static void pwm_bcm2836_config(struct pwm_t * pwm, int duty, int period, int polarity)
{
struct pwm_bcm2836_pdata_t * pdat = (struct pwm_bcm2836_pdata_t *)pwm->priv;
unsigned long scaler = (unsigned long)(1000000000ULL / clk_get_rate(pdat->clk));
u32_t ctrl;
if(pwm->__duty != duty)
{
write32(pdat->virt + PWM_DUTY(pdat->channel), duty / scaler);
}
if(pwm->__period != period)
{
write32(pdat->virt + PWM_PERIOD(pdat->channel), period /scaler);
}
if(pwm->__polarity != polarity)
{
ctrl = read32(pdat->virt + PWM_CTRL);
if(polarity)
ctrl |= (0x10 << PWM_CTRL_SHIFT(pdat->channel));
else
ctrl &= ~(0x10 << PWM_CTRL_SHIFT(pdat->channel));
write32(pdat->virt + PWM_CTRL, ctrl);
}
}
static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
unsigned long long c;
int period_cycles, duty_cycles;
u32 val;
c = clk_get_rate(lpc32xx->clk) / 256;
c = c * period_ns;
do_div(c, NSEC_PER_SEC);
/* Handle high and low extremes */
if (c == 0)
c = 1;
if (c > 255)
c = 0; /* 0 set division by 256 */
period_cycles = c;
/* The duty-cycle value is as follows:
*
* DUTY-CYCLE HIGH LEVEL
* 1 99.9%
* 25 90.0%
* 128 50.0%
* 220 10.0%
* 255 0.1%
* 0 0.0%
*
* In other words, the register value is duty-cycle % 256 with
* duty-cycle in the range 1-256.
*/
c = 256 * duty_ns;
do_div(c, period_ns);
if (c > 255)
c = 255;
duty_cycles = 256 - c;
val = readl(lpc32xx->base + (pwm->hwpwm << 2));
val &= ~0xFFFF;
val |= PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles);
writel(val, lpc32xx->base + (pwm->hwpwm << 2));
return 0;
}
void analogWrite(uint8_t pin, int val)
{
pinMode(pin, OUTPUT); // pin as output
if (val == 0)
{
digitalWrite(pin, LOW); // set pin to LOW when duty cycle is 0
// digitalWrite will take care of invalid pins
}
else if (val == 255)
{
digitalWrite(pin, HIGH); // set pin HIGH when duty cycle is 255
// digitalWrite will take care of invalid pins
}
else
{
uint8_t bit = digitalPinToBitMask(pin); // get pin bit
uint8_t port = digitalPinToPort(pin); // get pin port
volatile uint16_t *sel;
volatile uint16_t *sel2;
if (port == NOT_A_PORT) return; // pin on timer?
sel = portSelRegister(port); // get the port function select register address
*sel |= bit; // set bit in pin function select register
//TODO: Firgure out a better way to determine if SEL2 needs to be set
if(bit == BV(4) && port == P1) {
sel2 = portSel2Register(port); // get the port function select register address
*sel2 |= bit;
}
switch(digitalPinToTimer(pin)) { // which timer and CCR?
