X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;f=firmware%2Fpwm.c;h=da9fe3df679b9feb1faede1ed11205773890a824;hb=64a3d3a699cd60b7a6b4b06c5c38689975a3d460;hp=0c4f3d081a5b78ddbc9f2493255a17b0da6496bf;hpb=f956c1fa7f47b0e8b8afe323c2eff1b6c2607c2a;p=bike-lights.git

diff --git a/firmware/pwm.c b/firmware/pwm.c
index 0c4f3d0..da9fe3d 100644
--- a/firmware/pwm.c
+++ b/firmware/pwm.c
@@ -4,8 +4,18 @@
 
 #include "lights.h"
 
+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[n] = 0;
+
 	/* Async clock */
 	PLLCSR = _BV(PLLE);
 
@@ -15,32 +25,43 @@ void init_pwm()
 		;
 	PLLCSR |= _BV(PCKE);
 
-	TCCR1C = _BV(COM1D0) | _BV(COM1D1) | _BV(PWM1D);
-	TCCR1A = _BV(COM1A0) | _BV(COM1A1) | _BV(COM1B0) | _BV(COM1B1) | _BV(PWM1A) | _BV(PWM1B);
-	TCCR1B = _BV(7)				// PWM1X: PWM inversion mode
-		| _BV(CS10) 			// no clock prescaling
-		;
-	TC1H = 0x01;
-	OCR1C = 0xFF;				// TOP value
+	// PWM channel D is inverted, ...
+	TCCR1C = _BV(COM1D1) | _BV(COM1D0) | _BV(PWM1D);
+	// PWM channels A and B are not
+	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;		// PWM3 is inverted
+	OCR1D = PWM_MAX & 0xFF;
 
 	TC1H = 0x00;
-	OCR1D = OCR1B = OCR1A = 0;		// initial stride is 0
+	OCR1B = OCR1A = 0;		// initial stride is 0
 
 	DDRB  &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 )); // tristate it
 	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;
@@ -48,16 +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: OCR1D = stride; break;
+	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[n])
+			pwm_update_hw(n);
+}
+
 #if 0
 static void inline pwm_handler()
 {