X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;f=firmware%2Fpwm.c;h=b9b42c926cbd49cd449d36a76986bcdbc494b24d;hb=ee55592455c9628ca21142449d4b5918a59151fe;hp=2df2e6bb8b9abe762c1bb6208a13e6a4dde4cd7c;hpb=ddc8f4be4d90e7e709832b5135b2e7e4631b1554;p=bike-lights.git

diff --git a/firmware/pwm.c b/firmware/pwm.c
index 2df2e6b..b9b42c9 100644
--- a/firmware/pwm.c
+++ b/firmware/pwm.c
@@ -4,10 +4,18 @@
 
 #include "lights.h"
 
-#define PWM_MAX 0x1FF
+static uint16_t pwm[N_PWMLEDS];
+static volatile unsigned char step;
 
 void init_pwm()
 {
+	int i;
+
+	step = 0;
+
+	for (i = 0; i < N_PWMLEDS; i++)
+		pwm[i] = 0;
+
 	/* Async clock */
 	PLLCSR = _BV(PLLE);
 
@@ -23,10 +31,11 @@ void init_pwm()
 	TCCR1A = _BV(COM1A1) | _BV(COM1B1) | _BV(PWM1A) | _BV(PWM1B);
 	TCCR1D = 0;
 	TCCR1B = _BV(CS10); 			// no clock prescaling
+
 	TC1H = PWM_MAX >> 8;
 	OCR1C = PWM_MAX & 0xFF;				// TOP value
 
-	TC1H = PWM_MAX >> 8;
+	TC1H = PWM_MAX >> 8;		// PWM3 is inverted
 	OCR1D = PWM_MAX & 0xFF;
 
 	TC1H = 0x00;
@@ -36,17 +45,23 @@ void init_pwm()
 	PORTB &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 )); // set to zero
 }
 
-void pwm_on(unsigned char n)
+void susp_pwm()
 {
-	switch (n) {
-	case 0: DDRB |= _BV(PB1); break;
-	case 1: DDRB |= _BV(PB3); break;
-	case 2: DDRB |= _BV(PB5); break;
-	}
+	unsigned char i;
+
+	for (i = 0; i < N_PWMLEDS; i++)
+		pwm[i] = 0;
+
+	DDRB &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 ));
+	TCCR1D = TCCR1C = TCCR1B = TCCR1A = 0;
+	TIMSK = 0;
+	TIFR = 0;
 }
 
 void pwm_off(unsigned char n)
 {
+	pwm[n] = 0;
+
 	switch (n) {
 	case 0: DDRB &= ~_BV(PB1); break;
 	case 1: DDRB &= ~_BV(PB3); break;
@@ -54,24 +69,57 @@ void pwm_off(unsigned char n)
 	}
 }
 
-void pwm_set(unsigned char n, unsigned char stride)
+static void pwm_update_hw(unsigned char n)
 {
-	TC1H = 0x00;
+	unsigned char hi, lo;
+	uint16_t stride = (pwm[n] + step) >> PWM_STEP_SHIFT;
+
+	if (n == 2)
+		stride = PWM_MAX - stride;
+
+	hi = stride >> 8;
+	lo = stride & 0xFF;
+
 	switch (n) {
-	case 0: OCR1A = stride; break;
-	case 1: OCR1B = stride; break;
-	case 2: {
-			uint16_t s16 = PWM_MAX - (uint16_t)stride;
-			volatile unsigned char hi, lo;
-			hi = s16 >> 8;
-			lo = s16 & 0xFF;
-			TC1H = hi;
-			OCR1D = lo;
-		}
+	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;
 	}
 }
 
+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);
+}
+
+void pwm_timer()
+{
+	unsigned char i;
+
+	if (++step >= (1 << PWM_STEP_SHIFT))
+		step = 0;
+
+	for (i = 0; i < N_PWMLEDS; i++)
+		if (pwm[i])
+			pwm_update_hw(i);
+}
+
 #if 0
 static void inline pwm_handler()
 {