Ermanno Brusadin / mbed

mbed library sources

Dependents:   FRDM-KL46Z_LCD_Test FRDM-KL46Z_LCD_Test FRDM-KL46Z_Plantilla FRDM-KL46Z_Plantilla ... more

targets/hal/TARGET_Freescale/TARGET_K20D50M/pwmout_api.c@0:6bc4ac881c8e, 2016-07-28 (annotated)

Committer:
ebrus
Date:
Thu Jul 28 15:56:34 2016 +0000
Revision:
0:6bc4ac881c8e
1;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ebrus 0:6bc4ac881c8e 1 /* mbed Microcontroller Library
ebrus 0:6bc4ac881c8e 2 * Copyright (c) 2006-2013 ARM Limited
ebrus 0:6bc4ac881c8e 3 *
ebrus 0:6bc4ac881c8e 4 * Licensed under the Apache License, Version 2.0 (the "License");
ebrus 0:6bc4ac881c8e 5 * you may not use this file except in compliance with the License.
ebrus 0:6bc4ac881c8e 6 * You may obtain a copy of the License at
ebrus 0:6bc4ac881c8e 7 *
ebrus 0:6bc4ac881c8e 8 * http://www.apache.org/licenses/LICENSE-2.0
ebrus 0:6bc4ac881c8e 9 *
ebrus 0:6bc4ac881c8e 10 * Unless required by applicable law or agreed to in writing, software
ebrus 0:6bc4ac881c8e 11 * distributed under the License is distributed on an "AS IS" BASIS,
ebrus 0:6bc4ac881c8e 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ebrus 0:6bc4ac881c8e 13 * See the License for the specific language governing permissions and
ebrus 0:6bc4ac881c8e 14 * limitations under the License.
ebrus 0:6bc4ac881c8e 15 */
ebrus 0:6bc4ac881c8e 16 #include "mbed_assert.h"
ebrus 0:6bc4ac881c8e 17 #include "pwmout_api.h"
ebrus 0:6bc4ac881c8e 18
ebrus 0:6bc4ac881c8e 19 #include "cmsis.h"
ebrus 0:6bc4ac881c8e 20 #include "pinmap.h"
ebrus 0:6bc4ac881c8e 21
ebrus 0:6bc4ac881c8e 22 static const PinMap PinMap_PWM[] = {
ebrus 0:6bc4ac881c8e 23 // LEDs
ebrus 0:6bc4ac881c8e 24 {LED_RED , PWM_3 , 4}, // PTC3, FTM0 CH2
ebrus 0:6bc4ac881c8e 25 {LED_GREEN, PWM_5, 4}, // PTD4, FTM0 CH4
ebrus 0:6bc4ac881c8e 26 {LED_BLUE , PWM_8 , 3}, // PTA2, FTM0 CH7
ebrus 0:6bc4ac881c8e 27
ebrus 0:6bc4ac881c8e 28 // Arduino digital pinout
ebrus 0:6bc4ac881c8e 29 {D3, PWM_5 , 4}, // PTD4, FTM0 CH4
ebrus 0:6bc4ac881c8e 30 {D5, PWM_7 , 3}, // PTA1, FTM0 CH6
ebrus 0:6bc4ac881c8e 31 {D6, PWM_3 , 4}, // PTC3, FTM0 CH2
ebrus 0:6bc4ac881c8e 32 {D9, PWM_6 , 4}, // PTD5, FTM0 CH6
ebrus 0:6bc4ac881c8e 33 {D10, PWM_2 , 4}, // PTC2, FTM0 CH1
ebrus 0:6bc4ac881c8e 34
ebrus 0:6bc4ac881c8e 35 {PTA0, PWM_6 , 3}, // PTA0, FTM0 CH5
ebrus 0:6bc4ac881c8e 36 {PTA3, PWM_1 , 3}, // PTA3, FTM0 CH0
ebrus 0:6bc4ac881c8e 37 {PTA4, PWM_2 , 3}, // PTA4, FTM0 CH1
