atsam: Add ATSAM_POWER_WAIT_MODE

bsps/arm/atsam/include/bsp/power.h

@@ -179,9 +179,6 @@ void atsam_power_handler_rtc_driver(
 /**
  * @brief Power handler to enter the processor sleep mode.
  *
- * For the power off state, the processor is set into the sleep mode and issues
- * a wait for interrupt instruction.
- *
  * @see ATSAM_POWER_SLEEP_MODE().
  */
 void atsam_power_handler_sleep_mode(
@@ -189,6 +186,18 @@ void atsam_power_handler_sleep_mode(
   atsam_power_state state
 );
 
+/**
+ * @brief Power handler to enter the processor wait mode.
+ *
+ * The internal flash is put into deep sleep mode.
+ *
+ * @see ATSAM_POWER_WAIT_MODE().
+ */
+void atsam_power_handler_wait_mode(
+  const atsam_power_control *controls,
+  atsam_power_state state
+);
+
 /**
  * @brief Initializer for a peripheral power support.
  *
@@ -213,6 +222,9 @@ void atsam_power_handler_sleep_mode(
 #define ATSAM_POWER_SLEEP_MODE \
  { .handler = atsam_power_handler_sleep_mode }
 
+#define ATSAM_POWER_WAIT_MODE \
+ { .handler = atsam_power_handler_wait_mode }
+
 /**
  * @brief Data for RTC driver power support.
  *

