File content as of revision 189:f392fc9709a3:

/*******************************************************************************
 * Copyright (c) 2010-2017 Analog Devices, Inc.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
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 *   - 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.
 *   - Modified versions of the software must be conspicuously marked as such.
 *   - This software is licensed solely and exclusively for use with processors
 *     manufactured by or for Analog Devices, Inc.
 *   - This software may not be combined or merged with other code in any manner
 *     that would cause the software to become subject to terms and conditions
 *     which differ from those listed here.
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 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *   - The use of this software may or may not infringe the patent rights of one
 *     or more patent holders.  This license does not release you from the
 *     requirement that you obtain separate licenses from these patent holders
 *     to use this software.
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 ******************************************************************************/

#include "sleep_api.h"

#if DEVICE_SLEEP

#include "adi_pwr.h"
#include "adi_pwr_def.h"
#include "adi_rtos_map.h"
#include "ADuCM3029_device.h"
#include "sleep.h"

/**
 * Function to put processor into sleep (FLEXI mode only).
 */
static void go_into_WFI(const ADI_PWR_POWER_MODE PowerMode)
{
    uint32_t savedPriority;
    uint16_t savedWDT;
    uint32_t scrSetBits = 0u;
    uint32_t scrClrBits = 0u;
    ADI_INT_STATUS_ALLOC();

    /* pre-calculate the sleep-on-exit set/clear bits, FLEXI mode only */
    scrSetBits |= SCB_SCR_SLEEPONEXIT_Msk;

    /* wfi without deepsleep or sleep-on-exit */
    scrClrBits |= (uint32_t)(BITM_NVIC_INTCON0_SLEEPDEEP | BITM_NVIC_INTCON0_SLEEPONEXIT);

    /* put all the power mode and system control mods inside a critical section */
    ADI_ENTER_CRITICAL_REGION();

    { /* these three lines must be in a success-checking loop if they are not inside critical section */
        /* Uninterruptable unlock sequence */
        pADI_PMG0->PWRKEY = ADI_PMG_KEY;

        /* Clear the previous mode and set new mode */
        pADI_PMG0->PWRMOD =(uint32_t) ( ( pADI_PMG0->PWRMOD & (uint32_t) (~BITM_PMG_PWRMOD_MODE) ) | PowerMode );
    }

    /* Update the SCR (sleepdeep and sleep-on-exit bits) */
    SCB->SCR = ((SCB->SCR | scrSetBits) & ~scrClrBits);

    /* save current Base Priority Level */
    savedPriority = __get_BASEPRI();

    /* NOTE: the watchdog timer (WDT) of the GlueMicro (ADuCM302x) is reset
       by the core hardware with every exit from low-power mode.  Therefore,
       even though we may have disabled it during startup, it will reset
       itself on exit from every hibernation state.  Therefore, to avoid
       unintended system resets every 30 seconds because of unexpected WDT
       timeouts, we save/restore the WDT control register around
       hibernation entry and exit.
    */

    /* save WDT control register */
    savedWDT = pADI_WDT0->CTL;

    /* Set caller's priority threshold (left-justified) */
    __set_BASEPRI(0);

    /* bus sync to insure register writes from interrupt handlers are always complete before WFI */
    __DSB();

    /* Wait for interrupt */
    __WFI();

    ADI_EXIT_CRITICAL_REGION();

    ADI_ENTER_CRITICAL_REGION();

    /* Restore previous base priority */
    __set_BASEPRI(savedPriority);

    /* restore WDT control register */
    pADI_WDT0->CTL = savedWDT;

    /* clear sleep-on-exit bit to avoid sleeping on exception return to thread level */
    SCB->SCR &= ~SCB_SCR_SLEEPONEXIT_Msk;

    __DSB(); /* bus sync before re-enabling interrupts */

    ADI_EXIT_CRITICAL_REGION();
}


/**
 * Function to enable/disable clock gating for the available clocks.
 * PCLK overrides all the other clocks.
 */
void set_clock_gating(peripheral_clk_t eClk, int enable)
{
    uint32_t flag;

    switch (eClk) {
        case PCLK:
            flag = 1 << BITP_CLKG_CLK_CTL5_PERCLKOFF;
            break;
        case I2C_CLOCK:
            flag = 1 << BITP_CLKG_CLK_CTL5_UCLKI2COFF;
            break;
        case GPIO_CLOCK:
            flag = 1 << BITP_CLKG_CLK_CTL5_GPIOCLKOFF;
            break;
        case GPT0_CLOCK:
            flag = 1 << BITP_CLKG_CLK_CTL5_GPTCLK0OFF;
            break;
        case GPT1_CLOCK:
            flag = 1 << BITP_CLKG_CLK_CTL5_GPTCLK1OFF;
            break;
        case GPT2_CLOCK:
            flag = 1 << BITP_CLKG_CLK_CTL5_GPTCLK2OFF;
            break;
        default:
            return;
    }

    // if enable, set the bit otherwise clear the bit
    if (enable) {
        pADI_CLKG0_CLK->CTL5 |= flag;
    } else {
        pADI_CLKG0_CLK->CTL5 &= (~flag);
    }
}



/** Send the microcontroller to sleep
 *
 * The processor is setup ready for sleep, and sent to sleep using __WFI(). In this mode, the
 * system clock to the core is stopped until a reset or an interrupt occurs. This eliminates
 * dynamic power used by the processor, memory systems and buses. The processor, peripheral and
 * memory state are maintained, and the peripherals continue to work and can generate interrupts.
 *
 * The processor can be woken up by any internal peripheral interrupt or external pin interrupt.
 *
 * @note
 * The mbed interface semihosting is disconnected as part of going to sleep, and can not be restored.
 * Flash re-programming and the USB serial port will remain active, but the mbed program will no longer be
 * able to access the LocalFileSystem
 *
 * This mode puts the processor into FLEXI mode however the peripheral clocks are not gated
 * hence they are still active.
 */
void hal_sleep(void)
{
    // set to go into the FLEXI mode where the processor is asleep and all peripherals are
    // still active
    go_into_WFI(ADI_PWR_MODE_FLEXI);
}


/** Send the microcontroller to deep sleep
 *
 * This processor is setup ready for deep sleep, and sent to sleep using __WFI(). This mode
 * has the same sleep features as sleep plus it powers down peripherals and clocks. All state
 * is still maintained.
 *
 * The processor can only be woken up by an external interrupt on a pin or a watchdog timer.
 *
 * @note
 *  The mbed interface semihosting is disconnected as part of going to sleep, and can not be restored.
 * Flash re-programming and the USB serial port will remain active, but the mbed program will no longer be
 * able to access the LocalFileSystem
 *
 * This mode puts the processor into FLEXI mode and all the peripheral clocks are clock gated
 * hence they are inactive until interrupts are generated in which case the processor is awaken
 * from sleep.
 */
void hal_deepsleep(void)
{
    // set clock gating to all the peripheral clocks
    set_clock_gating(PCLK, 1);

    // set to go into the FLEXI mode with peripheral clocks gated.
    go_into_WFI(ADI_PWR_MODE_FLEXI);

    // when exiting, clear all peripheral clock gating bits. This is done to enable clocks that aren't
    // automatically re-enabled out of sleep such as the GPIO clock.
    pADI_CLKG0_CLK->CTL5 = 0;
}

#endif  // #if DEVICE_SLEEP