ext/hal/qmsi/soc/quark_d2000/drivers/power_states.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2016, Intel Corporation
  * All rights reserved.
  *
  * 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.
  * 3. Neither the name of the Intel Corporation nor the names of its
  *    contributors may be used to endorse or promote products derived from this
  *    software without specific prior written permission.
  *
  * 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 INTEL CORPORATION 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 "power_states.h"
 #include "clk.h"
 #include "qm_comparator.h"
 #include "qm_isr.h"
 #include "qm_adc.h"
 #include "qm_flash.h"

 #include "rar.h"
 #include "soc_watch.h"

 void power_cpu_halt(void)
 {
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_HALT, 0);
 	__asm__ __volatile__("hlt");
 }

 static void clear_all_pending_interrupts(void)
 {
 	/* Clear comparator interrupts. */
 	QM_SCSS_CMP->cmp_stat_clr = -1;

 	/* Clear RTC interrupts. */
 	QM_RTC->rtc_eoi;

 	/* Clear timers interrupt flag. */
 	QM_PWM->timerseoi;

 	/* Clear GPIO interrupts. */
 	QM_GPIO[QM_GPIO_0]->gpio_porta_eoi = -1;
 }

 void power_soc_sleep(void)
 {
 	/* Variables to save register values. */
 	uint32_t ac_power_save;
 	uint32_t clk_gate_save = QM_SCSS_CCU->ccu_periph_clk_gate_ctl;
 	uint32_t sys_clk_ctl_save = QM_SCSS_CCU->ccu_sys_clk_ctl;
 	uint32_t osc0_cfg_save = QM_SCSS_CCU->osc0_cfg1;
 	uint32_t adc_mode_save = QM_ADC->adc_op_mode;
 	uint32_t flash_tmg_save = QM_FLASH[QM_FLASH_0]->tmg_ctrl;

 	/* Clear any pending interrupts. */
 	clear_all_pending_interrupts();

 	qm_adc_set_mode(QM_ADC_0, QM_ADC_MODE_PWR_DOWN);

 	/* Turn off high power comparators. */
 	ac_power_save = QM_SCSS_CMP->cmp_pwr;
 	QM_SCSS_CMP->cmp_pwr &= QM_AC_HP_COMPARATORS_MASK;

 	/*
 	 * Program WAKE_MASK.WAKE_MASK[31:0],
 	 * CCU_LP_CLK_CTL.WAKE_PROBE_MODE_MASK registers identical to Interrupt
 	 * Mask registers.
 	 */
 	QM_SCSS_CCU->ccu_lp_clk_ctl &= ~QM_WAKE_PROBE_MODE_MASK;
 	/* Enable all wake sources as interrupts. */
 	QM_SCSS_CCU->wake_mask = 0;

 	/*
 	 * Ensure that powering down of oscillators is delayed by hardware until
 	 * core  executes HALT instruction.
 	 */
 	/* HYB_OSC_PD_LATCH_EN = 0, RTC_OSC_PD_LATCH_EN=0 */
 	QM_SCSS_CCU->ccu_lp_clk_ctl &=
 	    ~(QM_HYB_OSC_PD_LATCH_EN | QM_RTC_OSC_PD_LATCH_EN);

 	/* Ensure that at exit, hardware will switch system clock to Hybrid
 	 * oscillator clock so as to minimize exit latency by running at higher
 	 * frequency than RTC clock.
 	 */
 	/* CCU_LP_CLK_CTL.CCU_EXIT_TO_HYBOSC */
 	QM_SCSS_CCU->ccu_lp_clk_ctl |=
 	    QM_CCU_EXIT_TO_HYBOSC | QM_CCU_MEM_HALT_EN | QM_CCU_CPU_HALT_EN;
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_LP_CLK_CTL);

 	/*
 	 * Only the following peripherals can be used as a wakeup source:
 	 *  - GPIO Interrupts
 	 *  - AON timers
 	 *  - RTC
 	 *  - low power comparators
 	 */
 	clk_periph_disable(
 	    CLK_PERIPH_I2C_M0 | CLK_PERIPH_SPI_S | CLK_PERIPH_SPI_M0 |
 	    CLK_PERIPH_GPIO_DB | CLK_PERIPH_WDT_REGISTER |
 	    CLK_PERIPH_PWM_REGISTER | CLK_PERIPH_GPIO_REGISTER |
 	    CLK_PERIPH_SPI_M0_REGISTER | CLK_PERIPH_SPI_S_REGISTER |
 	    CLK_PERIPH_UARTA_REGISTER | CLK_PERIPH_UARTB_REGISTER |
 	    CLK_PERIPH_I2C_M0_REGISTER);

