Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Maxim/TARGET_MAX32610/rtc_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Child:
144:ef7eb2e8f9f7
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /*******************************************************************************
bogdanm 0:9b334a45a8ff 2 * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
bogdanm 0:9b334a45a8ff 3 *
bogdanm 0:9b334a45a8ff 4 * Permission is hereby granted, free of charge, to any person obtaining a
bogdanm 0:9b334a45a8ff 5 * copy of this software and associated documentation files (the "Software"),
bogdanm 0:9b334a45a8ff 6 * to deal in the Software without restriction, including without limitation
bogdanm 0:9b334a45a8ff 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
bogdanm 0:9b334a45a8ff 8 * and/or sell copies of the Software, and to permit persons to whom the
bogdanm 0:9b334a45a8ff 9 * Software is furnished to do so, subject to the following conditions:
bogdanm 0:9b334a45a8ff 10 *
bogdanm 0:9b334a45a8ff 11 * The above copyright notice and this permission notice shall be included
bogdanm 0:9b334a45a8ff 12 * in all copies or substantial portions of the Software.
bogdanm 0:9b334a45a8ff 13 *
bogdanm 0:9b334a45a8ff 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
bogdanm 0:9b334a45a8ff 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
bogdanm 0:9b334a45a8ff 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
bogdanm 0:9b334a45a8ff 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
bogdanm 0:9b334a45a8ff 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
bogdanm 0:9b334a45a8ff 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
bogdanm 0:9b334a45a8ff 20 * OTHER DEALINGS IN THE SOFTWARE.
bogdanm 0:9b334a45a8ff 21 *
bogdanm 0:9b334a45a8ff 22 * Except as contained in this notice, the name of Maxim Integrated
bogdanm 0:9b334a45a8ff 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
bogdanm 0:9b334a45a8ff 24 * Products, Inc. Branding Policy.
bogdanm 0:9b334a45a8ff 25 *
bogdanm 0:9b334a45a8ff 26 * The mere transfer of this software does not imply any licenses
bogdanm 0:9b334a45a8ff 27 * of trade secrets, proprietary technology, copyrights, patents,
bogdanm 0:9b334a45a8ff 28 * trademarks, maskwork rights, or any other form of intellectual
bogdanm 0:9b334a45a8ff 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
bogdanm 0:9b334a45a8ff 30 * ownership rights.
bogdanm 0:9b334a45a8ff 31 *******************************************************************************
bogdanm 0:9b334a45a8ff 32 */
bogdanm 0:9b334a45a8ff 33
bogdanm 0:9b334a45a8ff 34 #include "rtc_api.h"
bogdanm 0:9b334a45a8ff 35 #include "lp_ticker_api.h"
bogdanm 0:9b334a45a8ff 36 #include "cmsis.h"
bogdanm 0:9b334a45a8ff 37 #include "rtc_regs.h"
bogdanm 0:9b334a45a8ff 38 #include "pwrseq_regs.h"
bogdanm 0:9b334a45a8ff 39 #include "clkman_regs.h"
