void
i2c_outbyte(unsigned char x)
{
int i;
i2c_dir_out();
for (i = 0; i < 8; i++) {
if (x & 0x80) {
i2c_data(I2C_DATA_HIGH);
} else {
i2c_data(I2C_DATA_LOW);
}
i2c_delay(CLOCK_LOW_TIME/2);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME);
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME/2);
x <<= 1;
}
i2c_data(I2C_DATA_LOW);
i2c_delay(CLOCK_LOW_TIME/2);
/*
* enable input
*/
i2c_dir_in();
}
/*#---------------------------------------------------------------------------
*#
*# FUNCTION NAME: I2C::sendAck
*#
*# DESCRIPTION : Send ACK on received data
*#
*#--------------------------------------------------------------------------*/
void
i2c_sendack(void)
{
/*
* enable output
*/
i2c_delay(CLOCK_LOW_TIME);
i2c_dir_out();
/*
* set ack pulse high
*/
i2c_data(I2C_DATA_LOW);
/*
* generate clock pulse
*/
i2c_delay(CLOCK_HIGH_TIME/6);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME);
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME/6);
/*
* reset data out
*/
i2c_data(I2C_DATA_HIGH);
i2c_delay(CLOCK_LOW_TIME);
i2c_dir_in();
}
// Open the GPIOG dev
int i2c_open(void) {
i2c_fd = open("/dev/gpiog", O_RDWR);
i2c_data(I2C_DATA_HIGH);
i2c_dir_out();
i2c_clk(I2C_CLOCK_HIGH);
i2c_data(I2C_DATA_HIGH);
i2c_delay(100);
return i2c_fd;
}
void
i2c_start(void)
{
i2c_dir_out();
i2c_delay(CLOCK_HIGH_TIME/6);
i2c_data(I2C_DATA_HIGH);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME);
i2c_data(I2C_DATA_LOW);
i2c_delay(START_CONDITION_HOLD_TIME);
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME);
}
void
i2c_stop(void)
{
i2c_dir_out();
i2c_clk(I2C_CLOCK_LOW);
i2c_data(I2C_DATA_LOW);
i2c_delay(CLOCK_LOW_TIME*2);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME*2);
i2c_data(I2C_DATA_HIGH);
i2c_delay(STOP_CONDITION_HOLD_TIME);
i2c_dir_in();
}
// Read a byte from I2C bus and send the ack sequence
unsigned char i2c_inbyte(int ack) {
unsigned char value = 0;
int bitvalue;
int i;
// Read data byte
i2c_dir_in();
for (i=0;i<8;i++) {
i2c_clk(1);
udelay(5);
bitvalue = i2c_getbit();
value |= bitvalue;
if (i<7) value <<= 1;
i2c_clk(0);
udelay(5);
}
// Send Ack
if(ack){
i2c_dir_out();
i2c_data(0);
i2c_clk(1);
udelay(5);
i2c_clk(0);
}
udelay(200);
return value;
}
void
i2c_sendack(void)
{
i2c_delay(CLOCK_LOW_TIME);
i2c_dir_out();
i2c_data(I2C_DATA_LOW);
i2c_delay(CLOCK_HIGH_TIME/6);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME);
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME/6);
i2c_data(I2C_DATA_HIGH);
i2c_delay(CLOCK_LOW_TIME);
i2c_dir_in();
}
// �i��Ɂj�������A�����M���܂��B
uint8_t i2c_puts(unsigned char *s)
{
int8_t re;
while(*s){
re = i2c_data(*s++);
if(re<0) return re;
}
return 0;
}
/*
* SDカードのサンプル
*/
void sd_test()
{
FRESULT rc;
// DIR dir; /* Directory object */
// FILINFO fno; /* File information object */
UINT bw, br, i;
