pwmout - LPC11XX_11CXX - add read methods for period and pulsewidth

Author: talorion

targets/TARGET_NXP/TARGET_LPC11XX_11CXX/pwmout_api.c

@@ -28,17 +28,17 @@
  */
 static const PinMap PinMap_PWM[] = {
     /* CT16B0 */
-    {P0_8 , PWM_1, 0x02},   /* MR0 */
-    {P0_9 , PWM_2, 0x02},   /* MR1 */
+    {P0_8, PWM_1, 0x02},    /* MR0 */
+    {P0_9, PWM_2, 0x02},    /* MR1 */
 
     /* CT16B1 */
-    {P1_9 , PWM_3, 0x01},   /* MR0 */
+    {P1_9, PWM_3, 0x01},    /* MR0 */
     {P1_10, PWM_4, 0x02},   /* MR1 */
 
     /* CT32B0 */
-    {P0_1 , PWM_5, 0x02},   /* MR2 */
+    {P0_1, PWM_5, 0x02},    /* MR2 */
 
-    {NC   , NC    ,0x00}
+    {NC, NC, 0x00}
 };
 
 typedef struct {
@@ -61,49 +61,52 @@ static LPC_TMR_TypeDef *Timers[3] = {
     LPC_TMR32B0
 };
 
-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;
-    
+
     // Timer registers
     timer_mr tid = pwm_timer_map[pwm];
     LPC_TMR_TypeDef *timer = Timers[tid.timer];
-    
+
     // Disable timer
     timer->TCR = 0;
-    
+
     // Power the correspondent timer
     LPC_SYSCON->SYSAHBCLKCTRL |= 1 << (tid.timer + 7);
-    
+
     /* Enable PWM function */
-    timer->PWMC = (1 << 3)|(1 << 2)|(1 << 1)|(1 << 0);
-    
+    timer->PWMC = (1 << 3) | (1 << 2) | (1 << 1) | (1 << 0);
+
     /* Reset Functionality on MR3 controlling the PWM period */
     timer->MCR = 1 << 10;
-    
+
     if (timer == LPC_TMR16B0 || timer == LPC_TMR16B1) {
-    /* Set 16-bit timer prescaler to avoid timer expire for default 20ms */
-    /* This can be also modified by user application, but the prescaler value */
-    /* might be trade-off to timer accuracy */
+        /* Set 16-bit timer prescaler to avoid timer expire for default 20ms */
+        /* This can be also modified by user application, but the prescaler value */
+        /* might be trade-off to timer accuracy */
         timer->PR = 30;
     }
 
     // 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) {
@@ -123,61 +126,73 @@ void pwmout_write(pwmout_t* obj, float value) {
     timer->TCR = TCR_CNT_EN;
 }
 
-float pwmout_read(pwmout_t* obj) {
+float pwmout_read(pwmout_t *obj)
+{
     timer_mr tid = pwm_timer_map[obj->pwm];
     LPC_TMR_TypeDef *timer = Timers[tid.timer];
-    
+
     float v = (float)(timer->MR3 - timer->MR[tid.mr]) / (float)(timer->MR3);
     if (timer->MR[tid.mr] > timer->MR3) {
         v = 0.0f;
     }
     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)
+{
     int i = 0;
     uint32_t period_ticks;
-    
+
     timer_mr tid = pwm_timer_map[obj->pwm];
     LPC_TMR_TypeDef *timer = Timers[tid.timer];
     uint32_t old_period_ticks = timer->MR3;
     period_ticks = (SystemCoreClock / 1000000 * us) / (timer->PR + 1);
 
     timer->TCR = TCR_RESET;
     timer->MR3 = period_ticks;
-    
+
     // Scale the pulse width to preserve the duty ratio
     if (old_period_ticks > 0) {
-        for (i=0; i<3; i++) {
+        for (i = 0; i < 3; i++) {
             uint32_t t_off = period_ticks - (uint32_t)(((uint64_t)timer->MR[i] * (uint64_t)period_ticks) / (uint64_t)old_period_ticks);
             timer->MR[i] = t_off;
         }
     }
     timer->TCR = TCR_CNT_EN;
 }
 
-void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
+int pwmout_read_period_us(pwmout_t *obj)
+{
+    return (timer->MR3);
+}
+
+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)
+{
     timer_mr tid = pwm_timer_map[obj->pwm];
     LPC_TMR_TypeDef *timer = Timers[tid.timer];
     uint32_t t_on = (uint32_t)((((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000) / (timer->PR + 1));
-    
+
     timer->TCR = TCR_RESET;
     if (t_on > timer->MR3) {
         pwmout_period_us(obj, us);
@@ -187,6 +202,10 @@ void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
     timer->TCR = TCR_CNT_EN;
 }
 
+int pwmout_read_pulsewidth_us(pwmout_t *obj {
+    return (timer->MR3 - timer->MR[tid.mr]);
+}
+
 const PinMap *pwmout_pinmap()
 {
     return PinMap_PWM;