mbed library sources. Supersedes mbed-src.
Fork of mbed-dev by
targets/TARGET_Freescale/TARGET_KLXX/us_ticker.c@174:b96e65c34a4d, 2017-10-02 (annotated)
- Committer:
- AnnaBridge
- Date:
- Mon Oct 02 15:33:19 2017 +0100
- Revision:
- 174:b96e65c34a4d
- Parent:
- 162:e13f6fdb2ac4
This updates the lib to the mbed lib v 152
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
<> | 144:ef7eb2e8f9f7 | 1 | /* mbed Microcontroller Library |
<> | 144:ef7eb2e8f9f7 | 2 | * Copyright (c) 2006-2013 ARM Limited |
<> | 144:ef7eb2e8f9f7 | 3 | * |
<> | 144:ef7eb2e8f9f7 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
<> | 144:ef7eb2e8f9f7 | 5 | * you may not use this file except in compliance with the License. |
<> | 144:ef7eb2e8f9f7 | 6 | * You may obtain a copy of the License at |
<> | 144:ef7eb2e8f9f7 | 7 | * |
<> | 144:ef7eb2e8f9f7 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
<> | 144:ef7eb2e8f9f7 | 9 | * |
<> | 144:ef7eb2e8f9f7 | 10 | * Unless required by applicable law or agreed to in writing, software |
<> | 144:ef7eb2e8f9f7 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
<> | 144:ef7eb2e8f9f7 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
<> | 144:ef7eb2e8f9f7 | 13 | * See the License for the specific language governing permissions and |
<> | 144:ef7eb2e8f9f7 | 14 | * limitations under the License. |
<> | 144:ef7eb2e8f9f7 | 15 | */ |
<> | 144:ef7eb2e8f9f7 | 16 | #include <stddef.h> |
<> | 144:ef7eb2e8f9f7 | 17 | #include "us_ticker_api.h" |
<> | 144:ef7eb2e8f9f7 | 18 | #include "PeripheralNames.h" |
<> | 144:ef7eb2e8f9f7 | 19 | #include "clk_freqs.h" |
<> | 144:ef7eb2e8f9f7 | 20 | |
<> | 144:ef7eb2e8f9f7 | 21 | static void pit_init(void); |
<> | 144:ef7eb2e8f9f7 | 22 | static void lptmr_init(void); |
<> | 144:ef7eb2e8f9f7 | 23 | |
<> | 144:ef7eb2e8f9f7 | 24 | static int us_ticker_inited = 0; |
<> | 144:ef7eb2e8f9f7 | 25 | |
<> | 144:ef7eb2e8f9f7 | 26 | void us_ticker_init(void) { |
<> | 144:ef7eb2e8f9f7 | 27 | if (us_ticker_inited) return; |
<> | 144:ef7eb2e8f9f7 | 28 | us_ticker_inited = 1; |
<> | 144:ef7eb2e8f9f7 | 29 | |
<> | 144:ef7eb2e8f9f7 | 30 | pit_init(); |
<> | 144:ef7eb2e8f9f7 | 31 | lptmr_init(); |
<> | 144:ef7eb2e8f9f7 | 32 | } |
<> | 144:ef7eb2e8f9f7 | 33 | |
<> | 144:ef7eb2e8f9f7 | 34 | /****************************************************************************** |
<> | 144:ef7eb2e8f9f7 | 35 | * Timer for us timing. |
