tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/pwmout_api.c

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