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Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.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@227:7bd0639b8911, 2014-06-11 (annotated)

Committer:
mbed_official
Date:
Wed Jun 11 16:00:09 2014 +0100
Revision:
227:7bd0639b8911
Parent:
82:0b31dbcd4769
Child:
264:91fcbf887208
Synchronized with git revision d58d532ebc0e0a96f4fffb8edefc082b71b964af



Full URL: https://github.com/mbedmicro/mbed/commit/d58d532ebc0e0a96f4fffb8edefc082b71b964af/

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 227:7bd0639b8911 16 #include "mbed_assert.h"
mbed_official 82:0b31dbcd4769 17 #include "pwmout_api.h"
mbed_official 82:0b31dbcd4769 18
mbed_official 82:0b31dbcd4769 19 #include "cmsis.h"
mbed_official 82:0b31dbcd4769 20 #include "pinmap.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 227:7bd0639b8911 29 MBED_ASSERT(pwm != (PWMName)NC);
mbed_official 227:7bd0639b8911 30
mbed_official 82:0b31dbcd4769 31 uint32_t clkdiv = 0;
mbed_official 82:0b31dbcd4769 32 float clkval;
mbed_official 82:0b31dbcd4769 33 if (mcgpllfll_frequency()) {
mbed_official 82:0b31dbcd4769 34 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: MCGFLLCLK or MCGPLLCLK
mbed_official 82:0b31dbcd4769 35 clkval = mcgpllfll_frequency() / 1000000.0f;
mbed_official 82:0b31dbcd4769 36 } else {
mbed_official 82:0b31dbcd4769 37 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(2); // Clock source: ExtOsc
mbed_official 82:0b31dbcd4769 38 clkval = extosc_frequency() / 1000000.0f;
mbed_official 227:7bd0639b8911 39 }
mbed_official 82:0b31dbcd4769 40
mbed_official 82:0b31dbcd4769 41 while (clkval > 1) {
mbed_official 82:0b31dbcd4769 42 clkdiv++;
mbed_official 227:7bd0639b8911 43 clkval /= 2.0;
mbed_official 82:0b31dbcd4769 44 if (clkdiv == 7)
mbed_official 82:0b31dbcd4769 45 break;
mbed_official 82:0b31dbcd4769 46 }
mbed_official 82:0b31dbcd4769 47
mbed_official 82:0b31dbcd4769 48 pwm_clock = clkval;
mbed_official 82:0b31dbcd4769 49 unsigned int port = (unsigned int)pin >> PORT_SHIFT;
mbed_official 82:0b31dbcd4769 50 unsigned int tpm_n = (pwm >> TPM_SHIFT);
mbed_official 82:0b31dbcd4769 51 unsigned int ch_n = (pwm & 0xFF);
mbed_official 82:0b31dbcd4769 52
mbed_official 82:0b31dbcd4769 53 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
mbed_official 82:0b31dbcd4769 54 SIM->SCGC6 |= 1 << (SIM_SCGC6_TPM0_SHIFT + tpm_n);
mbed_official 82:0b31dbcd4769 55
mbed_official 82:0b31dbcd4769 56 TPM_Type *tpm = (TPM_Type *)(TPM0_BASE + 0x1000 * tpm_n);
mbed_official 82:0b31dbcd4769 57 tpm->SC = TPM_SC_CMOD(1) | TPM_SC_PS(clkdiv); // (clock)MHz / clkdiv ~= (0.75)MHz
mbed_official 82:0b31dbcd4769 58 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 59
mbed_official 82:0b31dbcd4769 60 obj->CnV = &tpm->CONTROLS[ch_n].CnV;
mbed_official 82:0b31dbcd4769 61 obj->MOD = &tpm->MOD;
mbed_official 82:0b31dbcd4769 62 obj->CNT = &tpm->CNT;
mbed_official 82:0b31dbcd4769 63