 	/* Set system clock source to hyb osc, 4 MHz, scaled to 512 kHz. */
 	clk_sys_set_mode(CLK_SYS_HYB_OSC_4MHZ, CLK_SYS_DIV_8);

 	/* Set the RAR to retention mode. */
 	rar_set_mode(RAR_RETENTION);

 	/*
 	 * If wake source is any of AON Timer, RTC, GPIO interrupt, program
 	 * CCU_SYS_CLK_CTL.CCU_SYS_CLK_SEL to RTC Oscillator.
 	 */
 	/* Enter SoC sleep mode. */
 	power_cpu_halt();

 	/* From here on, restore the SoC to an active state. */
 	/* Set the RAR to normal mode. */
 	rar_set_mode(RAR_NORMAL);

 	/*
 	 * Since we are running below 4MHz, 0 wait states are configured.
 	 * If the previous frequency was > 4MHz, 0 wait states will
 	 * violate the flash timings.
 	 * In the worst case scenario, when switching back to 32MHz,
 	 * 2 wait states will be restored.
 	 * This setting will be too conservative until the frequency has been
 	 * restored.
 	 */
 	QM_FLASH[QM_FLASH_0]->tmg_ctrl = flash_tmg_save;

 	/* Restore all previous values. */
 	QM_SCSS_CCU->ccu_sys_clk_ctl = sys_clk_ctl_save;
 	/* Re-apply clock divider values. DIV_EN must go 0 -> 1. */
 	QM_SCSS_CCU->ccu_sys_clk_ctl &=
 	    ~(QM_CCU_SYS_CLK_DIV_EN | QM_CCU_RTC_CLK_DIV_EN);
 	QM_SCSS_CCU->ccu_sys_clk_ctl |=
 	    QM_CCU_SYS_CLK_DIV_EN | QM_CCU_RTC_CLK_DIV_EN;

 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_SYS_CLK_CTL);

 	/* Wait for the XTAL or SI oscillator to stabilise. */
 	while (!(QM_SCSS_CCU->osc0_stat1 &
 		 (QM_OSC0_LOCK_SI | QM_OSC0_LOCK_XTAL))) {
 	};

 	/* Restore original clocking, ADC, analog comparator states. */
 	QM_SCSS_CCU->osc0_cfg1 = osc0_cfg_save;
 	QM_SCSS_CCU->ccu_periph_clk_gate_ctl = clk_gate_save;
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_OSC0_CFG1);
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER,
 			    SOCW_REG_CCU_PERIPH_CLK_GATE_CTL);
 	QM_SCSS_CMP->cmp_pwr = ac_power_save;
 	QM_ADC->adc_op_mode = adc_mode_save;
 }

 void power_soc_deep_sleep(const power_wake_event_t wake_event)
 {
 	/* Variables to save register values. */
 	uint32_t ac_power_save;
 	uint32_t clk_gate_save = QM_SCSS_CCU->ccu_periph_clk_gate_ctl;
 	uint32_t sys_clk_ctl_save = QM_SCSS_CCU->ccu_sys_clk_ctl;
 	uint32_t osc0_cfg_save = QM_SCSS_CCU->osc0_cfg1;
 	uint32_t osc1_cfg_save = QM_SCSS_CCU->osc1_cfg0;
 	uint32_t adc_mode_save = QM_ADC->adc_op_mode;
 	uint32_t aon_vr_save = QM_SCSS_PMU->aon_vr;
 	uint32_t flash_tmg_save = QM_FLASH[QM_FLASH_0]->tmg_ctrl;
 	uint32_t ext_clock_save;
 	uint32_t lp_clk_save, pmux_slew_save;

 	pmux_slew_save = QM_SCSS_PMUX->pmux_slew[0];
 	ext_clock_save = QM_SCSS_CCU->ccu_ext_clock_ctl;
 	lp_clk_save = QM_SCSS_CCU->ccu_lp_clk_ctl;

 	/* Clear any pending interrupts. */
 	clear_all_pending_interrupts();

 	/*
 	 * Clear the wake mask bits. Default behaviour is to wake from GPIO /
 	 * comparator.
 	 */
 	switch (wake_event) {
 	case POWER_WAKE_FROM_RTC:
 		QM_SCSS_CCU->wake_mask =
 		    SET_ALL_BITS & ~QM_CCU_WAKE_MASK_RTC_BIT;
 		break;
 	case POWER_WAKE_FROM_GPIO_COMP:
 	default:
 		QM_SCSS_CCU->wake_mask = SET_ALL_BITS &
 					 ~(QM_CCU_WAKE_MASK_COMPARATOR_BIT |
 					   QM_CCU_WAKE_MASK_GPIO_BIT);
 		break;
 	}

