mbed library sources. Supersedes mbed-src.
Fork of mbed by
targets/hal/TARGET_STM/TARGET_STM32L0/us_ticker.c@0:9b334a45a8ff, 2015-10-01 (annotated)
- Committer:
- bogdanm
- Date:
- Thu Oct 01 15:25:22 2015 +0300
- Revision:
- 0:9b334a45a8ff
- Child:
- 136:5728e9819171
Initial commit on mbed-dev
Replaces mbed-src (now inactive)
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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bogdanm | 0:9b334a45a8ff | 1 | /* mbed Microcontroller Library |
bogdanm | 0:9b334a45a8ff | 2 | * Copyright (c) 2015, STMicroelectronics |
bogdanm | 0:9b334a45a8ff | 3 | * All rights reserved. |
bogdanm | 0:9b334a45a8ff | 4 | * |
bogdanm | 0:9b334a45a8ff | 5 | * Redistribution and use in source and binary forms, with or without |
bogdanm | 0:9b334a45a8ff | 6 | * modification, are permitted provided that the following conditions are met: |
bogdanm | 0:9b334a45a8ff | 7 | * |
bogdanm | 0:9b334a45a8ff | 8 | * 1. Redistributions of source code must retain the above copyright notice, |
bogdanm | 0:9b334a45a8ff | 9 | * this list of conditions and the following disclaimer. |
bogdanm | 0:9b334a45a8ff | 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
bogdanm | 0:9b334a45a8ff | 11 | * this list of conditions and the following disclaimer in the documentation |
bogdanm | 0:9b334a45a8ff | 12 | * and/or other materials provided with the distribution. |
bogdanm | 0:9b334a45a8ff | 13 | * 3. Neither the name of STMicroelectronics nor the names of its contributors |
bogdanm | 0:9b334a45a8ff | 14 | * may be used to endorse or promote products derived from this software |
bogdanm | 0:9b334a45a8ff | 15 | * without specific prior written permission. |
bogdanm | 0:9b334a45a8ff | 16 | * |
bogdanm | 0:9b334a45a8ff | 17 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
bogdanm | 0:9b334a45a8ff | 18 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
bogdanm | 0:9b334a45a8ff | 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
bogdanm | 0:9b334a45a8ff | 20 | * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
bogdanm | 0:9b334a45a8ff | 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
bogdanm | 0:9b334a45a8ff | 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
bogdanm | 0:9b334a45a8ff | 23 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
bogdanm | 0:9b334a45a8ff | 24 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
bogdanm | 0:9b334a45a8ff | 25 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
bogdanm | 0:9b334a45a8ff | 26 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
bogdanm | 0:9b334a45a8ff | 27 | */ |
bogdanm | 0:9b334a45a8ff | 28 | #include <stddef.h> |
bogdanm | 0:9b334a45a8ff | 29 | #include "us_ticker_api.h" |
bogdanm | 0:9b334a45a8ff | 30 | #include "PeripheralNames.h" |
bogdanm | 0:9b334a45a8ff | 31 | |
bogdanm | 0:9b334a45a8ff | 32 | // Timer selection |
bogdanm | 0:9b334a45a8ff | 33 | #define TIM_MST TIM21 |
bogdanm | 0:9b334a45a8ff | 34 | |
bogdanm | 0:9b334a45a8ff | 35 | static TIM_HandleTypeDef TimMasterHandle; |
bogdanm | 0:9b334a45a8ff | 36 | static int us_ticker_inited = 0; |
bogdanm | 0:9b334a45a8ff | 37 | |
bogdanm | 0:9b334a45a8ff | 38 | volatile uint32_t SlaveCounter = 0; |
bogdanm | 0:9b334a45a8ff | 39 | volatile uint32_t oc_int_part = 0; |
bogdanm | 0:9b334a45a8ff | 40 | volatile uint16_t oc_rem_part = 0; |
bogdanm | 0:9b334a45a8ff | 41 | |
bogdanm | 0:9b334a45a8ff | 42 | void set_compare(uint16_t count) |
bogdanm | 0:9b334a45a8ff | 43 | { |
bogdanm | 0:9b334a45a8ff | 44 | TimMasterHandle.Instance = TIM_MST; |
bogdanm | 0:9b334a45a8ff | 45 | // Set new output compare value |
bogdanm | 0:9b334a45a8ff | 46 | __HAL_TIM_SetCompare(&TimMasterHandle, TIM_CHANNEL_1, count); |
bogdanm | 0:9b334a45a8ff | 47 | // Enable IT |
bogdanm | 0:9b334a45a8ff | 48 | __HAL_TIM_ENABLE_IT(&TimMasterHandle, TIM_IT_CC1); |
