Mouse code for the MacroRat
mbed-dev/targets/TARGET_NORDIC/TARGET_MCU_NRF51822/pwmout_api.c
- Committer:
- sahilmgandhi
- Date:
- 2017-05-14
- Revision:
- 18:6a4db94011d3
File content as of revision 18:6a4db94011d3:
/* mbed Microcontroller Library * Copyright (c) 2013 Nordic Semiconductor * * 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" #include "mbed_error.h" #define NO_PWMS 3 #define TIMER_PRECISION 4 //4us ticks #define TIMER_PRESCALER 6 //4us ticks = 16Mhz/(2**6) static const PinMap PinMap_PWM[] = { {P0_0, PWM_1, 1}, {P0_1, PWM_1, 1}, {P0_2, PWM_1, 1}, {P0_3, PWM_1, 1}, {P0_4, PWM_1, 1}, {P0_5, PWM_1, 1}, {P0_6, PWM_1, 1}, {P0_7, PWM_1, 1}, {P0_8, PWM_1, 1}, {P0_9, PWM_1, 1}, {P0_10, PWM_1, 1}, {P0_11, PWM_1, 1}, {P0_12, PWM_1, 1}, {P0_13, PWM_1, 1}, {P0_14, PWM_1, 1}, {P0_15, PWM_1, 1}, {P0_16, PWM_1, 1}, {P0_17, PWM_1, 1}, {P0_18, PWM_1, 1}, {P0_19, PWM_1, 1}, {P0_20, PWM_1, 1}, {P0_21, PWM_1, 1}, {P0_22, PWM_1, 1}, {P0_23, PWM_1, 1}, {P0_24, PWM_1, 1}, {P0_25, PWM_1, 1}, {P0_28, PWM_1, 1}, {P0_29, PWM_1, 1}, {P0_30, PWM_1, 1}, {NC, NC, 0} }; static NRF_TIMER_Type *Timers[1] = { NRF_TIMER2 }; uint16_t PERIOD = 20000 / TIMER_PRECISION; //20ms uint8_t PWM_taken[NO_PWMS] = {0, 0, 0}; uint16_t PULSE_WIDTH[NO_PWMS] = {1, 1, 1}; //set to 1 instead of 0 uint16_t ACTUAL_PULSE[NO_PWMS] = {0, 0, 0}; /** @brief Function for handling timer 2 peripheral interrupts. */ #ifdef __cplusplus extern "C" { #endif void TIMER2_IRQHandler(void) { NRF_TIMER2->EVENTS_COMPARE[3] = 0; NRF_TIMER2->CC[3] = PERIOD; if (PWM_taken[0]) { NRF_TIMER2->CC[0] = PULSE_WIDTH[0]; } if (PWM_taken[1]) { NRF_TIMER2->CC[1] = PULSE_WIDTH[1]; } if (PWM_taken[2]) { NRF_TIMER2->CC[2] = PULSE_WIDTH[2]; } NRF_TIMER2->TASKS_START = 1; } #ifdef __cplusplus } #endif /** @brief Function for initializing the Timer peripherals. */ void timer_init(uint8_t pwmChoice) { NRF_TIMER_Type *timer = Timers[0]; timer->TASKS_STOP = 0; if (pwmChoice == 0) { timer->POWER = 0; timer->POWER = 1; timer->MODE = TIMER_MODE_MODE_Timer; timer->BITMODE = TIMER_BITMODE_BITMODE_16Bit << TIMER_BITMODE_BITMODE_Pos; timer->PRESCALER = TIMER_PRESCALER; timer->CC[3] = PERIOD; } timer->CC[pwmChoice] = PULSE_WIDTH[pwmChoice]; //high priority application interrupt NVIC_SetPriority(TIMER2_IRQn, 1); NVIC_EnableIRQ(TIMER2_IRQn); timer->TASKS_START = 0x01; } static void timer_free() { NRF_TIMER_Type *timer = Timers[0]; for(uint8_t i = 1; i < NO_PWMS; i++){ if(PWM_taken[i]){ break; } if((i == NO_PWMS - 1) && (!PWM_taken[i])) timer->TASKS_STOP = 0x01; } } /** @brief Function for initializing the GPIO Tasks/Events peripheral. */ void gpiote_init(PinName pin, uint8_t channel_number) { // Connect GPIO input buffers and configure PWM_OUTPUT_PIN_NUMBER as an output. NRF_GPIO->PIN_CNF[pin] = (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos) | (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) | (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) | (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos); NRF_GPIO->OUTCLR = (1UL << pin); // Configure GPIOTE channel 0 to toggle the PWM pin state // @note Only one GPIOTE task can be connected to an output pin. /* Configure channel to Pin31, not connected to the pin, and configure as a tasks that will set it to