 	QM_SCSS_GP->gps1 |= QM_SCSS_GP_POWER_STATE_DEEP_SLEEP;

 	qm_adc_set_mode(QM_ADC_0, QM_ADC_MODE_DEEP_PWR_DOWN);

 	/* Turn off high power comparators. */
 	ac_power_save = QM_SCSS_CMP->cmp_pwr;
 	QM_SCSS_CMP->cmp_pwr &= QM_AC_HP_COMPARATORS_MASK;

 	/* Disable all peripheral clocks. */
 	clk_periph_disable(CLK_PERIPH_REGISTER);

 	/* Disable external clocks. */
 	QM_SCSS_CCU->ccu_ext_clock_ctl = 0;
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_EXT_CLK_CTL);

 	/* Set slew rate of all pins to 12mA. */
 	QM_SCSS_PMUX->pmux_slew[0] = 0;
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_PMUX_SLEW);

 	if (wake_event != POWER_WAKE_FROM_RTC) {
 		/* Disable RTC. */
 		QM_SCSS_CCU->osc1_cfg0 &= ~QM_OSC1_PD;

 		/* Set system clock source to
 		 * Silicon Oscillator 4 MHz, scaled down to 32 kHz. */
 		clk_sys_set_mode(CLK_SYS_HYB_OSC_4MHZ, CLK_SYS_DIV_128);
 	}

 	/* Power down the oscillator after the halt instruction is executed. */
 	QM_SCSS_CCU->ccu_lp_clk_ctl &= ~QM_HYB_OSC_PD_LATCH_EN;
 	/*
 	 * Enable memory halt and CPU halt. When exiting sleep mode, use hybrid
 	 * oscillator.
 	 */
 	QM_SCSS_CCU->ccu_lp_clk_ctl |=
 	    QM_CCU_EXIT_TO_HYBOSC | QM_CCU_MEM_HALT_EN | QM_CCU_CPU_HALT_EN;
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_LP_CLK_CTL);

 	/* Power down hybrid oscillator. */
 	QM_SCSS_CCU->osc0_cfg1 |= QM_OSC0_PD;

 	/* Disable gpio debounce clocking. */
 	QM_SCSS_CCU->ccu_gpio_db_clk_ctl &= ~QM_CCU_GPIO_DB_CLK_EN;
 	/* Set retention voltage to 1.35V. */
 	/* SCSS.OSC0_CFG0.OSC0_HYB_SET_REG1.OSC0_CFG0[0]  = 1; */
 	QM_SCSS_CCU->osc0_cfg0 |= QM_SI_OSC_1V2_MODE;

 	/* Enable low voltage mode for flash controller. */
 	/* FlashCtrl.CTRL.LVE_MODE = 1; */
 	QM_FLASH[QM_FLASH_0]->ctrl |= QM_FLASH_LVE_MODE;

 	/* Select 1.35V for voltage regulator. */
 	/* SCSS.AON_VR.VSEL = 0xB; */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE | (aon_vr_save & QM_AON_VR_VSEL_MASK) |
 	     QM_AON_VR_VSEL_1V35);
 	/* SCSS.AON_VR.ROK_BUF_VREG_MASK = 1; */
 	QM_SCSS_PMU->aon_vr = (QM_AON_VR_PASS_CODE | QM_SCSS_PMU->aon_vr |
 			       QM_AON_VR_ROK_BUF_VREG_MASK);

 	/* SCSS.AON_VR.VSEL_STROBE = 1;  */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE | QM_SCSS_PMU->aon_vr | QM_AON_VR_VSTRB);

 	/* Wait >= 1 usec, at 256 kHz this is 1 cycle. */
 	__asm__("nop");

 	/* SCSS.AON_VR.VSEL_STROBE = 0; */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE | (QM_SCSS_PMU->aon_vr & ~QM_AON_VR_VSTRB));

 	/* Wait >= 2 usec, at 256 kHz this is 1 cycle. */
 	__asm__("nop");

 	/* Set the RAR to retention mode. */
 	rar_set_mode(RAR_RETENTION);

 	if (wake_event == POWER_WAKE_FROM_RTC) {
 		/* Start running on the rtc clock */
 		clk_sys_set_mode(CLK_SYS_RTC_OSC, CLK_SYS_DIV_1);
 	}

 	/* Disable all peripheral clocks. */
 	clk_periph_disable(CLK_PERIPH_REGISTER | CLK_PERIPH_CLK);

