mbed library sources
Dependents: FRDM-KL46Z_LCD_Test FRDM-KL46Z_LCD_Test FRDM-KL46Z_Plantilla FRDM-KL46Z_Plantilla ... more
Diff: targets/hal/TARGET_Freescale/TARGET_K20D50M/pwmout_api.c
- Revision:
- 0:6bc4ac881c8e
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_Freescale/TARGET_K20D50M/pwmout_api.c Thu Jul 28 15:56:34 2016 +0000 @@ -0,0 +1,135 @@ +/* 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); +}