soc : realtek: ec: rts5912: add support ULPM

Port rts5912 ULPM on Zephyr

Signed-off-by: Titan Chen <titan.chen@realtek.com>

dts/arm/realtek/ec/rts5912.dtsi

@@ -372,6 +372,45 @@
 			     &jtag_clk_gpio90 &jtag_tms_gpio91>;
 		pinctrl-names = "default";
 	};
+
+	ulpm: ulpm {
+		compatible = "realtek,rts5912-ulpm";
+		wkup-pins-max = <6>; /* 6 system wake-up pins */
+		status = "disabled";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		wkup-pin@0 {
+			reg = <0x0>;
+			wkup-pin-mode = "gpio";
+		};
+
+		wkup-pin@1 {
+			reg = <0x1>;
+			wkup-pin-mode = "gpio";
+		};
+
+		wkup-pin@2 {
+			reg = <0x2>;
+			wkup-pin-mode = "gpio";
+		};
+
+		wkup-pin@3 {
+			reg = <0x3>;
+			wkup-pin-mode = "gpio";
+		};
+
+		wkup-pin@4 {
+			reg = <0x4>;
+			wkup-pin-mode = "gpio";
+		};
+
+		wkup-pin@5 {
+			reg = <0x5>;
+			wkup-pin-mode = "gpio";
+		};
+	};
 };
 
 &nvic {

dts/bindings/power/realtek,rts5912-ulpm.yaml

@@ -0,0 +1,45 @@
+# Copyright (c) 2025 Realtek Semiconductor Corporation, SIBG-SD7
+# SPDX-License-Identifier: Apache-2.0
+
+description: RTS5912 ULPM power controller
+
+compatible: "realtek,rts5912-ulpm"
+
+include: base.yaml
+
+properties:
+  wkup-pins-max:
+    type: int
+    description: |
+      Max nbr of system wake-up pins.
+      For example wkup-pins-nb = <5>; on the rts5912
+
+child-binding:
+  description: |
+    RTS5912 wake-up pin node.
+
+    All nodes using this binding must be named "wkup-pin@[index]"
+    index starts from 0
+
+  properties:
+    reg:
+      type: array
+      required: true
+      description: Wake-up pin identifier, same as "index" in node name
+
+    wkup-pin-pol:
+      type: string
+      default: rising
+      description: indicates a wakeup polarity
+      enum:
+        - rising
+        - falling
+
+    wkup-pin-mode:
+      type: string
+      default: vin
+      required: true
+      description: indicates a wakeup pin mode selection
+      enum:
+        - vin
+        - gpio

soc/realtek/ec/rts5912/CMakeLists.txt

@@ -13,5 +13,7 @@ zephyr_sources_ifdef(CONFIG_PM
   )
 
 zephyr_sources_ifdef(CONFIG_RTS5912_DEBUG_SWJ debug_swj.c)
+zephyr_sources_ifdef(CONFIG_POWEROFF poweroff.c)
+zephyr_sources_ifdef(CONFIG_SOC_RTS5912_ULPM rts5912_ulpm.c)
 
 set(SOC_LINKER_SCRIPT ${ZEPHYR_BASE}/include/zephyr/arch/arm/cortex_m/scripts/linker.ld CACHE INTERNAL "")

soc/realtek/ec/rts5912/Kconfig

@@ -29,4 +29,12 @@ config RTS5912_DEBUG_SWJ
 	help
 	  Enables the serial wire JTAG connection on the RTS5912 EC.
 
+config SOC_RTS5912_ULPM
+	bool "Realtek RTS5912 ULPM (Ultra Low Power Mode)"
+	default y
+	depends on DT_HAS_REALTEK_RTS5912_ULPM_ENABLED
+	select HAS_POWEROFF
+	help
+	  Enable support for RTS5912 ULPM PWR wake-up pins.
+
 endif # SOC_SERIES_RTS5912

soc/realtek/ec/rts5912/poweroff.c

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2025 Realtek Semiconductor Corporation, SIBG-SD7
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/sys/poweroff.h>
+#include <zephyr/toolchain.h>
+#include "rts5912_ulpm.h"
+
+void z_sys_poweroff(void)
+{
+	if (IS_ENABLED(CONFIG_SOC_RTS5912_ULPM)) {
+		rts5912_ulpm_enable();
+
+		/* Spin and wait for ULPM */
+		while (1) {
+			;
+		}
+		CODE_UNREACHABLE;
+	}
+}