 	/* Enter SoC deep sleep mode. */
 	power_cpu_halt();

 	/* We are now exiting from deep sleep mode. */
 	/* Set the RAR to normal mode. */
 	rar_set_mode(RAR_NORMAL);

 	/*
 	 * Since we are running below 4MHz, 0 wait states are configured.
 	 * If the previous frequency was > 4MHz, 0 wait states will
 	 * violate the flash timings.
 	 * In the worst case scenario, when switching back to 32MHz,
 	 * 2 wait states will be restored.
 	 * This setting will be too conservative until the frequency has been
 	 * restored.
 	 */
 	QM_FLASH[QM_FLASH_0]->tmg_ctrl = flash_tmg_save;

 	/* Restore operating voltage to 1.8V. */
 	/* SCSS.AON_VR.VSEL = 0x10; */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE | (QM_SCSS_PMU->aon_vr & QM_AON_VR_VSEL_MASK) |
 	     QM_AON_VR_VSEL_1V8 | QM_AON_VR_ROK_BUF_VREG_MASK);

 	/* SCSS.AON_VR.VSEL_STROBE = 1;  */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE | QM_SCSS_PMU->aon_vr | QM_AON_VR_VSTRB);

 	/* Wait >= 1 usec, at 256 kHz this is 1 cycle. */
 	__asm__("nop");

 	/* SCSS.AON_VR.VSEL_STROBE = 0; */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE | (QM_SCSS_PMU->aon_vr & ~QM_AON_VR_VSTRB));

 	/* Wait >= 2 usec, at 256 kHz this is 1 cycle. */
 	__asm__("nop");

 	/* SCSS.AON_VR.ROK_BUF_VREG_MASK = 0;  */
 	QM_SCSS_PMU->aon_vr =
 	    (QM_AON_VR_PASS_CODE |
 	     (QM_SCSS_PMU->aon_vr & ~QM_AON_VR_ROK_BUF_VREG_MASK));

 	/* Wait >= 1 usec, at 256 kHz this is 1 cycle. */
 	__asm__("nop");

 	/* SCSS.OSC0_CFG0.OSC0_HYB_SET_REG1.OSC0_CFG0[0]  = 0; */
 	QM_SCSS_CCU->osc0_cfg0 &= ~QM_SI_OSC_1V2_MODE;

 	/* FlashCtrl.CTRL.LVE_MODE = 0; */
 	QM_FLASH[QM_FLASH_0]->ctrl &= ~QM_FLASH_LVE_MODE;

 	/* Restore all previous values. */
 	QM_SCSS_CCU->ccu_sys_clk_ctl = sys_clk_ctl_save;
 	/* Re-apply clock divider values. DIV_EN must go 0 -> 1. */
 	QM_SCSS_CCU->ccu_sys_clk_ctl &=
 	    ~(QM_CCU_SYS_CLK_DIV_EN | QM_CCU_RTC_CLK_DIV_EN);
 	QM_SCSS_CCU->ccu_sys_clk_ctl |=
 	    QM_CCU_SYS_CLK_DIV_EN | QM_CCU_RTC_CLK_DIV_EN;

 	/* Wait for the XTAL or SI oscillator to stabilise. */
 	while (!(QM_SCSS_CCU->osc0_stat1 &
 		 (QM_OSC0_LOCK_SI | QM_OSC0_LOCK_XTAL))) {
 	};
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_SYS_CLK_CTL);

 	/* Re-enable clocks. */
 	clk_periph_enable(CLK_PERIPH_REGISTER);

 	/* Re-enable gpio debounce clocking. */
 	QM_SCSS_CCU->ccu_gpio_db_clk_ctl |= QM_CCU_GPIO_DB_CLK_EN;

 	/* Restore original clocking, ADC, analog comparator states. */
 	QM_SCSS_CCU->osc0_cfg1 = osc0_cfg_save;
 	QM_SCSS_CCU->ccu_periph_clk_gate_ctl = clk_gate_save;
 	QM_SCSS_CCU->osc1_cfg0 = osc1_cfg_save;

 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_OSC0_CFG1);
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER,
 			    SOCW_REG_CCU_PERIPH_CLK_GATE_CTL);
 	QM_SCSS_CMP->cmp_pwr = ac_power_save;
 	QM_ADC->adc_op_mode = adc_mode_save;

 	QM_SCSS_PMUX->pmux_slew[0] = pmux_slew_save;
 	QM_SCSS_CCU->ccu_ext_clock_ctl = ext_clock_save;
 	QM_SCSS_CCU->ccu_lp_clk_ctl = lp_clk_save;

