pwmout - LPC176X - add read methods for period and pulsewidth

Author: talorion

targets/TARGET_NXP/TARGET_LPC176X/pwmout_api.c

@@ -29,12 +29,12 @@ static const PinMap PinMap_PWM[] = {
     {P1_23, PWM_4, 2},
     {P1_24, PWM_5, 2},
     {P1_26, PWM_6, 2},
-    {P2_0 , PWM_1, 1},
-    {P2_1 , PWM_2, 1},
-    {P2_2 , PWM_3, 1},
-    {P2_3 , PWM_4, 1},
-    {P2_4 , PWM_5, 1},
-    {P2_5 , PWM_6, 1},
+    {P2_0, PWM_1, 1},
+    {P2_1, PWM_2, 1},
+    {P2_2, PWM_3, 1},
+    {P2_3, PWM_4, 1},
+    {P2_4, PWM_5, 1},
+    {P2_5, PWM_6, 1},
     {P3_25, PWM_2, 3},
     {P3_26, PWM_3, 3},
     {NC, NC, 0}
@@ -54,77 +54,84 @@ __IO uint32_t *PWM_MATCH[] = {
 
 static unsigned int pwm_clock_mhz;
 
-void pwmout_init(pwmout_t* obj, PinName pin) {
+void pwmout_init(pwmout_t *obj, PinName pin)
+{
     // determine the channel
     PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
     MBED_ASSERT(pwm != (PWMName)NC);
 
     obj->pwm = pwm;
     obj->MR = PWM_MATCH[pwm];
-    
+
     // ensure the power is on
     LPC_SC->PCONP |= 1 << 6;
-    
+
     // ensure clock to /4
     LPC_SC->PCLKSEL0 &= ~(0x3 << 12);     // pclk = /4
     LPC_PWM1->PR = 0;                     // no pre-scale
-    
+
     // ensure single PWM mode
     LPC_PWM1->MCR = 1 << 1; // reset TC on match 0
-    
+
     // enable the specific PWM output
     LPC_PWM1->PCR |= 1 << (8 + pwm);
-    
+
     pwm_clock_mhz = SystemCoreClock / 4000000;
-    
+
     // default to 20ms: standard for servos, and fine for e.g. brightness control
     pwmout_period_ms(obj, 20);
-    pwmout_write    (obj, 0);
-    
+    pwmout_write(obj, 0);
+
     // Wire pinout
     pinmap_pinout(pin, PinMap_PWM);
 }
 
-void pwmout_free(pwmout_t* obj) {
+void pwmout_free(pwmout_t *obj)
+{
     // [TODO]
 }
 
-void pwmout_write(pwmout_t* obj, float value) {
+void pwmout_write(pwmout_t *obj, float value)
+{
     if (value < 0.0f) {
         value = 0.0;
     } else if (value > 1.0f) {
         value = 1.0;
     }
-    
+
     // set channel match to percentage
     uint32_t v = (uint32_t)((float)(LPC_PWM1->MR0) * value);
-    
+
     // workaround for PWM1[1] - Never make it equal MR0, else we get 1 cycle dropout
     if (v == LPC_PWM1->MR0) {
         v++;
     }
-    
+
     *obj->MR = v;
-    
+
     // accept on next period start
     LPC_PWM1->LER |= 1 << obj->pwm;
 }
 
-float pwmout_read(pwmout_t* obj) {
+float pwmout_read(pwmout_t *obj)
+{
     float v = (float)(*obj->MR) / (float)(LPC_PWM1->MR0);
     return (v > 1.0f) ? (1.0f) : (v);
 }
 
-void pwmout_period(pwmout_t* obj, float seconds) {
+void pwmout_period(pwmout_t *obj, float seconds)
+{
     pwmout_period_us(obj, seconds * 1000000.0f);
 }
 
-void pwmout_period_ms(pwmout_t* obj, int ms) {
+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) {
+void pwmout_period_us(pwmout_t *obj, int us)
+{
     // calculate number of ticks
     uint32_t ticks = pwm_clock_mhz * us;
 
@@ -146,30 +153,42 @@ void pwmout_period_us(pwmout_t* obj, int us) {
     LPC_PWM1->TCR = TCR_CNT_EN | TCR_PWM_EN;
 }
 
-void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
+int pwmout_read_period_us(pwmout_t *obj)
+{
+    return (float)(LPC_PWM1->MR0);
+}
+
+void pwmout_pulsewidth(pwmout_t *obj, float seconds)
+{
     pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
 }
 
-void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
+void pwmout_pulsewidth_ms(pwmout_t *obj, int ms)
+{
     pwmout_pulsewidth_us(obj, ms * 1000);
 }
 
-void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
+void pwmout_pulsewidth_us(pwmout_t *obj, int us)
+{
     // calculate number of ticks
     uint32_t v = pwm_clock_mhz * us;
-    
+
     // workaround for PWM1[1] - Never make it equal MR0, else we get 1 cycle dropout
     if (v == LPC_PWM1->MR0) {
         v++;
     }
-    
+
     // set the match register value
     *obj->MR = v;
-    
+
     // set the channel latch to update value at next period start
     LPC_PWM1->LER |= 1 << obj->pwm;
 }
 
+int pwmout_read_pulsewidth_us(pwmout_t *obj {
+    return (timer->MR3 - timer->MR[tid.mr]);
+}
+
 const PinMap *pwmout_pinmap()
 {
     return PinMap_PWM;