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targets/hal/TARGET_NXP/TARGET_LPC43XX/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 /* mbed Microcontroller Library
bogdanm 0:9b334a45a8ff 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 0:9b334a45a8ff 3 *
bogdanm 0:9b334a45a8ff 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 0:9b334a45a8ff 5 * you may not use this file except in compliance with the License.
bogdanm 0:9b334a45a8ff 6 * You may obtain a copy of the License at
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 0:9b334a45a8ff 9 *
bogdanm 0:9b334a45a8ff 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 0:9b334a45a8ff 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 0:9b334a45a8ff 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 0:9b334a45a8ff 13 * See the License for the specific language governing permissions and
bogdanm 0:9b334a45a8ff 14 * limitations under the License.
bogdanm 0:9b334a45a8ff 15 *
bogdanm 0:9b334a45a8ff 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
bogdanm 0:9b334a45a8ff 17 */
bogdanm 0:9b334a45a8ff 18 #include "rtc_api.h"
bogdanm 0:9b334a45a8ff 19
bogdanm 0:9b334a45a8ff 20 // ensure rtc is running (unchanged if already running)
bogdanm 0:9b334a45a8ff 21
bogdanm 0:9b334a45a8ff 22 /* Setup the RTC based on a time structure, ensuring RTC is enabled
bogdanm 0:9b334a45a8ff 23 *
bogdanm 0:9b334a45a8ff 24 * Can be clocked by a 32.768KHz oscillator or prescale divider based on the APB clock
bogdanm 0:9b334a45a8ff 25 * - We want to use the 32khz clock, allowing for sleep mode
bogdanm 0:9b334a45a8ff 26 *
bogdanm 0:9b334a45a8ff 27 * Most registers are not changed by a Reset
bogdanm 0:9b334a45a8ff 28 * - We must initialize these registers between power-on and setting the RTC into operation
bogdanm 0:9b334a45a8ff 29
bogdanm 0:9b334a45a8ff 30 * Clock Control Register
bogdanm 0:9b334a45a8ff 31 * RTC_CCR[0] : Enable - 0 = Disabled, 1 = Enabled
bogdanm 0:9b334a45a8ff 32 * RTC_CCR[1] : Reset - 0 = Normal, 1 = Reset
bogdanm 0:9b334a45a8ff 33 * RTC_CCR[4] : Clock Source - 0 = Prescaler, 1 = 32k Xtal
bogdanm 0:9b334a45a8ff 34 *
bogdanm 0:9b334a45a8ff 35 * The RTC may already be running, so we should set it up
bogdanm 0:9b334a45a8ff 36 * without impacting if it is the case
bogdanm 0:9b334a45a8ff 37 */
bogdanm 0:9b334a45a8ff 38
bogdanm 0:9b334a45a8ff 39 void rtc_init(void) {
bogdanm 0:9b334a45a8ff 40 // Return, if already enabled
bogdanm 0:9b334a45a8ff 41 if (LPC_RTC->CCR & 1)
bogdanm 0:9b334a45a8ff 42 return;
bogdanm 0:9b334a45a8ff 43
bogdanm 0:9b334a45a8ff 44 // Enable 1kHz output of 32kHz oscillator
bogdanm 0:9b334a45a8ff 45 LPC_CREG->CREG0 &= ~((1 << 3) | (1 << 2));
bogdanm 0:9b334a45a8ff 46 LPC_CREG->CREG0 |= (0x03 << 6) | (1 << 1) | (1 << 0);
bogdanm 0:9b334a45a8ff 47
bogdanm 0:9b334a45a8ff 48 // Enable RTC
bogdanm 0:9b334a45a8ff 49 do {
bogdanm 0:9b334a45a8ff 50 LPC_RTC->CCR |= 1 << 0;
bogdanm 0:9b334a45a8ff 51 } while ((LPC_RTC->CCR & 1) == 0);
bogdanm 0:9b334a45a8ff 52 }
bogdanm 0:9b334a45a8ff 53
bogdanm 0:9b334a45a8ff 54 void rtc_free(void) {
bogdanm 0:9b334a45a8ff 55 // [TODO]
bogdanm 0:9b334a45a8ff 56 }
bogdanm 0:9b334a45a8ff 57
bogdanm 0:9b334a45a8ff 58 /*
bogdanm 0:9b334a45a8ff 59 * Little check routine to see if the RTC has been enabled
bogdanm 0:9b334a45a8ff 60 *
bogdanm 0:9b334a45a8ff 61 * Clock Control Register
bogdanm 0:9b334a45a8ff 62 * RTC_CCR[0] : 0 = Disabled, 1 = Enabled
bogdanm 0:9b334a45a8ff 63 *
bogdanm 0:9b334a45a8ff 64 */
bogdanm 0:9b334a45a8ff 65 int rtc_isenabled(void) {