proper level */ NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos) | (31UL << GPIOTE_CONFIG_PSEL_Pos) | (GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos); /* Three NOPs are required to make sure configuration is written before setting tasks or getting events */ __NOP(); __NOP(); __NOP(); /* Launch the task to take the GPIOTE channel output to the desired level */ NRF_GPIOTE->TASKS_OUT[channel_number] = 1; /* Finally configure the channel as the caller expects. If OUTINIT works, the channel is configured properly. If it does not, the channel output inheritance sets the proper level. */ NRF_GPIOTE->CONFIG[channel_number] = (GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos) | ((uint32_t)pin << GPIOTE_CONFIG_PSEL_Pos) | ((uint32_t)GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos) | ((uint32_t)GPIOTE_CONFIG_OUTINIT_Low << GPIOTE_CONFIG_OUTINIT_Pos); // ((uint32_t)GPIOTE_CONFIG_OUTINIT_High << // GPIOTE_CONFIG_OUTINIT_Pos);// /* Three NOPs are required to make sure configuration is written before setting tasks or getting events */ __NOP(); __NOP(); __NOP(); } static void gpiote_free(PinName pin,uint8_t channel_number) { NRF_GPIOTE->TASKS_OUT[channel_number] = 0; NRF_GPIOTE->CONFIG[channel_number] = 0; NRF_GPIO->PIN_CNF[pin] = (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos); } /** @brief Function for initializing the Programmable Peripheral Interconnect peripheral. */ static void ppi_init(uint8_t pwm) { //using ppi channels 0-7 (only 0-7 are available) uint8_t channel_number = 2 * pwm; NRF_TIMER_Type *timer = Timers[0]; // Configure PPI channel 0 to toggle ADVERTISING_LED_PIN_NO on every TIMER1 COMPARE[0] match NRF_PPI->CH[channel_number].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[pwm]; NRF_PPI->CH[channel_number + 1].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[pwm]; NRF_PPI->CH[channel_number].EEP = (uint32_t)&timer->EVENTS_COMPARE[pwm]; NRF_PPI->CH[channel_number + 1].EEP = (uint32_t)&timer->EVENTS_COMPARE[3]; // Enable PPI channels. NRF_PPI->CHEN |= (1 << channel_number) | (1 << (channel_number + 1)); } static void ppi_free(uint8_t pwm) { //using ppi channels 0-7 (only 0-7 are available) uint8_t channel_number = 2*pwm; // Disable PPI channels. NRF_PPI->CHEN &= (~(1 << channel_number)) & (~(1 << (channel_number+1))); } void setModulation(pwmout_t *obj, uint8_t toggle, uint8_t high) { if (high) { NRF_GPIOTE->CONFIG[obj->pwm] |= ((uint32_t)GPIOTE_CONFIG_OUTINIT_High << GPIOTE_CONFIG_OUTINIT_Pos); if (toggle) { NRF_GPIOTE->CONFIG[obj->pwm] |= (GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos) | ((uint32_t)GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos); } else { NRF_GPIOTE->CONFIG[obj->pwm] &= ~((uint32_t)GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos); NRF_GPIOTE->CONFIG[obj->pwm] |= ((uint32_t)GPIOTE_CONFIG_POLARITY_LoToHi << GPIOTE_CONFIG_POLARITY_Pos); } } else { NRF_GPIOTE->CONFIG[obj->pwm] &= ~((uint32_t)GPIOTE_CONFIG_OUTINIT_High << GPIOTE_CONFIG_OUTINIT_Pos); if (toggle) { NRF_GPIOTE->CONFIG[obj->pwm] |= (GPIOTE_CONFIG_MODE_Task << GPIOTE_CONFIG_MODE_Pos) | ((uint32_t)GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos); } else { NRF_GPIOTE->CONFIG[obj->pwm] &= ~((uint32_t)GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos); NRF_GPIOTE->CONFIG[obj->pwm] |= ((uint32_t)GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos); } } } void pwmout_init(pwmout_t *obj, PinName pin) { // determine the channel uint8_t pwmOutSuccess = 0; PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM); MBED_ASSERT(pwm != (PWMName)NC); if (PWM_taken[(uint8_t)pwm]) { for (uint8_t i = 1; !pwmOutSuccess && (i<NO_PWMS); i++) { if (!PWM_taken[i]) { pwm = (PWMName)i; PWM_taken[i] = 1; pwmOutSuccess = 1; } } } else { pwmOutSuccess = 1; PWM_taken[(uint8_t)pwm] = 1; } if (!pwmOutSuccess) { error("PwmOut pin mapping failed. All available PWM channels are in use."); } obj->pwm = pwm; obj->pin = pin; gpiote_init(pin, (uint8_t)pwm); ppi_init((uint8_t)pwm); if (pwm == 0) { NRF_POWER->TASKS_CONSTLAT = 1; } timer_init((uint8_t)pwm); //default to 20ms: standard for servos, and fine for e.g. brightness control pwmout_period_ms(obj, 20); pwmout_write (obj, 0); } void pwmout_free(pwmout_t* obj) { MBED_ASSERT(obj->pwm != (PWMName)NC); pwmout_write(obj, 0); PWM_taken[obj->pwm] = 0; timer_free(); ppi_free(obj->pwm); gpiote_free(obj->pin,obj->pwm); } void pwmout_write(pwmout_t *obj, float value) { uint16_t oldPulseWidth; NRF_TIMER2->EVENTS_COMPARE[3] = 0; NRF_TIMER2->TASKS_STOP = 1; if (value < 0.0f) { value = 0.0; } else if (value > 1.0f) { value = 1.0; } oldPulseWidth = ACTUAL_PULSE[obj->pwm]; ACTUAL_PULSE[obj->pwm] = PULSE_WIDTH[obj->pwm] = value * PERIOD; if (PULSE_WIDTH[obj->pwm] == 0) { PULSE_WIDTH[obj->pwm] = 1; setModulation(obj, 0, 0); } else if (PULSE_WIDTH[obj->pwm] == PERIOD) { PULSE_WIDTH[obj->pwm] = PERIOD - 1; setModulation(obj, 0, 1); } else if ((oldPulseWidth == 0) || (oldPulseWidth == PERIOD)) { setModulation(obj, 1, oldPulseWidth == PERIOD); } NRF_TIMER2->INTENSET = TIMER_INTENSET_COMPARE3_Msk; NRF_TIMER2->SHORTS = TIMER_SHORTS_COMPARE3_CLEAR_Msk | TIMER_SHORTS_COMPARE3_STOP_Msk; NRF_TIMER2->TASKS_START = 1; } float pwmout_read(pwmout_t *obj) { return ((float)PULSE_WIDTH[obj->pwm] / (float)PERIOD); } 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) { uint32_t periodInTicks = us / TIMER_PRECISION; NRF_TIMER2->EVENTS_COMPARE[3] = 0; NRF_TIMER2->TASKS_STOP = 1; if (periodInTicks>((1 << 16) - 1)) { PERIOD = (1 << 16) - 1; //131ms } else if (periodInTicks<5) { PERIOD = 5; } else { PERIOD = periodInTicks; } NRF_TIMER2->INTENSET = TIMER_INTENSET_COMPARE3_Msk; NRF_TIMER2->SHORTS = TIMER_SHORTS_COMPARE3_CLEAR_Msk | TIMER_SHORTS_COMPARE3_STOP_Msk; NRF_TIMER2->TASKS_START = 1; } 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) { uint32_t pulseInTicks = us / TIMER_PRECISION; uint16_t oldPulseWidth = ACTUAL_PULSE[obj->pwm]; NRF_TIMER2->EVENTS_COMPARE[3] = 0; NRF_TIMER2->TASKS_STOP = 1; ACTUAL_PULSE[obj->pwm] = PULSE_WIDTH[obj->pwm] = pulseInTicks; if (PULSE_WIDTH[obj->pwm] == 0) { PULSE_WIDTH[obj->pwm] = 1; setModulation(obj, 0, 0); } else if (PULSE_WIDTH[obj->pwm] == PERIOD) { PULSE_WIDTH[obj->pwm] = PERIOD - 1; setModulation(obj, 0, 1); } else if ((oldPulseWidth == 0) || (oldPulseWidth == PERIOD)) { setModulation(obj, 1, oldPulseWidth == PERIOD); } NRF_TIMER2->INTENSET = TIMER_INTENSET_COMPARE3_Msk; NRF_TIMER2->SHORTS = TIMER_SHORTS_COMPARE3_CLEAR_Msk | TIMER_SHORTS_COMPARE3_STOP_Msk; NRF_TIMER2->TASKS_START = 1; }