<> | 144:ef7eb2e8f9f7 | 36 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 37 | static void pit_init(void) { |
<> | 144:ef7eb2e8f9f7 | 38 | SIM->SCGC6 |= SIM_SCGC6_PIT_MASK; // Clock PIT |
<> | 144:ef7eb2e8f9f7 | 39 | PIT->MCR = 0; // Enable PIT |
<> | 144:ef7eb2e8f9f7 | 40 | |
<> | 144:ef7eb2e8f9f7 | 41 | // Channel 1 |
<> | 144:ef7eb2e8f9f7 | 42 | PIT->CHANNEL[1].LDVAL = 0xFFFFFFFF; |
<> | 144:ef7eb2e8f9f7 | 43 | PIT->CHANNEL[1].TCTRL = PIT_TCTRL_CHN_MASK; // Chain to timer 0, disable Interrupts |
<> | 144:ef7eb2e8f9f7 | 44 | PIT->CHANNEL[1].TCTRL |= PIT_TCTRL_TEN_MASK; // Start timer 1 |
<> | 144:ef7eb2e8f9f7 | 45 | |
<> | 144:ef7eb2e8f9f7 | 46 | // Use channel 0 as a prescaler for channel 1 |
<> | 144:ef7eb2e8f9f7 | 47 | PIT->CHANNEL[0].LDVAL = (bus_frequency() + 500000) / 1000000 - 1; |
<> | 144:ef7eb2e8f9f7 | 48 | PIT->CHANNEL[0].TCTRL = PIT_TCTRL_TEN_MASK; // Start timer 0, disable interrupts |
<> | 144:ef7eb2e8f9f7 | 49 | } |
<> | 144:ef7eb2e8f9f7 | 50 | |
<> | 144:ef7eb2e8f9f7 | 51 | uint32_t us_ticker_read() { |
<> | 144:ef7eb2e8f9f7 | 52 | if (!us_ticker_inited) |
<> | 144:ef7eb2e8f9f7 | 53 | us_ticker_init(); |
<> | 144:ef7eb2e8f9f7 | 54 | |
<> | 144:ef7eb2e8f9f7 | 55 | // The PIT is a countdown timer |
<> | 144:ef7eb2e8f9f7 | 56 | return ~(PIT->CHANNEL[1].CVAL); |
<> | 144:ef7eb2e8f9f7 | 57 | } |
<> | 144:ef7eb2e8f9f7 | 58 | |
<> | 144:ef7eb2e8f9f7 | 59 | /****************************************************************************** |
<> | 144:ef7eb2e8f9f7 | 60 | * Timer Event |
<> | 144:ef7eb2e8f9f7 | 61 | * |
<> | 144:ef7eb2e8f9f7 | 62 | * It schedules interrupts at given (32bit)us interval of time. |
<> | 144:ef7eb2e8f9f7 | 63 | * It is implemented used the 16bit Low Power Timer that remains powered in all |
<> | 144:ef7eb2e8f9f7 | 64 | * power modes. |
<> | 144:ef7eb2e8f9f7 | 65 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 66 | static void lptmr_isr(void); |
<> | 144:ef7eb2e8f9f7 | 67 | |
<> | 144:ef7eb2e8f9f7 | 68 | static void lptmr_init(void) { |
<> | 144:ef7eb2e8f9f7 | 69 | uint32_t extosc; |
<> | 144:ef7eb2e8f9f7 | 70 | |
<> | 144:ef7eb2e8f9f7 | 71 | /* Clock the timer */ |
<> | 144:ef7eb2e8f9f7 | 72 | SIM->SCGC5 |= SIM_SCGC5_LPTMR_MASK; |
<> | 144:ef7eb2e8f9f7 | 73 | |
<> | 144:ef7eb2e8f9f7 | 74 | /* Reset */ |
<> | 144:ef7eb2e8f9f7 | 75 | LPTMR0->CSR = 0; |
<> | 144:ef7eb2e8f9f7 | 76 | |
<> | 144:ef7eb2e8f9f7 | 77 | #if defined(TARGET_KL43Z) |
<> | 144:ef7eb2e8f9f7 | 78 | /* Set interrupt handler */ |
