soc: st: stm32: stm32wbax pm enhancements

Power management enhancements to support suspend to ram
with BLE activity.
ST system clock module is no more used.
Draft commit still to be refined.

Signed-off-by: Alessandro Manganaro <[email protected]>

Author: asm5878

boards/st/nucleo_wba55cg/nucleo_wba55cg.dts

@@ -100,7 +100,6 @@
 
 &clk_hse {
 	status = "okay";
-	hse-div2;
 };
 
 &clk_hsi {
@@ -109,9 +108,9 @@
 
 &rcc {
 	clocks = <&clk_hse>;
-	clock-frequency = <DT_FREQ_M(16)>;
+	clock-frequency = <DT_FREQ_M(32)>;
 	ahb-prescaler = <1>;
-	ahb5-prescaler = <2>;
+	ahb5-prescaler = <1>;
 	apb1-prescaler = <1>;
 	apb2-prescaler = <2>;
 	apb7-prescaler = <1>;

boards/st/nucleo_wba65ri/nucleo_wba65ri.dts

@@ -79,12 +79,15 @@
 	};
 };
 
+&clk_lsi {
+	status = "okay";
+};
+
 &clk_lse {
 	status = "okay";
 };
 
 &clk_hse {
-	hse-div2;
 	status = "okay";
 };
 
@@ -94,9 +97,9 @@
 
 &rcc {
 	clocks = <&clk_hse>;
-	clock-frequency = <DT_FREQ_M(16)>;
+	clock-frequency = <DT_FREQ_M(32)>;
 	ahb-prescaler = <1>;
-	ahb5-prescaler = <2>;
+	ahb5-prescaler = <1>;
 	apb1-prescaler = <1>;
 	apb2-prescaler = <2>;
 	apb7-prescaler = <1>;

drivers/bluetooth/hci/hci_stm32wba.c

@@ -13,6 +13,12 @@
 #include <zephyr/drivers/bluetooth.h>
 #include <zephyr/bluetooth/addr.h>
 #include <zephyr/drivers/clock_control/stm32_clock_control.h>
+#include <zephyr/pm/policy.h>
+#include <zephyr/pm/device.h>
+#include <zephyr/pm/pm.h>
+#ifdef CONFIG_PM_DEVICE
+#include "linklayer_plat.h"
+#endif
 #include <linklayer_plat_local.h>
 
 #include <zephyr/sys/byteorder.h>
@@ -454,6 +460,53 @@ static int bt_hci_stm32wba_setup(const struct device *dev,
 }
 #endif /* CONFIG_BT_HCI_SETUP */
 
+#ifdef CONFIG_PM_DEVICE
+static int radio_pm_action(const struct device *dev, enum pm_device_action action)
+{
+	switch (action) {
+	case PM_DEVICE_ACTION_RESUME:
+		LL_AHB5_GRP1_EnableClock(LL_AHB5_GRP1_PERIPH_RADIO);
+#if defined(CONFIG_PM_S2RAM)
+		if (LL_PWR_IsActiveFlag_SB() == 1U) {
+			/* Put the radio in active state */
+			link_layer_register_isr();
+		}
+#endif
+		LINKLAYER_PLAT_NotifyWFIExit();
+		ll_sys_dp_slp_exit();
+		break;
+	case PM_DEVICE_ACTION_SUSPEND:
+#if defined(CONFIG_PM_S2RAM)
+		uint32_t radio_remaining_time = 0;
+		enum pm_state state = pm_state_next_get(_current_cpu->id)->state;
+
+		if (state == PM_STATE_SUSPEND_TO_RAM) {
+			/* */
+			uint32_t cmd_status =
+				ll_intf_le_get_remaining_time_for_next_event(&radio_remaining_time);
+			UNUSED(cmd_status);
+			assert_param(cmd_status == SUCCESS);
+
+			if (radio_remaining_time == LL_DP_SLP_NO_WAKEUP) {
+				/* No next radio event scheduled */
+				(void)ll_sys_dp_slp_enter(LL_DP_SLP_NO_WAKEUP);
+			} else /* if (radio_remaining_time > RADIO_DEEPSLEEP_WAKEUP_TIME_US) */ {
+				/* No event in a "near" futur */
+				(void)ll_sys_dp_slp_enter(radio_remaining_time -
+							  CFG_LPM_STDBY_WAKEUP_TIME);
+			}
+		}
+#endif
+		LINKLAYER_PLAT_NotifyWFIEnter();
+		break;
+	default:
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PM_DEVICE */
+
 static DEVICE_API(bt_hci, drv) = {
 #if defined(CONFIG_BT_HCI_SETUP)
 	.setup          = bt_hci_stm32wba_setup,
@@ -463,10 +516,11 @@ static DEVICE_API(bt_hci, drv) = {
 };
 
