uint32_t pwm_init(pwm_t dev, pwm_mode_t mode, uint32_t freq, uint16_t res)
{
TIM_TypeDef *tim = NULL;
GPIO_TypeDef *port = NULL;
uint32_t pins[PWM_MAX_CHANNELS];
uint32_t af;
int channels;
uint32_t pwm_clk;
pwm_poweron(dev);
switch (dev) {
#if PWM_0_EN
case PWM_0:
tim = PWM_0_DEV;
port = PWM_0_PORT;
pins[0] = PWM_0_PIN_CH0;
pins[1] = PWM_0_PIN_CH1;
pins[2] = PWM_0_PIN_CH2;
pins[3] = PWM_0_PIN_CH3;
af = PWM_0_PIN_AF;
channels = PWM_0_CHANNELS;
pwm_clk = PWM_0_CLK;
PWM_0_PORT_CLKEN();
break;
#endif
#if PWM_1_EN
case PWM_1:
tim = PWM_1_DEV;
port = PWM_1_PORT;
pins[0] = PWM_1_PIN_CH0;
pins[1] = PWM_1_PIN_CH1;
pins[2] = PWM_1_PIN_CH2;
pins[3] = PWM_1_PIN_CH3;
af = PWM_1_PIN_AF;
channels = PWM_1_CHANNELS;
pwm_clk = PWM_1_CLK;
PWM_1_PORT_CLKEN();
break;
#endif
default:
pwm_poweroff(dev);
return 0;
}
/* setup pins: alternate function */
for (int i = 0; i < channels; i++) {
port->MODER &= ~(3 << (pins[i] * 2));
port->MODER |= (2 << (pins[i] * 2));
if (pins[i] < 8) {
port->AFR[0] &= ~(0xf << (pins[i] * 4));
port->AFR[0] |= (af << (pins[i] * 4));
}
else {
port->AFR[1] &= ~(0xf << ((pins[i] - 8) * 4));
port->AFR[1] |= (af << ((pins[i] - 8) * 4));
}
}
/* reset timer configuration registers */
tim->CR1 = 0;
tim->CR2 = 0;
tim->CCMR1 = 0;
tim->CCMR2 = 0;
/* set prescale and auto-reload registers to matching values for resolution and frequency */
if ((res > 0xffff) || ((res * freq) > pwm_clk)) {
return 0;
}
tim->PSC = (pwm_clk / (res * freq)) - 1;
tim->ARR = res - 1;
freq = (pwm_clk / (res * (tim->PSC + 1)));
/* set PWM mode */
switch (mode) {
case PWM_LEFT:
tim->CCMR1 |= (TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 |
TIM_CCMR1_OC2M_1 | TIM_CCMR1_OC2M_2);
tim->CCMR2 |= (TIM_CCMR2_OC3M_1 | TIM_CCMR2_OC3M_2 |
TIM_CCMR2_OC4M_1 | TIM_CCMR2_OC4M_2);
break;
case PWM_RIGHT:
tim->CCMR1 |= (TIM_CCMR1_OC1M_0 | TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1M_2 |
TIM_CCMR1_OC2M_0 | TIM_CCMR1_OC2M_1 | TIM_CCMR1_OC2M_2);
tim->CCMR2 |= (TIM_CCMR2_OC3M_0 | TIM_CCMR2_OC3M_1 | TIM_CCMR2_OC3M_2 |
TIM_CCMR2_OC4M_0 | TIM_CCMR2_OC4M_1 | TIM_CCMR2_OC4M_2);
break;
case PWM_CENTER:
tim->CR1 |= (TIM_CR1_CMS_0 | TIM_CR1_CMS_1);
break;
}
/* enable output on PWM pins */
tim->CCER |= (TIM_CCER_CC1E | TIM_CCER_CC2E | TIM_CCER_CC3E | TIM_CCER_CC4E);
/* enable PWM generation */
pwm_start(dev);
return freq;
}
int pwm_init(pwm_t dev, pwm_mode_t mode, unsigned int frequency, unsigned int resolution)
