driver: wdt: npcx: add WDT_OPT_PAUSE_HALTED_BY_DBG support.

This CL adds WDT_OPT_PAUSE_HALTED_BY_DBG support by enabling freeze mode.

Signed-off-by: Mulin Chao <mlchao@nuvoton.com>

drivers/watchdog/wdt_npcx.c

@@ -39,6 +39,7 @@
 #include <zephyr/logging/log.h>
 
 #include <soc.h>
+#include "soc_dbg.h"
 LOG_MODULE_REGISTER(wdt_npcx, CONFIG_WDT_LOG_LEVEL);
 
 /* Watchdog operating frequency is fixed to LFCLK (32.768) kHz */
@@ -227,9 +228,11 @@ static int wdt_npcx_setup(const struct device *dev, uint8_t options)
 		return -ENOTSUP;
 	}
 
+	/* Stall the WDT counter when halted by debugger */
 	if ((options & WDT_OPT_PAUSE_HALTED_BY_DBG) != 0) {
-		LOG_ERR("WDT_OPT_PAUSE_HALTED_BY_DBG is not supported");
-		return -ENOTSUP;
+		npcx_dbg_freeze_enable(true);
+	} else {
+		npcx_dbg_freeze_enable(false);
 	}
 
 	/*

dts/arm/nuvoton/npcx/npcx.dtsi

@@ -83,10 +83,12 @@
 		scfg: scfg@400c3000 {
 			compatible = "nuvoton,npcx-scfg";
 			/* First reg region is System Configuration Device */
-			/* Second reg region is System Glue Device */
+			/* Second reg region is Debugger Interface Device */
+			/* Third reg region is System Glue Device */
 			reg = <0x400c3000 0x70
+			       0x400c3070 0x30
 			       0x400a5000 0x2000>;
-			reg-names = "scfg", "glue";
+			reg-names = "scfg", "dbg", "glue";
 			#alt-cells = <3>;
 			#lvol-cells = <2>;
 		};

soc/arm/nuvoton_npcx/common/reg/reg_def.h

@@ -158,6 +158,48 @@ static inline uint32_t npcx_pwdwn_ctl_offset(uint32_t ctl_no)
 #define NPCX_ENIDL_CTL_PECI_ENI               2
 #define NPCX_ENIDL_CTL_ADC_ACC_DIS            1
 
+/* Macro functions for Development and Debugger Interface (DDI) registers */
+#define NPCX_DBGCTRL(base)   (*(volatile uint8_t *)(base + 0x004))
+#define NPCX_DBGFRZEN1(base) (*(volatile uint8_t *)(base + 0x006))
+#define NPCX_DBGFRZEN2(base) (*(volatile uint8_t *)(base + 0x007))
+#define NPCX_DBGFRZEN3(base) (*(volatile uint8_t *)(base + 0x008))
+#define NPCX_DBGFRZEN4(base) (*(volatile uint8_t *)(base + 0x009))
+
+/* DDI register fields */
+#define NPCX_DBGCTRL_CCDEV_SEL		FIELD(6, 2)
+#define NPCX_DBGCTRL_CCDEV_DIR		5
+#define NPCX_DBGCTRL_SEQ_WK_EN		4
+#define NPCX_DBGCTRL_FRCLK_SEL_DIS	3
+#define NPCX_DBGFRZEN1_SPIFEN		7
+#define NPCX_DBGFRZEN1_HIFEN		6
+#define NPCX_DBGFRZEN1_ESPISEN		5
+#define NPCX_DBGFRZEN1_UART1FEN		4
+#define NPCX_DBGFRZEN1_SMB3FEN		3
+#define NPCX_DBGFRZEN1_SMB2FEN		2
+#define NPCX_DBGFRZEN1_MFT2FEN		1
+#define NPCX_DBGFRZEN1_MFT1FEN		0
+#define NPCX_DBGFRZEN2_ITIM6FEN		7
+#define NPCX_DBGFRZEN2_ITIM5FEN		6
+#define NPCX_DBGFRZEN2_ITIM4FEN		5
+#define NPCX_DBGFRZEN2_ITIM64FEN	3
+#define NPCX_DBGFRZEN2_SMB1FEN		2
+#define NPCX_DBGFRZEN2_SMB0FEN		1
+#define NPCX_DBGFRZEN2_MFT3FEN		0
+#define NPCX_DBGFRZEN3_GLBL_FRZ_DIS	7
+#define NPCX_DBGFRZEN3_ITIM3FEN		6
+#define NPCX_DBGFRZEN3_ITIM2FEN		5
+#define NPCX_DBGFRZEN3_ITIM1FEN		4
+#define NPCX_DBGFRZEN3_I3CFEN		2
+#define NPCX_DBGFRZEN3_SMB4FEN		1
+#define NPCX_DBGFRZEN3_SHMFEN		0
+#define NPCX_DBGFRZEN4_UART2FEN		6
+#define NPCX_DBGFRZEN4_UART3FEN		5
+#define NPCX_DBGFRZEN4_UART4FEN		4
+#define NPCX_DBGFRZEN4_LCTFEN		3
+#define NPCX_DBGFRZEN4_SMB7FEN		2
+#define NPCX_DBGFRZEN4_SMB6FEN		1
+#define NPCX_DBGFRZEN4_SMB5FEN		0
+
 /*
  * System Configuration (SCFG) device registers
  */

