button: add basic button functionalities

- Provided a way to set handler for each button one-press/long-press
- Debouncing with RC filter and Schmitt trigger

Makefile

@@ -50,7 +50,8 @@ CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_usb2hostBase.c \
 CH5xx_ble_firmware_library/StdPeriphDriver/CH58x_spi1.c \
 CH5xx_ble_firmware_library/RVMSIS/core_riscv.c \
 src/main.c \
-src/leddrv.c
+src/leddrv.c \
+src/button.c
 
 
 # ASM sources

src/button.c

@@ -0,0 +1,89 @@
+#include "button.h"
+
+#define DEBOUNCE_HIGH_THRES (200) // 0-255
+#define DEBOUNCE_LOW_THRES  (55)  // 0-255
+#define LONGPRESS_THRES     (25)  // Hz
+#define BUTTON_SCAN_FREQ    (50)  // Hz
+
+static volatile void (*onePressHandler[KEY_INDEX])(void) = { NULL };
+static volatile void (*longPressHandler[KEY_INDEX])(void) = { NULL };
+
+void btn_init()
+{
+	GPIOA_ModeCfg(KEY1_PIN, GPIO_ModeIN_PD);
+	GPIOB_ModeCfg(KEY2_PIN, GPIO_ModeIN_PU);
+
+	TMR3_TimerInit(FREQ_SYS/BUTTON_SCAN_FREQ);
+	TMR3_ITCfg(ENABLE, TMR0_3_IT_CYC_END);
+	PFIC_EnableIRQ(TMR3_IRQn);
+}
+
+void btn_onOnePress(int key, void (*handler)(void))
+{
+	if (key >= KEY_INDEX) return;
+	onePressHandler[key] = handler;
+}
+
+void btn_onLongPress(int key, void (*handler)(void))
+{
+	if (key >= KEY_INDEX) return;
+	longPressHandler[key] = handler;
+}
+
+__HIGH_CODE
+static int debounce(int key, int is_press)
+{
+	static int y[KEY_INDEX], flag[KEY_INDEX];
+	if (key >= KEY_INDEX) return 0;
+	
+	// RC filter
+	y[key] -=  y[key] >> 2;
+	y[key] += is_press ? 0x3F : 0;
+
+	// Schmitt trigger
+	if ((y[key] > DEBOUNCE_HIGH_THRES) && (flag[key] == 0))
+		flag[key] = 1;
+	if ((y[key] < DEBOUNCE_LOW_THRES) && (flag[key] == 1))
+		flag[key] = 0;
+
+	return flag[key];
+}
+
+__HIGH_CODE
+static void check(int k)
+{
+	static int hold[KEY_INDEX], is_longpress[KEY_INDEX];
+	if (k >= KEY_INDEX) return; // TODO: assert instead
+
+	if (debounce(k, isPressed(k))) {
+		hold[k]++;
+		if (hold[k] >= LONGPRESS_THRES && is_longpress[k] == 0) {
+			is_longpress[k] = 1;
+			if (longPressHandler[k]) longPressHandler[k]();
+		}
+	} else {
+		if (hold[k] > 0 && hold[k] < LONGPRESS_THRES) {
+			if (onePressHandler[k]) onePressHandler[k]();
+		}
+		is_longpress[k] = 0;
+		hold[k] = 0;
+	}
+}
+
+__HIGH_CODE
+static void check_keys()
+{
+	for (int k=0; k<KEY_INDEX; k++) {
+		check(k);
+	}
+}
+
+__INTERRUPT
+__HIGH_CODE
+void TMR3_IRQHandler(void)
+{
+	if (TMR3_GetITFlag(TMR0_3_IT_CYC_END)) {		
+		check_keys();
+		TMR3_ClearITFlag(TMR0_3_IT_CYC_END);
+	}
+}

src/button.h

@@ -0,0 +1,23 @@
+#ifndef __BUTTON_H__
+#define __BUTTON_H__
+
+#include "CH58x_common.h"
+
+enum keys {
+	KEY1 = 0,
+	KEY2,
+	KEY_INDEX,
+};
+
+#define KEY2_PIN (GPIO_Pin_22) // PB
+#define KEY1_PIN (GPIO_Pin_1) // PA
+
+#define isPressed(key) 		((key) ? \
+				!GPIOB_ReadPortPin(KEY2_PIN) : \
+				GPIOA_ReadPortPin(KEY1_PIN))
+
+void btn_onOnePress(int key, void (*handler)(void));
+void btn_onLongPress(int key, void (*handler)(void));
+void btn_init();
+
+#endif /* __BUTTON_H__ */

src/main.c

@@ -1,11 +1,29 @@
 #include "CH58x_common.h"
 #include "CH58x_sys.h"
+
 #include "leddrv.h"
+#include "button.h"
 
