BA / SerialCom

Fork of OmniWheels by Gustav Atmel

Committer:
gustavatmel
Date:
Tue May 01 15:47:08 2018 +0000
Revision:
1:9c5af431a1f1
sdf

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gustavatmel 1:9c5af431a1f1 1 /*******************************************************************************
gustavatmel 1:9c5af431a1f1 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
gustavatmel 1:9c5af431a1f1 3 *
gustavatmel 1:9c5af431a1f1 4 * Permission is hereby granted, free of charge, to any person obtaining a
gustavatmel 1:9c5af431a1f1 5 * copy of this software and associated documentation files (the "Software"),
gustavatmel 1:9c5af431a1f1 6 * to deal in the Software without restriction, including without limitation
gustavatmel 1:9c5af431a1f1 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
gustavatmel 1:9c5af431a1f1 8 * and/or sell copies of the Software, and to permit persons to whom the
gustavatmel 1:9c5af431a1f1 9 * Software is furnished to do so, subject to the following conditions:
gustavatmel 1:9c5af431a1f1 10 *
gustavatmel 1:9c5af431a1f1 11 * The above copyright notice and this permission notice shall be included
gustavatmel 1:9c5af431a1f1 12 * in all copies or substantial portions of the Software.
gustavatmel 1:9c5af431a1f1 13 *
gustavatmel 1:9c5af431a1f1 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
gustavatmel 1:9c5af431a1f1 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
gustavatmel 1:9c5af431a1f1 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
gustavatmel 1:9c5af431a1f1 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
gustavatmel 1:9c5af431a1f1 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
gustavatmel 1:9c5af431a1f1 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
gustavatmel 1:9c5af431a1f1 20 * OTHER DEALINGS IN THE SOFTWARE.
gustavatmel 1:9c5af431a1f1 21 *
gustavatmel 1:9c5af431a1f1 22 * Except as contained in this notice, the name of Maxim Integrated
gustavatmel 1:9c5af431a1f1 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
gustavatmel 1:9c5af431a1f1 24 * Products, Inc. Branding Policy.
gustavatmel 1:9c5af431a1f1 25 *
gustavatmel 1:9c5af431a1f1 26 * The mere transfer of this software does not imply any licenses
gustavatmel 1:9c5af431a1f1 27 * of trade secrets, proprietary technology, copyrights, patents,
gustavatmel 1:9c5af431a1f1 28 * trademarks, maskwork rights, or any other form of intellectual
gustavatmel 1:9c5af431a1f1 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
gustavatmel 1:9c5af431a1f1 30 * ownership rights.
gustavatmel 1:9c5af431a1f1 31 *******************************************************************************
gustavatmel 1:9c5af431a1f1 32 */
gustavatmel 1:9c5af431a1f1 33
gustavatmel 1:9c5af431a1f1 34 #include "rtc_api.h"
gustavatmel 1:9c5af431a1f1 35 #include "lp_ticker_api.h"
gustavatmel 1:9c5af431a1f1 36 #include "rtc.h"
gustavatmel 1:9c5af431a1f1 37 #include "lp.h"
gustavatmel 1:9c5af431a1f1 38
