mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_Freescale/TARGET_KLXX/pwmout_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
149:156823d33999 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew 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 "mbed_assert.h"
<> 144:ef7eb2e8f9f7 17 #include "pwmout_api.h"
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 20 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 21 #include "clk_freqs.h"
<> 144:ef7eb2e8f9f7 22 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 23
<> 144:ef7eb2e8f9f7 24 static float pwm_clock;
<> 144:ef7eb2e8f9f7 25
<> 144:ef7eb2e8f9f7 26 void pwmout_init(pwmout_t* obj, PinName pin) {
<> 144:ef7eb2e8f9f7 27 // determine the channel
<> 144:ef7eb2e8f9f7 28 PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
<> 144:ef7eb2e8f9f7 29 MBED_ASSERT(pwm != (PWMName)NC);
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 uint32_t clkdiv = 0;
<> 144:ef7eb2e8f9f7 32 float clkval;
<> 144:ef7eb2e8f9f7 33
<> 144:ef7eb2e8f9f7 34 #if defined(TARGET_KL43Z)
<> 144:ef7eb2e8f9f7 35 if (mcgirc_frequency()) {
<> 144:ef7eb2e8f9f7 36 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(3); // Clock source: MCGIRCLK
<> 144:ef7eb2e8f9f7 37 clkval = mcgirc_frequency() / 1000000.0f;
<> 144:ef7eb2e8f9f7 38 } else {
<> 144:ef7eb2e8f9f7 39 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: IRC48M
<> 144:ef7eb2e8f9f7 40 clkval = CPU_INT_IRC_CLK_HZ / 1000000.0f;
<> 144:ef7eb2e8f9f7 41 }
<> 144:ef7eb2e8f9f7 42 #else
<> 144:ef7eb2e8f9f7 43 if (mcgpllfll_frequency()) {
<> 144:ef7eb2e8f9f7 44 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: MCGFLLCLK or MCGPLLCLK
<> 144:ef7eb2e8f9f7 45 clkval = mcgpllfll_frequency() / 1000000.0f;
<> 144:ef7eb2e8f9f7 46 } else {
<> 144:ef7eb2e8f9f7 47 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(2); // Clock source: ExtOsc
<> 144:ef7eb2e8f9f7 48 clkval = extosc_frequency() / 1000000.0f;
<> 144:ef7eb2e8f9f7 49 }
<> 144:ef7eb2e8f9f7 50 #endif
<> 144:ef7eb2e8f9f7 51 while (clkval > 1) {
<> 144:ef7eb2e8f9f7 52 clkdiv++;
<> 144:ef7eb2e8f9f7 53 clkval /= 2.0;
<> 144:ef7eb2e8f9f7 54 if (clkdiv == 7)
<> 144:ef7eb2e8f9f7 55 break;
<> 144:ef7eb2e8f9f7 56 }
<> 144:ef7eb2e8f9f7 57
<> 144:ef7eb2e8f9f7 58 pwm_clock = clkval;
<> 144:ef7eb2e8f9f7 59 unsigned int port = (unsigned int)pin >> PORT_SHIFT;
<> 144:ef7eb2e8f9f7 60 unsigned int tpm_n = (pwm >> TPM_SHIFT);
<> 144:ef7eb2e8f9f7 61 unsigned int ch_n = (pwm & 0xFF);
<> 144:ef7eb2e8f9f7 62
<> 144:ef7eb2e8f9f7 63 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
<> 144:ef7eb2e8f9f7 64 SIM->SCGC6 |= 1 << (SIM_SCGC6_TPM0_SHIFT + tpm_n);
<> 144:ef7eb2e8f9f7 65
<> 144:ef7eb2e8f9f7 66 TPM_Type *tpm = (TPM_Type *)(TPM0_BASE + 0x1000 * tpm_n);
<> 144:ef7eb2e8f9f7 67 tpm->SC = TPM_SC_CMOD(1) | TPM_SC_PS(clkdiv); // (clock)MHz / clkdiv ~= (0.75)MHz
