arch/arm/stm32h5: Add PM stop and standby support.

Implement PM STANDBY. Loosely based on stm32h7 with
simpler registers.

Implement PM STOP. Using a similar parameter to stm32h7's
LPDS mode bool. There is no LPDS on stm32h5 but there is
the same lower-power voltage scaling value, so rename the parameter
for stm32h5 and use SVOS5 without LPDS present.

Add arm_pminitialize implementation with default
pm subsystem initialization.

Co-authored-by: Austin.Chen <Austin.Chen@wnc.com.tw>
Signed-off-by: Liam Howatt <liamhowatt@geotab.com>

arch/arm/src/stm32h5/Make.defs

@@ -116,6 +116,13 @@ ifeq ($(CONFIG_STM32_PWM),y)
 CHIP_CSRCS += stm32_pwm.c
 endif
 
+ifeq ($(CONFIG_PM),y)
+CHIP_CSRCS += stm32_pmstandby.c stm32_pmstop.c
+ifneq ($(CONFIG_ARCH_CUSTOM_PMINIT),y)
+CHIP_CSRCS += stm32_pminitialize.c
+endif
+endif
+
 ifeq ($(CONFIG_STM32_IWDG),y)
 CHIP_CSRCS += stm32_iwdg.c
 endif

arch/arm/src/stm32h5/stm32_pm.h

@@ -0,0 +1,91 @@
+/****************************************************************************
+ * arch/arm/src/stm32h5/stm32_pm.h
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_STM32H5_STM32_PM_H
+#define __ARCH_ARM_SRC_STM32H5_STM32_PM_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+
+#include "chip.h"
+#include "arm_internal.h"
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: stm32_pmstop
+ *
+ * Description:
+ *   Enter STOP mode.
+ *
+ * Input Parameters:
+ *   svos5 - true: To further reduce power consumption in Stop mode, put the
+ *           internal voltage regulator in "stop mode voltage scaling"
+ *           scale 5 which is the lowest-power stop mode.
+ *           false: Use SVOS3 which is the default voltage scaling value.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void stm32_pmstop(bool svos5);
+
+/****************************************************************************
+ * Name: stm32_pmstandby
+ *
+ * Description:
+ *   Enter STANDBY mode.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void stm32_pmstandby(void);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ARCH_ARM_SRC_STM32H5_STM32_PM_H */

arch/arm/src/stm32h5/stm32_pminitialize.c

@@ -0,0 +1,64 @@
+/****************************************************************************
+ * arch/arm/src/stm32h5/stm32_pminitialize.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/power/pm.h>
+
+#include "arm_internal.h"
+#include "stm32_pm.h"
+
+#ifdef CONFIG_PM
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: arm_pminitialize
+ *
+ * Description:
+ *   This function is called by MCU-specific logic at power-on reset in
+ *   order to provide one-time initialization the power management subsystem.
+ *   This function must be called *very* early in the initialization sequence
+ *   *before* any other device drivers are initialized (since they may
+ *   attempt to register with the power management subsystem).
+ *
+ * Input Parameters:
+ *   None.
+ *
+ * Returned Value:
+ *   None.
+ *
+ ****************************************************************************/
+
+void arm_pminitialize(void)
+{
+  /* Initialize the NuttX power management subsystem proper */
+
+  pm_initialize();
+}
+
+#endif /* CONFIG_PM */