gustavatmel 1:9c5af431a1f1 39 #define PRESCALE_VAL RTC_PRESCALE_DIV_2_0 // Set the divider for the 4kHz clock
gustavatmel 1:9c5af431a1f1 40 #define SHIFT_AMT (RTC_PRESCALE_DIV_2_12 - PRESCALE_VAL)
gustavatmel 1:9c5af431a1f1 41
gustavatmel 1:9c5af431a1f1 42 #define WINDOW 1000
gustavatmel 1:9c5af431a1f1 43
gustavatmel 1:9c5af431a1f1 44 static int rtc_inited = 0;
gustavatmel 1:9c5af431a1f1 45 static volatile uint32_t overflow_cnt = 0;
gustavatmel 1:9c5af431a1f1 46
gustavatmel 1:9c5af431a1f1 47 static uint64_t rtc_read64(void);
gustavatmel 1:9c5af431a1f1 48
gustavatmel 1:9c5af431a1f1 49 //******************************************************************************
gustavatmel 1:9c5af431a1f1 50 static void overflow_handler(void)
gustavatmel 1:9c5af431a1f1 51 {
gustavatmel 1:9c5af431a1f1 52 overflow_cnt++;
gustavatmel 1:9c5af431a1f1 53 RTC_ClearFlags(MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS);
gustavatmel 1:9c5af431a1f1 54 }
gustavatmel 1:9c5af431a1f1 55
gustavatmel 1:9c5af431a1f1 56 //******************************************************************************
gustavatmel 1:9c5af431a1f1 57 void rtc_init(void)
gustavatmel 1:9c5af431a1f1 58 {
gustavatmel 1:9c5af431a1f1 59 if (rtc_inited) {
gustavatmel 1:9c5af431a1f1 60 return;
gustavatmel 1:9c5af431a1f1 61 }
gustavatmel 1:9c5af431a1f1 62 rtc_inited = 1;
gustavatmel 1:9c5af431a1f1 63
gustavatmel 1:9c5af431a1f1 64 overflow_cnt = 0;
gustavatmel 1:9c5af431a1f1 65
gustavatmel 1:9c5af431a1f1 66 /* Enable power for RTC for all LPx states */
gustavatmel 1:9c5af431a1f1 67 MXC_PWRSEQ->reg0 |= (MXC_F_PWRSEQ_REG0_PWR_RTCEN_RUN |
gustavatmel 1:9c5af431a1f1 68 MXC_F_PWRSEQ_REG0_PWR_RTCEN_SLP);
gustavatmel 1:9c5af431a1f1 69
gustavatmel 1:9c5af431a1f1 70 /* Enable clock to synchronizers */
gustavatmel 1:9c5af431a1f1 71 CLKMAN_SetClkScale(CLKMAN_CLK_SYNC, CLKMAN_SCALE_DIV_1);
gustavatmel 1:9c5af431a1f1 72
gustavatmel 1:9c5af431a1f1 73 // Prepare interrupt handlers
gustavatmel 1:9c5af431a1f1 74 NVIC_SetVector(RTC0_IRQn, (uint32_t)lp_ticker_irq_handler);
gustavatmel 1:9c5af431a1f1 75 NVIC_EnableIRQ(RTC0_IRQn);
gustavatmel 1:9c5af431a1f1 76 NVIC_SetVector(RTC3_IRQn, (uint32_t)overflow_handler);
gustavatmel 1:9c5af431a1f1 77 NVIC_EnableIRQ(RTC3_IRQn);
gustavatmel 1:9c5af431a1f1 78
gustavatmel 1:9c5af431a1f1 79 // Enable wakeup on RTC rollover
gustavatmel 1:9c5af431a1f1 80 LP_ConfigRTCWakeUp(0, 0, 0, 1);
gustavatmel 1:9c5af431a1f1 81
gustavatmel 1:9c5af431a1f1 82 /* RTC registers are only reset on a power cycle. Do not reconfigure the RTC
gustavatmel 1:9c5af431a1f1 83 * if it is already running.
gustavatmel 1:9c5af431a1f1 84 */
gustavatmel 1:9c5af431a1f1 85 if (!RTC_IsActive()) {
gustavatmel 1:9c5af431a1f1 86 rtc_cfg_t cfg = {0};
gustavatmel 1:9c5af431a1f1 87 cfg.prescaler = PRESCALE_VAL;
gustavatmel 1:9c5af431a1f1 88 cfg.snoozeMode = RTC_SNOOZE_DISABLE;
gustavatmel 1:9c5af431a1f1 89
gustavatmel 1:9c5af431a1f1 90 int retval = RTC_Init(&cfg);
gustavatmel 1:9c5af431a1f1 91 MBED_ASSERT(retval == E_NO_ERROR);