bogdanm 0:9b334a45a8ff 66 return(((LPC_RTC->CCR) & 0x01) != 0);
bogdanm 0:9b334a45a8ff 67 }
bogdanm 0:9b334a45a8ff 68
bogdanm 0:9b334a45a8ff 69 /*
bogdanm 0:9b334a45a8ff 70 * RTC Registers
bogdanm 0:9b334a45a8ff 71 * RTC_SEC Seconds 0-59
bogdanm 0:9b334a45a8ff 72 * RTC_MIN Minutes 0-59
bogdanm 0:9b334a45a8ff 73 * RTC_HOUR Hour 0-23
bogdanm 0:9b334a45a8ff 74 * RTC_DOM Day of Month 1-28..31
bogdanm 0:9b334a45a8ff 75 * RTC_DOW Day of Week 0-6
bogdanm 0:9b334a45a8ff 76 * RTC_DOY Day of Year 1-365
bogdanm 0:9b334a45a8ff 77 * RTC_MONTH Month 1-12
bogdanm 0:9b334a45a8ff 78 * RTC_YEAR Year 0-4095
bogdanm 0:9b334a45a8ff 79 *
bogdanm 0:9b334a45a8ff 80 * struct tm
bogdanm 0:9b334a45a8ff 81 * tm_sec seconds after the minute 0-61
bogdanm 0:9b334a45a8ff 82 * tm_min minutes after the hour 0-59
bogdanm 0:9b334a45a8ff 83 * tm_hour hours since midnight 0-23
bogdanm 0:9b334a45a8ff 84 * tm_mday day of the month 1-31
bogdanm 0:9b334a45a8ff 85 * tm_mon months since January 0-11
bogdanm 0:9b334a45a8ff 86 * tm_year years since 1900
bogdanm 0:9b334a45a8ff 87 * tm_wday days since Sunday 0-6
bogdanm 0:9b334a45a8ff 88 * tm_yday days since January 1 0-365
bogdanm 0:9b334a45a8ff 89 * tm_isdst Daylight Saving Time flag
bogdanm 0:9b334a45a8ff 90 */
bogdanm 0:9b334a45a8ff 91 time_t rtc_read(void) {
bogdanm 0:9b334a45a8ff 92 // Setup a tm structure based on the RTC
bogdanm 0:9b334a45a8ff 93 struct tm timeinfo;
bogdanm 0:9b334a45a8ff 94 timeinfo.tm_sec = LPC_RTC->TIME[RTC_TIMETYPE_SECOND];
bogdanm 0:9b334a45a8ff 95 timeinfo.tm_min = LPC_RTC->TIME[RTC_TIMETYPE_MINUTE];
bogdanm 0:9b334a45a8ff 96 timeinfo.tm_hour = LPC_RTC->TIME[RTC_TIMETYPE_HOUR];
bogdanm 0:9b334a45a8ff 97 timeinfo.tm_mday = LPC_RTC->TIME[RTC_TIMETYPE_DAYOFMONTH];
bogdanm 0:9b334a45a8ff 98 timeinfo.tm_wday = LPC_RTC->TIME[RTC_TIMETYPE_DAYOFWEEK];
bogdanm 0:9b334a45a8ff 99 timeinfo.tm_yday = LPC_RTC->TIME[RTC_TIMETYPE_DAYOFYEAR];
bogdanm 0:9b334a45a8ff 100 timeinfo.tm_mon = LPC_RTC->TIME[RTC_TIMETYPE_MONTH] - 1;
bogdanm 0:9b334a45a8ff 101 timeinfo.tm_year = LPC_RTC->TIME[RTC_TIMETYPE_YEAR] - 1900;
bogdanm 0:9b334a45a8ff 102
bogdanm 0:9b334a45a8ff 103 // Convert to timestamp
bogdanm 0:9b334a45a8ff 104 time_t t = mktime(&timeinfo);
bogdanm 0:9b334a45a8ff 105
bogdanm 0:9b334a45a8ff 106 return t;
bogdanm 0:9b334a45a8ff 107 }
bogdanm 0:9b334a45a8ff 108
bogdanm 0:9b334a45a8ff 109 void rtc_write(time_t t) {
bogdanm 0:9b334a45a8ff 110 // Convert the time in to a tm
bogdanm 0:9b334a45a8ff 111 struct tm *timeinfo = localtime(&t);
bogdanm 0:9b334a45a8ff 112
bogdanm 0:9b334a45a8ff 113 // Pause clock, and clear counter register (clears us count)
bogdanm 0:9b334a45a8ff 114 LPC_RTC->CCR |= 2;
bogdanm 0:9b334a45a8ff 115
bogdanm 0:9b334a45a8ff 116 // Set the RTC
bogdanm 0:9b334a45a8ff 117 LPC_RTC->TIME[RTC_TIMETYPE_SECOND] = timeinfo->tm_sec;
bogdanm 0:9b334a45a8ff 118 LPC_RTC->TIME[RTC_TIMETYPE_MINUTE] = timeinfo->tm_min;
bogdanm 0:9b334a45a8ff 119 LPC_RTC->TIME[RTC_TIMETYPE_HOUR] = timeinfo->tm_hour;
bogdanm 0:9b334a45a8ff 120 LPC_RTC->TIME[RTC_TIMETYPE_DAYOFMONTH] = timeinfo->tm_mday;
bogdanm 0:9b334a45a8ff 121 LPC_RTC->TIME[RTC_TIMETYPE_DAYOFWEEK] = timeinfo->tm_wday;
bogdanm 0:9b334a45a8ff 122 LPC_RTC->TIME[RTC_TIMETYPE_DAYOFYEAR] = timeinfo->tm_yday;
bogdanm 0:9b334a45a8ff 123 LPC_RTC->TIME[RTC_TIMETYPE_MONTH] = timeinfo->tm_mon + 1;
bogdanm 0:9b334a45a8ff 124 LPC_RTC->TIME[RTC_TIMETYPE_YEAR] = timeinfo->tm_year + 1900;
bogdanm 0:9b334a45a8ff 125
bogdanm 0:9b334a45a8ff 126 // Restart clock
bogdanm 0:9b334a45a8ff 127 LPC_RTC->CCR &= ~((uint32_t)2);
bogdanm 0:9b334a45a8ff 128 }