mbed library sources
Fork of mbed-src by
targets/hal/TARGET_Freescale/TARGET_K20D50M/pwmout_api.c
- Committer:
- todotani
- Date:
- 2014-09-05
- Revision:
- 308:59cc78a25982
- Parent:
- 264:91fcbf887208
File content as of revision 308:59cc78a25982:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "mbed_assert.h" #include "pwmout_api.h" #include "cmsis.h" #include "pinmap.h" static const PinMap PinMap_PWM[] = { // LEDs {LED_RED , PWM_3 , 4}, // PTC3, FTM0 CH2 {LED_GREEN, PWM_5, 4}, // PTD4, FTM0 CH4 {LED_BLUE , PWM_8 , 3}, // PTA2, FTM0 CH7 // Arduino digital pinout {D3, PWM_5 , 4}, // PTD4, FTM0 CH4 {D5, PWM_7 , 3}, // PTA1, FTM0 CH6 {D6, PWM_3 , 4}, // PTC3, FTM0 CH2 {D9, PWM_6 , 4}, // PTD5, FTM0 CH6 {D10, PWM_2 , 4}, // PTC2, FTM0 CH1 {PTA0, PWM_6 , 3}, // PTA0, FTM0 CH5 {PTA3, PWM_1 , 3}, // PTA3, FTM0 CH0 {PTA4, PWM_2 , 3}, // PTA4, FTM0 CH1 {PTA5, PWM_3 , 3}, // PTA5, FTM0 CH2 {PTA12, PWM_9 , 3}, // PTA12, FTM1 CH0 {PTA13, PWM_10, 3}, // PTA13, FTM1 CH1 {PTB0, PWM_9 , 3}, // PTB0, FTM1 CH0 {PTB1, PWM_10, 3}, // PTB1, FTM1 CH1 {PTC1, PWM_1 , 4}, // PTC1, FTM0 CH0 {PTD4, PWM_4 , 4}, // PTD4, FTM0 CH3 {PTD6, PWM_7 , 4}, // PTD6, FTM0 CH6 {PTD7, PWM_8 , 4}, // PTD7, FTM0 CH7 {NC , NC , 0} }; static float pwm_clock = 0; void pwmout_init(pwmout_t* obj, PinName pin) { // determine the channel PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM); MBED_ASSERT(pwm != (PWMName)NC); uint32_t clkdiv = 0; float clkval = SystemCoreClock / 1000000.0f; while (clkval > 1) { clkdiv++; clkval /= 2.0; if (clkdiv == 7) break; } pwm_clock = clkval; unsigned int port = (unsigned int)pin >> PORT_SHIFT; unsigned int ftm_n = (pwm >> TPM_SHIFT); unsigned int ch_n = (pwm & 0xFF); SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port); SIM->SCGC6 |= 1 << (SIM_SCGC6_FTM0_SHIFT + ftm_n); FTM_Type *ftm = (FTM_Type *)(FTM0_BASE + 0x1000 * ftm_n); ftm->CONF |= FTM_CONF_BDMMODE(3); ftm->SC = FTM_SC_CLKS(1) | FTM_SC_PS(clkdiv); // (clock)MHz / clkdiv ~= (0.75)MHz ftm->CONTROLS[ch_n].CnSC = (FTM_CnSC_MSB_MASK | FTM_CnSC_ELSB_MASK); /* No Interrupts; High True pulses on Edge Aligned PWM */ obj->CnV = &ftm->CONTROLS[ch_n].CnV; obj->MOD = &ftm->MOD; obj->CNT = &ftm->CNT; // default to 20ms: standard for servos, and fine for e.g. brightness control pwmout_period_ms(obj, 20); pwmout_write(obj, 0); // Wire pinout pinmap_pinout(pin, PinMap_PWM); } void pwmout_free(pwmout_t* obj) {} void pwmout_write(pwmout_t* obj, float value) { if (value < 0.0) { value = 0.0; } else if (value > 1.0) { value = 1.0; } *obj->CnV = (uint32_t)((float)(*obj->MOD + 1) * value); } float pwmout_read(pwmout_t* obj) { float v = (float)(*obj->CnV) / (float)(*obj->MOD + 1); return (v > 1.0) ? (1.0) : (v); } void pwmout_period(pwmout_t* obj, float seconds) { pwmout_period_us(obj, seconds * 1000000.0f); } void pwmout_period_ms(pwmout_t* obj, int ms) { pwmout_period_us(obj, ms * 1000); } // Set the PWM period, keeping the duty cycle the same. void pwmout_period_us(pwmout_t* obj, int us) { float dc = pwmout_read(obj); *obj->MOD = (uint32_t)(pwm_clock * (float)us) - 1; pwmout_write(obj, dc); } void pwmout_pulsewidth(pwmout_t* obj, float seconds) { pwmout_pulsewidth_us(obj, seconds * 1000000.0f); } void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) { pwmout_pulsewidth_us(obj, ms * 1000); } void pwmout_pulsewidth_us(pwmout_t* obj, int us) { *obj->CnV = (uint32_t)(pwm_clock * (float)us); }