 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_PMUX_SLEW);
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_LP_CLK_CTL);
 	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_EXT_CLK_CTL);

 	QM_SCSS_CCU->wake_mask = SET_ALL_BITS;
 	QM_SCSS_GP->gps1 &= ~QM_SCSS_GP_POWER_STATE_DEEP_SLEEP;
 }
	/*
	* Copyright (c) 2016, Intel Corporation
	* All rights reserved.
	*
	* 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.
	* 3. Neither the name of the Intel Corporation nor the names of its
	* contributors may be used to endorse or promote products derived from this
	* software without specific prior written permission.
	*
	* 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 INTEL CORPORATION 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 "power_states.h"
	#include "clk.h"
	#include "qm_comparator.h"
	#include "qm_isr.h"
	#include "qm_adc.h"
	#include "qm_flash.h"

	#include "rar.h"
	#include "soc_watch.h"

	void power_cpu_halt(void)
	{
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_HALT, 0);
	__asm__ __volatile__("hlt");
	}

	static void clear_all_pending_interrupts(void)
	{
	/* Clear comparator interrupts. */
	QM_SCSS_CMP->cmp_stat_clr = -1;

	/* Clear RTC interrupts. */
	QM_RTC->rtc_eoi;

	/* Clear timers interrupt flag. */
	QM_PWM->timerseoi;

	/* Clear GPIO interrupts. */
	QM_GPIO[QM_GPIO_0]->gpio_porta_eoi = -1;
	}

	void power_soc_sleep(void)
	{
	/* Variables to save register values. */
	uint32_t ac_power_save;
	uint32_t clk_gate_save = QM_SCSS_CCU->ccu_periph_clk_gate_ctl;
	uint32_t sys_clk_ctl_save = QM_SCSS_CCU->ccu_sys_clk_ctl;
	uint32_t osc0_cfg_save = QM_SCSS_CCU->osc0_cfg1;
	uint32_t adc_mode_save = QM_ADC->adc_op_mode;
	uint32_t flash_tmg_save = QM_FLASH[QM_FLASH_0]->tmg_ctrl;

	/* Clear any pending interrupts. */
	clear_all_pending_interrupts();

	qm_adc_set_mode(QM_ADC_0, QM_ADC_MODE_PWR_DOWN);

	/* Turn off high power comparators. */
	ac_power_save = QM_SCSS_CMP->cmp_pwr;
	QM_SCSS_CMP->cmp_pwr &= QM_AC_HP_COMPARATORS_MASK;

	/*
	* Program WAKE_MASK.WAKE_MASK[31:0],
	* CCU_LP_CLK_CTL.WAKE_PROBE_MODE_MASK registers identical to Interrupt
	* Mask registers.
	*/
	QM_SCSS_CCU->ccu_lp_clk_ctl &= ~QM_WAKE_PROBE_MODE_MASK;
	/* Enable all wake sources as interrupts. */
	QM_SCSS_CCU->wake_mask = 0;

	/*
	* Ensure that powering down of oscillators is delayed by hardware until
	* core executes HALT instruction.
	*/
	/* HYB_OSC_PD_LATCH_EN = 0, RTC_OSC_PD_LATCH_EN=0 */
	QM_SCSS_CCU->ccu_lp_clk_ctl &=
	~(QM_HYB_OSC_PD_LATCH_EN \| QM_RTC_OSC_PD_LATCH_EN);

	/* Ensure that at exit, hardware will switch system clock to Hybrid
	* oscillator clock so as to minimize exit latency by running at higher
	* frequency than RTC clock.
	*/
	/* CCU_LP_CLK_CTL.CCU_EXIT_TO_HYBOSC */
	QM_SCSS_CCU->ccu_lp_clk_ctl \|=
	QM_CCU_EXIT_TO_HYBOSC \| QM_CCU_MEM_HALT_EN \| QM_CCU_CPU_HALT_EN;
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_LP_CLK_CTL);

	/*
	* Only the following peripherals can be used as a wakeup source:
	* - GPIO Interrupts
	* - AON timers
	* - RTC
	* - low power comparators
	*/
	clk_periph_disable(
	CLK_PERIPH_I2C_M0 \| CLK_PERIPH_SPI_S \| CLK_PERIPH_SPI_M0 \|
	CLK_PERIPH_GPIO_DB \| CLK_PERIPH_WDT_REGISTER \|
	CLK_PERIPH_PWM_REGISTER \| CLK_PERIPH_GPIO_REGISTER \|
	CLK_PERIPH_SPI_M0_REGISTER \| CLK_PERIPH_SPI_S_REGISTER \|
	CLK_PERIPH_UARTA_REGISTER \| CLK_PERIPH_UARTB_REGISTER \|
	CLK_PERIPH_I2C_M0_REGISTER);

