Added support for block reading and writing (#127)

* Added support for block reading and writing

Added three functions to support reading and writing blocks with a specified size to the I2C device. For writing, I added two versions, one that implicitly sends the size as the first byte to the slave device and one that doesn't.

src/i2c-dev.c

@@ -70,4 +70,38 @@ extern inline __s32 i2c_smbus_write_word_data(int fd, int cmd, __u16 value) {
 	return i2c_smbus_access(fd, I2C_SMBUS_WRITE, cmd, I2C_SMBUS_WORD_DATA, &data);
 }
 
+extern inline __s32 i2c_smbus_read_data_block(int fd, int cmd, unsigned char *block, int block_size) {
+	union i2c_smbus_data data;
+	if (block_size > I2C_SMBUS_BLOCK_MAX) {
+		block_size = I2C_SMBUS_BLOCK_MAX;
+	}
+	data.block[0] = block_size;
+	if(i2c_smbus_access(fd, I2C_SMBUS_READ, cmd, I2C_SMBUS_I2C_BLOCK_DATA, &data) < 0) {
+		return -1;
+	} else {
+		memcpy(block, data.block+1, block_size);
+		return data.block[0];
+	}
+}
+
+extern inline __s32 i2c_smbus_write_data_block(int fd, int cmd, unsigned char *block, int block_size) {
+	union i2c_smbus_data data;
+	if (block_size > I2C_SMBUS_BLOCK_MAX) {
+		block_size = I2C_SMBUS_BLOCK_MAX;
+	}
+	data.block[0] = block_size;
+	memcpy(data.block+1, block, block_size);
+	return i2c_smbus_access(fd, I2C_SMBUS_WRITE, cmd, I2C_SMBUS_I2C_BLOCK_BROKEN, &data);
+}
+
+extern inline __s32 i2c_smbus_write_data_block_with_size(int fd, int cmd, unsigned char *block, int block_size) {
+	union i2c_smbus_data data;
+	if (block_size > I2C_SMBUS_BLOCK_MAX) {
+		block_size = I2C_SMBUS_BLOCK_MAX;
+	}
+	data.block[0] = block_size;
+	memcpy(data.block+1, block, block_size);
+	return i2c_smbus_access(fd, I2C_SMBUS_WRITE, cmd, I2C_SMBUS_I2C_BLOCK_DATA, &data);
+}
+
 #endif

src/i2c-dev.h

@@ -34,5 +34,8 @@ inline __s32 i2c_smbus_read_byte_data(int fd, int cmd);
 inline __s32 i2c_smbus_write_byte_data(int fd, int cmd, int value);
 inline __s32 i2c_smbus_read_word_data(int fd, int cmd);
 inline __s32 i2c_smbus_write_word_data(int fd, int cmd, __u16 value);
+inline __s32 i2c_smbus_read_data_block(int fd, int cmd, unsigned char *block, int block_size);
+inline __s32 i2c_smbus_write_data_block(int fd, int cmd, unsigned char *block, int block_size);
+inline __s32 i2c_smbus_write_data_block_with_size(int fd, int cmd, unsigned char *block, int block_size);
 
 #endif

src/wiringx.c

@@ -14,9 +14,7 @@
 #include <errno.h>
 #include <string.h>
 #include <fcntl.h>
-#include <time.h>
 #include <termios.h>
-#include <sys/time.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #ifndef __FreeBSD__
@@ -154,7 +152,7 @@ EXPORT void delayMicroseconds(unsigned int howLong) {
 #ifdef _WIN32
 		sleeper.tv_sec = wSecs;
 #else
-		sleeper.tv_sec = (__time_t)wSecs;	
+		sleeper.tv_sec = (__time_t)wSecs;
 #endif
 		sleeper.tv_nsec = (long)(uSecs * 1000L);
 		nanosleep(&sleeper, NULL);
@@ -398,6 +396,10 @@ EXPORT int wiringXI2CReadReg16(int fd, int reg) {
 	return i2c_smbus_read_word_data(fd, reg);
 }
 
+EXPORT int wiringXI2CReadBlockData(int fd, int reg, unsigned char *block, int block_size) {
+	return i2c_smbus_read_data_block(fd, reg, block, block_size);
+}
+
 EXPORT int wiringXI2CWrite(int fd, int data) {
 	return i2c_smbus_write_byte(fd, data);
 }
@@ -410,6 +412,14 @@ EXPORT int wiringXI2CWriteReg16(int fd, int reg, int data) {
 	return i2c_smbus_write_word_data(fd, reg, data);
 }
 
+EXPORT int wiringXI2CWriteBlockData(int fd, int reg, unsigned char *block, int block_size) {
+	return i2c_smbus_write_data_block(fd, reg, block, block_size);
+}
+
+EXPORT int wiringXI2CWriteBlockDataWithSize(int fd, int reg, unsigned char *block, int block_size) {
+	return i2c_smbus_write_data_block_with_size(fd, reg, block, block_size);
+}
+
 EXPORT int wiringXI2CSetup(const char *path, int devId) {
 	int fd = 0;
 

src/wiringx.h

@@ -13,6 +13,8 @@
 extern "C" {
 #endif
 
+#include <time.h>
+#include <sys/time.h>
 #include <errno.h>
 #include <syslog.h>
 
@@ -66,6 +68,11 @@ typedef struct wiringXSerial_t {
 	unsigned int flowcontrol;
 } wiringXSerial_t;
 
+#ifdef __riscv
+typedef time_t __time_t;
+typedef suseconds_t __suseconds_t;
+#endif
+
 void delayMicroseconds(unsigned int);
 int pinMode(int, enum pinmode_t);
 int wiringXSetup(char *name, void (*func)(int, char *, int, const char *, ...));
@@ -80,9 +87,13 @@ int wiringXISR(int, enum isr_mode_t);
 int wiringXI2CRead(int);
 int wiringXI2CReadReg8(int, int);
 int wiringXI2CReadReg16(int, int);
+int wiringXI2CReadBlockData(int, int, unsigned char*, int);
 int wiringXI2CWrite(int, int);
 int wiringXI2CWriteReg8(int, int, int);
 int wiringXI2CWriteReg16(int, int, int);
+int wiringXI2CWriteBlockData(int, int, unsigned char*, int);
+int wiringXI2CWriteBlockDataWithSize(int, int, unsigned char*, int);
+
 int wiringXI2CSetup(const char *, int);
 
 int wiringXSPIGetFd(int channel);