X-Git-Url: https://www.fi.muni.cz/~kas/git//home/kas/public_html/git/?a=blobdiff_plain;f=firmware%2Fpwm.c;h=3ef52c3fd436bc733ab7567b722487981fd3c133;hb=d38628afb3104c15743afaac8e899b2b009e6074;hp=4eb2f83183a1ee411176b58815180afe12d786d0;hpb=50b66ac17ddb7c5cf2105959905bdb3ca183a978;p=bike-lights.git

diff --git a/firmware/pwm.c b/firmware/pwm.c
index 4eb2f83..3ef52c3 100644
--- a/firmware/pwm.c
+++ b/firmware/pwm.c
@@ -4,18 +4,31 @@
 
 #include "lights.h"
 
-#define PWM_MAX 0x0FF
+static uint16_t pwm[N_PWMLEDS];
+static volatile unsigned char step;
 
-void init_pwm()
+static void enable_pll()
 {
 	/* Async clock */
 	PLLCSR = _BV(PLLE);
 
 	/* Synchronize to the phase lock */
-	_delay_ms(1);
+	_delay_us(100);
 	while ((PLLCSR & _BV(PLOCK)) == 0)
 		;
 	PLLCSR |= _BV(PCKE);
+}
+
+void init_pwm()
+{
+	int i;
+
+	step = 0;
+
+	for (i = 0; i < N_PWMLEDS; i++)
+		pwm[i] = 0;
+
+	enable_pll();
 
 	// PWM channel D is inverted, ...
 	TCCR1C = _BV(COM1D1) | _BV(COM1D0) | _BV(PWM1D);
@@ -23,10 +36,11 @@ 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;
@@ -36,8 +50,25 @@ void init_pwm()
 	PORTB &= ~(_BV( PB1 ) | _BV( PB3 ) | _BV( PB5 )); // set to zero
 }
 
+void susp_pwm()
+{
+	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;
+
+	PLLCSR &= ~(_BV(PLLE) | _BV(PCKE));
+}
+
 void pwm_off(unsigned char n)
 {
+	pwm[n] = 0;
+
 	switch (n) {
 	case 0: DDRB &= ~_BV(PB1); break;
 	case 1: DDRB &= ~_BV(PB3); break;
@@ -45,30 +76,57 @@ 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;
+		TC1H = hi;
+		OCR1A = lo;
 		DDRB |= _BV(PB1);
 		break;
-	case 1: OCR1B = stride;
+	case 1:
+		TC1H = hi;
+		OCR1B = lo;
 		DDRB |= _BV(PB3);
 		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;
-			DDRB |= _BV(PB5);
-		}
+	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()
 {