<> | 144:ef7eb2e8f9f7 | 79 | NVIC_SetVector(LPTMR0_IRQn, (uint32_t)lptmr_isr); |
<> | 144:ef7eb2e8f9f7 | 80 | NVIC_EnableIRQ(LPTMR0_IRQn); |
<> | 144:ef7eb2e8f9f7 | 81 | |
<> | 144:ef7eb2e8f9f7 | 82 | |
<> | 144:ef7eb2e8f9f7 | 83 | MCG->C1 |= MCG_C1_IRCLKEN_MASK; |
<> | 144:ef7eb2e8f9f7 | 84 | extosc = mcgirc_frequency(); |
<> | 144:ef7eb2e8f9f7 | 85 | #else |
<> | 144:ef7eb2e8f9f7 | 86 | /* Set interrupt handler */ |
<> | 144:ef7eb2e8f9f7 | 87 | NVIC_SetVector(LPTimer_IRQn, (uint32_t)lptmr_isr); |
<> | 144:ef7eb2e8f9f7 | 88 | NVIC_EnableIRQ(LPTimer_IRQn); |
<> | 144:ef7eb2e8f9f7 | 89 | |
<> | 144:ef7eb2e8f9f7 | 90 | /* Clock at (1)MHz -> (1)tick/us */ |
<> | 144:ef7eb2e8f9f7 | 91 | /* Check if the external oscillator can be divided to 1MHz */ |
<> | 144:ef7eb2e8f9f7 | 92 | extosc = extosc_frequency(); |
<> | 144:ef7eb2e8f9f7 | 93 | #endif |
<> | 144:ef7eb2e8f9f7 | 94 | if (extosc != 0) { //If external oscillator found |
<> | 144:ef7eb2e8f9f7 | 95 | if (extosc % 1000000u == 0) { //If it is a multiple if 1MHz |
<> | 144:ef7eb2e8f9f7 | 96 | extosc /= 1000000; |
<> | 144:ef7eb2e8f9f7 | 97 | if (extosc == 1) { //1MHz, set timerprescaler in bypass mode |
<> | 144:ef7eb2e8f9f7 | 98 | LPTMR0->PSR = LPTMR_PSR_PCS(3) | LPTMR_PSR_PBYP_MASK; |
<> | 144:ef7eb2e8f9f7 | 99 | return; |
<> | 144:ef7eb2e8f9f7 | 100 | } else { //See if we can divide it to 1MHz |
<> | 144:ef7eb2e8f9f7 | 101 | uint32_t divider = 0; |
<> | 144:ef7eb2e8f9f7 | 102 | extosc >>= 1; |
<> | 144:ef7eb2e8f9f7 | 103 | while (1) { |
<> | 144:ef7eb2e8f9f7 | 104 | if (extosc == 1) { |
<> | 144:ef7eb2e8f9f7 | 105 | LPTMR0->PSR = LPTMR_PSR_PCS(3) | LPTMR_PSR_PRESCALE(divider); |
<> | 144:ef7eb2e8f9f7 | 106 | return; |
<> | 144:ef7eb2e8f9f7 | 107 | } |
<> | 144:ef7eb2e8f9f7 | 108 | if (extosc % 2 != 0) //If we can't divide by two anymore |
<> | 144:ef7eb2e8f9f7 | 109 | break; |
<> | 144:ef7eb2e8f9f7 | 110 | divider++; |
<> | 144:ef7eb2e8f9f7 | 111 | extosc >>= 1; |
<> | 144:ef7eb2e8f9f7 | 112 | } |
<> | 144:ef7eb2e8f9f7 | 113 | } |
<> | 144:ef7eb2e8f9f7 | 114 | } |
<> | 144:ef7eb2e8f9f7 | 115 | } |
<> | 144:ef7eb2e8f9f7 | 116 | #if defined(TARGET_KL43Z) |
<> | 144:ef7eb2e8f9f7 | 117 | //No suitable actual IRC oscillator clock -> Set it to (8MHz / divider) |
<> | 144:ef7eb2e8f9f7 | 118 | MCG->SC &= ~MCG_SC_FCRDIV_MASK; |
<> | 144:ef7eb2e8f9f7 | 119 | MCG->MC &= ~MCG->MC & MCG_MC_LIRC_DIV2_MASK; |
<> | 144:ef7eb2e8f9f7 | 120 | LPTMR0->PSR = LPTMR_PSR_PCS(0) | LPTMR_PSR_PRESCALE(2); |