 #define HCI_DEVICE_INIT(inst) \
-	static struct hci_data hci_data_##inst = { \
-	}; \
-	DEVICE_DT_INST_DEFINE(inst, NULL, NULL, &hci_data_##inst, NULL, \
-			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &drv)
+	static struct hci_data hci_data_##inst = {}; \
+	PM_DEVICE_DT_INST_DEFINE(inst, radio_pm_action); \
+	DEVICE_DT_INST_DEFINE(inst, NULL, PM_DEVICE_DT_INST_GET(inst), &hci_data_##inst, NULL, \
+			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &drv);
 
 /* Only one instance supported */
 HCI_DEVICE_INIT(0)
+

samples/bluetooth/peripheral_hr/boards/nucleo_wba55cg.overlay

@@ -0,0 +1,29 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2023 STMicroelectronics
+ */
+
+/ {
+	/* Change min residency time to ease power consumption measurement */
+	cpus {
+		cpu0: cpu@0 {
+			cpu-power-states = <&stop0 &stop1 &standby>;
+		};
+
+		power-states {
+			standby: state2 {
+				compatible = "zephyr,power-state";
+				power-state-name = "suspend-to-ram";
+				substate-id = <1>;
+				min-residency-us = <10000>;
+				exit-latency-us = <1000>;
+			};
+		};
+	};
+
+};
+
+&lptim1 {
+	status = "okay";
+};

samples/bluetooth/peripheral_hr/boards/nucleo_wba65ri.overlay

@@ -0,0 +1,28 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2023 STMicroelectronics
+ */
+
+/ {
+	/* Change min residency time to ease power consumption measurement */
+	cpus {
+		cpu0: cpu@0 {
+			cpu-power-states = <&stop0 &stop1 &standby>;
+		};
+
+		power-states {
+			standby: state2 {
+				compatible = "zephyr,power-state";
+				power-state-name = "suspend-to-ram";
+				substate-id = <1>;
+				min-residency-us = <10000>;
+				exit-latency-us = <1000>;
+			};
+		};
+	};
+};
+
+&lptim1 {
+	status = "okay";
+};

samples/bluetooth/peripheral_hr/prj.conf

@@ -8,3 +8,9 @@ CONFIG_BT_BAS=y
 CONFIG_BT_HRS=y
 CONFIG_BT_DEVICE_NAME="Zephyr Heartrate Sensor"
 CONFIG_BT_DEVICE_APPEARANCE=833
+
+CONFIG_PM=y
+CONFIG_PM_DEVICE=y
+CONFIG_PM_DEVICE_RUNTIME=y
+CONFIG_PM_DEVICE_SYSTEM_MANAGED=y
+CONFIG_PM_S2RAM=y

soc/st/stm32/stm32wbax/hci_if/linklayer_plat_adapt.c

@@ -10,7 +10,8 @@
 
 #include <stm32_backup_domain.h>
 
-#include "scm.h"
+#include "app_conf.h"
+#include "bsp.h"
 
 #define LOG_LEVEL CONFIG_SOC_LOG_LEVEL
 LOG_MODULE_REGISTER(linklayer_plat_adapt);
@@ -245,17 +246,13 @@ void LINKLAYER_PLAT_StartRadioEvt(void)
 	__HAL_RCC_RADIO_CLK_SLEEP_ENABLE();
 
 	NVIC_SetPriority((IRQn_Type)RADIO_INTR_NUM, RADIO_INTR_PRIO_HIGH_Z);
-
-	scm_notifyradiostate(SCM_RADIO_ACTIVE);
 }
 
 void LINKLAYER_PLAT_StopRadioEvt(void)
 {
 	__HAL_RCC_RADIO_CLK_SLEEP_DISABLE();
 
 	NVIC_SetPriority((IRQn_Type)RADIO_INTR_NUM, RADIO_INTR_PRIO_LOW_Z);
-
-	scm_notifyradiostate(SCM_RADIO_NOT_ACTIVE);
 }
 
 /* Link Layer notification for RCO calibration start */