Umar Naeem / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by Umar Naeem

targets/TARGET_Maxim/TARGET_MAX32630/rtc_api.c@165:2dd56e6daeec, 2017-05-23 (annotated)

Committer:
ranaumarnaeem
Date:
Tue May 23 12:54:50 2017 +0000
Revision:
165:2dd56e6daeec
Parent:
157:ff67d9f36b67 
jhjg

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 157:ff67d9f36b67 1 /*******************************************************************************
<> 157:ff67d9f36b67 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
<> 157:ff67d9f36b67 3 *
<> 157:ff67d9f36b67 4 * Permission is hereby granted, free of charge, to any person obtaining a
<> 157:ff67d9f36b67 5 * copy of this software and associated documentation files (the "Software"),
<> 157:ff67d9f36b67 6 * to deal in the Software without restriction, including without limitation
<> 157:ff67d9f36b67 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
<> 157:ff67d9f36b67 8 * and/or sell copies of the Software, and to permit persons to whom the
<> 157:ff67d9f36b67 9 * Software is furnished to do so, subject to the following conditions:
<> 157:ff67d9f36b67 10 *
<> 157:ff67d9f36b67 11 * The above copyright notice and this permission notice shall be included
<> 157:ff67d9f36b67 12 * in all copies or substantial portions of the Software.
<> 157:ff67d9f36b67 13 *
<> 157:ff67d9f36b67 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
<> 157:ff67d9f36b67 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
<> 157:ff67d9f36b67 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
<> 157:ff67d9f36b67 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
<> 157:ff67d9f36b67 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
<> 157:ff67d9f36b67 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
<> 157:ff67d9f36b67 20 * OTHER DEALINGS IN THE SOFTWARE.
<> 157:ff67d9f36b67 21 *
<> 157:ff67d9f36b67 22 * Except as contained in this notice, the name of Maxim Integrated
<> 157:ff67d9f36b67 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
<> 157:ff67d9f36b67 24 * Products, Inc. Branding Policy.
<> 157:ff67d9f36b67 25 *
<> 157:ff67d9f36b67 26 * The mere transfer of this software does not imply any licenses
<> 157:ff67d9f36b67 27 * of trade secrets, proprietary technology, copyrights, patents,
<> 157:ff67d9f36b67 28 * trademarks, maskwork rights, or any other form of intellectual
<> 157:ff67d9f36b67 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
<> 157:ff67d9f36b67 30 * ownership rights.
<> 157:ff67d9f36b67 31 *******************************************************************************
<> 157:ff67d9f36b67 32 */
<> 157:ff67d9f36b67 33
<> 157:ff67d9f36b67 34 #include "rtc_api.h"
<> 157:ff67d9f36b67 35 #include "lp_ticker_api.h"
<> 157:ff67d9f36b67 36 #include "rtc.h"
<> 157:ff67d9f36b67 37 #include "lp.h"
<> 157:ff67d9f36b67 38
<> 157:ff67d9f36b67 39 #define PRESCALE_VAL RTC_PRESCALE_DIV_2_0 // Set the divider for the 4kHz clock
<> 157:ff67d9f36b67 40 #define SHIFT_AMT (RTC_PRESCALE_DIV_2_12 - PRESCALE_VAL)
<> 157:ff67d9f36b67 41
<> 157:ff67d9f36b67 42 #define WINDOW 1000
<> 157:ff67d9f36b67 43
<> 157:ff67d9f36b67 44 static int rtc_inited = 0;
<> 157:ff67d9f36b67 45 static volatile uint32_t overflow_cnt = 0;
<> 157:ff67d9f36b67 46
<> 157:ff67d9f36b67 47 static uint64_t rtc_read64(void);
<> 157:ff67d9f36b67 48
<> 157:ff67d9f36b67 49 //******************************************************************************
<> 157:ff67d9f36b67 50 static void overflow_handler(void)
<> 157:ff67d9f36b67 51 {
<> 157:ff67d9f36b67 52 overflow_cnt++;
