Alessandro Angelino / target-freescale-ksdk

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pwmout_api.c@0:e4d670b91a9a, 2016-03-23 (annotated)

Committer:
screamer
Date:
Wed Mar 23 21:26:50 2016 +0000
Revision:
0:e4d670b91a9a
Initial revision

Who changed what in which revision?

UserRevisionLine numberNew contents of line
screamer 0:e4d670b91a9a 1 /* mbed Microcontroller Library
screamer 0:e4d670b91a9a 2 * Copyright (c) 2006-2013 ARM Limited
screamer 0:e4d670b91a9a 3 *
screamer 0:e4d670b91a9a 4 * Licensed under the Apache License, Version 2.0 (the "License");
screamer 0:e4d670b91a9a 5 * you may not use this file except in compliance with the License.
screamer 0:e4d670b91a9a 6 * You may obtain a copy of the License at
screamer 0:e4d670b91a9a 7 *
screamer 0:e4d670b91a9a 8 * http://www.apache.org/licenses/LICENSE-2.0
screamer 0:e4d670b91a9a 9 *
screamer 0:e4d670b91a9a 10 * Unless required by applicable law or agreed to in writing, software
screamer 0:e4d670b91a9a 11 * distributed under the License is distributed on an "AS IS" BASIS,
screamer 0:e4d670b91a9a 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
screamer 0:e4d670b91a9a 13 * See the License for the specific language governing permissions and
screamer 0:e4d670b91a9a 14 * limitations under the License.
screamer 0:e4d670b91a9a 15 */
screamer 0:e4d670b91a9a 16 #include "mbed_assert.h"
screamer 0:e4d670b91a9a 17 #include "pwmout_api.h"
screamer 0:e4d670b91a9a 18
screamer 0:e4d670b91a9a 19 #if DEVICE_PWMOUT
screamer 0:e4d670b91a9a 20
screamer 0:e4d670b91a9a 21 #include "cmsis.h"
screamer 0:e4d670b91a9a 22 #include "pinmap.h"
screamer 0:e4d670b91a9a 23 #include "fsl_ftm_hal.h"
screamer 0:e4d670b91a9a 24 #include "fsl_mcg_hal.h"
screamer 0:e4d670b91a9a 25 #include "fsl_clock_manager.h"
screamer 0:e4d670b91a9a 26 #include "PeripheralPins.h"
screamer 0:e4d670b91a9a 27
screamer 0:e4d670b91a9a 28 static float pwm_clock_mhz;
screamer 0:e4d670b91a9a 29
screamer 0:e4d670b91a9a 30 void pwmout_init(pwmout_t* obj, PinName pin) {
screamer 0:e4d670b91a9a 31 PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
screamer 0:e4d670b91a9a 32 MBED_ASSERT(pwm != (PWMName)NC);
screamer 0:e4d670b91a9a 33
screamer 0:e4d670b91a9a 34 obj->pwm_name = pwm;
screamer 0:e4d670b91a9a 35
screamer 0:e4d670b91a9a 36 uint32_t pwm_base_clock;
screamer 0:e4d670b91a9a 37 CLOCK_SYS_GetFreq(kBusClock, &pwm_base_clock);
screamer 0:e4d670b91a9a 38 float clkval = (float)pwm_base_clock / 1000000.0f;
screamer 0:e4d670b91a9a 39 uint32_t clkdiv = 0;
screamer 0:e4d670b91a9a 40 while (clkval > 1) {
screamer 0:e4d670b91a9a 41 clkdiv++;
screamer 0:e4d670b91a9a 42 clkval /= 2.0f;
screamer 0:e4d670b91a9a 43 if (clkdiv == 7) {
screamer 0:e4d670b91a9a 44 break;