char tmp[64];
f_mount(0, &Fatfs); /* Register volume work area (never fails) */
/*
* SDカードのMESSAGE.TXTを開いてI2C液晶に表示します。英数カナのみ
* ２行分のみ
*/
rc = f_open(&Fil, "MESSAGE.TXT", FA_READ);
if (!rc){
i2c_cmd(0x80);
// xprintf("\nType the file content.\n");
for (;;) {
rc = f_read(&Fil, buff, sizeof(buff), &br); /* Read a chunk of file */
if (rc || !br) break; /* Error or end of file */
for (i = 0; i < br; i++){
if(i==0x10) i2c_cmd(0xC0);
i2c_data(buff[i]);
}
xprintf("%s\n", buff);
}
if (rc) die(rc);
rc = f_close(&Fil);
}
/*
* ファイル書き込みテスト
* SD0001.TXTファイルを作成し、Strawberry Linuxの文字を永遠に書き込む
*/
rc = f_open(&Fil, "SD0001.TXT", FA_WRITE | FA_OPEN_ALWAYS);
f_lseek(&Fil, f_size(&Fil));
if (rc) die(rc);
i = 0;
// 無限ループでこの関数からは抜けない
while(i < 100){
sprintf(tmp, "Strawberry Linux %d\r\n", i);
rc = f_write(&Fil, tmp, strlen(tmp), &bw);
if (rc) die(rc);
xprintf("%s\n", tmp);
// SDカードに書き出します。
f_sync(&Fil);
i++;
}
// return;
f_mount(0, NULL);
}
int
i2c_getack(void)
{
int ack = 1;
i2c_dir_out();
i2c_data(I2C_DATA_HIGH);
i2c_dir_in();
i2c_delay(CLOCK_HIGH_TIME/4);
i2c_clk(I2C_CLOCK_HIGH);
#if 0
i2c_clk(1);
i2c_data(1);
i2c_data(1);
i2c_disable();
i2c_dir_in();
#endif
i2c_delay(CLOCK_HIGH_TIME/2);
if (i2c_getbit())
ack = 0;
i2c_delay(CLOCK_HIGH_TIME/2);
if (!ack) {
if (!i2c_getbit())
ack = 1;
i2c_delay(CLOCK_HIGH_TIME/2);
}
#if 0
i2c_data(I2C_DATA_LOW);
i2c_enable();
i2c_dir_out();
#endif
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_HIGH_TIME/4);
i2c_dir_out();
i2c_data(I2C_DATA_HIGH);
i2c_delay(CLOCK_LOW_TIME/2);
return ack;
}
int
i2c_getack(void)
{
int ack = 1;
/*
* enable output
*/
i2c_dir_out();
/*
* Release data bus by setting
* data high
*/
i2c_data(I2C_DATA_HIGH);
/*
* enable input
*/
i2c_dir_in();
i2c_delay(CLOCK_HIGH_TIME/4);
/*
* generate ACK clock pulse
*/
i2c_clk(I2C_CLOCK_HIGH);
/*
* Use PORT PB instead of I2C
* for input. (I2C not working)
*/
i2c_clk(1);
i2c_data(1);
/*
* switch off I2C
*/
i2c_data(1);
i2c_disable();
i2c_dir_in();
/*
* now wait for ack
*/
i2c_delay(CLOCK_HIGH_TIME/2);
/*
* check for ack
*/
if(i2c_getbit())
ack = 0;
i2c_delay(CLOCK_HIGH_TIME/2);
if(!ack){
if(!i2c_getbit()) /* receiver pulld SDA low */
ack = 1;
i2c_delay(CLOCK_HIGH_TIME/2);
}
/*
* our clock is high now, make sure data is low
* before we enable our output. If we keep data high
* and enable output, we would generate a stop condition.
*/
i2c_data(I2C_DATA_LOW);
/*
* end clock pulse
*/
i2c_enable();
i2c_dir_out();
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_HIGH_TIME/4);
/*
* enable output
*/
i2c_dir_out();
/*
* remove ACK clock pulse
*/
i2c_data(I2C_DATA_HIGH);
i2c_delay(CLOCK_LOW_TIME/2);
return ack;
}
/*#---------------------------------------------------------------------------
*#
*# FUNCTION NAME: i2c_readreg
*#
*# DESCRIPTION : Reads a value from the decoder registers.
