display: Interrupt driven ADC sampling for the touch screen

display/Makefile

@@ -71,13 +71,13 @@ COMMONDEPS = src/config.h
 default: bin/firmware.hex
 
 inc/lpc111x.h:
-	ln -s ../$(CODEBASEDIR)/lpc111x.h $@
+	ln -sf ../$(CODEBASEDIR)/lpc111x.h $@
 
 inc/sysdefs.h:
-	ln -s ../$(CODEBASEDIR)/sysdefs.h $@
+	ln -sf ../$(CODEBASEDIR)/sysdefs.h $@
 
 inc/projectconfig.h:
-	ln -s ../src/config.h $@
+	ln -sf ../src/config.h $@
 
 src/generated_font_data.inc: $(GENFONT)
 	$(GENFONT) --no-flip \

display/src/comm_i2c.inc.c

@@ -214,6 +214,7 @@ void I2C_IRQHandler()
                     backbuffer_ready = true;
                 }
                 NVIC_SetPendingIRQ(received_irqn);
+                __attribute__((fallthrough));
             }
             case MSG_ADDRESS_HOST:
             {

display/src/comm_uart.inc.c

@@ -45,14 +45,11 @@ static struct msg_header_t ping_header VAR_RAM =
         MSG_ADDRESS_HOST,
         0,
         MSG_FLAG_ACK | MSG_FLAG_ECHO);
-static volatile uint32_t buffer = 0;
 
 static inline void uart_init(const uint32_t baudrate)
 {
     NVIC_DisableIRQ(UART_IRQn);
 
-    buffer = 0xdeadbeef;
-
     /* Set 1.6 UART RXD */
     IOCON_PIO1_6 &= ~IOCON_PIO1_6_FUNC_MASK;
     IOCON_PIO1_6 |= IOCON_PIO1_6_FUNC_UART_RXD;
@@ -141,6 +138,7 @@ void uart_tx_irq()
             uart.state.trns_src = (const volatile uint8_t*)uart.queue.items[uart.queue.active_item].header;
             uart.state.trns_end = uart.state.trns_src + sizeof(struct msg_header_t);
         }
+        __attribute__((fallthrough));
     }
     case TXU_SEND_HEADER:
     {
@@ -298,6 +296,7 @@ void uart_rx_irq()
         // missing break is intentional: receive the first bytes immediately
         // turn the timer on
         TMR_COMM_TIMEOUT_TCR = (1<<0) | (0<<1);
+        __attribute__((fallthrough));
     }
     case RXU_RECEIVE_HEADER:
     {
@@ -376,6 +375,7 @@ void uart_rx_irq()
         uart.state.recv_dest = &uart.state.dest_msg->msg.data[0];
         uart.state.recv_end = uart.state.recv_dest + HDR_GET_PAYLOAD_LENGTH(uart.state.curr_header);
         // we can smoothly continue here if more data is available
+        __attribute__((fallthrough));
     }
     case RXU_RECEIVE_PAYLOAD:
     {
@@ -385,6 +385,7 @@ void uart_rx_irq()
         uart_rx_state = RXU_RECEIVE_CHECKSUM;
         uart.state.recv_dest = (uint8_t*)&uart.state.dest_msg->msg.checksum;
         uart.state.recv_end = uart.state.recv_dest + sizeof(msg_checksum_t);
+        __attribute__((fallthrough));
     }
     case RXU_RECEIVE_CHECKSUM:
     {

display/src/draw.c

@@ -2,7 +2,7 @@
 
 #include "lcd.h"
 
-inline void clamp_x(coord_int_t *x)
+static inline void clamp_x(coord_int_t *x)
 {
     if (*x < 0) {
         *x = 0;
@@ -11,7 +11,7 @@ inline void clamp_x(coord_int_t *x)
     }
 }
 
-inline void clamp_y(coord_int_t *y)
+static inline void clamp_y(coord_int_t *y)
 {
     if (*y < 0) {
         *y = 0;
@@ -20,17 +20,17 @@ inline void clamp_y(coord_int_t *y)
     }
 }
 