screamer 0:e4d670b91a9a 45 }
screamer 0:e4d670b91a9a 46 }
screamer 0:e4d670b91a9a 47
screamer 0:e4d670b91a9a 48 pwm_clock_mhz = clkval;
screamer 0:e4d670b91a9a 49 uint32_t channel = pwm & 0xF;
screamer 0:e4d670b91a9a 50 uint32_t instance = pwm >> TPM_SHIFT;
screamer 0:e4d670b91a9a 51 uint32_t ftm_addrs[] = FTM_BASE_ADDRS;
screamer 0:e4d670b91a9a 52 CLOCK_SYS_EnableFtmClock(instance);
screamer 0:e4d670b91a9a 53
screamer 0:e4d670b91a9a 54 FTM_HAL_SetTofFreq(ftm_addrs[instance], 3);
screamer 0:e4d670b91a9a 55 FTM_HAL_SetClockSource(ftm_addrs[instance], kClock_source_FTM_SystemClk);
screamer 0:e4d670b91a9a 56 FTM_HAL_SetClockPs(ftm_addrs[instance], (ftm_clock_ps_t)clkdiv);
screamer 0:e4d670b91a9a 57 FTM_HAL_SetCounter(ftm_addrs[instance], 0);
screamer 0:e4d670b91a9a 58 // default to 20ms: standard for servos, and fine for e.g. brightness control
screamer 0:e4d670b91a9a 59 pwmout_period_ms(obj, 20);
screamer 0:e4d670b91a9a 60 pwmout_write (obj, 0);
screamer 0:e4d670b91a9a 61 ftm_pwm_param_t config = {
screamer 0:e4d670b91a9a 62 .mode = kFtmEdgeAlignedPWM,
screamer 0:e4d670b91a9a 63 .edgeMode = kFtmHighTrue
screamer 0:e4d670b91a9a 64 };
screamer 0:e4d670b91a9a 65 FTM_HAL_EnablePwmMode(ftm_addrs[instance], &config, channel);
screamer 0:e4d670b91a9a 66
screamer 0:e4d670b91a9a 67 // Wire pinout
screamer 0:e4d670b91a9a 68 pinmap_pinout(pin, PinMap_PWM);
screamer 0:e4d670b91a9a 69 }
screamer 0:e4d670b91a9a 70
screamer 0:e4d670b91a9a 71 void pwmout_free(pwmout_t* obj) {
screamer 0:e4d670b91a9a 72 }
screamer 0:e4d670b91a9a 73
screamer 0:e4d670b91a9a 74 void pwmout_write(pwmout_t* obj, float value) {
screamer 0:e4d670b91a9a 75 uint32_t instance = obj->pwm_name >> TPM_SHIFT;
screamer 0:e4d670b91a9a 76 if (value < 0.0f) {
screamer 0:e4d670b91a9a 77 value = 0.0f;
screamer 0:e4d670b91a9a 78 } else if (value > 1.0f) {
screamer 0:e4d670b91a9a 79 value = 1.0f;
screamer 0:e4d670b91a9a 80 }
screamer 0:e4d670b91a9a 81 uint32_t ftm_addrs[] = FTM_BASE_ADDRS;
screamer 0:e4d670b91a9a 82 uint16_t mod = FTM_HAL_GetMod(ftm_addrs[instance]);
screamer 0:e4d670b91a9a 83 uint32_t new_count = (uint32_t)((float)(mod) * value);
screamer 0:e4d670b91a9a 84 // Stop FTM clock to ensure instant update of MOD register
screamer 0:e4d670b91a9a 85 FTM_HAL_SetClockSource(ftm_addrs[instance], kClock_source_FTM_None);
screamer 0:e4d670b91a9a 86 FTM_HAL_SetChnCountVal(ftm_addrs[instance], obj->pwm_name & 0xF, new_count);
screamer 0:e4d670b91a9a 87 FTM_HAL_SetCounter(ftm_addrs[instance], 0);
screamer 0:e4d670b91a9a 88 FTM_HAL_SetClockSource(ftm_addrs[instance], kClock_source_FTM_SystemClk);
screamer 0:e4d670b91a9a 89 }
screamer 0:e4d670b91a9a 90
screamer 0:e4d670b91a9a 91 float pwmout_read(pwmout_t* obj) {
