	BIT(3)
 
 #endif /* __TPS6598X_H__ */
-- 
2.34.1