	/* Set system clock source to hyb osc, 4 MHz, scaled to 512 kHz. */
	clk_sys_set_mode(CLK_SYS_HYB_OSC_4MHZ, CLK_SYS_DIV_8);

	/* Set the RAR to retention mode. */
	rar_set_mode(RAR_RETENTION);

	/*
	* If wake source is any of AON Timer, RTC, GPIO interrupt, program
	* CCU_SYS_CLK_CTL.CCU_SYS_CLK_SEL to RTC Oscillator.
	*/
	/* Enter SoC sleep mode. */
	power_cpu_halt();

	/* From here on, restore the SoC to an active state. */
	/* Set the RAR to normal mode. */
	rar_set_mode(RAR_NORMAL);

	/*
	* Since we are running below 4MHz, 0 wait states are configured.
	* If the previous frequency was > 4MHz, 0 wait states will
	* violate the flash timings.
	* In the worst case scenario, when switching back to 32MHz,
	* 2 wait states will be restored.
	* This setting will be too conservative until the frequency has been
	* restored.
	*/
	QM_FLASH[QM_FLASH_0]->tmg_ctrl = flash_tmg_save;

	/* Restore all previous values. */
	QM_SCSS_CCU->ccu_sys_clk_ctl = sys_clk_ctl_save;
	/* Re-apply clock divider values. DIV_EN must go 0 -> 1. */
	QM_SCSS_CCU->ccu_sys_clk_ctl &=
	~(QM_CCU_SYS_CLK_DIV_EN \| QM_CCU_RTC_CLK_DIV_EN);
	QM_SCSS_CCU->ccu_sys_clk_ctl \|=
	QM_CCU_SYS_CLK_DIV_EN \| QM_CCU_RTC_CLK_DIV_EN;

	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_SYS_CLK_CTL);

	/* Wait for the XTAL or SI oscillator to stabilise. */
	while (!(QM_SCSS_CCU->osc0_stat1 &
	(QM_OSC0_LOCK_SI \| QM_OSC0_LOCK_XTAL))) {
	};

	/* Restore original clocking, ADC, analog comparator states. */
	QM_SCSS_CCU->osc0_cfg1 = osc0_cfg_save;
	QM_SCSS_CCU->ccu_periph_clk_gate_ctl = clk_gate_save;
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_OSC0_CFG1);
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER,
	SOCW_REG_CCU_PERIPH_CLK_GATE_CTL);
	QM_SCSS_CMP->cmp_pwr = ac_power_save;
	QM_ADC->adc_op_mode = adc_mode_save;
	}

	void power_soc_deep_sleep(const power_wake_event_t wake_event)
	{
	/* Variables to save register values. */
	uint32_t ac_power_save;
	uint32_t clk_gate_save = QM_SCSS_CCU->ccu_periph_clk_gate_ctl;
	uint32_t sys_clk_ctl_save = QM_SCSS_CCU->ccu_sys_clk_ctl;
	uint32_t osc0_cfg_save = QM_SCSS_CCU->osc0_cfg1;
	uint32_t osc1_cfg_save = QM_SCSS_CCU->osc1_cfg0;
	uint32_t adc_mode_save = QM_ADC->adc_op_mode;
	uint32_t aon_vr_save = QM_SCSS_PMU->aon_vr;
	uint32_t flash_tmg_save = QM_FLASH[QM_FLASH_0]->tmg_ctrl;
	uint32_t ext_clock_save;
	uint32_t lp_clk_save, pmux_slew_save;

	pmux_slew_save = QM_SCSS_PMUX->pmux_slew[0];
	ext_clock_save = QM_SCSS_CCU->ccu_ext_clock_ctl;
	lp_clk_save = QM_SCSS_CCU->ccu_lp_clk_ctl;

	/* Clear any pending interrupts. */
	clear_all_pending_interrupts();

	/*
	* Clear the wake mask bits. Default behaviour is to wake from GPIO /
	* comparator.
	*/
	switch (wake_event) {
	case POWER_WAKE_FROM_RTC:
	QM_SCSS_CCU->wake_mask =
	SET_ALL_BITS & ~QM_CCU_WAKE_MASK_RTC_BIT;
	break;
	case POWER_WAKE_FROM_GPIO_COMP:
	default:
	QM_SCSS_CCU->wake_mask = SET_ALL_BITS &
	~(QM_CCU_WAKE_MASK_COMPARATOR_BIT \|
	QM_CCU_WAKE_MASK_GPIO_BIT);
	break;
	}