-#define FB_WIDTH 	LED_COLS*4
-#define SCROLL_IRATIO 	3
+#define FB_WIDTH 	(LED_COLS * 4)
+#define SCROLL_IRATIO   (16)
+#define FB_NUM_SPARE    (8)
+#define SCAN_F          (2000)
+#define SCAN_T          (FREQ_SYS / SCAN_F)
 
-uint16_t fb[2][FB_WIDTH];
+#define NEXT_STATE(v, min, max) \
+				(v)++; \
+				if ((v) >= (max)) \
+					(v) = (min)
+
+enum MODES {
+	NORMAL = 0,
+	DOWNLOAD,
+	POWER_OFF,
+	MODES_COUNT,
+};
+#define BRIGHTNESS_LEVELS   (4)
+
+uint16_t fb[FB_NUM_SPARE][FB_WIDTH];
 
 uint8_t test_font[][11] = {
 	0x00, 0xFE, 0x66, 0x62, 0x68, 0x78, 0x68, 0x60, 0x60, 0xF0, 0x00, // F
@@ -31,21 +49,41 @@ void draw2fb(uint16_t *fb, int c, int col)
 	}
 }
 
-volatile int fb_sel = 0;
+volatile int fb_sel, fb_num;
+volatile int mode, brightness;
+volatile uint64_t tick;
+
+__HIGH_CODE
+static void change_brightness()
+{
+	NEXT_STATE(brightness, 0, BRIGHTNESS_LEVELS);
+}
+
+__HIGH_CODE
+static void change_mode()
+{
+	NEXT_STATE(mode, 0, MODES_COUNT);
+}
+
+__HIGH_CODE
+static void change_fb()
+{
+	NEXT_STATE(fb_sel, 0, fb_num);
+}
 
 int main()
 {
 	SetSysClock(CLK_SOURCE_PLL_60MHz);
 
 	led_init();
-	draw2fb(fb[0], 0, 8*5);
-	draw2fb(fb[0], 1, 8*6);
-	draw2fb(fb[0], 2, 8*7);
-	draw2fb(fb[0], 3, 8*8);
-	draw2fb(fb[0], 4, 8*9);
-	draw2fb(fb[0], 5, 8*10);
-	draw2fb(fb[0], 6, 8*11);
-	draw2fb(fb[0], 7, 8*12);
+	draw2fb(fb[0], 0, 8*(5-1));
+	draw2fb(fb[0], 1, 8*(6-1));
+	draw2fb(fb[0], 2, 8*(7-1));
+	draw2fb(fb[0], 3, 8*(8-1));
+	draw2fb(fb[0], 4, 8*(9-1));
+	draw2fb(fb[0], 5, 8*(10-1));
+	draw2fb(fb[0], 6, 8*(11-1));
+	draw2fb(fb[0], 7, 8*(12-1));
 
 	draw2fb(fb[1], 4, 8*5);
 	draw2fb(fb[1], 5, 8*6);
@@ -55,16 +93,23 @@ int main()
 	draw2fb(fb[1], 1, 8*10);
 	draw2fb(fb[1], 2, 8*11);
 	draw2fb(fb[1], 3, 8*12);
+	fb_num = 2;
 
-	TMR0_TimerInit(1500);
+	TMR0_TimerInit(SCAN_T);
 	TMR0_ITCfg(ENABLE, TMR0_3_IT_CYC_END);
 	PFIC_EnableIRQ(TMR0_IRQn);
 
+	btn_init();
+	btn_onOnePress(KEY1, change_mode);
+	btn_onOnePress(KEY2, change_fb);
+	btn_onLongPress(KEY1, change_brightness);
+
 	while (1) {
 	}
 }
 
-__attribute__((interrupt))
+__INTERRUPT
+__HIGH_CODE
 void TMR0_IRQHandler(void)
 {
 	static int i, scroll;
@@ -77,7 +122,6 @@ void TMR0_IRQHandler(void)
 			scroll++;
 			if (scroll >= (FB_WIDTH-LED_COLS)*SCROLL_IRATIO) {
 				scroll = 0;
-				fb_sel = fb_sel == 0;
 			}
 		}
 		// This is a mess