gustavatmel 1:9c5af431a1f1 92
gustavatmel 1:9c5af431a1f1 93 RTC_EnableINT(MXC_F_RTC_FLAGS_OVERFLOW);
gustavatmel 1:9c5af431a1f1 94 RTC_Start();
gustavatmel 1:9c5af431a1f1 95 }
gustavatmel 1:9c5af431a1f1 96 }
gustavatmel 1:9c5af431a1f1 97
gustavatmel 1:9c5af431a1f1 98 //******************************************************************************
gustavatmel 1:9c5af431a1f1 99 void lp_ticker_init(void)
gustavatmel 1:9c5af431a1f1 100 {
gustavatmel 1:9c5af431a1f1 101 rtc_init();
gustavatmel 1:9c5af431a1f1 102 }
gustavatmel 1:9c5af431a1f1 103
gustavatmel 1:9c5af431a1f1 104 //******************************************************************************
gustavatmel 1:9c5af431a1f1 105 void rtc_free(void)
gustavatmel 1:9c5af431a1f1 106 {
gustavatmel 1:9c5af431a1f1 107 if (RTC_IsActive()) {
gustavatmel 1:9c5af431a1f1 108 // Clear and disable RTC
gustavatmel 1:9c5af431a1f1 109 MXC_RTCTMR->ctrl |= MXC_F_RTC_CTRL_CLEAR;
gustavatmel 1:9c5af431a1f1 110 RTC_Stop();
gustavatmel 1:9c5af431a1f1 111 }
gustavatmel 1:9c5af431a1f1 112 }
gustavatmel 1:9c5af431a1f1 113
gustavatmel 1:9c5af431a1f1 114 //******************************************************************************
gustavatmel 1:9c5af431a1f1 115 int rtc_isenabled(void)
gustavatmel 1:9c5af431a1f1 116 {
gustavatmel 1:9c5af431a1f1 117 return RTC_IsActive();
gustavatmel 1:9c5af431a1f1 118 }
gustavatmel 1:9c5af431a1f1 119
gustavatmel 1:9c5af431a1f1 120 //******************************************************************************
gustavatmel 1:9c5af431a1f1 121 time_t rtc_read(void)
gustavatmel 1:9c5af431a1f1 122 {
gustavatmel 1:9c5af431a1f1 123 uint32_t ovf_cnt_1, ovf_cnt_2, timer_cnt;
gustavatmel 1:9c5af431a1f1 124 uint32_t ovf1, ovf2;
gustavatmel 1:9c5af431a1f1 125
gustavatmel 1:9c5af431a1f1 126 // Make sure RTC is setup before trying to read
gustavatmel 1:9c5af431a1f1 127 if (!rtc_inited) {
gustavatmel 1:9c5af431a1f1 128 rtc_init();
gustavatmel 1:9c5af431a1f1 129 }
gustavatmel 1:9c5af431a1f1 130
gustavatmel 1:9c5af431a1f1 131 // Ensure coherency between overflow_cnt and timer
gustavatmel 1:9c5af431a1f1 132 do {
gustavatmel 1:9c5af431a1f1 133 ovf_cnt_1 = overflow_cnt;
gustavatmel 1:9c5af431a1f1 134 ovf1 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
gustavatmel 1:9c5af431a1f1 135 timer_cnt = RTC_GetCount();
gustavatmel 1:9c5af431a1f1 136 ovf2 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
gustavatmel 1:9c5af431a1f1 137 ovf_cnt_2 = overflow_cnt;
gustavatmel 1:9c5af431a1f1 138 } while ((ovf_cnt_1 != ovf_cnt_2) || (ovf1 != ovf2));
gustavatmel 1:9c5af431a1f1 139
gustavatmel 1:9c5af431a1f1 140 // Account for an unserviced interrupt
gustavatmel 1:9c5af431a1f1 141 if (ovf1) {
gustavatmel 1:9c5af431a1f1 142 ovf_cnt_1++;
gustavatmel 1:9c5af431a1f1 143 }
gustavatmel 1:9c5af431a1f1 144
gustavatmel 1:9c5af431a1f1 145 return (timer_cnt >> SHIFT_AMT) + (ovf_cnt_1 << (32 - SHIFT_AMT));
gustavatmel 1:9c5af431a1f1 146 }
gustavatmel 1:9c5af431a1f1 147