-inline void rectangle_clamp(coord_int_t *x0, coord_int_t *y0,
-                            coord_int_t *x1, coord_int_t *y1)
+static inline void rectangle_clamp(coord_int_t *x0, coord_int_t *y0,
+                                   coord_int_t *x1, coord_int_t *y1)
 {
     clamp_x(x0);
     clamp_x(x1);
     clamp_y(y0);
     clamp_y(y1);
 }
 
-inline void rectangle_clamp_and_swap(coord_int_t *x0, coord_int_t *y0,
-                                     coord_int_t *x1, coord_int_t *y1)
+static inline void rectangle_clamp_and_swap(coord_int_t *x0, coord_int_t *y0,
+                                            coord_int_t *x1, coord_int_t *y1)
 {
     rectangle_clamp(x0, y0, x1, y1);
 

display/src/font.c

@@ -2,8 +2,8 @@
 
 #include <stdlib.h>
 
-inline const struct glyph_t *font_find_glyph(const struct font_t *font,
-                                             const codepoint_t codepoint)
+static inline const struct glyph_t *font_find_glyph(const struct font_t *font,
+                                                    const codepoint_t codepoint)
 {
     uint16_t offset = 0;
 

display/src/lcd.c

@@ -31,22 +31,22 @@ static uint16_t lcd_brightness_awake_backup VAR_RAM = 0xC000;
 
 /* alphabetical order broken so that inlines appear before their use */
 
-inline void _configure_pwm()
+static inline void _configure_pwm()
 {
     GPIO_GPIO1DIR |= (1<<9);
     GPIO_GPIO1DATA &= ~(1<<9);
     IOCON_PIO1_9 = (0x1<<0);
 }
 
-inline void _disable_pwm()
+static inline void _disable_pwm()
 {
     TMR_TMR16B0TCR = 0; // pwm timer
     TMR_TMR16B1TCR = 0; // fade timer
     IOCON_PIO1_9 = 0;
     GPIO_GPIO1DATA &= ~(1<<9);
 }
 
-inline void _enable_pwm()
+static inline void _enable_pwm()
 {
     GPIO_GPIO1DATA &= ~(1<<9);
     TMR_TMR16B0TC = 0;
@@ -58,7 +58,7 @@ inline void _enable_pwm()
     TMR_TMR16B1TCR = 1; // fade timer
 }
 
-inline void lcd_wrcmd8(uint8_t cmd)
+void lcd_wrcmd8(uint8_t cmd)
 {
     LCD_MASKED_GPIO(LCD_RS_MASK, 0);
     LCD_MASKED_GPIO(LCD_WR_MASK, 0);
@@ -68,41 +68,41 @@ inline void lcd_wrcmd8(uint8_t cmd)
     LCD_MASKED_GPIO(LCD_RS_MASK, LCD_RS_MASK);
 }
 
-inline void lcd_wrdata8(uint8_t data)
+void lcd_wrdata8(uint8_t data)
 {
     LCD_MASKED_GPIO(LCD_WR_MASK, 0);
     LCD_MASKED_GPIO(LCD_DATA_MASK, data);
     NOP();
     LCD_MASKED_GPIO(LCD_WR_MASK, LCD_WR_MASK);
 }
 
-inline void lcd_wrdata16(uint16_t data)
+void lcd_wrdata16(uint16_t data)
 {
     lcd_wrdata8((data >> 8) & 0xff);
     lcd_wrdata8(data & 0xff);
 }
 
-inline void lcd_draw(uint16_t colour)
+void lcd_draw(uint16_t colour)
 {
     lcd_wrdata16(colour);
 }
 
-inline void lcd_disable()
+void lcd_disable()
 {
     LCD_MASKED_GPIO(LCD_CS_MASK, LCD_CS_MASK);
 }
 
-inline void lcd_enable()
+void lcd_enable()
 {
     LCD_MASKED_GPIO(LCD_CS_MASK, 0);
 }
 
-inline void lcd_drawstart()
+void lcd_drawstart()
 {
     lcd_wrcmd8(LCD_CMD_WRITE);
 }
 
-inline void lcd_drawstop()
+void lcd_drawstop()
 {
 
 }

display/src/main.c

@@ -49,14 +49,11 @@ void uint32_to_hex(const uint32_t c, uint8_t *dest)
     } while (shift);
 }
 