bogdanm 0:9b334a45a8ff 40
bogdanm 0:9b334a45a8ff 41 #define PRESCALE_VAL MXC_E_RTC_PRESCALE_DIV_2_0 // Set the divider for the 4kHz clock
bogdanm 0:9b334a45a8ff 42 #define SHIFT_AMT (MXC_E_RTC_PRESCALE_DIV_2_12 - PRESCALE_VAL)
bogdanm 0:9b334a45a8ff 43
bogdanm 0:9b334a45a8ff 44 #define WINDOW 1000
bogdanm 0:9b334a45a8ff 45
bogdanm 0:9b334a45a8ff 46 static int rtc_inited = 0;
bogdanm 0:9b334a45a8ff 47 static volatile uint32_t overflow_cnt = 0;
bogdanm 0:9b334a45a8ff 48
bogdanm 0:9b334a45a8ff 49 static uint64_t rtc_read64(void);
bogdanm 0:9b334a45a8ff 50
bogdanm 0:9b334a45a8ff 51 //******************************************************************************
bogdanm 0:9b334a45a8ff 52 static void overflow_handler(void)
bogdanm 0:9b334a45a8ff 53 {
bogdanm 0:9b334a45a8ff 54 MXC_RTCTMR->flags = MXC_F_RTC_FLAGS_OVERFLOW;
bogdanm 0:9b334a45a8ff 55 MXC_PWRSEQ->flags = MXC_F_PWRSEQ_MSK_FLAGS_RTC_ROLLOVER;
bogdanm 0:9b334a45a8ff 56 overflow_cnt++;
bogdanm 0:9b334a45a8ff 57 }
bogdanm 0:9b334a45a8ff 58
bogdanm 0:9b334a45a8ff 59 //******************************************************************************
bogdanm 0:9b334a45a8ff 60 void rtc_init(void)
bogdanm 0:9b334a45a8ff 61 {
bogdanm 0:9b334a45a8ff 62 if (rtc_inited) {
bogdanm 0:9b334a45a8ff 63 return;
bogdanm 0:9b334a45a8ff 64 }
bogdanm 0:9b334a45a8ff 65 rtc_inited = 1;
bogdanm 0:9b334a45a8ff 66
bogdanm 0:9b334a45a8ff 67 overflow_cnt = 0;
bogdanm 0:9b334a45a8ff 68
bogdanm 0:9b334a45a8ff 69 // Enable the clock to the synchronizer
bogdanm 0:9b334a45a8ff 70 MXC_CLKMAN->clk_ctrl_13_rtc_int_sync = MXC_E_CLKMAN_CLK_SCALE_ENABLED;
bogdanm 0:9b334a45a8ff 71
bogdanm 0:9b334a45a8ff 72 // Enable the clock to the RTC
bogdanm 0:9b334a45a8ff 73 MXC_PWRSEQ->reg0 |= MXC_F_PWRSEQ_REG0_PWR_RTCEN_RUN;
bogdanm 0:9b334a45a8ff 74
bogdanm 0:9b334a45a8ff 75 // Prepare interrupt handlers
bogdanm 0:9b334a45a8ff 76 NVIC_SetVector(RTC0_IRQn, (uint32_t)lp_ticker_irq_handler);
bogdanm 0:9b334a45a8ff 77 NVIC_EnableIRQ(RTC0_IRQn);
bogdanm 0:9b334a45a8ff 78 NVIC_SetVector(RTC3_IRQn, (uint32_t)overflow_handler);
bogdanm 0:9b334a45a8ff 79 NVIC_EnableIRQ(RTC3_IRQn);
bogdanm 0:9b334a45a8ff 80
bogdanm 0:9b334a45a8ff 81 // Enable wakeup on RTC rollover
bogdanm 0:9b334a45a8ff 82 MXC_PWRSEQ->msk_flags &= ~MXC_F_PWRSEQ_MSK_FLAGS_RTC_ROLLOVER;
bogdanm 0:9b334a45a8ff 83
bogdanm 0:9b334a45a8ff 84 /* RTC registers are only reset on a power cycle. Do not reconfigure the RTC
bogdanm 0:9b334a45a8ff 85 * if it is already running.
bogdanm 0:9b334a45a8ff 86 */
bogdanm 0:9b334a45a8ff 87 if (!(MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_ENABLE)) {
bogdanm 0:9b334a45a8ff 88 // Set the clock divider
bogdanm 0:9b334a45a8ff 89 MXC_RTCTMR->prescale = PRESCALE_VAL;
bogdanm 0:9b334a45a8ff 90
bogdanm 0:9b334a45a8ff 91 // Enable the overflow interrupt
bogdanm 0:9b334a45a8ff 92 MXC_RTCTMR->inten |= MXC_F_RTC_FLAGS_OVERFLOW;
bogdanm 0:9b334a45a8ff 93
