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Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

Import librarymbed

The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_Freescale/TARGET_KLXX/pwmout_api.c@111:ae4891ca7084, 2014-03-06 (annotated)

Committer:
mbed_official
Date:
Thu Mar 06 10:00:06 2014 +0000
Revision:
111:ae4891ca7084
Parent:
82:0b31dbcd4769
Child:
227:7bd0639b8911
Synchronized with git revision 955bd9a5c9e042f1cf30bbae2a99afaab8eb4cbf



Full URL: https://github.com/mbedmicro/mbed/commit/955bd9a5c9e042f1cf30bbae2a99afaab8eb4cbf/

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 }