//case: T0A0 // CCR0 used as period register
case T0A1: // Timer0 / CCR1
TA0CCR0 = PWM_PERIOD; // PWM Period
TA0CCTL1 = OUTMOD_7; // reset/set
TA0CCR1 = PWM_DUTY(val); // PWM duty cycle
TA0CTL = TASSEL_2 + MC_1 + analog_div; // SMCLK, up mode
break;
#if defined(__MSP430_HAS_TA3__)
case T0A2: // Timer0 / CCR1
TA0CCR0 = PWM_PERIOD; // PWM Period
TA0CCTL2 = OUTMOD_7; // reset/set
TA0CCR2 = PWM_DUTY(val); // PWM duty cycle
TA0CTL = TASSEL_2 + MC_1+ analog_div; // SMCLK, up mode
break;
#endif
#if defined(__MSP430_HAS_T1A3__)
//case: T1A0 // CCR0 used as period register
case T1A1: // Timer0 / CCR1
TA1CCR0 = PWM_PERIOD; // PWM Period
TA1CCTL1 = OUTMOD_7; // reset/set
TA1CCR1 = PWM_DUTY(val); // PWM duty cycle
TA1CTL = TASSEL_2 + MC_1+ analog_div; // SMCLK, up mode
break;
case T1A2: // Timer0 / CCR1
TA1CCR0 = PWM_PERIOD; // PWM Period
TA1CCTL2 = OUTMOD_7; // reset/set
TA1CCR2 = PWM_DUTY(val); // PWM duty cycle
TA1CTL = TASSEL_2 + MC_1+ analog_div; // SMCLK, up mode
break;
#endif
#if defined(__MSP430_HAS_T2A3__)
//case: T2A0 // CCR0 used as period register
case T2A1: // Timer0 / CCR1
TA2CCR0 = PWM_PERIOD; // PWM Period
TA2CCTL1 = OUTMOD_7; // reset/set
TA2CCR1 = PWM_DUTY(val); // PWM duty cycle
TA2CTL = TASSEL_2 + MC_1+ analog_div; // SMCLK, up mode
break;
case T2A2: // Timer0 / CCR1
TA2CCR0 = PWM_PERIOD; // PWM Period
TA2CCTL2 = OUTMOD_7; // reset/set
TA2CCR2 = PWM_DUTY(val); // PWM duty cycle
TA2CTL = TASSEL_2 + MC_1+ analog_div; // SMCLK, up mode
break;
#endif
case NOT_ON_TIMER: // not on a timer output pin
default: // or TxA0 pin
if (val < 128) {
digitalWrite(pin, LOW); //
} else {
digitalWrite(pin, HIGH);
}
}
}
}
/**
* analogWrite
*
* set PWM output level
*
* @param pin pin number
* @param val duty cycle
*/
void analogWrite(uint8_t pin, uint16_t val)
{
if (val == 0)
{
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
}
else
{
uint8_t bit = digitalPinToBitMask(pin);
uint8_t port = digitalPinToPort(pin);
volatile uint8_t *dir = portDirRegister(port);
volatile uint8_t *sel = portSelRegister(port);
volatile uint8_t *map = digitalPinToPortMap(pin);
*dir |= bit; // Config pin as an output
*sel |= bit; // Select alternate function
// Set PWM period
TA0CCR0 = analogPeriod;
TA1CCR0 = analogPeriod;
uint8_t timer = digitalPinToTimer(pin);
PMAPPWD = 0x02D52; // Get write-access to port mapping regs
PMAPCTL |= PMAPRECFG; // Leave Pin mapping open
switch(timer)
{
case T0A1:
*map = PM_TA0CCR1A;
TA0CCTL1 = OUTMOD_7; // CCR1 reset/set
TA0CCR1 = PWM_DUTY(val); // CCR1 PWM duty cycle
break;
case T0A2:
*map = PM_TA0CCR2A;
TA0CCTL2 = OUTMOD_7; // CCR1 reset/set
TA0CCR2 = PWM_DUTY(val); // CCR1 PWM duty cycle
break;
case T0A3:
*map = PM_TA0CCR3A;
TA0CCTL3 = OUTMOD_7; // CCR1 reset/set
TA0CCR3 = PWM_DUTY(val); // CCR1 PWM duty cycle
break;
case T0A4:
*map = PM_TA0CCR4A;
TA0CCTL4 = OUTMOD_7; // CCR1 reset/set
TA0CCR4 = PWM_DUTY(val); // CCR1 PWM duty cycle
break;
case T1A1:
*map = PM_TA1CCR1A;
TA1CCTL1 = OUTMOD_7; // CCR1 reset/set
TA1CCR1 = PWM_DUTY(val); // CCR1 PWM duty cycle
break;
case T1A2:
*map = PM_TA1CCR2A;
TA1CCTL2 = OUTMOD_7; // CCR1 reset/set
TA1CCR2 = PWM_DUTY(val); // CCR1 PWM duty cycle
break;
default:
break;
}
PMAPPWD = 0; // Lock port mapping registers
if (timer < T1A1)
{
if (val == TA0CCR0) // duty cycle = period?
{
pinMode(pin, OUTPUT);
digitalWrite(pin, HIGH);
}
else
TA0CTL = TASSEL_2 + MC_1 + TACLR; // SMCLK, up mode, clear TAR
}
else
{
if (val == TA1CCR0) // duty cycle = period?
{
pinMode(pin, OUTPUT);
digitalWrite(pin, HIGH);
}
else
TA1CTL = TASSEL_2 + MC_1 + TACLR; // SMCLK, up mode, clear TAR
}
}
}
