Diff: targets/hal/TARGET_Maxim/TARGET_MAX32610/sleep.c

Revision:

507:d4fc7603a669

Child:

536:c48d7048ab6e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Maxim/TARGET_MAX32610/sleep.c	Wed Apr 08 07:45:08 2015 +0100
@@ -0,0 +1,169 @@
+/*******************************************************************************
+ * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+ * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Maxim Integrated
+ * Products, Inc. shall not be used except as stated in the Maxim Integrated
+ * Products, Inc. Branding Policy.
+ *
+ * The mere transfer of this software does not imply any licenses
+ * of trade secrets, proprietary technology, copyrights, patents,
+ * trademarks, maskwork rights, or any other form of intellectual
+ * property whatsoever. Maxim Integrated Products, Inc. retains all
+ * ownership rights.
+ *******************************************************************************
+ */
+ 
+#include "sleep_api.h"
+#include "us_ticker_api.h"
+#include "cmsis.h"
+#include "pwrman_regs.h"
+#include "pwrseq_regs.h"
+#include "ioman_regs.h"
+#include "rtc_regs.h"
+
+#define MIN_DEEP_SLEEP_US       500
+
+uint64_t rtc_read_us(void);
+void rtc_set_wakeup(uint64_t wakeupUs);
+void us_ticker_deinit(void);
+void us_ticker_set(timestamp_t timestamp);
+
+static mxc_uart_regs_t *stdio_uart = (mxc_uart_regs_t*)STDIO_UART;
+
+// Normal wait mode
+void sleep(void)
+{
+    // Normal sleep mode for ARM core
+    SCB->SCR = 0;
+
+    __DSB();
+    __WFI();
+}
+
+// Work-around for issue of clearing power sequencer I/O flag
+static void clearAllGPIOWUD(void)
+{
+    uint32_t wud_req0 = MXC_IOMAN->wud_req0;
+    uint32_t wud_req1 = MXC_IOMAN->wud_req1;
+
+    // I/O must be a wakeup detect to clear
+    MXC_IOMAN->wud_req0 = 0xffffffff;
+    MXC_IOMAN->wud_req1 = 0xffffffff;
+
+    // Clear all WUDs
+    MXC_PWRMAN->wud_ctrl = (MXC_E_PWRMAN_PAD_MODE_CLEAR_SET << MXC_F_PWRMAN_WUD_CTRL_PAD_MODE_POS) | MXC_F_PWRMAN_WUD_CTRL_CLEAR_ALL;
+    MXC_PWRMAN->wud_pulse0 = 1;
+
+    // Restore WUD requests
+    MXC_IOMAN->wud_req0 = wud_req0;
+    MXC_IOMAN->wud_req1 = wud_req1;
+}
+
+// Low-power stop mode
+void deepsleep(void)
+{
+    uint64_t sleepStartRtcUs;
+    uint32_t sleepStartTickerUs;
+    int32_t sleepDurationUs;
+    uint64_t sleepEndRtcUs;
+    uint64_t elapsedUs;
+
+    __disable_irq();
+
+    // Wait for all STDIO characters to be sent. The UART clock will stop.
+    while (stdio_uart->status & MXC_F_UART_STATUS_TX_BUSY);
+
+    // Record the current times
+    sleepStartRtcUs = rtc_read_us();
+    sleepStartTickerUs = us_ticker_read();
+
+    // Get the next mbed timer expiration
+    timestamp_t next_event = 0;
+    us_ticker_get_next_timestamp(&next_event);
+    sleepDurationUs = next_event - sleepStartTickerUs;
+
+    if (sleepDurationUs < MIN_DEEP_SLEEP_US) {
+        /* The next wakeup is too soon. */
+        __enable_irq();
+        return;
+    }
+
+    // Disable the us_ticker. It won't be clocked in DeepSleep
+    us_ticker_deinit();
+
+    // Prepare to wakeup from the RTC
+    rtc_set_wakeup(sleepStartRtcUs + sleepDurationUs);
+
+    // Prepare for LP1
+    uint32_t reg0 = MXC_PWRSEQ->reg0;
+    reg0 &= ~MXC_F_PWRSEQ_REG0_PWR_SVM3EN_SLP;  // disable VDD3 SVM during sleep mode
+    reg0 &= ~MXC_F_PWRSEQ_REG0_PWR_SVM1EN_SLP;  // disable VREG18 SVM during sleep mode
+    if (reg0 & MXC_F_PWRSEQ_REG0_PWR_RTCEN_RUN) {   // if real-time clock enabled during run
+        reg0 |= MXC_F_PWRSEQ_REG0_PWR_RTCEN_SLP;    // enable real-time clock during sleep mode
+    } else {
+        reg0 &= ~MXC_F_PWRSEQ_REG0_PWR_RTCEN_SLP;   // disable real-time clock during sleep mode
+    }
+    reg0 |= MXC_F_PWRSEQ_REG0_PWR_CHZYEN_SLP;   // enable CHZY regulator during sleep mode
+    reg0 |= MXC_F_PWRSEQ_REG0_PWR_LP1;          // go into LP1
+    reg0 &= ~MXC_F_PWRSEQ_REG0_PWR_FIRST_BOOT;  // clear first boot flag
+    MXC_PWRSEQ->reg0 = reg0;
+
+    MXC_PWRSEQ->reg3 = (MXC_PWRSEQ->reg3 & ~MXC_F_PWRSEQ_REG3_PWR_ROSEL_QUICK) | (3 << MXC_F_PWRSEQ_REG3_PWR_ROSEL_QUICK_POS);
+
+    // Deep sleep for ARM core
+    SCB->SCR = SCB_SCR_SLEEPDEEP_Msk;
+
+    // clear latches for wakeup detect
+    MXC_PWRSEQ->flags = MXC_PWRSEQ->flags;
+    if (MXC_PWRSEQ->flags & MXC_F_PWRSEQ_FLAGS_PWR_IO_WAKEUP) {
+        // attempt work-around for I/O flag clearing issue
+        clearAllGPIOWUD();
+        MXC_PWRSEQ->flags = MXC_F_PWRSEQ_FLAGS_PWR_IO_WAKEUP;
+    }
+
+    // Wait for pending RTC transaction
+    while (MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_PENDING);
+
+    // Ensure that the event register is clear
+    __SEV();    // set event
+    __WFE();    // clear event
+
+    // Enter LP1
+    __WFE();
+    // Woke up from LP1
+
+    // The RTC timer does not update until the next tick
+    uint64_t tempUs = rtc_read_us();
+    do {
+        sleepEndRtcUs = rtc_read_us();
+    } while(sleepEndRtcUs == tempUs);
+
+    // Get the elapsed time from the RTC. Wakeup could have been from some other event.
+    elapsedUs = sleepEndRtcUs - sleepStartRtcUs;
+
+    // Update the us_ticker. It was not clocked during DeepSleep
+    us_ticker_init();
+    us_ticker_set(sleepStartTickerUs + elapsedUs);
+    us_ticker_get_next_timestamp(&next_event);
+    us_ticker_set_interrupt(next_event);
+
+    __enable_irq();
+}