<> 157:ff67d9f36b67 53 RTC_ClearFlags(MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS);
<> 157:ff67d9f36b67 54 }
<> 157:ff67d9f36b67 55
<> 157:ff67d9f36b67 56 //******************************************************************************
<> 157:ff67d9f36b67 57 void rtc_init(void)
<> 157:ff67d9f36b67 58 {
<> 157:ff67d9f36b67 59 if (rtc_inited) {
<> 157:ff67d9f36b67 60 return;
<> 157:ff67d9f36b67 61 }
<> 157:ff67d9f36b67 62 rtc_inited = 1;
<> 157:ff67d9f36b67 63
<> 157:ff67d9f36b67 64 overflow_cnt = 0;
<> 157:ff67d9f36b67 65
<> 157:ff67d9f36b67 66 /* Enable power for RTC for all LPx states */
<> 157:ff67d9f36b67 67 MXC_PWRSEQ->reg0 |= (MXC_F_PWRSEQ_REG0_PWR_RTCEN_RUN |
<> 157:ff67d9f36b67 68 MXC_F_PWRSEQ_REG0_PWR_RTCEN_SLP);
<> 157:ff67d9f36b67 69
<> 157:ff67d9f36b67 70 /* Enable clock to synchronizers */
<> 157:ff67d9f36b67 71 CLKMAN_SetClkScale(CLKMAN_CLK_SYNC, CLKMAN_SCALE_DIV_1);
<> 157:ff67d9f36b67 72
<> 157:ff67d9f36b67 73 // Prepare interrupt handlers
<> 157:ff67d9f36b67 74 NVIC_SetVector(RTC0_IRQn, lp_ticker_irq_handler);
<> 157:ff67d9f36b67 75 NVIC_EnableIRQ(RTC0_IRQn);
<> 157:ff67d9f36b67 76 NVIC_SetVector(RTC3_IRQn, overflow_handler);
<> 157:ff67d9f36b67 77 NVIC_EnableIRQ(RTC3_IRQn);
<> 157:ff67d9f36b67 78
<> 157:ff67d9f36b67 79 // Enable wakeup on RTC rollover
<> 157:ff67d9f36b67 80 LP_ConfigRTCWakeUp(0, 0, 0, 1);
<> 157:ff67d9f36b67 81
<> 157:ff67d9f36b67 82 /* RTC registers are only reset on a power cycle. Do not reconfigure the RTC
<> 157:ff67d9f36b67 83 * if it is already running.
<> 157:ff67d9f36b67 84 */
<> 157:ff67d9f36b67 85 if (!RTC_IsActive()) {
<> 157:ff67d9f36b67 86 rtc_cfg_t cfg = {0};
<> 157:ff67d9f36b67 87 cfg.prescaler = PRESCALE_VAL;
<> 157:ff67d9f36b67 88 cfg.snoozeMode = RTC_SNOOZE_DISABLE;
<> 157:ff67d9f36b67 89
<> 157:ff67d9f36b67 90 int retval = RTC_Init(&cfg);
<> 157:ff67d9f36b67 91 MBED_ASSERT(retval == E_NO_ERROR);
<> 157:ff67d9f36b67 92
<> 157:ff67d9f36b67 93 RTC_EnableINT(MXC_F_RTC_FLAGS_OVERFLOW);
<> 157:ff67d9f36b67 94 RTC_Start();
<> 157:ff67d9f36b67 95 }
<> 157:ff67d9f36b67 96 }
<> 157:ff67d9f36b67 97
<> 157:ff67d9f36b67 98 //******************************************************************************
<> 157:ff67d9f36b67 99 void lp_ticker_init(void)
<> 157:ff67d9f36b67 100 {
<> 157:ff67d9f36b67 101 rtc_init();
<> 157:ff67d9f36b67 102 }
<> 157:ff67d9f36b67 103
<> 157:ff67d9f36b67 104 //******************************************************************************
<> 157:ff67d9f36b67 105 void rtc_free(void)
<> 157:ff67d9f36b67 106 {
<> 157:ff67d9f36b67 107 if (RTC_IsActive()) {
<> 157:ff67d9f36b67 108 // Clear and disable RTC
<> 157:ff67d9f36b67 109 MXC_RTCTMR->ctrl |= MXC_F_RTC_CTRL_CLEAR;
<> 157:ff67d9f36b67 110 RTC_Stop();
<> 157:ff67d9f36b67 111 }
<> 157:ff67d9f36b67 112 }
<> 157:ff67d9f36b67 113
<> 157:ff67d9f36b67 114 //******************************************************************************
<> 157:ff67d9f36b67 115 int rtc_isenabled(void)
<> 157:ff67d9f36b67 116 {
<> 157:ff67d9f36b67 117 return RTC_IsActive();
<> 157:ff67d9f36b67 118 }
<> 157:ff67d9f36b67 119
<> 157:ff67d9f36b67 120 //******************************************************************************
<> 157:ff67d9f36b67 121 time_t rtc_read(void)
<> 157:ff67d9f36b67 122 {
<> 157:ff67d9f36b67 123 uint32_t ovf_cnt_1, ovf_cnt_2, timer_cnt;
<> 157:ff67d9f36b67 124 uint32_t ovf1, ovf2;
<> 157:ff67d9f36b67 125
<> 157:ff67d9f36b67 126 // Make sure RTC is setup before trying to read
<> 157:ff67d9f36b67 127 if (!rtc_inited) {