bogdanm 0:9b334a45a8ff 94 // Restart the timer from 0
bogdanm 0:9b334a45a8ff 95 MXC_RTCTMR->timer = 0;
bogdanm 0:9b334a45a8ff 96
bogdanm 0:9b334a45a8ff 97 // Enable the RTC
bogdanm 0:9b334a45a8ff 98 MXC_RTCTMR->ctrl |= MXC_F_RTC_CTRL_ENABLE;
bogdanm 0:9b334a45a8ff 99 }
bogdanm 0:9b334a45a8ff 100 }
bogdanm 0:9b334a45a8ff 101
bogdanm 0:9b334a45a8ff 102 //******************************************************************************
bogdanm 0:9b334a45a8ff 103 void lp_ticker_init(void)
bogdanm 0:9b334a45a8ff 104 {
bogdanm 0:9b334a45a8ff 105 rtc_init();
bogdanm 0:9b334a45a8ff 106 }
bogdanm 0:9b334a45a8ff 107
bogdanm 0:9b334a45a8ff 108 //******************************************************************************
bogdanm 0:9b334a45a8ff 109 void rtc_free(void)
bogdanm 0:9b334a45a8ff 110 {
bogdanm 0:9b334a45a8ff 111 if (MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_ENABLE) {
bogdanm 0:9b334a45a8ff 112 // Clear and disable RTC
bogdanm 0:9b334a45a8ff 113 MXC_RTCTMR->ctrl |= MXC_F_RTC_CTRL_CLEAR;
bogdanm 0:9b334a45a8ff 114 MXC_RTCTMR->ctrl &= ~MXC_F_RTC_CTRL_ENABLE;
bogdanm 0:9b334a45a8ff 115
bogdanm 0:9b334a45a8ff 116 // Wait for pending transactions
bogdanm 0:9b334a45a8ff 117 while(MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_PENDING);
bogdanm 0:9b334a45a8ff 118 }
bogdanm 0:9b334a45a8ff 119
bogdanm 0:9b334a45a8ff 120 // Disable the clock to the RTC
bogdanm 0:9b334a45a8ff 121 MXC_PWRSEQ->reg0 &= ~(MXC_F_PWRSEQ_REG0_PWR_RTCEN_RUN | MXC_F_PWRSEQ_REG0_PWR_RTCEN_SLP);
bogdanm 0:9b334a45a8ff 122
bogdanm 0:9b334a45a8ff 123 // Disable the clock to the synchronizer
bogdanm 0:9b334a45a8ff 124 MXC_CLKMAN->clk_ctrl_13_rtc_int_sync = MXC_E_CLKMAN_CLK_SCALE_DISABLED;
bogdanm 0:9b334a45a8ff 125 }
bogdanm 0:9b334a45a8ff 126
bogdanm 0:9b334a45a8ff 127 //******************************************************************************
bogdanm 0:9b334a45a8ff 128 int rtc_isenabled(void)
bogdanm 0:9b334a45a8ff 129 {
bogdanm 0:9b334a45a8ff 130 return (MXC_RTCTMR->ctrl & MXC_F_RTC_CTRL_ENABLE);
bogdanm 0:9b334a45a8ff 131 }
bogdanm 0:9b334a45a8ff 132
bogdanm 0:9b334a45a8ff 133 //******************************************************************************
bogdanm 0:9b334a45a8ff 134 time_t rtc_read(void)
bogdanm 0:9b334a45a8ff 135 {
bogdanm 0:9b334a45a8ff 136 uint32_t ovf_cnt_1, ovf_cnt_2, timer_cnt;
bogdanm 0:9b334a45a8ff 137 uint32_t ovf1, ovf2;
bogdanm 0:9b334a45a8ff 138
bogdanm 0:9b334a45a8ff 139 // Ensure coherency between overflow_cnt and timer
bogdanm 0:9b334a45a8ff 140 do {
bogdanm 0:9b334a45a8ff 141 ovf_cnt_1 = overflow_cnt;
bogdanm 0:9b334a45a8ff 142 ovf1 = MXC_RTCTMR->flags & MXC_F_RTC_FLAGS_OVERFLOW;
bogdanm 0:9b334a45a8ff 143 timer_cnt = MXC_RTCTMR->timer;
bogdanm 0:9b334a45a8ff 144 ovf2 = MXC_RTCTMR->flags & MXC_F_RTC_FLAGS_OVERFLOW;
bogdanm 0:9b334a45a8ff 145 ovf_cnt_2 = overflow_cnt;
bogdanm 0:9b334a45a8ff 146 } while ((ovf_cnt_1 != ovf_cnt_2) || (ovf1 != ovf2));