<> | 144:ef7eb2e8f9f7 | 121 | #else |
<> | 144:ef7eb2e8f9f7 | 122 | //No suitable external oscillator clock -> Use fast internal oscillator (4MHz / divider) |
<> | 144:ef7eb2e8f9f7 | 123 | MCG->C1 |= MCG_C1_IRCLKEN_MASK; |
<> | 144:ef7eb2e8f9f7 | 124 | MCG->C2 |= MCG_C2_IRCS_MASK; |
<> | 144:ef7eb2e8f9f7 | 125 | LPTMR0->PSR = LPTMR_PSR_PCS(0); |
<> | 144:ef7eb2e8f9f7 | 126 | switch (MCG->SC & MCG_SC_FCRDIV_MASK) { |
<> | 144:ef7eb2e8f9f7 | 127 | case MCG_SC_FCRDIV(0): //4MHz |
<> | 144:ef7eb2e8f9f7 | 128 | LPTMR0->PSR |= LPTMR_PSR_PRESCALE(1); |
<> | 144:ef7eb2e8f9f7 | 129 | break; |
<> | 144:ef7eb2e8f9f7 | 130 | case MCG_SC_FCRDIV(1): //2MHz |
<> | 144:ef7eb2e8f9f7 | 131 | LPTMR0->PSR |= LPTMR_PSR_PRESCALE(0); |
<> | 144:ef7eb2e8f9f7 | 132 | break; |
<> | 144:ef7eb2e8f9f7 | 133 | default: //1MHz or anything else, in which case we put it on 1MHz |
<> | 144:ef7eb2e8f9f7 | 134 | MCG->SC &= ~MCG_SC_FCRDIV_MASK; |
<> | 144:ef7eb2e8f9f7 | 135 | MCG->SC |= MCG_SC_FCRDIV(2); |
<> | 144:ef7eb2e8f9f7 | 136 | LPTMR0->PSR |= LPTMR_PSR_PBYP_MASK; |
<> | 144:ef7eb2e8f9f7 | 137 | } |
<> | 144:ef7eb2e8f9f7 | 138 | #endif |
<> | 144:ef7eb2e8f9f7 | 139 | } |
<> | 144:ef7eb2e8f9f7 | 140 | |
<> | 144:ef7eb2e8f9f7 | 141 | void us_ticker_disable_interrupt(void) { |
<> | 144:ef7eb2e8f9f7 | 142 | LPTMR0->CSR &= ~LPTMR_CSR_TIE_MASK; |
<> | 144:ef7eb2e8f9f7 | 143 | } |
<> | 144:ef7eb2e8f9f7 | 144 | |
<> | 144:ef7eb2e8f9f7 | 145 | void us_ticker_clear_interrupt(void) { |
<> | 144:ef7eb2e8f9f7 | 146 | // we already clear interrupt in lptmr_isr |
<> | 144:ef7eb2e8f9f7 | 147 | } |
<> | 144:ef7eb2e8f9f7 | 148 | |
<> | 144:ef7eb2e8f9f7 | 149 | static uint32_t us_ticker_int_counter = 0; |
<> | 144:ef7eb2e8f9f7 | 150 | static uint16_t us_ticker_int_remainder = 0; |
<> | 144:ef7eb2e8f9f7 | 151 | |
<> | 144:ef7eb2e8f9f7 | 152 | static void lptmr_set(unsigned short count) { |
<> | 144:ef7eb2e8f9f7 | 153 | /* Reset */ |
<> | 144:ef7eb2e8f9f7 | 154 | LPTMR0->CSR = 0; |
<> | 144:ef7eb2e8f9f7 | 155 | |
<> | 144:ef7eb2e8f9f7 | 156 | /* Set the compare register */ |
<> | 144:ef7eb2e8f9f7 | 157 | LPTMR0->CMR = count; |
<> | 144:ef7eb2e8f9f7 | 158 | |
<> | 144:ef7eb2e8f9f7 | 159 | /* Enable interrupt */ |
<> | 144:ef7eb2e8f9f7 | 160 | LPTMR0->CSR |= LPTMR_CSR_TIE_MASK; |
<> | 144:ef7eb2e8f9f7 | 161 | |
<> | 144:ef7eb2e8f9f7 | 162 | /* Start the timer */ |
<> | 144:ef7eb2e8f9f7 | 163 | LPTMR0->CSR |= LPTMR_CSR_TEN_MASK; |
<> | 144:ef7eb2e8f9f7 | 164 | } |