soc/arm/nuvoton_npcx/common/scfg.c

@@ -19,6 +19,7 @@ LOG_MODULE_REGISTER(pimux_npcx, LOG_LEVEL_ERR);
 struct npcx_scfg_config {
 	/* scfg device base address */
 	uintptr_t base_scfg;
+	uintptr_t base_dbg;
 	uintptr_t base_glue;
 };
 
@@ -45,6 +46,7 @@ static const struct npcx_alt def_alts[] = {
 
 static const struct npcx_scfg_config npcx_scfg_cfg = {
 	.base_scfg = DT_REG_ADDR_BY_NAME(DT_NODELABEL(scfg), scfg),
+	.base_dbg = DT_REG_ADDR_BY_NAME(DT_NODELABEL(scfg), dbg),
 	.base_glue = DT_REG_ADDR_BY_NAME(DT_NODELABEL(scfg), glue),
 };
 
@@ -129,6 +131,17 @@ void npcx_host_interface_sel(enum npcx_hif_type hif_type)
 	SET_FIELD(inst_scfg->DEVCNT, NPCX_DEVCNT_HIF_TYP_SEL_FIELD, hif_type);
 }
 
+void npcx_dbg_freeze_enable(bool enable)
+{
+	const uintptr_t dbg_base = npcx_scfg_cfg.base_dbg;
+
+	if (enable) {
+		NPCX_DBGFRZEN3(dbg_base) &= ~BIT(NPCX_DBGFRZEN3_GLBL_FRZ_DIS);
+	} else {
+		NPCX_DBGFRZEN3(dbg_base) |= BIT(NPCX_DBGFRZEN3_GLBL_FRZ_DIS);
+	}
+}
+
 /* Pin-control driver registration */
 static int npcx_scfg_init(void)
 {

soc/arm/nuvoton_npcx/common/soc_dbg.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2023 Nuvoton Technology Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _NUVOTON_NPCX_SOC_DBG_H_
+#define _NUVOTON_NPCX_SOC_DBG_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Configure the Automatic Freeze mode. If this mode is enabled, whenever
+ * the Core is halted, various modules’ clocks, counters are stopped and
+ * destructive reads are disabled, pending the respective module enable bit for
+ * debugging.
+ */
+void npcx_dbg_freeze_enable(bool enable);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _NUVOTON_NPCX_SOC_DBG_H_ */