soc/realtek/ec/rts5912/reg/reg_system.h

@@ -294,8 +294,8 @@ typedef struct {
 #define SYSTEM_VIVOCTRL_VIN2POL_Msk          BIT(SYSTEM_VIVOCTRL_VIN2POL_Pos)
 #define SYSTEM_VIVOCTRL_VIN3POL_Pos          (15UL)
 #define SYSTEM_VIVOCTRL_VIN3POL_Msk          BIT(SYSTEM_VIVOCTRL_VIN3POL_Pos)
-#define SYSTEM_VIVOCTRL_VIN4POL_Pos          (16UL)
-#define SYSTEM_VIVOCTRL_VIN4POL_Msk          BIT(SYSTEM_VIVOCTRL_VIN4POL_Pos)
+#define SYSTEM_VIVOCTRL_VODEF_Pos            (16UL)
+#define SYSTEM_VIVOCTRL_VODEF_Msk            BIT(SYSTEM_VIVOCTRL_VODEF_Pos)
 #define SYSTEM_VIVOCTRL_VIN5POL_Pos          (17UL)
 #define SYSTEM_VIVOCTRL_VIN5POL_Msk          BIT(SYSTEM_VIVOCTRL_VIN5POL_Pos)
 #define SYSTEM_VIVOCTRL_REGWREN_Pos          (30UL)
@@ -332,4 +332,6 @@ typedef struct {
 #define SYSTEM_PERICLKPWR2_RC32KSRC_Pos      (30UL)
 #define SYSTEM_PERICLKPWR2_RC32KSRC_Msk      GENMASK(31, 30)
 
+#define RTS5912_SCCON_REG_BASE ((SYSTEM_Type *)(DT_REG_ADDR(DT_NODELABEL(sccon))))
+
 #endif /* ZEPHYR_SOC_REALTEK_RTS5912_REG_SYSTEM_H */