-static int irq_called VAR_RAM = 0;
 static volatile bool msg_pending = false;
 
 
 void ADC_IRQHandler(void)
 {
-    // only used for touch right now
-    irq_called = 1;
     touch_intr_sm();
 }
 
@@ -112,23 +109,28 @@ static coord_int_t prevz VAR_RAM = 0;
 
 static inline enum event_t wait_for_event()
 {
-    struct ticks_t t1 = ticks_get();
     while (1) {
-        do {
-            if (msg_pending) {
-                msg_pending = false;
-                return EV_COMM;
+        __asm__ volatile("wfi");
+        struct ticks_t t1 = ticks_get();
+        if (ticks_delta(&last_touch_sample, &t1) > TOUCH_SAMPLE_INTERVAL) {
+            touch_intr_start();
+        }
+
+        if (msg_pending) {
+            msg_pending = false;
+            return EV_COMM;
+        }
+
+        if (touch_pending) {
+            last_touch_sample = ticks_get();
+            touch_pending = false;
+            if (touch_get_raw_z() > TOUCH_MIN_PRESSURE) {
+                prevz = 1;
+                return EV_TOUCH;
+            } else if (prevz > 0) {
+                prevz = 0;
+                return EV_TOUCH;
             }
-            t1 = ticks_get();
-        } while (ticks_delta(&last_touch_sample, &t1) < TOUCH_SAMPLE_INTERVAL);
-        touch_sample();
-        last_touch_sample = ticks_get();
-        if (touch_get_raw_z() != 0) {
-            prevz = 1;
-            return EV_TOUCH;
-        } else if (prevz > 0) {
-            prevz = 0;
-            return EV_TOUCH;
         }
     }
 }
@@ -421,7 +423,6 @@ int main(void)
     DISABLE_IRQ();
 
     SCB_PDRUNCFG &= ~SCB_PDRUNCFG_ADC;
-    //~ NVIC_EnableIRQ(ADC_IRQn);
 
     SCB_SYSAHBCLKCTRL |= SCB_SYSAHBCLKCTRL_GPIO
                       |  SCB_SYSAHBCLKCTRL_IOCON
@@ -509,6 +510,8 @@ int main(void)
         touch_wait_for_clear();
     }
 
+    NVIC_EnableIRQ(ADC_IRQn);
+
     //~ comm_debug_tx_pong();
 
     fill_rectangle(0, 0, LCD_WIDTH-1, LCD_HEIGHT-1, 0x0000);
@@ -541,26 +544,21 @@ int main(void)
             z = touch_get_z();
 
             if ((z > 0) && (abs(prevx - x) + abs(prevy - y) <= 3)) {
-                prevx = x;
-                prevy = y;
                 break;
             }
 
-            prevx = x;
-            prevy = y;
-
-            if (z == 0) {
-                prevx = -100;
-                prevy = -100;
-            }
-
             //~ lcd_enable();
             //~ fill_rectangle(x-2, y-2, x+2, y+2, 0x001f);
             //~ lcd_disable();
 
             msg_payload.subject = LPC_SUBJECT_TOUCH_EVENT;
-            msg_payload.payload.touch_ev.x = x;
-            msg_payload.payload.touch_ev.y = y;
+            if (z == 0) {
+                msg_payload.payload.touch_ev.x = prevx;
+                msg_payload.payload.touch_ev.y = prevy;
+            } else {
+                msg_payload.payload.touch_ev.x = x;
+                msg_payload.payload.touch_ev.y = y;
+            }
             msg_payload.payload.touch_ev.z = z;
             HDR_SET_PAYLOAD_LENGTH(msg_header, sizeof(struct lpc_msg_t));
             msg_checksum = checksum((const uint8_t*)&msg_payload,
@@ -570,6 +568,14 @@ int main(void)
                             (const uint8_t*)&msg_payload,
                             msg_checksum);
 
+            prevx = x;
+            prevy = y;
+
+            if (z == 0) {
+                prevx = -100;
+                prevy = -100;
+            }
+
             break;
         }
         case EV_NONE: