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Bug fix in PWM APIs

pull/1297/head
vimalrajr 2015-08-06 13:26:18 +05:30 committed by Karthik Purushothaman
parent fa56bfd164
commit 149244d474
2 changed files with 11 additions and 4 deletions
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1
libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM0/objects.h
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@ -78,6 +78,7 @@ struct pwmout_s {
PinName pin;
uint32_t period;
float duty_cycle;
double us_per_cycle;
enum gclk_generator clock_source;
enum tc_clock_prescaler clock_prescaler;
};

14
libraries/mbed/targets/hal/TARGET_Atmel/TARGET_SAM0/pwmout_api.c
View File

@ -46,8 +46,9 @@ extern const uint32_t _tcc_maxs[TCC_INST_NUM];
*/
static void pwmout_set_period(pwmout_t* obj, int period_us)
{
uint32_t i;
uint8_t i;
uint32_t freq_hz;
uint32_t div_freq;
double us_per_cycle;
uint64_t max_period = 0;
uint32_t us_period = period_us;
@ -63,11 +64,14 @@ static void pwmout_set_period(pwmout_t* obj, int period_us)
freq_hz = system_gclk_gen_get_hz(obj->clock_source);
for (i=0; i<sizeof(tcc_prescaler); i++) {
us_per_cycle = 1000000.00 / (freq_hz >> tcc_prescaler[i]);
div_freq = freq_hz >> tcc_prescaler[i];
if (!div_freq) break;
us_per_cycle = 1000000.00 / div_freq;
max_period = us_per_cycle * count_max;
if (max_period >= us_period) {
obj->clock_prescaler = tcc_prescaler[i];
obj->period = us_period / us_per_cycle;
obj->us_per_cycle = us_per_cycle;
break;
}
}
@ -127,7 +131,7 @@ void pwmout_init(pwmout_t* obj, PinName pin)
/* Sanity check arguments */
MBED_ASSERT(obj);
if (NC == pinmap_peripheral(pin, PinMap_PWM)) {
if ((uint32_t)NC == pinmap_peripheral(pin, PinMap_PWM)) {
/* Pin not supported */
return;
}
@ -281,8 +285,10 @@ void pwmout_pulsewidth_us(pwmout_t* obj, int us)
/* Sanity check arguments */
MBED_ASSERT(obj);
uint32_t us_pulse = us;
/* Find the new duty cycle */
double duty_cycle = us / (double)obj->period;
double duty_cycle = us_pulse / ((double)obj->period * obj->us_per_cycle);
/* This call updates pulse width as well as period */
pwmout_write(obj, duty_cycle);