static inline int i2c_do_read(i2c_t *obj, int last) {
if (obj->dummy) {
volatile int dummy = REG(DRR.UINT32);
obj->dummy = 0;
}
// wait for it to arrive
i2c_wait_RDRF(obj);
if (last == 2) {
/* this time is befor last byte read */
/* Set MR3 WATI bit is 1 */;
REG(MR3.UINT32) |= (1 << 6);
} else if (last == 1) {
// send a NOT ACK
REG(MR3.UINT32) |= (1 <<4);
REG(MR3.UINT32) |= (1 <<3);
REG(MR3.UINT32) &= ~(1 <<4);
} else {
// send a ACK
REG(MR3.UINT32) |= (1 <<4);
REG(MR3.UINT32) &= ~(1 <<3);
REG(MR3.UINT32) &= ~(1 <<4);
}
// return the data
return (REG(DRR.UINT32) & 0xFF);
}
int i2c_byte_read(i2c_t *obj, int last) {
int status;
/* wait for it to arrive */
status = i2c_wait_RDRF(obj);
if (status != 0) {
i2c_set_err_noslave(obj, 1);
return I2C_ERROR_NO_SLAVE;
}
return (i2c_do_read(obj, last));
}
int i2c_byte_read(i2c_t *obj, int last) {
int status;
int data;
data = i2c_do_read(obj, last);
/* wait for it to arrive */
status = i2c_wait_RDRF(obj);
if (status != 0) {
i2c_set_SR2_NACKF_STOP(obj);
return I2C_ERROR_NO_SLAVE;
}
return data;
}
int i2c_slave_read(i2c_t *obj, char *data, int length) {
int count = 0;
int status;
volatile int dummy = REG(DRR.UINT32) ;
do {
i2c_wait_RDRF(obj);
status = i2c_status(obj);
if(!(status & 0x10)) {
data[count] = REG(DRR.UINT32) & 0xFF;
}
count++;
} while ( !(status & 0x10) && (count < length) );
if(status & 0x10) {
i2c_stop(obj);
i2c_wait_STOP(obj);
}
//i2c_clear_TDRE(obj);
return count;
}
int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
int count = 0;
int status;
int value;
volatile uint32_t work_reg = 0;
// full reset
i2c_reg_reset(obj);
obj->dummy = 1;
status = i2c_start(obj);
if (status == 0xff) {
i2c_stop(obj);
i2c_wait_STOP(obj);
return I2C_ERROR_BUS_BUSY;
}
status = i2c_do_write(obj, (address | 0x01));
if (status & 0x01) {
i2c_stop(obj);
i2c_wait_STOP(obj);
return I2C_ERROR_NO_SLAVE;
}
/* wati RDRF */
i2c_wait_RDRF(obj);
/* check ACK/NACK */
if ((REG(SR2.UINT32) & (1 << 4) == 1)) {
/* Slave sends NACK */
i2c_stop(obj);
// dummy read
value = REG(DRR.UINT32);
i2c_wait_STOP(obj);
return I2C_ERROR_NO_SLAVE;
}
// Read in all except last byte
if (length > 2) {
for (count = 0; count < (length - 1); count++) {
if (count == (length - 2)) {
value = i2c_do_read(obj, 1);
} else if ((length >= 3) && (count == (length - 3))) {
value = i2c_do_read(obj, 2);
} else {
value = i2c_do_read(obj, 0);
}
status = i2c_status(obj);
if (status & 0x10) {
i2c_stop(obj);
i2c_wait_STOP(obj);
return count;
}
data[count] = (char) value;
}
} else if (length == 2) {
/* Set MR3 WATI bit is 1 */;
REG(MR3.UINT32) |= (1 << 6);
// dummy read
value = REG(DRR.UINT32);
// wait for it to arrive
i2c_wait_RDRF(obj);
// send a NOT ACK
REG(MR3.UINT32) |= (1 <<4);
REG(MR3.UINT32) |= (1 <<3);
REG(MR3.UINT32) &= ~(1 <<4);
data[count] = (char)REG(DRR.UINT32);
count++;
} else if (length == 1) {
/* Set MR3 WATI bit is 1 */;
REG(MR3.UINT32) |= (1 << 6);
// send a NOT ACK
REG(MR3.UINT32) |= (1 <<4);
REG(MR3.UINT32) |= (1 <<3);
REG(MR3.UINT32) &= ~(1 <<4);
// dummy read
value = REG(DRR.UINT32);
} else {
// Do Nothing
}
// read in last byte
i2c_wait_RDRF(obj);
// If not repeated start, send stop.