<> 157:ff67d9f36b67 128 rtc_init();
<> 157:ff67d9f36b67 129 }
<> 157:ff67d9f36b67 130
<> 157:ff67d9f36b67 131 // Ensure coherency between overflow_cnt and timer
<> 157:ff67d9f36b67 132 do {
<> 157:ff67d9f36b67 133 ovf_cnt_1 = overflow_cnt;
<> 157:ff67d9f36b67 134 ovf1 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
<> 157:ff67d9f36b67 135 timer_cnt = RTC_GetCount();
<> 157:ff67d9f36b67 136 ovf2 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
<> 157:ff67d9f36b67 137 ovf_cnt_2 = overflow_cnt;
<> 157:ff67d9f36b67 138 } while ((ovf_cnt_1 != ovf_cnt_2) || (ovf1 != ovf2));
<> 157:ff67d9f36b67 139
<> 157:ff67d9f36b67 140 // Account for an unserviced interrupt
<> 157:ff67d9f36b67 141 if (ovf1) {
<> 157:ff67d9f36b67 142 ovf_cnt_1++;
<> 157:ff67d9f36b67 143 }
<> 157:ff67d9f36b67 144
<> 157:ff67d9f36b67 145 return (timer_cnt >> SHIFT_AMT) + (ovf_cnt_1 << (32 - SHIFT_AMT));
<> 157:ff67d9f36b67 146 }
<> 157:ff67d9f36b67 147
<> 157:ff67d9f36b67 148 //******************************************************************************
<> 157:ff67d9f36b67 149 static uint64_t rtc_read64(void)
<> 157:ff67d9f36b67 150 {
<> 157:ff67d9f36b67 151 uint32_t ovf_cnt_1, ovf_cnt_2, timer_cnt;
<> 157:ff67d9f36b67 152 uint32_t ovf1, ovf2;
<> 157:ff67d9f36b67 153 uint64_t current_us;
<> 157:ff67d9f36b67 154
<> 157:ff67d9f36b67 155 // Make sure RTC is setup before trying to read
<> 157:ff67d9f36b67 156 if (!rtc_inited) {
<> 157:ff67d9f36b67 157 rtc_init();
<> 157:ff67d9f36b67 158 }
<> 157:ff67d9f36b67 159
<> 157:ff67d9f36b67 160 // Ensure coherency between overflow_cnt and timer
<> 157:ff67d9f36b67 161 do {
<> 157:ff67d9f36b67 162 ovf_cnt_1 = overflow_cnt;
<> 157:ff67d9f36b67 163 ovf1 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
<> 157:ff67d9f36b67 164 timer_cnt = RTC_GetCount();
<> 157:ff67d9f36b67 165 ovf2 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
<> 157:ff67d9f36b67 166 ovf_cnt_2 = overflow_cnt;
<> 157:ff67d9f36b67 167 } while ((ovf_cnt_1 != ovf_cnt_2) || (ovf1 != ovf2));
<> 157:ff67d9f36b67 168
<> 157:ff67d9f36b67 169 // Account for an unserviced interrupt
<> 157:ff67d9f36b67 170 if (ovf1) {
<> 157:ff67d9f36b67 171 ovf_cnt_1++;
<> 157:ff67d9f36b67 172 }
<> 157:ff67d9f36b67 173
<> 157:ff67d9f36b67 174 current_us = (((uint64_t)timer_cnt * 1000000) >> SHIFT_AMT) + (((uint64_t)ovf_cnt_1 * 1000000) << (32 - SHIFT_AMT));
<> 157:ff67d9f36b67 175
<> 157:ff67d9f36b67 176 return current_us;
<> 157:ff67d9f36b67 177 }
<> 157:ff67d9f36b67 178
<> 157:ff67d9f36b67 179 //******************************************************************************
<> 157:ff67d9f36b67 180 void rtc_write(time_t t)
<> 157:ff67d9f36b67 181 {
<> 157:ff67d9f36b67 182 // Make sure RTC is setup before accessing
<> 157:ff67d9f36b67 183 if (!rtc_inited) {
<> 157:ff67d9f36b67 184 rtc_init();
<> 157:ff67d9f36b67 185 }
<> 157:ff67d9f36b67 186
<> 157:ff67d9f36b67 187 RTC_Stop();
<> 157:ff67d9f36b67 188 RTC_SetCount(t << SHIFT_AMT);
<> 157:ff67d9f36b67 189 overflow_cnt = t >> (32 - SHIFT_AMT);
<> 157:ff67d9f36b67 190 RTC_Start();
<> 157:ff67d9f36b67 191 }
<> 157:ff67d9f36b67 192
<> 157:ff67d9f36b67 193 //******************************************************************************
<> 157:ff67d9f36b67 194 void lp_ticker_set_interrupt(timestamp_t timestamp)
<> 157:ff67d9f36b67 195 {
<> 157:ff67d9f36b67 196 uint32_t comp_value;
<> 157:ff67d9f36b67 197 uint64_t curr_ts64;
<> 157:ff67d9f36b67 198 uint64_t ts64;
<> 157:ff67d9f36b67 199
<> 157:ff67d9f36b67 200 // Note: interrupts are disabled before this function is called.
