Put dac config in struct

crowbx.c

@@ -35,13 +35,20 @@ uint16_t dac_pitch_delta(uint8_t semitones) {
 	return dac_semitone_offset(semitones);
 }
 
-uint8_t spi_io(uint8_t data) {
-	SPDR = data;
-	loop_until_bit_is_set(SPSR, SPIF);
-	return SPDR;
-}
+struct {
+	volatile uint8_t *port;
+	volatile uint8_t *ddr;
+	uint8_t bit;
+} dac_sync = {.port = &PORTB, .ddr = &DDRB, .bit = PORTB1};
 
-#define DAC_SYNC PORTB1
+void dac_sync_enable(void) { *dac_sync.port &= ~_BV(dac_sync.bit); }
+void dac_sync_disable(void) { *dac_sync.port |= _BV(dac_sync.bit); }
+
+void dac_sync_init(void) {
+	*dac_sync.ddr |= _BV(dac_sync.bit);
+	dac_sync_disable();
+	_delay_ms(1); // let dac boot up
+}
 
 uint8_t dac_command_set(uint8_t v) {
 	struct dac *d = dac(v);
@@ -52,12 +59,17 @@ uint8_t dac_command_set(uint8_t v) {
 	return 0b00110000 | d->channel;
 }
 
+void spi_send(uint8_t data) {
+	SPDR = data;
+	loop_until_bit_is_set(SPSR, SPIF);
+}
+
 void dac_send(uint8_t command, uint16_t data) {
-	PORTB &= ~_BV(DAC_SYNC);
-	spi_io(command);
-	spi_io(data >> 8);
-	spi_io(data & 0xff);
-	PORTB |= _BV(DAC_SYNC);
+	dac_sync_enable();
+	spi_send(command);
+	spi_send(data >> 8);
+	spi_send(data & 0xff);
+	dac_sync_disable();
 }
 
 void spi_init(void) {
@@ -74,14 +86,8 @@ void spi_init(void) {
 }
 
 void dac_init(void) {
-	DDRB |= _BV(DAC_SYNC);
-
+	dac_sync_init();
 	spi_init();
-
-	// dac sync high for power saving
-	PORTB |= _BV(DAC_SYNC);
-
-	_delay_ms(1); // let dac boot up
 }
 
 uint16_t dac_note_pitch(uint8_t v, uint8_t note) {