From: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
Date: Thu, 6 Dec 2012 23:10:20 +0000 (+0100)
Subject: pwm.c: make it usable from non-atomic blocks
X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?p=bike-lights.git;a=commitdiff_plain;h=8650676310d5304199ffe174b45a9a396c9610a7

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

diff --git a/firmware/Makefile b/firmware/Makefile
index 7be101d..1b0113e 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -10,7 +10,7 @@ MCU=attiny861a
 AVRDUDE_MCU=attiny861
 AVRDUDE_PROGRAMMER=usbasp
 
-CFLAGS=-Wall -Os -mmcu=$(MCU) -DUSE_LOGGING=1 -DF_CPU=1000000UL
+CFLAGS=-Wall -Os -mmcu=$(MCU) -DUSE_LOGGING=1 -DF_CPU=1000000UL -std=gnu99
 LDFLAGS=
 AVRDUDE_FLAGS= -p$(AVRDUDE_MCU) -c $(AVRDUDE_PROGRAMMER)
 
diff --git a/firmware/pwm.c b/firmware/pwm.c
index 8c95619..56fb088 100644
--- 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()