bogdanm | 0:9b334a45a8ff | 49 | } |
bogdanm | 0:9b334a45a8ff | 50 | |
bogdanm | 0:9b334a45a8ff | 51 | void us_ticker_init(void) |
bogdanm | 0:9b334a45a8ff | 52 | { |
bogdanm | 0:9b334a45a8ff | 53 | if (us_ticker_inited) return; |
bogdanm | 0:9b334a45a8ff | 54 | us_ticker_inited = 1; |
bogdanm | 0:9b334a45a8ff | 55 | |
bogdanm | 0:9b334a45a8ff | 56 | HAL_InitTick(0); // The passed value is not used |
bogdanm | 0:9b334a45a8ff | 57 | } |
bogdanm | 0:9b334a45a8ff | 58 | |
bogdanm | 0:9b334a45a8ff | 59 | uint32_t us_ticker_read() |
bogdanm | 0:9b334a45a8ff | 60 | { |
bogdanm | 0:9b334a45a8ff | 61 | uint32_t counter, counter2; |
bogdanm | 0:9b334a45a8ff | 62 | if (!us_ticker_inited) us_ticker_init(); |
bogdanm | 0:9b334a45a8ff | 63 | // A situation might appear when Master overflows right after Slave is read and before the |
bogdanm | 0:9b334a45a8ff | 64 | // new (overflowed) value of Master is read. Which would make the code below consider the |
bogdanm | 0:9b334a45a8ff | 65 | // previous (incorrect) value of Slave and the new value of Master, which would return a |
bogdanm | 0:9b334a45a8ff | 66 | // value in the past. Avoid this by computing consecutive values of the timer until they |
bogdanm | 0:9b334a45a8ff | 67 | // are properly ordered. |
bogdanm | 0:9b334a45a8ff | 68 | counter = (uint32_t)(SlaveCounter << 16); |
bogdanm | 0:9b334a45a8ff | 69 | counter += TIM_MST->CNT; |
bogdanm | 0:9b334a45a8ff | 70 | while (1) { |
bogdanm | 0:9b334a45a8ff | 71 | counter2 = (uint32_t)(SlaveCounter << 16); |
bogdanm | 0:9b334a45a8ff | 72 | counter2 += TIM_MST->CNT; |
bogdanm | 0:9b334a45a8ff | 73 | if (counter2 > counter) { |
bogdanm | 0:9b334a45a8ff | 74 | break; |
bogdanm | 0:9b334a45a8ff | 75 | } |
bogdanm | 0:9b334a45a8ff | 76 | counter = counter2; |
bogdanm | 0:9b334a45a8ff | 77 | } |
bogdanm | 0:9b334a45a8ff | 78 | return counter2; |
bogdanm | 0:9b334a45a8ff | 79 | } |
bogdanm | 0:9b334a45a8ff | 80 | |
bogdanm | 0:9b334a45a8ff | 81 | void us_ticker_set_interrupt(timestamp_t timestamp) |
bogdanm | 0:9b334a45a8ff | 82 | { |
bogdanm | 0:9b334a45a8ff | 83 | int delta = (int)((uint32_t)timestamp - us_ticker_read()); |
bogdanm | 0:9b334a45a8ff | 84 | uint16_t cval = TIM_MST->CNT; |
bogdanm | 0:9b334a45a8ff | 85 | |
bogdanm | 0:9b334a45a8ff | 86 | if (delta <= 0) { // This event was in the past |
bogdanm | 0:9b334a45a8ff | 87 | us_ticker_irq_handler(); |
bogdanm | 0:9b334a45a8ff | 88 | } else { |
bogdanm | 0:9b334a45a8ff | 89 | oc_int_part = (uint32_t)(delta >> 16); |
bogdanm | 0:9b334a45a8ff | 90 | oc_rem_part = (uint16_t)(delta & 0xFFFF); |
bogdanm | 0:9b334a45a8ff | 91 | if (oc_rem_part <= (0xFFFF - cval)) { |
bogdanm | 0:9b334a45a8ff | 92 | set_compare(cval + oc_rem_part); |
bogdanm | 0:9b334a45a8ff | 93 | oc_rem_part = 0; |
bogdanm | 0:9b334a45a8ff | 94 | } else { |
bogdanm | 0:9b334a45a8ff | 95 | set_compare(0xFFFF); |
bogdanm | 0:9b334a45a8ff | 96 | oc_rem_part = oc_rem_part - (0xFFFF - cval); |
bogdanm | 0:9b334a45a8ff | 97 | } |
bogdanm | 0:9b334a45a8ff | 98 | } |
bogdanm | 0:9b334a45a8ff | 99 | } |
bogdanm | 0:9b334a45a8ff | 100 | |
bogdanm | 0:9b334a45a8ff | 101 | void us_ticker_disable_interrupt(void) |
bogdanm | 0:9b334a45a8ff | 102 | { |
bogdanm | 0:9b334a45a8ff | 103 | TimMasterHandle.Instance = TIM_MST; |
bogdanm | 0:9b334a45a8ff | 104 | __HAL_TIM_DISABLE_IT(&TimMasterHandle, TIM_IT_CC1); |
bogdanm | 0:9b334a45a8ff | 105 | } |
bogdanm | 0:9b334a45a8ff | 106 | |
bogdanm | 0:9b334a45a8ff | 107 | void us_ticker_clear_interrupt(void) |
bogdanm | 0:9b334a45a8ff | 108 | { |
bogdanm | 0:9b334a45a8ff | 109 | TimMasterHandle.Instance = TIM_MST; |
bogdanm | 0:9b334a45a8ff | 110 | if (__HAL_TIM_GET_FLAG(&TimMasterHandle, TIM_FLAG_CC1) == SET) { |
bogdanm | 0:9b334a45a8ff | 111 | __HAL_TIM_CLEAR_FLAG(&TimMasterHandle, TIM_FLAG_CC1); |
bogdanm | 0:9b334a45a8ff | 112 | } |
bogdanm | 0:9b334a45a8ff | 113 | } |