arch/arm/src/stm32h5/stm32_pmstandby.c

@@ -0,0 +1,88 @@
+/****************************************************************************
+ * arch/arm/src/stm32h5/stm32_pmstandby.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+
+#include "arm_internal.h"
+#include "nvic.h"
+#include "stm32_rcc.h"
+#include "stm32_pwr.h"
+#include "stm32_pm.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_pmstandby
+ *
+ * Description:
+ *   Enter STANDBY mode.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void stm32_pmstandby(void)
+{
+  uint32_t regval;
+
+  /* Clear the wake-up flags before resetting. */
+
+  modifyreg32(STM32_PWR_PMCR, 0, PWR_PMCR_CSSF);
+  modifyreg32(STM32_PWR_WUSCR, 0, PWR_WUSCR_CWUF1 | PWR_WUSCR_CWUF2 |
+                                  PWR_WUSCR_CWUF3 | PWR_WUSCR_CWUF4 |
+                                  PWR_WUSCR_CWUF5 | PWR_WUSCR_CWUF6 |
+                                  PWR_WUSCR_CWUF7 | PWR_WUSCR_CWUF8);
+
+  /* Clear reset flags. */
+
+  modifyreg32(STM32_RCC_RSR, 0, RCC_RSR_RMVF);
+
+  /* Set the Low Power Mode to Standby in the Power Mode Control Register.
+   * Unlike H7 which has multiple power domains (D1, D2, D3), H5 uses a
+   * single bit in PMCR to select between Stop and Standby modes.
+   * Setting LPMS bit to 1 selects Standby mode.
+   */
+
+  modifyreg32(STM32_PWR_PMCR, 0, PWR_PMCR_LPMS);
+
+  /* Set SLEEPDEEP bit of Cortex System Control Register */
+
+  regval  = getreg32(NVIC_SYSCON);
+  regval |= NVIC_SYSCON_SLEEPDEEP;
+  putreg32(regval, NVIC_SYSCON);
+
+  /* Sleep until the wakeup reset occurs */
+
+  asm("wfi");
+}

arch/arm/src/stm32h5/stm32_pmstop.c

@@ -0,0 +1,110 @@
+/****************************************************************************
+ * arch/arm/src/stm32h5/stm32_pmstop.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+
+#include "arm_internal.h"
+#include "nvic.h"
+#include "stm32_pwr.h"
+#include "stm32_pm.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_pmstop
+ *
+ * Description:
+ *   Enter STOP mode.
+ *
+ * Input Parameters:
+ *   svos5 - true: To further reduce power consumption in Stop mode, put the
+ *           internal voltage regulator in "stop mode voltage scaling"
+ *           scale 5 which is the lowest-power stop mode.
+ *           false: Use SVOS3 which is the default voltage scaling value.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void stm32_pmstop(bool svos5)
+{
+  uint32_t regval;
+
+  /* Clear the Low Power Mode Selection (LPMS) bit in the power mode control
+   * register to specify Stop mode when entering DeepSleep.
+   */
+
+  regval  = getreg32(STM32_PWR_PMCR);
+  regval &= ~(PWR_PMCR_LPMS | PWR_PMCR_SVOS_MASK);
+
+  /* Set low-power voltage scaling.  */
+
+  if (svos5)
+    {
+      regval |= PWR_PMCR_SVOS_SVOS5;
+    }
+  else
+    {
+      /* Set regulator to normal (S3) mode */
+
+      regval |= PWR_PMCR_SVOS_SVOS3;
+    }
+
+  putreg32(regval, STM32_PWR_PMCR);
+
+  /* Set SLEEPDEEP bit of Cortex System Control Register */
+
+  regval  = getreg32(NVIC_SYSCON);
+  regval |= NVIC_SYSCON_SLEEPDEEP;
+  putreg32(regval, NVIC_SYSCON);
+
+  /* Sleep until the wakeup interrupt or event occurs */
+
+#ifdef CONFIG_PM_WFE
+  /* Mode: SLEEP + Entry with WFE */
+
+  asm volatile ("wfe");
+#else
+  /* Mode: SLEEP + Entry with WFI */
+
+  asm volatile ("wfi");
+#endif
+
+  /* Clear deep sleep bits, so that MCU does not go into deep sleep in
+   * idle.
+   */
+
+  /* Clear SLEEPDEEP bit of Cortex System Control Register */
+
+  regval  = getreg32(NVIC_SYSCON);
+  regval &= ~NVIC_SYSCON_SLEEPDEEP;
+  putreg32(regval, NVIC_SYSCON);
+}