bogdanm 0:9b334a45a8ff 147
bogdanm 0:9b334a45a8ff 148 // Account for an unserviced interrupt
bogdanm 0:9b334a45a8ff 149 if (ovf1) {
bogdanm 0:9b334a45a8ff 150 ovf_cnt_1++;
bogdanm 0:9b334a45a8ff 151 }
bogdanm 0:9b334a45a8ff 152
bogdanm 0:9b334a45a8ff 153 return (timer_cnt >> SHIFT_AMT) + (ovf_cnt_1 << (32 - SHIFT_AMT));
bogdanm 0:9b334a45a8ff 154 }
bogdanm 0:9b334a45a8ff 155
bogdanm 0:9b334a45a8ff 156 //******************************************************************************
bogdanm 0:9b334a45a8ff 157 static uint64_t rtc_read64(void)
bogdanm 0:9b334a45a8ff 158 {
bogdanm 0:9b334a45a8ff 159 uint32_t ovf_cnt_1, ovf_cnt_2, timer_cnt;
bogdanm 0:9b334a45a8ff 160 uint32_t ovf1, ovf2;
bogdanm 0:9b334a45a8ff 161 uint64_t current_us;
bogdanm 0:9b334a45a8ff 162
bogdanm 0:9b334a45a8ff 163 // Ensure coherency between overflow_cnt and timer
bogdanm 0:9b334a45a8ff 164 do {
bogdanm 0:9b334a45a8ff 165 ovf_cnt_1 = overflow_cnt;
bogdanm 0:9b334a45a8ff 166 ovf1 = MXC_RTCTMR->flags & MXC_F_RTC_FLAGS_OVERFLOW;
bogdanm 0:9b334a45a8ff 167 timer_cnt = MXC_RTCTMR->timer;
bogdanm 0:9b334a45a8ff 168 ovf2 = MXC_RTCTMR->flags & MXC_F_RTC_FLAGS_OVERFLOW;
bogdanm 0:9b334a45a8ff 169 ovf_cnt_2 = overflow_cnt;
bogdanm 0:9b334a45a8ff 170 } while ((ovf_cnt_1 != ovf_cnt_2) || (ovf1 != ovf2));
bogdanm 0:9b334a45a8ff 171
bogdanm 0:9b334a45a8ff 172 // Account for an unserviced interrupt
bogdanm 0:9b334a45a8ff 173 if (ovf1) {
bogdanm 0:9b334a45a8ff 174 ovf_cnt_1++;
bogdanm 0:9b334a45a8ff 175 }
bogdanm 0:9b334a45a8ff 176
bogdanm 0:9b334a45a8ff 177 current_us = (((uint64_t)timer_cnt * 1000000) >> SHIFT_AMT) + (((uint64_t)ovf_cnt_1 * 1000000) << (32 - SHIFT_AMT));
bogdanm 0:9b334a45a8ff 178
bogdanm 0:9b334a45a8ff 179 return current_us;
bogdanm 0:9b334a45a8ff 180 }
bogdanm 0:9b334a45a8ff 181
bogdanm 0:9b334a45a8ff 182 //******************************************************************************
bogdanm 0:9b334a45a8ff 183 void rtc_write(time_t t)
bogdanm 0:9b334a45a8ff 184 {
bogdanm 0:9b334a45a8ff 185 MXC_RTCTMR->ctrl &= ~MXC_F_RTC_CTRL_ENABLE; // disable the timer while updating
bogdanm 0:9b334a45a8ff 186 MXC_RTCTMR->timer = t << SHIFT_AMT;
bogdanm 0:9b334a45a8ff 187 overflow_cnt = t >> (32 - SHIFT_AMT);
bogdanm 0:9b334a45a8ff 188 MXC_RTCTMR->ctrl |= MXC_F_RTC_CTRL_ENABLE; // enable the timer while updating
bogdanm 0:9b334a45a8ff 189 }
bogdanm 0:9b334a45a8ff 190
bogdanm 0:9b334a45a8ff 191 //******************************************************************************
bogdanm 0:9b334a45a8ff 192 void lp_ticker_set_interrupt(timestamp_t timestamp)
bogdanm 0:9b334a45a8ff 193 {
bogdanm 0:9b334a45a8ff 194 uint32_t comp_value;
bogdanm 0:9b334a45a8ff 195 uint64_t curr_ts64;
bogdanm 0:9b334a45a8ff 196 uint64_t ts64;
bogdanm 0:9b334a45a8ff 197
bogdanm 0:9b334a45a8ff 198 // Note: interrupts are disabled before this function is called.
