soc: it8xxx2: Disable EGAD pin output of external gpio control

Setting IT8XXX2_EGPIO_EEPODD bit will disable EGAD pin output driving
to avoid leakage when GPIO E1/E2 on it82002 are set to alternate
function.

Signed-off-by: Tim Lin <[email protected]>
Signed-off-by: Dino Li <[email protected]>

Author: Dino-Li

soc/riscv/ite_ec/common/chip_chipregs.h

@@ -45,6 +45,17 @@
 #define IT8XXX2_GCTRL_BASE      0x00F02000
 #define IT8XXX2_GCTRL_EIDSR     ECREG(IT8XXX2_GCTRL_BASE + 0x31)
 
+/* --- External GPIO Control (EGPIO) --- */
+#define IT8XXX2_EGPIO_BASE      0x00F02100
+#define IT8XXX2_EGPIO_EGCR      ECREG(IT8XXX2_EGPIO_BASE + 0x04)
+
+/* EGPIO register fields */
+/*
+ * 0x04: External GPIO Control
+ * BIT(4): EXGPIO EGAD Pin Output Driving Disable
+ */
+#define IT8XXX2_EGPIO_EEPODD    BIT(4)
+
 /**
  *
  * (11xxh) Interrupt controller (INTC)

soc/riscv/ite_ec/it8xxx2/soc.c

@@ -287,6 +287,11 @@ static int ite_it8xxx2_init(void)
 	IT8XXX2_SMB_SFFCTL &= ~IT8XXX2_SMB_HSAPE;
 #elif CONFIG_SOC_IT8XXX2_REG_SET_V2
 	IT8XXX2_SMB_SCLKTS_BRGS &= ~IT8XXX2_SMB_PREDEN;
+	/*
+	 * Setting this bit will disable EGAD pin output driving to avoid
+	 * leakage when GPIO E1/E2 on it82002 are set to alternate function.
+	 */
+	IT8XXX2_EGPIO_EGCR |= IT8XXX2_EGPIO_EEPODD;
 #endif
 
 #if DT_NODE_HAS_STATUS(DT_NODELABEL(uart1), okay)