mbed_official 82:0b31dbcd4769 64 // default to 20ms: standard for servos, and fine for e.g. brightness control
mbed_official 82:0b31dbcd4769 65 pwmout_period_ms(obj, 20);
mbed_official 82:0b31dbcd4769 66 pwmout_write (obj, 0);
mbed_official 82:0b31dbcd4769 67
mbed_official 82:0b31dbcd4769 68 // Wire pinout
mbed_official 82:0b31dbcd4769 69 pinmap_pinout(pin, PinMap_PWM);
mbed_official 82:0b31dbcd4769 70 }
mbed_official 82:0b31dbcd4769 71
mbed_official 82:0b31dbcd4769 72 void pwmout_free(pwmout_t* obj) {}
mbed_official 82:0b31dbcd4769 73
mbed_official 82:0b31dbcd4769 74 void pwmout_write(pwmout_t* obj, float value) {
mbed_official 82:0b31dbcd4769 75 if (value < 0.0) {
mbed_official 82:0b31dbcd4769 76 value = 0.0;
mbed_official 82:0b31dbcd4769 77 } else if (value > 1.0) {
mbed_official 82:0b31dbcd4769 78 value = 1.0;
mbed_official 82:0b31dbcd4769 79 }
mbed_official 82:0b31dbcd4769 80
mbed_official 82:0b31dbcd4769 81 *obj->CnV = (uint32_t)((float)(*obj->MOD) * value);
mbed_official 82:0b31dbcd4769 82 *obj->CNT = 0;
mbed_official 82:0b31dbcd4769 83 }
mbed_official 82:0b31dbcd4769 84
mbed_official 82:0b31dbcd4769 85 float pwmout_read(pwmout_t* obj) {
mbed_official 82:0b31dbcd4769 86 float v = (float)(*obj->CnV) / (float)(*obj->MOD);
mbed_official 82:0b31dbcd4769 87 return (v > 1.0) ? (1.0) : (v);
mbed_official 82:0b31dbcd4769 88 }
mbed_official 82:0b31dbcd4769 89
mbed_official 82:0b31dbcd4769 90 void pwmout_period(pwmout_t* obj, float seconds) {
mbed_official 82:0b31dbcd4769 91 pwmout_period_us(obj, seconds * 1000000.0f);
mbed_official 82:0b31dbcd4769 92 }
mbed_official 82:0b31dbcd4769 93
mbed_official 82:0b31dbcd4769 94 void pwmout_period_ms(pwmout_t* obj, int ms) {
mbed_official 82:0b31dbcd4769 95 pwmout_period_us(obj, ms * 1000);
mbed_official 82:0b31dbcd4769 96 }
mbed_official 82:0b31dbcd4769 97
mbed_official 82:0b31dbcd4769 98 // Set the PWM period, keeping the duty cycle the same.
mbed_official 82:0b31dbcd4769 99 void pwmout_period_us(pwmout_t* obj, int us) {
mbed_official 82:0b31dbcd4769 100 float dc = pwmout_read(obj);
mbed_official 82:0b31dbcd4769 101 *obj->MOD = (uint32_t)(pwm_clock * (float)us);
mbed_official 82:0b31dbcd4769 102 pwmout_write(obj, dc);
mbed_official 82:0b31dbcd4769 103 }
mbed_official 82:0b31dbcd4769 104
mbed_official 82:0b31dbcd4769 105 void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
mbed_official 82:0b31dbcd4769 106 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
mbed_official 82:0b31dbcd4769 107 }
mbed_official 82:0b31dbcd4769 108
mbed_official 82:0b31dbcd4769 109 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
mbed_official 82:0b31dbcd4769 110 pwmout_pulsewidth_us(obj, ms * 1000);
mbed_official 82:0b31dbcd4769 111 }
mbed_official 82:0b31dbcd4769 112
mbed_official 82:0b31dbcd4769 113 void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
mbed_official 82:0b31dbcd4769 114 *obj->CnV = (uint32_t)(pwm_clock * (float)us);
mbed_official 82:0b31dbcd4769 115 }