ebrus 0:6bc4ac881c8e 38 {PTA5, PWM_3 , 3}, // PTA5, FTM0 CH2
ebrus 0:6bc4ac881c8e 39 {PTA12, PWM_9 , 3}, // PTA12, FTM1 CH0
ebrus 0:6bc4ac881c8e 40 {PTA13, PWM_10, 3}, // PTA13, FTM1 CH1
ebrus 0:6bc4ac881c8e 41 {PTB0, PWM_9 , 3}, // PTB0, FTM1 CH0
ebrus 0:6bc4ac881c8e 42 {PTB1, PWM_10, 3}, // PTB1, FTM1 CH1
ebrus 0:6bc4ac881c8e 43 {PTC1, PWM_1 , 4}, // PTC1, FTM0 CH0
ebrus 0:6bc4ac881c8e 44 {PTD4, PWM_4 , 4}, // PTD4, FTM0 CH3
ebrus 0:6bc4ac881c8e 45 {PTD6, PWM_7 , 4}, // PTD6, FTM0 CH6
ebrus 0:6bc4ac881c8e 46 {PTD7, PWM_8 , 4}, // PTD7, FTM0 CH7
ebrus 0:6bc4ac881c8e 47
ebrus 0:6bc4ac881c8e 48 {NC , NC , 0}
ebrus 0:6bc4ac881c8e 49 };
ebrus 0:6bc4ac881c8e 50
ebrus 0:6bc4ac881c8e 51 static float pwm_clock = 0;
ebrus 0:6bc4ac881c8e 52
ebrus 0:6bc4ac881c8e 53 void pwmout_init(pwmout_t* obj, PinName pin) {
ebrus 0:6bc4ac881c8e 54 // determine the channel
ebrus 0:6bc4ac881c8e 55 PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
ebrus 0:6bc4ac881c8e 56 MBED_ASSERT(pwm != (PWMName)NC);
ebrus 0:6bc4ac881c8e 57
ebrus 0:6bc4ac881c8e 58 uint32_t clkdiv = 0;
ebrus 0:6bc4ac881c8e 59 float clkval = SystemCoreClock / 1000000.0f;
ebrus 0:6bc4ac881c8e 60
ebrus 0:6bc4ac881c8e 61 while (clkval > 1) {
ebrus 0:6bc4ac881c8e 62 clkdiv++;
ebrus 0:6bc4ac881c8e 63 clkval /= 2.0;
ebrus 0:6bc4ac881c8e 64 if (clkdiv == 7)
ebrus 0:6bc4ac881c8e 65 break;
ebrus 0:6bc4ac881c8e 66 }
ebrus 0:6bc4ac881c8e 67
ebrus 0:6bc4ac881c8e 68 pwm_clock = clkval;
ebrus 0:6bc4ac881c8e 69 unsigned int port = (unsigned int)pin >> PORT_SHIFT;
ebrus 0:6bc4ac881c8e 70 unsigned int ftm_n = (pwm >> TPM_SHIFT);
ebrus 0:6bc4ac881c8e 71 unsigned int ch_n = (pwm & 0xFF);
ebrus 0:6bc4ac881c8e 72
ebrus 0:6bc4ac881c8e 73 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
ebrus 0:6bc4ac881c8e 74 SIM->SCGC6 |= 1 << (SIM_SCGC6_FTM0_SHIFT + ftm_n);
ebrus 0:6bc4ac881c8e 75
ebrus 0:6bc4ac881c8e 76 FTM_Type *ftm = (FTM_Type *)(FTM0_BASE + 0x1000 * ftm_n);
ebrus 0:6bc4ac881c8e 77 ftm->CONF |= FTM_CONF_BDMMODE(3);
ebrus 0:6bc4ac881c8e 78 ftm->SC = FTM_SC_CLKS(1) | FTM_SC_PS(clkdiv); // (clock)MHz / clkdiv ~= (0.75)MHz
ebrus 0:6bc4ac881c8e 79 ftm->CONTROLS[ch_n].CnSC = (FTM_CnSC_MSB_MASK | FTM_CnSC_ELSB_MASK); /* No Interrupts; High True pulses on Edge Aligned PWM */
ebrus 0:6bc4ac881c8e 80
ebrus 0:6bc4ac881c8e 81 obj->CnV = &ftm->CONTROLS[ch_n].CnV;
ebrus 0:6bc4ac881c8e 82 obj->MOD = &ftm->MOD;
ebrus 0:6bc4ac881c8e 83 obj->CNT = &ftm->CNT;
ebrus 0:6bc4ac881c8e 84
