software/videomixer: connect crossfade and blackout pots

software/videomixer/Makefile

@@ -1,7 +1,7 @@
 M2DIR=../..
 include $(M2DIR)/software/common.mak
 
-OBJECTS=crt0.o isr.o dvisampler0.o dvisampler1.o main.o
+OBJECTS=crt0.o isr.o time.o dvisampler0.o dvisampler1.o main.o
 
 all: videomixer.bin
 

software/videomixer/dvisamplerX.c

@@ -6,6 +6,7 @@
 #include <hw/csr.h>
 #include <hw/flags.h>
 
+#include "time.h"
 #include "dvisamplerX.h"
 
 #define FRAMEBUFFER_COUNT 4
@@ -152,22 +153,7 @@ int dvisamplerX_init_phase(void)
 }
 
 static int dvisamplerX_locked;
-
-static int elapsed(int period)
-{
-	static int last_event;
-	int t, dt;
-
-	t = timer0_reload_read() - timer0_value_read(); // TODO: atomic read
-	dt = t - last_event;
-	if(dt < 0)
-		dt += timer0_reload_read();
-	if((dt > period) || (dt < 0)) {
-		last_event = t;
-		return 1;
-	} else
-		return 0;
-}
+static int dvisamplerX_last_event;
 
 void dvisamplerX_service(void)
 {
@@ -175,7 +161,7 @@ void dvisamplerX_service(void)
 
 	if(dvisamplerX_locked) {
 		if(dvisamplerX_clocking_locked_read()) {
-			if(elapsed(identifier_frequency_read())) {
+			if(elapsed(&dvisamplerX_last_event, identifier_frequency_read())) {
 				dvisamplerX_adjust_phase();
 				dvisamplerX_print_status();
 			}
@@ -196,9 +182,9 @@ void dvisamplerX_service(void)
 			dvisamplerX_print_status();
 			dvisamplerX_locked = 1;
 		} else {
-			if(elapsed(identifier_frequency_read()/4)) {
+			if(elapsed(&dvisamplerX_last_event, identifier_frequency_read()/4)) {
 				dvisamplerX_clocking_pll_reset_write(1);
-				while(!elapsed(identifier_frequency_read()/16));
+				while(!elapsed(&dvisamplerX_last_event, identifier_frequency_read()/16));
 				dvisamplerX_clocking_pll_reset_write(0);
 			}
 		}

software/videomixer/main.c

@@ -7,40 +7,75 @@
 #include <hw/flags.h>
 #include <console.h>
 
+#include "time.h"
 #include "dvisampler0.h"
 #include "dvisampler1.h"
 
-int main(void)
+static int scale_pot(int raw, int range)
+{
+	int pot_min = 54000;
+	int pot_max = 105400;
+	int scaled;
+
+	scaled = range*(raw - pot_min)/(pot_max - pot_min);
+	if(scaled < 0)
+		scaled = 0;
+	if(scaled > range)
+		scaled = range;
+	return scaled;
+}
+
+static void pots_service(void)
+{
+	static int last_event;
+	int blackout;
+	int crossfade;
+
+	if(elapsed(&last_event, identifier_frequency_read()/32)) {
+		pots_start_busy_write(1);
+		while(pots_start_busy_read());
+		blackout = scale_pot(pots_res0_read(), 256);
+		crossfade = scale_pot(pots_res1_read(), 255);
+
+		fb_blender_f0_write(crossfade*blackout >> 8);
+		fb_blender_f1_write((255-crossfade)*blackout >> 8);	
+	}
+}
+
+static void fb_service(void)
 {
 	int c;
 
+	if(readchar_nonblock()) {
+		c = readchar();
+		if(c == '1') {
+			fb_enable_write(1);
+			printf("Framebuffer is ON\n");
+		} else if(c == '0') {
+			fb_enable_write(0);
+			printf("Framebuffer is OFF\n");
+		}
+	}
+}
+
+int main(void)
+{
 	irq_setmask(0);
 	irq_setie(1);
 	uart_init();
 	
 	puts("Minimal video mixer software built "__DATE__" "__TIME__"\n");
 	
-	timer0_reload_write(2*identifier_frequency_read());
-	timer0_en_write(1);
-
+	time_init();
 	dvisampler0_init_video();
 	dvisampler1_init_video();
 	fb_enable_write(1);
-	fb_blender_f0_write(127);
-	fb_blender_f1_write(127);
+
 	while(1) {
 		dvisampler0_service();
 		dvisampler1_service();
-		if(readchar_nonblock()) {
-			c = readchar();
-			if(c == '1') {
-				fb_enable_write(1);
-				printf("Framebuffer is ON\n");
-			} else if(c == '0') {
-				fb_enable_write(0);
-				printf("Framebuffer is OFF\n");
-			}
-		}
+		pots_service();
+		fb_service();
 	}
 	
 	return 0;

software/videomixer/time.c

@@ -0,0 +1,24 @@
+#include <hw/csr.h>
+
+#include "time.h"
+
+void time_init(void)
+{
+	timer0_reload_write(2*identifier_frequency_read());
+	timer0_en_write(1);
+}
+
+int elapsed(int *last_event, int period)
+{
+	int t, dt;
+
+	t = timer0_reload_read() - timer0_value_read(); // TODO: atomic read
+	dt = t - *last_event;
+	if(dt < 0)
+		dt += timer0_reload_read();
+	if((dt > period) || (dt < 0)) {
+		*last_event = t;
+		return 1;
+	} else
+		return 0;
+}

software/videomixer/time.h

@@ -0,0 +1,7 @@
+#ifndef __TIME_H
+#define __TIME_H
+
+void time_init(void);
+int elapsed(int *last_event, int period);
+
+#endif /* __TIME_H */