<> 144:ef7eb2e8f9f7 68 tpm->CONTROLS[ch_n].CnSC = (TPM_CnSC_MSB_MASK | TPM_CnSC_ELSB_MASK); /* No Interrupts; High True pulses on Edge Aligned PWM */
<> 144:ef7eb2e8f9f7 69
<> 144:ef7eb2e8f9f7 70 obj->CnV = &tpm->CONTROLS[ch_n].CnV;
<> 144:ef7eb2e8f9f7 71 obj->MOD = &tpm->MOD;
<> 144:ef7eb2e8f9f7 72 obj->CNT = &tpm->CNT;
<> 144:ef7eb2e8f9f7 73
<> 144:ef7eb2e8f9f7 74 // default to 20ms: standard for servos, and fine for e.g. brightness control
<> 144:ef7eb2e8f9f7 75 pwmout_period_ms(obj, 20);
<> 144:ef7eb2e8f9f7 76 pwmout_write (obj, 0);
<> 144:ef7eb2e8f9f7 77
<> 144:ef7eb2e8f9f7 78 // Wire pinout
<> 144:ef7eb2e8f9f7 79 pinmap_pinout(pin, PinMap_PWM);
<> 144:ef7eb2e8f9f7 80 }
<> 144:ef7eb2e8f9f7 81
<> 144:ef7eb2e8f9f7 82 void pwmout_free(pwmout_t* obj) {}
<> 144:ef7eb2e8f9f7 83
<> 144:ef7eb2e8f9f7 84 void pwmout_write(pwmout_t* obj, float value) {
<> 144:ef7eb2e8f9f7 85 if (value < 0.0) {
<> 144:ef7eb2e8f9f7 86 value = 0.0;
<> 144:ef7eb2e8f9f7 87 } else if (value > 1.0) {
<> 144:ef7eb2e8f9f7 88 value = 1.0;
<> 144:ef7eb2e8f9f7 89 }
<> 144:ef7eb2e8f9f7 90
<> 144:ef7eb2e8f9f7 91 *obj->CnV = (uint32_t)((float)(*obj->MOD + 1) * value);
<> 144:ef7eb2e8f9f7 92 *obj->CNT = 0;
<> 144:ef7eb2e8f9f7 93 }
<> 144:ef7eb2e8f9f7 94
<> 144:ef7eb2e8f9f7 95 float pwmout_read(pwmout_t* obj) {
<> 144:ef7eb2e8f9f7 96 float v = (float)(*obj->CnV) / (float)(*obj->MOD + 1);
<> 144:ef7eb2e8f9f7 97 return (v > 1.0) ? (1.0) : (v);
<> 144:ef7eb2e8f9f7 98 }
<> 144:ef7eb2e8f9f7 99
<> 144:ef7eb2e8f9f7 100 void pwmout_period(pwmout_t* obj, float seconds) {
<> 144:ef7eb2e8f9f7 101 pwmout_period_us(obj, seconds * 1000000.0f);
<> 144:ef7eb2e8f9f7 102 }
<> 144:ef7eb2e8f9f7 103
<> 144:ef7eb2e8f9f7 104 void pwmout_period_ms(pwmout_t* obj, int ms) {
<> 144:ef7eb2e8f9f7 105 pwmout_period_us(obj, ms * 1000);
<> 144:ef7eb2e8f9f7 106 }
<> 144:ef7eb2e8f9f7 107
<> 144:ef7eb2e8f9f7 108 // Set the PWM period, keeping the duty cycle the same.
<> 144:ef7eb2e8f9f7 109 void pwmout_period_us(pwmout_t* obj, int us) {
<> 144:ef7eb2e8f9f7 110 float dc = pwmout_read(obj);
<> 144:ef7eb2e8f9f7 111 *obj->MOD = (uint32_t)(pwm_clock * (float)us) - 1;
<> 144:ef7eb2e8f9f7 112 pwmout_write(obj, dc);
<> 144:ef7eb2e8f9f7 113 }
<> 144:ef7eb2e8f9f7 114
<> 144:ef7eb2e8f9f7 115 void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
<> 144:ef7eb2e8f9f7 116 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
<> 144:ef7eb2e8f9f7 117 }
<> 144:ef7eb2e8f9f7 118
<> 144:ef7eb2e8f9f7 119 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
<> 144:ef7eb2e8f9f7 120 pwmout_pulsewidth_us(obj, ms * 1000);
<> 144:ef7eb2e8f9f7 121 }
<> 144:ef7eb2e8f9f7 122
<> 144:ef7eb2e8f9f7 123 void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
<> 144:ef7eb2e8f9f7 124 *obj->CnV = (uint32_t)(pwm_clock * (float)us);
<> 144:ef7eb2e8f9f7 125 }