screamer 0:e4d670b91a9a 92 uint32_t ftm_addrs[] = FTM_BASE_ADDRS;
screamer 0:e4d670b91a9a 93 uint16_t count = FTM_HAL_GetChnCountVal(ftm_addrs[obj->pwm_name >> TPM_SHIFT], obj->pwm_name & 0xF, 0);
screamer 0:e4d670b91a9a 94 uint16_t mod = FTM_HAL_GetMod(ftm_addrs[obj->pwm_name >> TPM_SHIFT]);
screamer 0:e4d670b91a9a 95 if (mod == 0)
screamer 0:e4d670b91a9a 96 return 0.0;
screamer 0:e4d670b91a9a 97 float v = (float)(count) / (float)(mod);
screamer 0:e4d670b91a9a 98 return (v > 1.0f) ? (1.0f) : (v);
screamer 0:e4d670b91a9a 99 }
screamer 0:e4d670b91a9a 100
screamer 0:e4d670b91a9a 101 void pwmout_period(pwmout_t* obj, float seconds) {
screamer 0:e4d670b91a9a 102 pwmout_period_us(obj, seconds * 1000000.0f);
screamer 0:e4d670b91a9a 103 }
screamer 0:e4d670b91a9a 104
screamer 0:e4d670b91a9a 105 void pwmout_period_ms(pwmout_t* obj, int ms) {
screamer 0:e4d670b91a9a 106 pwmout_period_us(obj, ms * 1000);
screamer 0:e4d670b91a9a 107 }
screamer 0:e4d670b91a9a 108
screamer 0:e4d670b91a9a 109 // Set the PWM period, keeping the duty cycle the same.
screamer 0:e4d670b91a9a 110 void pwmout_period_us(pwmout_t* obj, int us) {
screamer 0:e4d670b91a9a 111 uint32_t instance = obj->pwm_name >> TPM_SHIFT;
screamer 0:e4d670b91a9a 112 uint32_t ftm_addrs[] = FTM_BASE_ADDRS;
screamer 0:e4d670b91a9a 113 float dc = pwmout_read(obj);
screamer 0:e4d670b91a9a 114 // Stop FTM clock to ensure instant update of MOD register
screamer 0:e4d670b91a9a 115 FTM_HAL_SetClockSource(ftm_addrs[instance], kClock_source_FTM_None);
screamer 0:e4d670b91a9a 116 FTM_HAL_SetMod(ftm_addrs[instance], (uint32_t)(pwm_clock_mhz * (float)us) - 1);
screamer 0:e4d670b91a9a 117 pwmout_write(obj, dc);
screamer 0:e4d670b91a9a 118 FTM_HAL_SetClockSource(ftm_addrs[instance], kClock_source_FTM_SystemClk);
screamer 0:e4d670b91a9a 119 }
screamer 0:e4d670b91a9a 120
screamer 0:e4d670b91a9a 121 void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
screamer 0:e4d670b91a9a 122 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
screamer 0:e4d670b91a9a 123 }
screamer 0:e4d670b91a9a 124
screamer 0:e4d670b91a9a 125 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
screamer 0:e4d670b91a9a 126 pwmout_pulsewidth_us(obj, ms * 1000);
screamer 0:e4d670b91a9a 127 }
screamer 0:e4d670b91a9a 128
screamer 0:e4d670b91a9a 129 void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
screamer 0:e4d670b91a9a 130 uint32_t ftm_addrs[] = FTM_BASE_ADDRS;
screamer 0:e4d670b91a9a 131 uint32_t value = (uint32_t)(pwm_clock_mhz * (float)us);
screamer 0:e4d670b91a9a 132 FTM_HAL_SetChnCountVal(ftm_addrs[obj->pwm_name >> TPM_SHIFT], obj->pwm_name & 0xF, value);
screamer 0:e4d670b91a9a 133 }
screamer 0:e4d670b91a9a 134
screamer 0:e4d670b91a9a 135 #endif