Efficiently wait for pin change

RaspberryPi&JetsonNano/c/.gitignore

@@ -0,0 +1,2 @@
+bin/
+epd

RaspberryPi_JetsonNano/c/Makefile

@@ -17,12 +17,13 @@ DEBUG = -D DEBUG
 USELIB_RPI = USE_WIRINGPI_LIB
 # USELIB_RPI = USE_DEV_LIB
 
+LIB_RPI=-Wl,--gc-sections
 ifeq ($(USELIB_RPI), USE_BCM2835_LIB)
-    LIB_RPI = -lbcm2835 -lm 
+    LIB_RPI += -lbcm2835 -lm 
 else ifeq ($(USELIB_RPI), USE_WIRINGPI_LIB)
-    LIB_RPI = -lwiringPi -lm 
+    LIB_RPI += -lwiringPi -lm 
 else ifeq ($(USELIB_RPI), USE_DEV_LIB)
-    LIB_RPI = -lm 
+    LIB_RPI += -lm 
 endif
 DEBUG_RPI = -D $(USELIB_RPI) -D RPI
 
@@ -42,7 +43,7 @@ JETSON: JETSON_DEV JETSON_epd
 
 TARGET = epd
 CC = gcc
-MSG = -g -O0 -Wall
+MSG = -g -O -ffunction-sections -fdata-sections -Wall
 CFLAGS += $(MSG)
 
 RPI_epd:${OBJ_O}
@@ -53,6 +54,8 @@ JETSON_epd:${OBJ_O}
 	echo $(@)
 	$(CC) $(CFLAGS) $(OBJ_O) $(JETSON_DEV_C) -o $(TARGET) $(LIB_JETSONI) $(DEBUG)
 
+$(shell mkdir -p $(DIR_BIN))
+
 ${DIR_BIN}/%.o:$(DIR_Examples)/%.c
 	$(CC) $(CFLAGS) -c  $< -o $@ -I $(DIR_Config) -I $(DIR_GUI) -I $(DIR_EPD) $(DEBUG)
 

RaspberryPi_JetsonNano/c/lib/Config/DEV_Config.c

@@ -29,6 +29,7 @@
 ******************************************************************************/
 #include "DEV_Config.h"
 #include <fcntl.h>
+#include <time.h>
 
 /**
  * GPIO
@@ -85,6 +86,31 @@ UBYTE DEV_Digital_Read(UWORD Pin)
 	return Read_value;
 }
 
+void DEV_Digital_Wait(UWORD Pin, UBYTE Value)
+{
+#ifdef RPI
+#ifdef USE_BCM2835_LIB
+	do {
+		DEV_Delay_ms(10);
+	} while(bcm2835_gpio_lev(Pin) != Value);
+#elif USE_WIRINGPI_LIB
+	do {
+		DEV_Delay_ms(10);
+	} while(digitalRead(Pin) != Value);
+#elif USE_DEV_LIB
+	SYSFS_GPIO_Wait(Pin, Value);
+#endif
+#endif
+
+#ifdef JETSON
+#ifdef USE_DEV_LIB
+	SYSFS_GPIO_Wait(Pin, Value);
+#elif USE_HARDWARE_LIB
+	Debug("not support");
+#endif
+#endif
+}
+
 /**
  * SPI
 **/
@@ -185,10 +211,10 @@ void DEV_Delay_ms(UDOUBLE xms)
 #elif USE_WIRINGPI_LIB
 	delay(xms);
 #elif USE_DEV_LIB
-	UDOUBLE i;
-	for(i=0; i < xms; i++) {
-		usleep(1000);
-	}
+	struct timespec tv;
+	tv.tv_nsec=(xms%1000)*1000000;
+	tv.tv_sec=xms/1000;
+	nanosleep(&tv, NULL);
 #endif
 #endif
 
@@ -229,7 +255,7 @@ static int DEV_Equipment_Testing(void)
 	if(i<5) {
 		printf("Unrecognizable\r\n");
 	} else {
-		char RPI_System[10]   = {"Raspbian"};
+		char RPI_System[10]   = {"Debian"};
 		for(i=0; i<6; i++) {
 			if(RPI_System[i]!= value_str[i]) {
 				printf("Please make JETSON !!!!!!!!!!\r\n");
@@ -366,10 +392,10 @@ void DEV_Module_Exit(void)
 	DEV_Digital_Write(EPD_DC_PIN, 0);
 	DEV_Digital_Write(EPD_RST_PIN, 0);
 #elif USE_DEV_LIB
-	DEV_HARDWARE_SPI_end();
 	DEV_Digital_Write(EPD_CS_PIN, 0);
 	DEV_Digital_Write(EPD_DC_PIN, 0);
 	DEV_Digital_Write(EPD_RST_PIN, 0);
+	DEV_HARDWARE_SPI_end();
 #endif
 