gustavatmel 1:9c5af431a1f1 148 //******************************************************************************
gustavatmel 1:9c5af431a1f1 149 static uint64_t rtc_read64(void)
gustavatmel 1:9c5af431a1f1 150 {
gustavatmel 1:9c5af431a1f1 151 uint32_t ovf_cnt_1, ovf_cnt_2, timer_cnt;
gustavatmel 1:9c5af431a1f1 152 uint32_t ovf1, ovf2;
gustavatmel 1:9c5af431a1f1 153 uint64_t current_us;
gustavatmel 1:9c5af431a1f1 154
gustavatmel 1:9c5af431a1f1 155 // Make sure RTC is setup before trying to read
gustavatmel 1:9c5af431a1f1 156 if (!rtc_inited) {
gustavatmel 1:9c5af431a1f1 157 rtc_init();
gustavatmel 1:9c5af431a1f1 158 }
gustavatmel 1:9c5af431a1f1 159
gustavatmel 1:9c5af431a1f1 160 // Ensure coherency between overflow_cnt and timer
gustavatmel 1:9c5af431a1f1 161 do {
gustavatmel 1:9c5af431a1f1 162 ovf_cnt_1 = overflow_cnt;
gustavatmel 1:9c5af431a1f1 163 ovf1 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
gustavatmel 1:9c5af431a1f1 164 timer_cnt = RTC_GetCount();
gustavatmel 1:9c5af431a1f1 165 ovf2 = RTC_GetFlags() & MXC_F_RTC_FLAGS_OVERFLOW;
gustavatmel 1:9c5af431a1f1 166 ovf_cnt_2 = overflow_cnt;
gustavatmel 1:9c5af431a1f1 167 } while ((ovf_cnt_1 != ovf_cnt_2) || (ovf1 != ovf2));
gustavatmel 1:9c5af431a1f1 168
gustavatmel 1:9c5af431a1f1 169 // Account for an unserviced interrupt
gustavatmel 1:9c5af431a1f1 170 if (ovf1) {
gustavatmel 1:9c5af431a1f1 171 ovf_cnt_1++;
gustavatmel 1:9c5af431a1f1 172 }
gustavatmel 1:9c5af431a1f1 173
gustavatmel 1:9c5af431a1f1 174 current_us = (((uint64_t)timer_cnt * 1000000) >> SHIFT_AMT) + (((uint64_t)ovf_cnt_1 * 1000000) << (32 - SHIFT_AMT));
gustavatmel 1:9c5af431a1f1 175
gustavatmel 1:9c5af431a1f1 176 return current_us;
gustavatmel 1:9c5af431a1f1 177 }
gustavatmel 1:9c5af431a1f1 178
gustavatmel 1:9c5af431a1f1 179 //******************************************************************************
gustavatmel 1:9c5af431a1f1 180 void rtc_write(time_t t)
gustavatmel 1:9c5af431a1f1 181 {
gustavatmel 1:9c5af431a1f1 182 // Make sure RTC is setup before accessing
gustavatmel 1:9c5af431a1f1 183 if (!rtc_inited) {
gustavatmel 1:9c5af431a1f1 184 rtc_init();
gustavatmel 1:9c5af431a1f1 185 }
gustavatmel 1:9c5af431a1f1 186
gustavatmel 1:9c5af431a1f1 187 RTC_Stop();
gustavatmel 1:9c5af431a1f1 188 RTC_SetCount(t << SHIFT_AMT);
gustavatmel 1:9c5af431a1f1 189 overflow_cnt = t >> (32 - SHIFT_AMT);
gustavatmel 1:9c5af431a1f1 190 RTC_Start();
gustavatmel 1:9c5af431a1f1 191 }
gustavatmel 1:9c5af431a1f1 192
gustavatmel 1:9c5af431a1f1 193 //******************************************************************************
gustavatmel 1:9c5af431a1f1 194 void lp_ticker_set_interrupt(timestamp_t timestamp)
gustavatmel 1:9c5af431a1f1 195 {
gustavatmel 1:9c5af431a1f1 196 uint32_t comp_value;
gustavatmel 1:9c5af431a1f1 197 uint64_t curr_ts64;
gustavatmel 1:9c5af431a1f1 198 uint64_t ts64;
gustavatmel 1:9c5af431a1f1 199
gustavatmel 1:9c5af431a1f1 200 // Note: interrupts are disabled before this function is called.
