shao ziyang / mbed-src-kl05

mbed library sources

Dependents:   frdm_kl05z_gpio_test

Fork of mbed-src by mbed official

targets/hal/TARGET_Freescale/TARGET_KLXX/pwmout_api.c@82:0b31dbcd4769, 2014-01-31 (annotated)

Committer:
mbed_official
Date:
Fri Jan 31 10:00:06 2014 +0000
Revision:
82:0b31dbcd4769
Child:
227:7bd0639b8911
Synchronized with git revision 74409cbd593d1daab530a57baaa563f30b04b018



Full URL: https://github.com/mbedmicro/mbed/commit/74409cbd593d1daab530a57baaa563f30b04b018/

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 82:0b31dbcd4769 1 /* mbed Microcontroller Library
mbed_official 82:0b31dbcd4769 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 82:0b31dbcd4769 3 *
mbed_official 82:0b31dbcd4769 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 82:0b31dbcd4769 5 * you may not use this file except in compliance with the License.
mbed_official 82:0b31dbcd4769 6 * You may obtain a copy of the License at
mbed_official 82:0b31dbcd4769 7 *
mbed_official 82:0b31dbcd4769 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 82:0b31dbcd4769 9 *
mbed_official 82:0b31dbcd4769 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 82:0b31dbcd4769 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 82:0b31dbcd4769 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 82:0b31dbcd4769 13 * See the License for the specific language governing permissions and
mbed_official 82:0b31dbcd4769 14 * limitations under the License.
mbed_official 82:0b31dbcd4769 15 */
mbed_official 82:0b31dbcd4769 16 #include "pwmout_api.h"
mbed_official 82:0b31dbcd4769 17
mbed_official 82:0b31dbcd4769 18 #include "cmsis.h"
mbed_official 82:0b31dbcd4769 19 #include "pinmap.h"
mbed_official 82:0b31dbcd4769 20 #include "error.h"
mbed_official 82:0b31dbcd4769 21 #include "clk_freqs.h"
mbed_official 82:0b31dbcd4769 22 #include "PeripheralPins.h"
mbed_official 82:0b31dbcd4769 23
mbed_official 82:0b31dbcd4769 24 static float pwm_clock;
mbed_official 82:0b31dbcd4769 25
mbed_official 82:0b31dbcd4769 26 void pwmout_init(pwmout_t* obj, PinName pin) {
mbed_official 82:0b31dbcd4769 27 // determine the channel
mbed_official 82:0b31dbcd4769 28 PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
mbed_official 82:0b31dbcd4769 29 if (pwm == (PWMName)NC)
mbed_official 82:0b31dbcd4769 30 error("PwmOut pin mapping failed");
mbed_official 82:0b31dbcd4769 31
mbed_official 82:0b31dbcd4769 32 uint32_t clkdiv = 0;
mbed_official 82:0b31dbcd4769 33 float clkval;
mbed_official 82:0b31dbcd4769 34 if (mcgpllfll_frequency()) {
mbed_official 82:0b31dbcd4769 35 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: MCGFLLCLK or MCGPLLCLK
mbed_official 82:0b31dbcd4769 36 clkval = mcgpllfll_frequency() / 1000000.0f;
mbed_official 82:0b31dbcd4769 37 } else {
mbed_official 82:0b31dbcd4769 38 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(2); // Clock source: ExtOsc
mbed_official 82:0b31dbcd4769 39 clkval = extosc_frequency() / 1000000.0f;
mbed_official 82:0b31dbcd4769 40 }
mbed_official 82:0b31dbcd4769 41
mbed_official 82:0b31dbcd4769 42 while (clkval > 1) {
mbed_official 82:0b31dbcd4769 43 clkdiv++;
mbed_official 82:0b31dbcd4769 44 clkval /= 2.0;
mbed_official 82:0b31dbcd4769 45 if (clkdiv == 7)
mbed_official 82:0b31dbcd4769 46 break;
mbed_official 82:0b31dbcd4769 47 }
mbed_official 82:0b31dbcd4769 48
mbed_official 82:0b31dbcd4769 49 pwm_clock = clkval;
mbed_official 82:0b31dbcd4769 50 unsigned int port = (unsigned int)pin >> PORT_SHIFT;
mbed_official 82:0b31dbcd4769 51 unsigned int tpm_n = (pwm >> TPM_SHIFT);
mbed_official 82:0b31dbcd4769 52 unsigned int ch_n = (pwm & 0xFF);
mbed_official 82:0b31dbcd4769 53
mbed_official 82:0b31dbcd4769 54 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