 #elif JETSON

RaspberryPi_JetsonNano/c/lib/Config/DEV_Config.h

@@ -96,6 +96,7 @@ extern int EPD_BUSY_PIN;
 /*------------------------------------------------------------------------------------------------------*/
 void DEV_Digital_Write(UWORD Pin, UBYTE Value);
 UBYTE DEV_Digital_Read(UWORD Pin);
+void DEV_Digital_Wait(UWORD Pin, UBYTE Value);
 
 void DEV_SPI_WriteByte(UBYTE Value);
 void DEV_SPI_Write_nByte(uint8_t *pData, uint32_t Len);

RaspberryPi_JetsonNano/c/lib/Config/RPI_sysfs_gpio.c

@@ -36,6 +36,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/poll.h>
 
 int SYSFS_GPIO_Export(int Pin)
 {
@@ -107,6 +108,32 @@ int SYSFS_GPIO_Direction(int Pin, int Dir)
     return 0;
 }
 
+int SYSFS_GPIO_Edge(int Pin, int edge)
+{
+    const char *edge_str[]  = {"rising","falling","both"};
+	const int edge_str_l[]  = {6, 7, 4};
+    char path[DIR_MAXSIZ];
+    int fd;
+
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/edge", Pin);
+    fd = open(path, O_WRONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Set Edge failed: Pin%d\n", Pin);
+        return -1;
+    }
+
+	if (edge>2) edge=2;
+    if (write(fd, edge_str[edge], edge_str_l[edge]) < 0) {
+        SYSFS_GPIO_Debug("failed to set edge!\r\n");
+        return -1;
+    }
+
+	SYSFS_GPIO_Debug("Pin%d:%s edge\r\n", Pin, edge_str[edge]);
+
+    close(fd);
+    return 0;
+}
+
 int SYSFS_GPIO_Read(int Pin)
 {
     char path[DIR_MAXSIZ];
@@ -122,13 +149,58 @@ int SYSFS_GPIO_Read(int Pin)
 
     if (read(fd, value_str, 3) < 0) {
         SYSFS_GPIO_Debug( "failed to read value!\n");
+        close(fd);
         return -1;
     }
 
     close(fd);
     return(atoi(value_str));
 }
 
+int SYSFS_GPIO_Wait(int Pin, int value)
+{
+    char path[DIR_MAXSIZ];
+    char value_str[3];
+    int fd;
+    struct pollfd pfd[1];
+
+    SYSFS_GPIO_Edge(Pin, SYSFS_GPIO_BOTH);
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/value", Pin);
+    fd = open(path, O_RDONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Read failed Pin%d\n", Pin);
+        return -1;
+    }
+
+	while (1) {
+		int n;
+		if (read(fd, value_str, 3) < 0) {
+			SYSFS_GPIO_Debug( "failed to read value!\n");
+			close(fd);
+			return -1;
+		}
+		if (atoi(value_str) == value) break;
+		pfd[0].fd=fd;
+		pfd[0].events=POLLPRI;
+		n = poll(pfd, 1, -1);
+		if (n < 0) {
+			SYSFS_GPIO_Debug( "poll failed: %m!\n");
+			close(fd);
+			return -1;
+		}
+		/* lseek(0) doesn't seem to work reliably */
+		close(fd);
+		fd = open(path, O_RDONLY);
+		if (fd < 0) {
+			SYSFS_GPIO_Debug( "open failed: %m\n");
+			return -1;
+		}
+	}
+
+    close(fd);
+    return 0;
+}
+
 int SYSFS_GPIO_Write(int Pin, int value)
 {
     const char s_values_str[] = "01";
@@ -144,6 +216,7 @@ int SYSFS_GPIO_Write(int Pin, int value)
 
     if (write(fd, &s_values_str[value == SYSFS_GPIO_LOW ? 0 : 1], 1) < 0) {
         SYSFS_GPIO_Debug( "failed to write value!\n");
+        close(fd);
         return -1;
     }
 

RaspberryPi_JetsonNano/c/lib/Config/RPI_sysfs_gpio.h

@@ -39,6 +39,10 @@
 #define SYSFS_GPIO_LOW  0
 #define SYSFS_GPIO_HIGH 1
 
+#define SYSFS_GPIO_RISING 0
+#define SYSFS_GPIO_FALLING 1
+#define SYSFS_GPIO_BOTH 2
+
 #define NUM_MAXBUF  4
 #define DIR_MAXSIZ  60
 
@@ -78,5 +82,6 @@ int SYSFS_GPIO_Unexport(int Pin);
 int SYSFS_GPIO_Direction(int Pin, int Dir);
 int SYSFS_GPIO_Read(int Pin);
 int SYSFS_GPIO_Write(int Pin, int value);
+int SYSFS_GPIO_Wait(int Pin, int value);
 