bogdanm 0:9b334a45a8ff 199
bogdanm 0:9b334a45a8ff 200 // Disable the alarm while it is prepared
bogdanm 0:9b334a45a8ff 201 MXC_RTCTMR->inten &= ~MXC_F_RTC_INTEN_COMP0;
bogdanm 0:9b334a45a8ff 202
bogdanm 0:9b334a45a8ff 203 curr_ts64 = rtc_read64();
bogdanm 0:9b334a45a8ff 204 ts64 = (uint64_t)timestamp | (curr_ts64 & 0xFFFFFFFF00000000ULL);
bogdanm 0:9b334a45a8ff 205
bogdanm 0:9b334a45a8ff 206 // If this event is older than a recent window, it must be in the future
bogdanm 0:9b334a45a8ff 207 if ((ts64 < (curr_ts64 - WINDOW)) && ((curr_ts64 - WINDOW) < curr_ts64)) {
bogdanm 0:9b334a45a8ff 208 ts64 += 0x100000000ULL;
bogdanm 0:9b334a45a8ff 209 }
bogdanm 0:9b334a45a8ff 210
bogdanm 0:9b334a45a8ff 211 uint32_t timer = MXC_RTCTMR->timer;
bogdanm 0:9b334a45a8ff 212 if (ts64 <= curr_ts64) {
bogdanm 0:9b334a45a8ff 213 // This event has already occurred. Set the alarm to expire immediately.
bogdanm 0:9b334a45a8ff 214 comp_value = timer + 1;
bogdanm 0:9b334a45a8ff 215 } else {
bogdanm 0:9b334a45a8ff 216 comp_value = (ts64 << SHIFT_AMT) / 1000000;
bogdanm 0:9b334a45a8ff 217 }
bogdanm 0:9b334a45a8ff 218
bogdanm 0:9b334a45a8ff 219 // Ensure that the compare value is far enough in the future to guarantee the interrupt occurs.
bogdanm 0:9b334a45a8ff 220 if ((comp_value < (timer + 2)) && (comp_value > (timer - 10))) {
bogdanm 0:9b334a45a8ff 221 comp_value = timer + 2;
bogdanm 0:9b334a45a8ff 222 }
bogdanm 0:9b334a45a8ff 223
bogdanm 0:9b334a45a8ff 224 MXC_RTCTMR->comp[0] = comp_value;
bogdanm 0:9b334a45a8ff 225 MXC_RTCTMR->flags = MXC_F_RTC_FLAGS_COMP0; // clear interrupt
bogdanm 0:9b334a45a8ff 226 MXC_RTCTMR->inten |= MXC_F_RTC_INTEN_COMP0; // enable the interrupt
bogdanm 0:9b334a45a8ff 227
bogdanm 0:9b334a45a8ff 228 // Enable wakeup from RTC
bogdanm 0:9b334a45a8ff 229 MXC_PWRSEQ->msk_flags &= ~MXC_F_PWRSEQ_MSK_FLAGS_RTC_CMPR0;
bogdanm 0:9b334a45a8ff 230 }
bogdanm 0:9b334a45a8ff 231
bogdanm 0:9b334a45a8ff 232 //******************************************************************************
bogdanm 0:9b334a45a8ff 233 inline void lp_ticker_disable_interrupt(void)
bogdanm 0:9b334a45a8ff 234 {
bogdanm 0:9b334a45a8ff 235 MXC_RTCTMR->inten &= ~MXC_F_RTC_INTEN_COMP0;
bogdanm 0:9b334a45a8ff 236 }
bogdanm 0:9b334a45a8ff 237
bogdanm 0:9b334a45a8ff 238 //******************************************************************************
bogdanm 0:9b334a45a8ff 239 inline void lp_ticker_clear_interrupt(void)
bogdanm 0:9b334a45a8ff 240 {
bogdanm 0:9b334a45a8ff 241 MXC_RTCTMR->flags = MXC_F_RTC_FLAGS_ASYNC_CLR_FLAGS;
bogdanm 0:9b334a45a8ff 242 MXC_PWRSEQ->flags = MXC_F_PWRSEQ_MSK_FLAGS_RTC_CMPR0;
bogdanm 0:9b334a45a8ff 243 }
bogdanm 0:9b334a45a8ff 244
bogdanm 0:9b334a45a8ff 245 //******************************************************************************
bogdanm 0:9b334a45a8ff 246 inline uint32_t lp_ticker_read(void)
bogdanm 0:9b334a45a8ff 247 {
bogdanm 0:9b334a45a8ff 248 return rtc_read64();
bogdanm 0:9b334a45a8ff 249 }