mbed_official 82:0b31dbcd4769 55 SIM->SCGC6 |= 1 << (SIM_SCGC6_TPM0_SHIFT + tpm_n);
mbed_official 82:0b31dbcd4769 56
mbed_official 82:0b31dbcd4769 57 TPM_Type *tpm = (TPM_Type *)(TPM0_BASE + 0x1000 * tpm_n);
mbed_official 82:0b31dbcd4769 58 tpm->SC = TPM_SC_CMOD(1) | TPM_SC_PS(clkdiv); // (clock)MHz / clkdiv ~= (0.75)MHz
mbed_official 82:0b31dbcd4769 59 tpm->CONTROLS[ch_n].CnSC = (TPM_CnSC_MSB_MASK | TPM_CnSC_ELSB_MASK); /* No Interrupts; High True pulses on Edge Aligned PWM */
mbed_official 82:0b31dbcd4769 60
mbed_official 82:0b31dbcd4769 61 obj->CnV = &tpm->CONTROLS[ch_n].CnV;
mbed_official 82:0b31dbcd4769 62 obj->MOD = &tpm->MOD;
mbed_official 82:0b31dbcd4769 63 obj->CNT = &tpm->CNT;
mbed_official 82:0b31dbcd4769 64
mbed_official 82:0b31dbcd4769 65 // default to 20ms: standard for servos, and fine for e.g. brightness control
mbed_official 82:0b31dbcd4769 66 pwmout_period_ms(obj, 20);
mbed_official 82:0b31dbcd4769 67 pwmout_write (obj, 0);
mbed_official 82:0b31dbcd4769 68
mbed_official 82:0b31dbcd4769 69 // Wire pinout
mbed_official 82:0b31dbcd4769 70 pinmap_pinout(pin, PinMap_PWM);
mbed_official 82:0b31dbcd4769 71 }
mbed_official 82:0b31dbcd4769 72
mbed_official 82:0b31dbcd4769 73 void pwmout_free(pwmout_t* obj) {}
mbed_official 82:0b31dbcd4769 74
mbed_official 82:0b31dbcd4769 75 void pwmout_write(pwmout_t* obj, float value) {
mbed_official 82:0b31dbcd4769 76 if (value < 0.0) {
mbed_official 82:0b31dbcd4769 77 value = 0.0;
mbed_official 82:0b31dbcd4769 78 } else if (value > 1.0) {
mbed_official 82:0b31dbcd4769 79 value = 1.0;
mbed_official 82:0b31dbcd4769 80 }
mbed_official 82:0b31dbcd4769 81
mbed_official 82:0b31dbcd4769 82 *obj->CnV = (uint32_t)((float)(*obj->MOD) * value);
mbed_official 82:0b31dbcd4769 83 *obj->CNT = 0;
mbed_official 82:0b31dbcd4769 84 }
mbed_official 82:0b31dbcd4769 85
mbed_official 82:0b31dbcd4769 86 float pwmout_read(pwmout_t* obj) {
mbed_official 82:0b31dbcd4769 87 float v = (float)(*obj->CnV) / (float)(*obj->MOD);
mbed_official 82:0b31dbcd4769 88 return (v > 1.0) ? (1.0) : (v);
mbed_official 82:0b31dbcd4769 89 }
mbed_official 82:0b31dbcd4769 90
mbed_official 82:0b31dbcd4769 91 void pwmout_period(pwmout_t* obj, float seconds) {
mbed_official 82:0b31dbcd4769 92 pwmout_period_us(obj, seconds * 1000000.0f);
mbed_official 82:0b31dbcd4769 93 }
mbed_official 82:0b31dbcd4769 94
mbed_official 82:0b31dbcd4769 95 void pwmout_period_ms(pwmout_t* obj, int ms) {
mbed_official 82:0b31dbcd4769 96 pwmout_period_us(obj, ms * 1000);
mbed_official 82:0b31dbcd4769 97 }
mbed_official 82:0b31dbcd4769 98
mbed_official 82:0b31dbcd4769 99 // Set the PWM period, keeping the duty cycle the same.
mbed_official 82:0b31dbcd4769 100 void pwmout_period_us(pwmout_t* obj, int us) {
mbed_official 82:0b31dbcd4769 101 float dc = pwmout_read(obj);
mbed_official 82:0b31dbcd4769 102 *obj->MOD = (uint32_t)(pwm_clock * (float)us);
mbed_official 82:0b31dbcd4769 103 pwmout_write(obj, dc);
mbed_official 82:0b31dbcd4769 104 }
mbed_official 82:0b31dbcd4769 105
mbed_official 82:0b31dbcd4769 106 void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
mbed_official 82:0b31dbcd4769 107 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
mbed_official 82:0b31dbcd4769 108 }
mbed_official 82:0b31dbcd4769 109
mbed_official 82:0b31dbcd4769 110 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
mbed_official 82:0b31dbcd4769 111 pwmout_pulsewidth_us(obj, ms * 1000);
mbed_official 82:0b31dbcd4769 112 }
mbed_official 82:0b31dbcd4769 113
mbed_official 82:0b31dbcd4769 114 void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
mbed_official 82:0b31dbcd4769 115 *obj->CnV = (uint32_t)(pwm_clock * (float)us);
mbed_official 82:0b31dbcd4769 116 }