Migrate display to new peripheral model

3 files changed, 29 insertions, 13 deletions

diff --git a/altimeter.c b/altimeter.c
index db45eb7..db18659 100644
--- a/altimeter.c
+++ b/altimeter.c
@@ -49,12 +49,14 @@ ISR(TIMER1_COMPA_vect)
 
 int main(void)
 {
+	struct display display;
 	struct barometer barometer;
 	struct timer timer;
 
 	/* Initialise display before enabling interrupts */
-	display_init();
-	display_clear();
+	get_system_display(&display);
+	display.init();
+	display.clear();
 
 	/* get descriptors for system default peripherals */
 	get_system_barometer(&barometer);
diff --git a/display.h b/display.h
index 771323c..ab8c078 100644
--- a/display.h
+++ b/display.h
@@ -8,7 +8,11 @@
 #define C_IDLE    (3)
 #define C_ASC     (4)
 
-void display_clear(void);
-void display_init(void);
-void display_write(const char *text);
-void display_set_cursor(int x, int y);
+struct display {
+	void (*clear)(void);
+	void (*init)(void);
+	void (*write)(const char *text);
+	void (*set_cursor)(int x, int y);
+};
+
+void get_system_display(struct display *);
diff --git a/display_sim.c b/display_sim.c
index c87329e..93e62c4 100644
--- a/display_sim.c
+++ b/display_sim.c
@@ -63,7 +63,7 @@ static FILE uart_out = FDEV_SETUP_STREAM(uart_putc, NULL, _FDEV_SETUP_WRITE);
 
 /* internal function to dump the display contents to stdout, since there
  * is no background thread for doing this constantly */
-void display_display(void)
+static void full_display(void)
 {
 	int y = 0;
 	printf("\033[6A"); // hack: raw ANSI escape sequence to move up 6
@@ -74,7 +74,9 @@ void display_display(void)
 	printf("`--------------------'\n");
 }
 
-void display_clear(void)
+/**/
+
+static void display_clear(void)
 {
 	int x = 0;
 	int y = 0;
@@ -85,10 +87,10 @@ void display_clear(void)
 		display[y][x] = '\0';
 	}
 
-	display_display();
+	full_display();
 }
 
-void display_init(void)
+static void display_init(void)
 {
 	uart_init();
 	/* FIXME hack: stdout not guaranteed to be assignable */
@@ -98,7 +100,7 @@ void display_init(void)
 	cursor_x = cursor_y = 0;
 }
 
-void display_write(const char *text)
+static void display_write(const char *text)
 {
 	char c = '\0';
 	while (cursor_x < LCD_WIDTH && *text) {
@@ -108,11 +110,19 @@ void display_write(const char *text)
 			c = '_';
 		display[cursor_y][cursor_x++] = c;
 	}
-	display_display();
+	full_display();
 }
 
-void display_set_cursor(int x, int y)
+static void display_set_cursor(int x, int y)
 {
 	cursor_x = x;
 	cursor_y = y;
 }
+
+void get_system_display(struct display *display)
+{
+	display->init = display_init;
+	display->clear = display_clear;
+	display->write = display_write;
+	display->set_cursor = display_set_cursor;
+}