bsps/arm/atsam/start/power-wait.c

@@ -0,0 +1,195 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (C) 2019 embedded brains GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <bsp/power.h>
+#include <bsp/linker-symbols.h>
+
+#include <libchip/chip.h>
+
+BSP_FAST_TEXT_SECTION static void
+pmc_wait_for_master_clock_ready(volatile Pmc *pmc)
+{
+  while ((pmc->PMC_SR & PMC_SR_MCKRDY) == 0) {
+    /* Wait */
+  }
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_set_master_clock_source(volatile Pmc *pmc, uint32_t mckr)
+{
+  pmc->PMC_MCKR =
+    (pmc->PMC_MCKR & ~PMC_MCKR_CSS_Msk) | (mckr & PMC_MCKR_CSS_Msk);
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_set_master_clock_prescaler(volatile Pmc *pmc, uint32_t mckr)
+{
+  pmc->PMC_MCKR =
+    (pmc->PMC_MCKR & ~PMC_MCKR_PRES_Msk) | (mckr & PMC_MCKR_PRES_Msk);
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_set_master_clock_division(volatile Pmc *pmc, uint32_t mckr)
+{
+  pmc->PMC_MCKR =
+    (pmc->PMC_MCKR & ~PMC_MCKR_MDIV_Msk) | (mckr & PMC_MCKR_MDIV_Msk);
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_wait_for_main_rc_osc(volatile Pmc *pmc)
+{
+  while ((pmc->PMC_SR & PMC_SR_MOSCRCS) == 0) {
+    /* Wait */
+  }
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_wait_for_main_osc_selection(volatile Pmc *pmc)
+{
+  while ((pmc->PMC_SR & PMC_SR_MOSCSELS) == 0) {
+    /* Wait */
+  }
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_use_main_rc_osc_4mhz(volatile Pmc *pmc)
+{
+  uint32_t ckgr_mor;
+
+  ckgr_mor = pmc->CKGR_MOR;
+  ckgr_mor |= CKGR_MOR_KEY_PASSWD;
+
+  /* Enable main RC oscillator */
+  ckgr_mor |= CKGR_MOR_MOSCRCEN;
+  PMC->CKGR_MOR = ckgr_mor;
+  pmc_wait_for_main_rc_osc(pmc);
+
+  /* Set main RC oscillator frequency to 4MHz */
+  ckgr_mor &= ~CKGR_MOR_MOSCRCF_Msk;
+  ckgr_mor |= CKGR_MOR_MOSCRCF_4_MHz;
+  pmc->CKGR_MOR = ckgr_mor;
+  pmc_wait_for_main_rc_osc(pmc);
+
+  /* Switch to main RC oscillator */
+  ckgr_mor &= ~CKGR_MOR_MOSCSEL;
+  pmc->CKGR_MOR = ckgr_mor;
+  pmc_wait_for_main_osc_selection(pmc);
+  pmc_wait_for_master_clock_ready(pmc);
+}
+
+BSP_FAST_TEXT_SECTION static void
+pmc_use_main_ext_osc(volatile Pmc *pmc)
+{
+  uint32_t ckgr_mor;
+
+  ckgr_mor = pmc->CKGR_MOR;
+  ckgr_mor |= CKGR_MOR_KEY_PASSWD;
+
+  /* Enable main external oscillator */
+  ckgr_mor |= CKGR_MOR_MOSCRCF_12_MHz | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCRCEN |
+    CKGR_MOR_MOSCXTST(DEFAUTL_MAIN_OSC_COUNT);
+  PMC->CKGR_MOR = ckgr_mor;
+  pmc_wait_for_main_rc_osc(pmc);
+  pmc_wait_for_master_clock_ready(pmc);
+
+  /* Switch to main external oscillator */
+  ckgr_mor |= CKGR_MOR_MOSCSEL;
+  pmc->CKGR_MOR = ckgr_mor;
+  pmc_wait_for_main_osc_selection(pmc);
+  pmc_wait_for_master_clock_ready(pmc);
+}
+
+BSP_FAST_TEXT_SECTION void
+atsam_power_handler_wait_mode(
+  const atsam_power_control *control,
+  atsam_power_state state
+)
+{
+  rtems_interrupt_level level;
+  volatile Pmc *pmc;
+  uint32_t mckr;
+  uint32_t fmr;
+  uint32_t fsmr;
+
+  (void) control;
+  pmc = PMC;
+
+  switch (state) {
+    case ATSAM_POWER_OFF:
+      rtems_interrupt_disable(level);
+
+      mckr = pmc->PMC_MCKR;
+
+      /* Switch main clock to main RC oscillator (4MHz) */
+      pmc_use_main_rc_osc_4mhz(pmc);
+      pmc_set_master_clock_source(pmc, PMC_MCKR_CSS_MAIN_CLK);
+      pmc_wait_for_master_clock_ready(pmc);
+      pmc_set_master_clock_prescaler(pmc, PMC_MCKR_PRES_CLK_1);
+      pmc_wait_for_master_clock_ready(pmc);
+      pmc_set_master_clock_division(pmc, PMC_MCKR_MDIV_EQ_PCK);
+      pmc_wait_for_master_clock_ready(pmc);
+
+      /* Set flash wait state to 0 */
+      fmr = EFC->EEFC_FMR;
+      EFC->EEFC_FMR = EEFC_FMR_FWS(0);
+
+      /* Enter wait mode */
+      fsmr = pmc->PMC_FSMR;
+      pmc->PMC_FSMR = fsmr | PMC_FSMR_LPM;
+      pmc->CKGR_MOR = CKGR_MOR_KEY_PASSWD | CKGR_MOR_WAITMODE;
+      pmc_wait_for_master_clock_ready(pmc);
+      __asm__ volatile ( "wfe" : : : "memory" );
+      pmc->PMC_FSMR = fsmr;
+
+      /* Restore main clock */
+      pmc_set_master_clock_prescaler(pmc, mckr);
+      pmc_wait_for_master_clock_ready(pmc);
+      pmc_set_master_clock_division(pmc, mckr);
+      pmc_wait_for_master_clock_ready(pmc);
+      pmc_set_master_clock_source(pmc, mckr);
+      pmc_wait_for_master_clock_ready(pmc);
+      pmc_use_main_ext_osc(pmc);
+
+      /* Restore flash wait state */
+      EFC->EEFC_FMR = fmr;
+
+      rtems_interrupt_enable(level);
+      break;
+    case ATSAM_POWER_INIT:
+      rtems_interrupt_disable(level);
+
+      pmc->PMC_FSMR = (pmc->PMC_FSMR & ~PMC_FSMR_FLPM_Msk)
+        | PMC_FSMR_FLPM(PMC_FSMR_FLPM_FLASH_DEEP_POWERDOWN);
+
+      /*  No Cortex-M7 Deep Sleep mode (Backup Mode) */
+      SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;
+
+      rtems_interrupt_enable(level);
+    default:
+      break;
+  }
+}

c/src/lib/libbsp/arm/atsam/Makefile.am

@@ -100,6 +100,7 @@ librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/pin-config.c
 librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/pmc-config.c
 librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/power-clock.c
 librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/power-rtc.c
+librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/power-wait.c
 librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/power.c
 librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/restart.c
 librtemsbsp_a_SOURCES += ../../../../../../bsps/arm/atsam/start/sdram-config.c