gustavatmel 1:9c5af431a1f1 201
gustavatmel 1:9c5af431a1f1 202 // Disable the alarm while it is prepared
gustavatmel 1:9c5af431a1f1 203 RTC_DisableINT(MXC_F_RTC_INTEN_COMP0);
gustavatmel 1:9c5af431a1f1 204
gustavatmel 1:9c5af431a1f1 205 curr_ts64 = rtc_read64();
gustavatmel 1:9c5af431a1f1 206 ts64 = (uint64_t)timestamp | (curr_ts64 & 0xFFFFFFFF00000000ULL);
gustavatmel 1:9c5af431a1f1 207
gustavatmel 1:9c5af431a1f1 208 // If this event is older than a recent window, it must be in the future
gustavatmel 1:9c5af431a1f1 209 if ((ts64 < (curr_ts64 - WINDOW)) && ((curr_ts64 - WINDOW) < curr_ts64)) {
gustavatmel 1:9c5af431a1f1 210 ts64 += 0x100000000ULL;
gustavatmel 1:9c5af431a1f1 211 }
gustavatmel 1:9c5af431a1f1 212
gustavatmel 1:9c5af431a1f1 213 uint32_t timer = RTC_GetCount();
gustavatmel 1:9c5af431a1f1 214 if (ts64 <= curr_ts64) {
gustavatmel 1:9c5af431a1f1 215 // This event has already occurred. Set the alarm to expire immediately.
gustavatmel 1:9c5af431a1f1 216 comp_value = timer + 1;
gustavatmel 1:9c5af431a1f1 217 } else {
gustavatmel 1:9c5af431a1f1 218 comp_value = (ts64 << SHIFT_AMT) / 1000000;
gustavatmel 1:9c5af431a1f1 219 }
gustavatmel 1:9c5af431a1f1 220
gustavatmel 1:9c5af431a1f1 221 // Ensure that the compare value is far enough in the future to guarantee the interrupt occurs.
gustavatmel 1:9c5af431a1f1 222 if ((comp_value < (timer + 2)) && (comp_value > (timer - 10))) {
gustavatmel 1:9c5af431a1f1 223 comp_value = timer + 2;
gustavatmel 1:9c5af431a1f1 224 }
gustavatmel 1:9c5af431a1f1 225
gustavatmel 1:9c5af431a1f1 226 MXC_RTCTMR->comp[0] = comp_value;
gustavatmel 1:9c5af431a1f1 227 MXC_RTCTMR->flags = MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS;
gustavatmel 1:9c5af431a1f1 228 RTC_EnableINT(MXC_F_RTC_INTEN_COMP0);
gustavatmel 1:9c5af431a1f1 229
gustavatmel 1:9c5af431a1f1 230 // Enable wakeup from RTC
gustavatmel 1:9c5af431a1f1 231 LP_ConfigRTCWakeUp(1, 0, 0, 1);
gustavatmel 1:9c5af431a1f1 232
gustavatmel 1:9c5af431a1f1 233 // Wait for pending transactions
gustavatmel 1:9c5af431a1f1 234 while (MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_PENDING);
gustavatmel 1:9c5af431a1f1 235 }
gustavatmel 1:9c5af431a1f1 236
gustavatmel 1:9c5af431a1f1 237 void lp_ticker_fire_interrupt(void)
gustavatmel 1:9c5af431a1f1 238 {
gustavatmel 1:9c5af431a1f1 239 NVIC_SetPendingIRQ(RTC0_IRQn);
gustavatmel 1:9c5af431a1f1 240 }
gustavatmel 1:9c5af431a1f1 241
gustavatmel 1:9c5af431a1f1 242 //******************************************************************************
gustavatmel 1:9c5af431a1f1 243 inline void lp_ticker_disable_interrupt(void)
gustavatmel 1:9c5af431a1f1 244 {
gustavatmel 1:9c5af431a1f1 245 RTC_DisableINT(MXC_F_RTC_INTEN_COMP0);
gustavatmel 1:9c5af431a1f1 246 }
gustavatmel 1:9c5af431a1f1 247
gustavatmel 1:9c5af431a1f1 248 //******************************************************************************
gustavatmel 1:9c5af431a1f1 249 inline void lp_ticker_clear_interrupt(void)
gustavatmel 1:9c5af431a1f1 250 {
gustavatmel 1:9c5af431a1f1 251 RTC_ClearFlags(MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS);
gustavatmel 1:9c5af431a1f1 252 }
gustavatmel 1:9c5af431a1f1 253
gustavatmel 1:9c5af431a1f1 254 //******************************************************************************
gustavatmel 1:9c5af431a1f1 255 inline uint32_t lp_ticker_read(void)
gustavatmel 1:9c5af431a1f1 256 {
gustavatmel 1:9c5af431a1f1 257 return rtc_read64();
gustavatmel 1:9c5af431a1f1 258 }