soc/realtek/ec/rts5912/rts5912_ulpm.c

@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2025 Realtek Semiconductor Corporation, SIBG-SD7
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/devicetree.h>
+
+#include "rts5912_ulpm.h"
+#include "reg/reg_system.h"
+#include "reg/reg_gpio.h"
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_REGISTER(ulpm, CONFIG_SOC_LOG_LEVEL);
+
+#define DT_DRV_COMPAT realtek_rts5912_ulpm
+
+BUILD_ASSERT(DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) <= 1, "Unsupported number of instances");
+
+#define RTS5912_ULPM_NODE DT_DRV_INST(0)
+
+#define ULPM_RTS5912_MAX_NB_WKUP_PINS DT_INST_PROP(0, wkup_pins_max)
+
+/** @cond INTERNAL_HIDDEN */
+
+/**
+ * @brief flags for wake-up pin polarity configuration
+ * @{
+ */
+enum wkup_pin_mode {
+	RTS5912_ULPM_WKUP_PIN_MODE_VIN = 0,
+	RTS5912_ULPM_WKUP_PIN_MODE_GPIO = 1,
+};
+
+enum wkup_pin_pol {
+	/* detection of wake-up event on the high level : rising edge */
+	RTS5912_ULPM_WKUP_PIN_POL_RISING = 0,
+	/* detection of wake-up event on the low level : falling edge */
+	RTS5912_ULPM_WKUP_PIN_POL_FALLING = 1,
+};
+/** @} */
+
+/**
+ * @brief Structure for storing the devicetree configuration of a wake-up pin.
+ */
+struct wkup_pin_dt_cfg_t {
+	/* starts from 0 */
+	uint32_t wkup_pin_id;
+	/* wake up polarity */
+	enum wkup_pin_pol pin_pol;
+	/* wake up pin mode, VIN / GPIO */
+	enum wkup_pin_mode pin_mode;
+};
+
+/**
+ * @brief Get wake-up pin configuration from a given devicetree node.
+ *
+ * This returns a static initializer for a <tt>struct wkup_pin_dt_cfg_t</tt>
+ * filled with data from a given devicetree node.
+ *
+ * @param node_id Devicetree node identifier.
+ *
+ * @return Static initializer for a wkup_pin_dt_cfg_t structure.
+ */
+#define WKUP_PIN_CFG_DT(node_id)                                                                   \
+	{                                                                                          \
+		.wkup_pin_id = DT_REG_ADDR(node_id),                                               \
+		.pin_pol = (uint8_t)DT_ENUM_IDX(node_id, wkup_pin_pol),                            \
+		.pin_mode = (uint8_t)DT_ENUM_IDX(node_id, wkup_pin_mode),                          \
+	}
+
+/* wkup_pin idx starts from 0 */
+#define WKUP_PIN_CFG_DT_COMMA(wkup_pin_id) WKUP_PIN_CFG_DT(wkup_pin_id),
+
+/** @endcond */
+
+static struct wkup_pin_dt_cfg_t wkup_pins_cfgs[] = {
+	DT_INST_FOREACH_CHILD(0, WKUP_PIN_CFG_DT_COMMA)};
+
+#define WKUP_PIN_SIZE ARRAY_SIZE(wkup_pins_cfgs)
+/**
+ * @brief Enable VOUT function and set the VOUT default value.
+ */
+void ulpm_start(void)
+{
+	SYSTEM_Type *sys_reg = RTS5912_SCCON_REG_BASE;
+	/* enable VOUT */
+	sys_reg->VIVOCTRL &= ~(SYSTEM_VIVOCTRL_VOUTMD_Msk);
+	k_msleep(10);
+	/* Set the VOUT to low */
+	sys_reg->VIVOCTRL &= ~(SYSTEM_VIVOCTRL_VODEF_Msk);
+	k_msleep(10);
+	/* update to ULPM */
+	sys_reg->VIVOCTRL |= SYSTEM_VIVOCTRL_REGWREN_Msk;
+	k_msleep(10);
+}
+/**
+ * @brief Update register value to ULPM IP
+ */
+void update_vivo_register(void)
+{
+	SYSTEM_Type *sys_reg = RTS5912_SCCON_REG_BASE;
+	/* Update Register & reset bit */
+	k_msleep(10);
+	sys_reg->VIVOCTRL |= SYSTEM_VIVOCTRL_REGWREN_Msk;
+	k_msleep(10);
+	sys_reg->VIVOCTRL &= ~(SYSTEM_VIVOCTRL_REGWREN_Msk);
+	k_msleep(10);
+}
+
+/**
+ * @brief Configure & enable a wake-up pin.
+ *
+ * @param wakeup_pin_cfg wake-up pin runtime configuration.
+ *
+ */
+void rts5912_ulpm_enable(void)
+{
+	SYSTEM_Type *sys_reg = RTS5912_SCCON_REG_BASE;
+	int i, id;
+
+	LOG_INF("rts5912 ULPM enabled\n");
+	/* VoutEnable, Keep VOUT output default value as bit 16 */
+	sys_reg->VIVOCTRL |= SYSTEM_VIVOCTRL_VODEF_Msk;
+	k_msleep(10);
+
+	/* set to GPIO mode to clear status and aviod mis-trigger */
+	sys_reg->VIVOCTRL |= (SYSTEM_VIVOCTRL_VIN0MD_Msk | SYSTEM_VIVOCTRL_VIN1MD_Msk |
+			      SYSTEM_VIVOCTRL_VIN2MD_Msk | SYSTEM_VIVOCTRL_VIN3MD_Msk |
+			      SYSTEM_VIVOCTRL_VIN4MD_Msk | SYSTEM_VIVOCTRL_VIN5MD_Msk);
+
+	/* Update Status Bit to ULPM IP */
+	update_vivo_register();
+	/* Configure Mode (VIN/GPIO) and Edge (Falling/Rising) */
+	for (i = 0; i < WKUP_PIN_SIZE; i++) {
+		id = wkup_pins_cfgs[i].wkup_pin_id;
+		/* corner case test */
+		if ((id < 0) || (id >= ULPM_RTS5912_MAX_NB_WKUP_PINS)) {
+			continue;
+		}
+
+		/* Configure Mode */
+		if (wkup_pins_cfgs[i].pin_mode == RTS5912_ULPM_WKUP_PIN_MODE_VIN) {
+			LOG_DBG("setup VIN%d in ", id);
+			/* Configure Polarity */
+			if (wkup_pins_cfgs[i].pin_pol == RTS5912_ULPM_WKUP_PIN_POL_RISING) {
+				/* Falling Edge */
+				sys_reg->VIVOCTRL |= BIT(SYSTEM_VIVOCTRL_VIN0POL_Pos + id);
+				LOG_DBG("Falling Edge\n");
+			} else {
+				/* Rising Edge */
+				sys_reg->VIVOCTRL &= ~BIT(SYSTEM_VIVOCTRL_VIN0POL_Pos + id);
+				LOG_DBG("Rising Edge\n");
+			}
+			/* VIN Mode */
+			sys_reg->VIVOCTRL &= ~BIT(SYSTEM_VIVOCTRL_VIN0MD_Pos + id);
+		}
+	}
+
+	/* Update Status Bit to ULPM IP */
+	update_vivo_register();
+
+	/* Disable LDO 2 power. */
+	sys_reg->LDOCTRL &= ~(SYSTEM_LDOCTRL_LDO2EN_Msk);
+
+	/* ULPM Start */
+	ulpm_start();
+}

soc/realtek/ec/rts5912/rts5912_ulpm.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2025 Realtek Semiconductor Corporation, SIBG-SD7
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_SOC_REALTEK_RTS5912_ULPM_H_
+#define ZEPHYR_SOC_REALTEK_RTS5912_ULPM_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void rts5912_ulpm_enable(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZEPHYR_SOC_REALTEK_RTS5912_ULPM_H_ */