ebrus 0:6bc4ac881c8e 85 // default to 20ms: standard for servos, and fine for e.g. brightness control
ebrus 0:6bc4ac881c8e 86 pwmout_period_ms(obj, 20);
ebrus 0:6bc4ac881c8e 87 pwmout_write(obj, 0);
ebrus 0:6bc4ac881c8e 88
ebrus 0:6bc4ac881c8e 89 // Wire pinout
ebrus 0:6bc4ac881c8e 90 pinmap_pinout(pin, PinMap_PWM);
ebrus 0:6bc4ac881c8e 91 }
ebrus 0:6bc4ac881c8e 92
ebrus 0:6bc4ac881c8e 93 void pwmout_free(pwmout_t* obj) {}
ebrus 0:6bc4ac881c8e 94
ebrus 0:6bc4ac881c8e 95 void pwmout_write(pwmout_t* obj, float value) {
ebrus 0:6bc4ac881c8e 96 if (value < 0.0) {
ebrus 0:6bc4ac881c8e 97 value = 0.0;
ebrus 0:6bc4ac881c8e 98 } else if (value > 1.0) {
ebrus 0:6bc4ac881c8e 99 value = 1.0;
ebrus 0:6bc4ac881c8e 100 }
ebrus 0:6bc4ac881c8e 101
ebrus 0:6bc4ac881c8e 102 *obj->CnV = (uint32_t)((float)(*obj->MOD + 1) * value);
ebrus 0:6bc4ac881c8e 103 }
ebrus 0:6bc4ac881c8e 104
ebrus 0:6bc4ac881c8e 105 float pwmout_read(pwmout_t* obj) {
ebrus 0:6bc4ac881c8e 106 float v = (float)(*obj->CnV) / (float)(*obj->MOD + 1);
ebrus 0:6bc4ac881c8e 107 return (v > 1.0) ? (1.0) : (v);
ebrus 0:6bc4ac881c8e 108 }
ebrus 0:6bc4ac881c8e 109
ebrus 0:6bc4ac881c8e 110 void pwmout_period(pwmout_t* obj, float seconds) {
ebrus 0:6bc4ac881c8e 111 pwmout_period_us(obj, seconds * 1000000.0f);
ebrus 0:6bc4ac881c8e 112 }
ebrus 0:6bc4ac881c8e 113
ebrus 0:6bc4ac881c8e 114 void pwmout_period_ms(pwmout_t* obj, int ms) {
ebrus 0:6bc4ac881c8e 115 pwmout_period_us(obj, ms * 1000);
ebrus 0:6bc4ac881c8e 116 }
ebrus 0:6bc4ac881c8e 117
ebrus 0:6bc4ac881c8e 118 // Set the PWM period, keeping the duty cycle the same.
ebrus 0:6bc4ac881c8e 119 void pwmout_period_us(pwmout_t* obj, int us) {
ebrus 0:6bc4ac881c8e 120 float dc = pwmout_read(obj);
ebrus 0:6bc4ac881c8e 121 *obj->MOD = (uint32_t)(pwm_clock * (float)us) - 1;
ebrus 0:6bc4ac881c8e 122 pwmout_write(obj, dc);
ebrus 0:6bc4ac881c8e 123 }
ebrus 0:6bc4ac881c8e 124
ebrus 0:6bc4ac881c8e 125 void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
ebrus 0:6bc4ac881c8e 126 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
ebrus 0:6bc4ac881c8e 127 }
ebrus 0:6bc4ac881c8e 128
ebrus 0:6bc4ac881c8e 129 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
ebrus 0:6bc4ac881c8e 130 pwmout_pulsewidth_us(obj, ms * 1000);
ebrus 0:6bc4ac881c8e 131 }
ebrus 0:6bc4ac881c8e 132
ebrus 0:6bc4ac881c8e 133 void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
ebrus 0:6bc4ac881c8e 134 *obj->CnV = (uint32_t)(pwm_clock * (float)us);
ebrus 0:6bc4ac881c8e 135 }