pwm.c: make it usable from non-atomic blocks

[bike-lights.git] / firmware / pwm.c

diff --git a/firmware/pwm.c b/firmware/pwm.c
index 8c95619a8f06ec423abce77a25f0a32f59f55258..56fb0884e125113a6885a3deb45cba9efe5ad6c8 100644 (file)
--- a/firmware/pwm.c
+++ b/firmware/pwm.c
@@ -1,6 +1,7 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #include <util/delay.h>
+#include <util/atomic.h>
 
 #include "lights.h"
 
@@ -67,12 +68,14 @@ void susp_pwm()
 
 void pwm_off(unsigned char n)
 {
-       pwm[n] = 0;
-
-       switch (n) {
-       case 0: DDRB &= ~_BV(PB1); break;
-       case 1: DDRB &= ~_BV(PB3); break;
-       case 2: DDRB &= ~_BV(PB5); break;
+       ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+               pwm[n] = 0;
+
+               switch (n) {
+               case 0: DDRB &= ~_BV(PB1); break;
+               case 1: DDRB &= ~_BV(PB3); break;
+               case 2: DDRB &= ~_BV(PB5); break;
+               }
        }
 }
 
@@ -91,17 +94,14 @@ static void pwm_update_hw(unsigned char n)
        case 0:
                TC1H = hi;
                OCR1A = lo;
-               DDRB |= _BV(PB1);
                break;
        case 1:
                TC1H = hi;
                OCR1B = lo;
-               DDRB |= _BV(PB3);
                break;
        case 2:
                TC1H = hi;
                OCR1D = lo;
-               DDRB |= _BV(PB5);
                break;
        }
 }
@@ -111,8 +111,17 @@ void pwm_set(unsigned char n, uint16_t stride)
        if (((stride + (1 << PWM_STEP_SHIFT)) >> PWM_STEP_SHIFT) >= PWM_MAX)
                stride = PWM_MAX << PWM_STEP_SHIFT;
 
-       pwm[n] = stride;
-       pwm_update_hw(n);
+       ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+               pwm[n] = stride;
+
+               pwm_update_hw(n);
+
+               switch(n) {
+               case 0: DDRB |= _BV(PB1); break;
+               case 1: DDRB |= _BV(PB3); break;
+               case 2: DDRB |= _BV(PB5); break;
+               }
+       }
 }
 
 void pwm_timer()