	QM_SCSS_GP->gps1 \|= QM_SCSS_GP_POWER_STATE_DEEP_SLEEP;

	qm_adc_set_mode(QM_ADC_0, QM_ADC_MODE_DEEP_PWR_DOWN);

	/* Turn off high power comparators. */
	ac_power_save = QM_SCSS_CMP->cmp_pwr;
	QM_SCSS_CMP->cmp_pwr &= QM_AC_HP_COMPARATORS_MASK;

	/* Disable all peripheral clocks. */
	clk_periph_disable(CLK_PERIPH_REGISTER);

	/* Disable external clocks. */
	QM_SCSS_CCU->ccu_ext_clock_ctl = 0;
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_EXT_CLK_CTL);

	/* Set slew rate of all pins to 12mA. */
	QM_SCSS_PMUX->pmux_slew[0] = 0;
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_PMUX_SLEW);

	if (wake_event != POWER_WAKE_FROM_RTC) {
	/* Disable RTC. */
	QM_SCSS_CCU->osc1_cfg0 &= ~QM_OSC1_PD;

	/* Set system clock source to
	* Silicon Oscillator 4 MHz, scaled down to 32 kHz. */
	clk_sys_set_mode(CLK_SYS_HYB_OSC_4MHZ, CLK_SYS_DIV_128);
	}

	/* Power down the oscillator after the halt instruction is executed. */
	QM_SCSS_CCU->ccu_lp_clk_ctl &= ~QM_HYB_OSC_PD_LATCH_EN;
	/*
	* Enable memory halt and CPU halt. When exiting sleep mode, use hybrid
	* oscillator.
	*/
	QM_SCSS_CCU->ccu_lp_clk_ctl \|=
	QM_CCU_EXIT_TO_HYBOSC \| QM_CCU_MEM_HALT_EN \| QM_CCU_CPU_HALT_EN;
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_LP_CLK_CTL);

	/* Power down hybrid oscillator. */
	QM_SCSS_CCU->osc0_cfg1 \|= QM_OSC0_PD;

	/* Disable gpio debounce clocking. */
	QM_SCSS_CCU->ccu_gpio_db_clk_ctl &= ~QM_CCU_GPIO_DB_CLK_EN;
	/* Set retention voltage to 1.35V. */
	/* SCSS.OSC0_CFG0.OSC0_HYB_SET_REG1.OSC0_CFG0[0] = 1; */
	QM_SCSS_CCU->osc0_cfg0 \|= QM_SI_OSC_1V2_MODE;

	/* Enable low voltage mode for flash controller. */
	/* FlashCtrl.CTRL.LVE_MODE = 1; */
	QM_FLASH[QM_FLASH_0]->ctrl \|= QM_FLASH_LVE_MODE;

	/* Select 1.35V for voltage regulator. */
	/* SCSS.AON_VR.VSEL = 0xB; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \| (aon_vr_save & QM_AON_VR_VSEL_MASK) \|
	QM_AON_VR_VSEL_1V35);
	/* SCSS.AON_VR.ROK_BUF_VREG_MASK = 1; */
	QM_SCSS_PMU->aon_vr = (QM_AON_VR_PASS_CODE \| QM_SCSS_PMU->aon_vr \|
	QM_AON_VR_ROK_BUF_VREG_MASK);

	/* SCSS.AON_VR.VSEL_STROBE = 1; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \| QM_SCSS_PMU->aon_vr \| QM_AON_VR_VSTRB);

	/* Wait >= 1 usec, at 256 kHz this is 1 cycle. */
	__asm__("nop");

	/* SCSS.AON_VR.VSEL_STROBE = 0; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \| (QM_SCSS_PMU->aon_vr & ~QM_AON_VR_VSTRB));

	/* Wait >= 2 usec, at 256 kHz this is 1 cycle. */
	__asm__("nop");

	/* Set the RAR to retention mode. */
	rar_set_mode(RAR_RETENTION);

	if (wake_event == POWER_WAKE_FROM_RTC) {
	/* Start running on the rtc clock */
	clk_sys_set_mode(CLK_SYS_RTC_OSC, CLK_SYS_DIV_1);
	}

	/* Disable all peripheral clocks. */
	clk_periph_disable(CLK_PERIPH_REGISTER \| CLK_PERIPH_CLK);

	/* Enter SoC deep sleep mode. */
	power_cpu_halt();

	/* We are now exiting from deep sleep mode. */
	/* Set the RAR to normal mode. */
	rar_set_mode(RAR_NORMAL);