if (stop) {
/* RIICnSR2.STOP = 0 */
REG(SR2.UINT32) &= ~(1 << 3);
/* RIICnCR2.SP = 1 */
REG(CR2.UINT32) |= (1 << 3);
/* RIICnDRR read */
value = REG(DRR.UINT32) & 0xFF;
data[count] = (char) value;
/* RIICnMR3.WAIT = 0 */
REG(MR3.UINT32) &= ~(1 << 6);
i2c_wait_STOP(obj);
} else {
/* RIICnDRR read */
value = REG(DRR.UINT32) & 0xFF;
data[count] = (char) value;
}
return length;
}
int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
int count = 0;
int status;
int value;
volatile uint32_t work_reg = 0;
if(length <= 0) {
return 0;
}
i2c_set_MR3_ACK(obj);
/* There is a STOP condition for last processing */
if (obj->last_stop_flag != 0) {
status = i2c_start(obj);
if (status != 0) {
i2c_set_err_noslave(obj);
return I2C_ERROR_BUS_BUSY;
}
}
obj->last_stop_flag = stop;
/* Send Slave address */
status = i2c_read_address_write(obj, (address | 0x01));
if (status != 0) {
i2c_set_err_noslave(obj);
return I2C_ERROR_NO_SLAVE;
}
/* wait RDRF */
status = i2c_wait_RDRF(obj);
/* check ACK/NACK */
if ((status != 0) || ((REG(SR2.UINT32) & SR2_NACKF) != 0)) {
/* Slave sends NACK */
(void)i2c_set_STOP(obj);
/* dummy read */
value = REG(DRR.UINT32);
(void)i2c_wait_STOP(obj);
i2c_set_SR2_NACKF_STOP(obj);
obj->last_stop_flag = 1;
return I2C_ERROR_NO_SLAVE;
}
/* Read in all except last byte */
if (length > 2) {
/* dummy read */
value = REG(DRR.UINT32);
for (count = 0; count < (length - 1); count++) {
/* wait for it to arrive */
status = i2c_wait_RDRF(obj);
if (status != 0) {
i2c_set_err_noslave(obj);
return I2C_ERROR_NO_SLAVE;
}
/* Recieve the data */
if (count == (length - 2)) {
value = i2c_do_read(obj, 1);
} else if ((length >= 3) && (count == (length - 3))) {
value = i2c_do_read(obj, 2);
} else {
value = i2c_do_read(obj, 0);
}
data[count] = (char)value;
}
} else if (length == 2) {
/* Set MR3 WATI bit is 1 */
REG(MR3.UINT32) |= MR3_WAIT;
/* dummy read */
value = REG(DRR.UINT32);
/* wait for it to arrive */
status = i2c_wait_RDRF(obj);
if (status != 0) {
i2c_set_err_noslave(obj);
return I2C_ERROR_NO_SLAVE;
}
i2c_set_MR3_NACK(obj);
data[count] = (char)REG(DRR.UINT32);
count++;
} else {
/* length == 1 */
/* Set MR3 WATI bit is 1 */;
REG(MR3.UINT32) |= MR3_WAIT;
i2c_set_MR3_NACK(obj);
/* dummy read */
value = REG(DRR.UINT32);
}
/* wait for it to arrive */
status = i2c_wait_RDRF(obj);
if (status != 0) {
i2c_set_err_noslave(obj);
return I2C_ERROR_NO_SLAVE;
}
/* If not repeated start, send stop. */
if (stop) {
(void)i2c_set_STOP(obj);
/* RIICnDRR read */
value = (REG(DRR.UINT32) & 0xFF);
data[count] = (char)value;
/* RIICnMR3.WAIT = 0 */
REG(MR3.UINT32) &= ~MR3_WAIT;
(void)i2c_wait_STOP(obj);
i2c_set_SR2_NACKF_STOP(obj);
} else {
(void)i2c_restart(obj);
/* RIICnDRR read */
value = (REG(DRR.UINT32) & 0xFF);
data[count] = (char)value;
/* RIICnMR3.WAIT = 0 */
REG(MR3.UINT32) &= ~MR3_WAIT;
(void)i2c_wait_START(obj);
/* SR2.START = 0 */
REG(SR2.UINT32) &= ~SR2_START;
}
return length;
}