-#endif
+#endif

RaspberryPi_JetsonNano/c/lib/Config/dev_hardware_SPI.c

@@ -330,18 +330,13 @@ function: SPI port sends one byte of data
 uint8_t DEV_HARDWARE_SPI_TransferByte(uint8_t buf)
 {
     uint8_t rbuf[1];
-    tr.len = 1;
-    tr.tx_buf =  (unsigned long)&buf;
-    tr.rx_buf =  (unsigned long)rbuf;
-
-    //ioctl Operation, transmission of data
-    if ( ioctl(hardware_SPI.fd, SPI_IOC_MESSAGE(1), &tr) < 1 )  
-        DEV_HARDWARE_SPI_Debug("can't send spi message\r\n"); 
+	rbuf[0] = buf;
+    DEV_HARDWARE_SPI_Transfer(rbuf, 1);
     return rbuf[0];
 }
 
 /******************************************************************************
-function: The SPI port reads a byte
+function: The SPI port reads some bytes
 parameter:
 Info: Return read data
 ******************************************************************************/

RaspberryPi_JetsonNano/c/lib/Config/sysfs_gpio.c

@@ -36,6 +36,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/poll.h>
 
 int SYSFS_GPIO_Export(int Pin)
 {
@@ -107,6 +108,32 @@ int SYSFS_GPIO_Direction(int Pin, int Dir)
     return 0;
 }
 
+int SYSFS_GPIO_Edge(int Pin, int edge)
+{
+    const char *edge_str[]  = {"rising","falling","both"};
+	const int edge_str_l[]  = {6, 7, 4};
+    char path[DIR_MAXSIZ];
+    int fd;
+
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/edge", Pin);
+    fd = open(path, O_WRONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Set Edge failed: Pin%d\n", Pin);
+        return -1;
+    }
+
+	if (edge>2) edge=2;
+    if (write(fd, edge_str[edge], edge_str_l[edge]) < 0) {
+        SYSFS_GPIO_Debug("failed to set edge!\r\n");
+        return -1;
+    }
+
+	SYSFS_GPIO_Debug("Pin%d:%s edge\r\n", Pin, edge_str[edge]);
+
+    close(fd);
+    return 0;
+}
+
 int SYSFS_GPIO_Read(int Pin)
 {
     char path[DIR_MAXSIZ];
@@ -122,13 +149,58 @@ int SYSFS_GPIO_Read(int Pin)
 
     if (read(fd, value_str, 3) < 0) {
         SYSFS_GPIO_Debug( "failed to read value!\n");
+        close(fd);
         return -1;
     }
 
     close(fd);
     return(atoi(value_str));
 }
 
+int SYSFS_GPIO_Wait(int Pin, int value)
+{
+    char path[DIR_MAXSIZ];
+    char value_str[3];
+    int fd;
+    struct pollfd pfd[1];
+
+    SYSFS_GPIO_Edge(Pin, SYSFS_GPIO_BOTH);
+    snprintf(path, DIR_MAXSIZ, "/sys/class/gpio/gpio%d/value", Pin);
+    fd = open(path, O_RDONLY);
+    if (fd < 0) {
+        SYSFS_GPIO_Debug( "Read failed Pin%d\n", Pin);
+        return -1;
+    }
+
+	while (1) {
+		int n;
+		if (read(fd, value_str, 3) < 0) {
+			SYSFS_GPIO_Debug( "failed to read value!\n");
+			close(fd);
+			return -1;
+		}
+		if (atoi(value_str) == value) break;
+		pfd[0].fd=fd;
+		pfd[0].events=POLLPRI;
+		n = poll(pfd, 1, -1);
+		if (n < 0) {
+			SYSFS_GPIO_Debug( "poll failed: %m!\n");
+			close(fd);
+			return -1;
+		}
+		/* lseek(0) doesn't seem to work reliably */
+		close(fd);
+		fd = open(path, O_RDONLY);
+		if (fd < 0) {
+			SYSFS_GPIO_Debug( "open failed: %m\n");
+			return -1;
+		}
+	}
+
+    close(fd);
+    return 0;
+}
+
 int SYSFS_GPIO_Write(int Pin, int value)
 {
     const char s_values_str[] = "01";
@@ -144,6 +216,7 @@ int SYSFS_GPIO_Write(int Pin, int value)
 
     if (write(fd, &s_values_str[value == LOW ? 0 : 1], 1) < 0) {
         SYSFS_GPIO_Debug( "failed to write value!\n");
+        close(fd);
         return -1;
     }
 

RaspberryPi_JetsonNano/c/lib/Config/sysfs_gpio.h

@@ -39,6 +39,10 @@
 #define LOW  0
 #define HIGH 1
 
+#define SYSFS_GPIO_RISING 0
+#define SYSFS_GPIO_FALLING 1
+#define SYSFS_GPIO_BOTH 2
+
 #define NUM_MAXBUF  4
 #define DIR_MAXSIZ  60
 
@@ -80,5 +84,6 @@ int SYSFS_GPIO_Unexport(int Pin);
 int SYSFS_GPIO_Direction(int Pin, int Dir);
 int SYSFS_GPIO_Read(int Pin);
 int SYSFS_GPIO_Write(int Pin, int value);
+int SYSFS_GPIO_Wait(int Pin, int value);
 
-#endif
+#endif