<> 157:ff67d9f36b67 201
<> 157:ff67d9f36b67 202 // Disable the alarm while it is prepared
<> 157:ff67d9f36b67 203 RTC_DisableINT(MXC_F_RTC_INTEN_COMP0);
<> 157:ff67d9f36b67 204
<> 157:ff67d9f36b67 205 curr_ts64 = rtc_read64();
<> 157:ff67d9f36b67 206 ts64 = (uint64_t)timestamp | (curr_ts64 & 0xFFFFFFFF00000000ULL);
<> 157:ff67d9f36b67 207
<> 157:ff67d9f36b67 208 // If this event is older than a recent window, it must be in the future
<> 157:ff67d9f36b67 209 if ((ts64 < (curr_ts64 - WINDOW)) && ((curr_ts64 - WINDOW) < curr_ts64)) {
<> 157:ff67d9f36b67 210 ts64 += 0x100000000ULL;
<> 157:ff67d9f36b67 211 }
<> 157:ff67d9f36b67 212
<> 157:ff67d9f36b67 213 uint32_t timer = RTC_GetCount();
<> 157:ff67d9f36b67 214 if (ts64 <= curr_ts64) {
<> 157:ff67d9f36b67 215 // This event has already occurred. Set the alarm to expire immediately.
<> 157:ff67d9f36b67 216 comp_value = timer + 1;
<> 157:ff67d9f36b67 217 } else {
<> 157:ff67d9f36b67 218 comp_value = (ts64 << SHIFT_AMT) / 1000000;
<> 157:ff67d9f36b67 219 }
<> 157:ff67d9f36b67 220
<> 157:ff67d9f36b67 221 // Ensure that the compare value is far enough in the future to guarantee the interrupt occurs.
<> 157:ff67d9f36b67 222 if ((comp_value < (timer + 2)) && (comp_value > (timer - 10))) {
<> 157:ff67d9f36b67 223 comp_value = timer + 2;
<> 157:ff67d9f36b67 224 }
<> 157:ff67d9f36b67 225
<> 157:ff67d9f36b67 226 MXC_RTCTMR->comp[0] = comp_value;
<> 157:ff67d9f36b67 227 MXC_RTCTMR->flags = MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS;
<> 157:ff67d9f36b67 228 RTC_EnableINT(MXC_F_RTC_INTEN_COMP0);
<> 157:ff67d9f36b67 229
<> 157:ff67d9f36b67 230 // Enable wakeup from RTC
<> 157:ff67d9f36b67 231 LP_ConfigRTCWakeUp(1, 0, 0, 1);
<> 157:ff67d9f36b67 232
<> 157:ff67d9f36b67 233 // Wait for pending transactions
<> 157:ff67d9f36b67 234 while (MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_PENDING);
<> 157:ff67d9f36b67 235 }
<> 157:ff67d9f36b67 236
<> 157:ff67d9f36b67 237 //******************************************************************************
<> 157:ff67d9f36b67 238 inline void lp_ticker_disable_interrupt(void)
<> 157:ff67d9f36b67 239 {
<> 157:ff67d9f36b67 240 RTC_DisableINT(MXC_F_RTC_INTEN_COMP0);
<> 157:ff67d9f36b67 241 }
<> 157:ff67d9f36b67 242
<> 157:ff67d9f36b67 243 //******************************************************************************
<> 157:ff67d9f36b67 244 inline void lp_ticker_clear_interrupt(void)
<> 157:ff67d9f36b67 245 {
<> 157:ff67d9f36b67 246 RTC_ClearFlags(MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS);
<> 157:ff67d9f36b67 247 }
<> 157:ff67d9f36b67 248
<> 157:ff67d9f36b67 249 //******************************************************************************
<> 157:ff67d9f36b67 250 inline uint32_t lp_ticker_read(void)
<> 157:ff67d9f36b67 251 {
<> 157:ff67d9f36b67 252 return rtc_read64();
<> 157:ff67d9f36b67 253 }