	/*
	* Since we are running below 4MHz, 0 wait states are configured.
	* If the previous frequency was > 4MHz, 0 wait states will
	* violate the flash timings.
	* In the worst case scenario, when switching back to 32MHz,
	* 2 wait states will be restored.
	* This setting will be too conservative until the frequency has been
	* restored.
	*/
	QM_FLASH[QM_FLASH_0]->tmg_ctrl = flash_tmg_save;

	/* Restore operating voltage to 1.8V. */
	/* SCSS.AON_VR.VSEL = 0x10; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \| (QM_SCSS_PMU->aon_vr & QM_AON_VR_VSEL_MASK) \|
	QM_AON_VR_VSEL_1V8 \| QM_AON_VR_ROK_BUF_VREG_MASK);

	/* SCSS.AON_VR.VSEL_STROBE = 1; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \| QM_SCSS_PMU->aon_vr \| QM_AON_VR_VSTRB);

	/* Wait >= 1 usec, at 256 kHz this is 1 cycle. */
	__asm__("nop");

	/* SCSS.AON_VR.VSEL_STROBE = 0; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \| (QM_SCSS_PMU->aon_vr & ~QM_AON_VR_VSTRB));

	/* Wait >= 2 usec, at 256 kHz this is 1 cycle. */
	__asm__("nop");

	/* SCSS.AON_VR.ROK_BUF_VREG_MASK = 0; */
	QM_SCSS_PMU->aon_vr =
	(QM_AON_VR_PASS_CODE \|
	(QM_SCSS_PMU->aon_vr & ~QM_AON_VR_ROK_BUF_VREG_MASK));

	/* Wait >= 1 usec, at 256 kHz this is 1 cycle. */
	__asm__("nop");

	/* SCSS.OSC0_CFG0.OSC0_HYB_SET_REG1.OSC0_CFG0[0] = 0; */
	QM_SCSS_CCU->osc0_cfg0 &= ~QM_SI_OSC_1V2_MODE;

	/* FlashCtrl.CTRL.LVE_MODE = 0; */
	QM_FLASH[QM_FLASH_0]->ctrl &= ~QM_FLASH_LVE_MODE;

	/* Restore all previous values. */
	QM_SCSS_CCU->ccu_sys_clk_ctl = sys_clk_ctl_save;
	/* Re-apply clock divider values. DIV_EN must go 0 -> 1. */
	QM_SCSS_CCU->ccu_sys_clk_ctl &=
	~(QM_CCU_SYS_CLK_DIV_EN \| QM_CCU_RTC_CLK_DIV_EN);
	QM_SCSS_CCU->ccu_sys_clk_ctl \|=
	QM_CCU_SYS_CLK_DIV_EN \| QM_CCU_RTC_CLK_DIV_EN;

	/* Wait for the XTAL or SI oscillator to stabilise. */
	while (!(QM_SCSS_CCU->osc0_stat1 &
	(QM_OSC0_LOCK_SI \| QM_OSC0_LOCK_XTAL))) {
	};
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_SYS_CLK_CTL);

	/* Re-enable clocks. */
	clk_periph_enable(CLK_PERIPH_REGISTER);

	/* Re-enable gpio debounce clocking. */
	QM_SCSS_CCU->ccu_gpio_db_clk_ctl \|= QM_CCU_GPIO_DB_CLK_EN;

	/* Restore original clocking, ADC, analog comparator states. */
	QM_SCSS_CCU->osc0_cfg1 = osc0_cfg_save;
	QM_SCSS_CCU->ccu_periph_clk_gate_ctl = clk_gate_save;
	QM_SCSS_CCU->osc1_cfg0 = osc1_cfg_save;

	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_OSC0_CFG1);
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER,
	SOCW_REG_CCU_PERIPH_CLK_GATE_CTL);
	QM_SCSS_CMP->cmp_pwr = ac_power_save;
	QM_ADC->adc_op_mode = adc_mode_save;

	QM_SCSS_PMUX->pmux_slew[0] = pmux_slew_save;
	QM_SCSS_CCU->ccu_ext_clock_ctl = ext_clock_save;
	QM_SCSS_CCU->ccu_lp_clk_ctl = lp_clk_save;

	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_PMUX_SLEW);
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_LP_CLK_CTL);
	SOC_WATCH_LOG_EVENT(SOCW_EVENT_REGISTER, SOCW_REG_CCU_EXT_CLK_CTL);

	QM_SCSS_CCU->wake_mask = SET_ALL_BITS;
	QM_SCSS_GP->gps1 &= ~QM_SCSS_GP_POWER_STATE_DEEP_SLEEP;
	}