<> | 144:ef7eb2e8f9f7 | 165 | |
<> | 144:ef7eb2e8f9f7 | 166 | static void lptmr_isr(void) { |
<> | 144:ef7eb2e8f9f7 | 167 | // write 1 to TCF to clear the LPT timer compare flag |
<> | 144:ef7eb2e8f9f7 | 168 | LPTMR0->CSR |= LPTMR_CSR_TCF_MASK; |
<> | 144:ef7eb2e8f9f7 | 169 | |
<> | 144:ef7eb2e8f9f7 | 170 | if (us_ticker_int_counter > 0) { |
<> | 144:ef7eb2e8f9f7 | 171 | lptmr_set(0xFFFF); |
<> | 144:ef7eb2e8f9f7 | 172 | us_ticker_int_counter--; |
<> | 144:ef7eb2e8f9f7 | 173 | |
<> | 144:ef7eb2e8f9f7 | 174 | } else { |
<> | 144:ef7eb2e8f9f7 | 175 | if (us_ticker_int_remainder > 0) { |
<> | 144:ef7eb2e8f9f7 | 176 | lptmr_set(us_ticker_int_remainder); |
<> | 144:ef7eb2e8f9f7 | 177 | us_ticker_int_remainder = 0; |
<> | 144:ef7eb2e8f9f7 | 178 | |
<> | 144:ef7eb2e8f9f7 | 179 | } else { |
<> | 144:ef7eb2e8f9f7 | 180 | // This function is going to disable the interrupts if there are |
<> | 144:ef7eb2e8f9f7 | 181 | // no other events in the queue |
<> | 144:ef7eb2e8f9f7 | 182 | us_ticker_irq_handler(); |
<> | 144:ef7eb2e8f9f7 | 183 | } |
<> | 144:ef7eb2e8f9f7 | 184 | } |
<> | 144:ef7eb2e8f9f7 | 185 | } |
<> | 144:ef7eb2e8f9f7 | 186 | |
<> | 144:ef7eb2e8f9f7 | 187 | void us_ticker_set_interrupt(timestamp_t timestamp) { |
AnnaBridge | 174:b96e65c34a4d | 188 | uint32_t delta = timestamp - us_ticker_read(); |
<> | 144:ef7eb2e8f9f7 | 189 | us_ticker_int_counter = (uint32_t)(delta >> 16); |
<> | 144:ef7eb2e8f9f7 | 190 | us_ticker_int_remainder = (uint16_t)(0xFFFF & delta); |
<> | 144:ef7eb2e8f9f7 | 191 | if (us_ticker_int_counter > 0) { |
<> | 144:ef7eb2e8f9f7 | 192 | lptmr_set(0xFFFF); |
<> | 144:ef7eb2e8f9f7 | 193 | us_ticker_int_counter--; |
<> | 144:ef7eb2e8f9f7 | 194 | } else { |
<> | 144:ef7eb2e8f9f7 | 195 | lptmr_set(us_ticker_int_remainder); |
<> | 144:ef7eb2e8f9f7 | 196 | us_ticker_int_remainder = 0; |
<> | 144:ef7eb2e8f9f7 | 197 | } |
<> | 144:ef7eb2e8f9f7 | 198 | } |
AnnaBridge | 174:b96e65c34a4d | 199 | |
AnnaBridge | 174:b96e65c34a4d | 200 | void us_ticker_fire_interrupt(void) |
AnnaBridge | 174:b96e65c34a4d | 201 | { |
AnnaBridge | 174:b96e65c34a4d | 202 | #if defined(TARGET_KL43Z) |
AnnaBridge | 174:b96e65c34a4d | 203 | NVIC_SetPendingIRQ(LPTMR0_IRQn); |
AnnaBridge | 174:b96e65c34a4d | 204 | #else |
AnnaBridge | 174:b96e65c34a4d | 205 | NVIC_SetPendingIRQ(LPTimer_IRQn); |
AnnaBridge | 174:b96e65c34a4d | 206 | |
AnnaBridge | 174:b96e65c34a4d | 207 | #endif |
AnnaBridge | 174:b96e65c34a4d | 208 | } |