{
FTM_Type *tim = NULL;
PORT_Type *port[PWM_MAX_CHANNELS];
/* cppcheck-suppress unassignedVariable */
uint8_t pins[PWM_MAX_CHANNELS];
uint8_t af[PWM_MAX_CHANNELS];
/* cppcheck-suppress unassignedVariable */
uint8_t ftmchan[PWM_MAX_CHANNELS];
int channels = 0;
uint32_t pwm_clk = 0;
pwm_poweron(dev);
switch (dev) {
#if PWM_0_EN
case PWM_0:
tim = PWM_0_DEV;
port[0] = PWM_0_PORT_CH0;
port[1] = PWM_0_PORT_CH1;
port[2] = PWM_0_PORT_CH2;
port[3] = PWM_0_PORT_CH3;
pins[0] = PWM_0_PIN_CH0;
pins[1] = PWM_0_PIN_CH1;
pins[2] = PWM_0_PIN_CH2;
pins[3] = PWM_0_PIN_CH3;
ftmchan[0] = PWM_0_FTMCHAN_CH0;
ftmchan[1] = PWM_0_FTMCHAN_CH1;
ftmchan[2] = PWM_0_FTMCHAN_CH2;
ftmchan[3] = PWM_0_FTMCHAN_CH3;
af[0] = PWM_0_PIN_AF_CH0;
af[1] = PWM_0_PIN_AF_CH1;
af[2] = PWM_0_PIN_AF_CH2;
af[3] = PWM_0_PIN_AF_CH3;
channels = PWM_0_CHANNELS;
pwm_clk = PWM_0_CLK;
PWM_0_PORT_CLKEN();
break;
#endif
default:
return -1;
}
if (channels > PWM_MAX_CHANNELS) {
return -1;
}
/* cppcheck-suppress nullPointer */
tim->MODE = (1 << FTM_MODE_WPDIS_SHIFT);
/* setup pins, reset timer match value */
for (int i = 0; i < channels; i++) {
port[i]->PCR[pins[i]] = PORT_PCR_MUX(af[i]);
/* cppcheck-suppress nullPointer */
tim->CONTROLS[i].CnV = 0;
}
/* reset timer configuration registers */
/* cppcheck-suppress nullPointer */
tim->COMBINE = 0;
/* set prescale and mod registers to matching values for resolution and frequency */
if (resolution > 0xffff || (resolution * frequency) > pwm_clk) {
return -2;
}
/* cppcheck-suppress nullPointer */
tim->SC = FTM_SC_PS((pwm_clk / (resolution * frequency)) - 1);
/* cppcheck-suppress nullPointer */
tim->MOD = resolution;
/* set PWM mode */
switch (mode) {
case PWM_LEFT:
for (int i = 0; i < channels; i++) {
/* cppcheck-suppress nullPointer */
tim->CONTROLS[ftmchan[i]].CnSC = (1 << FTM_CnSC_MSB_SHIFT |
1 << FTM_CnSC_ELSB_SHIFT);
}
break;
case PWM_RIGHT:
for (int i = 0; i < channels; i++) {
/* cppcheck-suppress nullPointer */
tim->CONTROLS[ftmchan[i]].CnSC = (1 << FTM_CnSC_MSB_SHIFT |
1 << FTM_CnSC_ELSA_SHIFT);
}
break;
case PWM_CENTER:
for (int i = 0; i < channels; i++) {
/* cppcheck-suppress nullPointer */
tim->CONTROLS[ftmchan[i]].CnSC = (1 << FTM_CnSC_MSB_SHIFT);
}
/* cppcheck-suppress nullPointer */
tim->SC |= (1 << FTM_SC_CPWMS_SHIFT);
break;
}
/* enable timer ergo the PWM generation */
pwm_start(dev);
return 0;
}