*#
*#--------------------------------------------------------------------------*/
unsigned char
i2c_readreg(unsigned char theSlave, unsigned char theReg)
{
unsigned char b = 0;
int error, cntr = 3;
unsigned long flags;
do {
error = 0;
/*
* we don't like to be interrupted
*/
save_flags(flags);
cli();
/*
* generate start condition
*/
i2c_start();
/*
* dummy preamble
*/
i2c_outbyte(0x01);
i2c_data(I2C_DATA_HIGH);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME); /* Dummy Acknowledge */
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_LOW_TIME); /* Repeated Start Condition */
i2c_data(I2C_DATA_LOW);
i2c_delay(CLOCK_HIGH_TIME);
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME);
i2c_start();
/*
* send slave address
*/
i2c_outbyte(theSlave);
/*
* wait for ack
*/
if(!i2c_getack())
error = 1;
/*
* now select register
*/
i2c_dir_out();
i2c_outbyte(theReg);
/*
* now it's time to wait for ack
*/
if(!i2c_getack())
error = 1;
/*
* repeat start condition
*/
i2c_delay(CLOCK_LOW_TIME);
i2c_start();
/*
* send slave address
*/
i2c_outbyte(theSlave | 0x01);
/*
* wait for ack
*/
if(!i2c_getack())
error = 1;
/*
* fetch register
*/
b = i2c_inbyte();
/*
* send Ack
*/
i2c_sendack();
/*
* end sequence
*/
i2c_stop();
/*
* enable interrupt again
*/
restore_flags(flags);
} while(error && cntr--);
return b;
}
/*#---------------------------------------------------------------------------
*#
*# FUNCTION NAME: i2c_writereg
*#
*# DESCRIPTION : Writes a value to an I2C device
*#
*#--------------------------------------------------------------------------*/
int
i2c_writereg(unsigned char theSlave, unsigned char theReg,
unsigned char theValue)
{
int error, cntr = 3;
unsigned long flags;
do {
error = 0;
/*
* we don't like to be interrupted
*/
save_flags(flags);
cli();
/*
* generate start condition
*/
i2c_start();
/*
* dummy preamble
*/
i2c_outbyte(0x01);
i2c_data(I2C_DATA_HIGH);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_HIGH_TIME); /* Dummy Acknowledge */
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME);
i2c_clk(I2C_CLOCK_HIGH);
i2c_delay(CLOCK_LOW_TIME); /* Repeated Start Condition */
i2c_data(I2C_DATA_LOW);
i2c_delay(CLOCK_HIGH_TIME);
i2c_clk(I2C_CLOCK_LOW);
i2c_delay(CLOCK_LOW_TIME);
i2c_start();
/*
* send slave address
*/
i2c_outbyte(theSlave);
/*
* wait for ack
*/
if(!i2c_getack())
error = 1;
/*
* now select register
*/
i2c_dir_out();
i2c_outbyte(theReg);
/*
* now it's time to wait for ack
*/
if(!i2c_getack())
error |= 2;
/*
* send register register data
*/
i2c_outbyte(theValue);
/*
* now it's time to wait for ack
*/
if(!i2c_getack())
error |= 4;
/*
* end byte stream
*/
i2c_stop();
/*
* enable interrupt again
*/
restore_flags(flags);
} while(error && cntr--);
i2c_delay(CLOCK_LOW_TIME);
return -error;
}
unsigned char
i2c_inbyte(void)
{
unsigned char aBitByte = 0;
int i;
int iaa;
/*
* enable output
*/
i2c_dir_out();
/*
* Release data bus by setting
* data high
*/
i2c_data(I2C_DATA_HIGH);
/*
* enable input
*/
i2c_dir_in();
/*
* Use PORT PB instead of I2C
* for input. (I2C not working)
*/
i2c_clk(1);
i2c_data(1);
/*
* get bits
*/
for (i = 0; i < 8; i++) {
i2c_delay(CLOCK_LOW_TIME/2);
/*
* low clock period
*/
i2c_clk(I2C_CLOCK_HIGH);
/*
* switch off I2C
*/
i2c_data(1);
i2c_disable();
i2c_dir_in();
/*
* wait before getting bit
*/
i2c_delay(CLOCK_HIGH_TIME/2);
aBitByte = (aBitByte << 1);
iaa = i2c_getbit();
aBitByte = aBitByte | iaa ;
/*
* wait
*/
i2c_delay(CLOCK_HIGH_TIME/2);
/*
* end clock puls
*/
i2c_enable();
i2c_dir_out();
i2c_clk(I2C_CLOCK_LOW);
/*
* low clock period
*/
i2c_delay(CLOCK_LOW_TIME/2);
}
i2c_dir_out();
return aBitByte;
}
// （主に）文字列を連続送信します。
void i2c_puts(unsigned char *s)
{
while(*s){
i2c_data(*s++);
}
}
