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MIMXRT1050: Fix I2C Byte transfer functions #7843

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Merged
merged 1 commit into from
Aug 23, 2018
Merged

MIMXRT1050: Fix I2C Byte transfer functions #7843

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69 changes: 48 additions & 21 deletions targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_IMX/i2c_api.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,8 +23,6 @@
#include "fsl_lpi2c.h"
#include "PeripheralPins.h"

/* 7 bit IIC addr - R/W flag not included */
static int i2c_address = 0;
/* Array of I2C peripheral base address. */
static LPI2C_Type *const i2c_addrs[] = LPI2C_BASE_PTRS;

Expand Down Expand Up @@ -59,11 +57,24 @@ void i2c_init(i2c_t *obj, PinName sda, PinName scl)

int i2c_start(i2c_t *obj)
{
if (LPI2C_MasterStart(i2c_addrs[obj->instance], 0, kLPI2C_Write) != kStatus_Success) {
return 1;
}
LPI2C_Type *base = i2c_addrs[obj->instance];
int status = 0;

return 0;
obj->address_set = 0;

/* Clear all flags. */
LPI2C_MasterClearStatusFlags(base, kLPI2C_MasterEndOfPacketFlag |
kLPI2C_MasterStopDetectFlag |
kLPI2C_MasterNackDetectFlag |
kLPI2C_MasterArbitrationLostFlag |
kLPI2C_MasterFifoErrFlag |
kLPI2C_MasterPinLowTimeoutFlag |
kLPI2C_MasterDataMatchFlag);

/* Turn off auto-stop option. */
base->MCFGR1 &= ~LPI2C_MCFGR1_AUTOSTOP_MASK;
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Is this ever turned on again, or is it simply not needed anymore?

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It is not needed.


return status;
}

int i2c_stop(i2c_t *obj)
Expand All @@ -72,6 +83,8 @@ int i2c_stop(i2c_t *obj)
return 1;
}

obj->address_set = 0;

return 0;
}

Expand All @@ -88,7 +101,6 @@ int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
LPI2C_Type *base = i2c_addrs[obj->instance];
lpi2c_master_transfer_t master_xfer;

i2c_address = address >> 1;
memset(&master_xfer, 0, sizeof(master_xfer));
master_xfer.slaveAddress = address >> 1;
master_xfer.direction = kLPI2C_Read;
Expand Down Expand Up @@ -164,11 +176,10 @@ int i2c_byte_read(i2c_t *obj, int last)
lpi2c_master_transfer_t master_xfer;

memset(&master_xfer, 0, sizeof(master_xfer));
master_xfer.slaveAddress = i2c_address;
master_xfer.direction = kLPI2C_Read;
master_xfer.data = &data;
master_xfer.dataSize = 1;
master_xfer.flags = kLPI2C_TransferNoStopFlag;
master_xfer.flags = kLPI2C_TransferNoStopFlag | kLPI2C_TransferNoStartFlag;

if (LPI2C_MasterTransferBlocking(base, &master_xfer) != kStatus_Success) {
return I2C_ERROR_NO_SLAVE;
Expand All @@ -179,21 +190,37 @@ int i2c_byte_read(i2c_t *obj, int last)
int i2c_byte_write(i2c_t *obj, int data)
{
LPI2C_Type *base = i2c_addrs[obj->instance];
lpi2c_master_transfer_t master_xfer;
status_t ret_value;

memset(&master_xfer, 0, sizeof(master_xfer));
master_xfer.slaveAddress = i2c_address;
master_xfer.direction = kLPI2C_Write;
master_xfer.data = &data;
master_xfer.dataSize = 1;
master_xfer.flags = kLPI2C_TransferNoStopFlag;
uint32_t status;
size_t txCount;
size_t txFifoSize = FSL_FEATURE_LPI2C_FIFO_SIZEn(base);

/* Clear error flags. */
LPI2C_MasterClearStatusFlags(base, LPI2C_MasterGetStatusFlags(base));

/* Wait till there is room in the TX FIFO */
do {
/* Get the number of words in the tx fifo and compute empty slots. */
LPI2C_MasterGetFifoCounts(base, NULL, &txCount);
txCount = txFifoSize - txCount;
} while (!txCount);

if (!obj->address_set) {
obj->address_set = 1;
/* Issue start command. */
base->MTDR = LPI2C_MTDR_CMD(0x4U) | LPI2C_MTDR_DATA(data);
} else {
/* Write byte into LPI2C master data register. */
base->MTDR = data;
}

ret_value = LPI2C_MasterTransferBlocking(base, &master_xfer);
/* Wait till data is pushed out of the FIFO */
while (!(base->MSR & kLPI2C_MasterTxReadyFlag)) {
}

if (ret_value == kStatus_Success) {
status = LPI2C_MasterCheckAndClearError(base, LPI2C_MasterGetStatusFlags(base));
if (status == kStatus_Success) {
return 1;
} else if (ret_value == kStatus_LPI2C_Nak) {
} else if (status == kStatus_LPI2C_Nak) {
return 0;
} else {
return 2;
Expand Down
1 change: 1 addition & 0 deletions targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_IMX/objects.h
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Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@ struct analogin_s {

struct i2c_s {
uint32_t instance;
uint8_t address_set;
};

struct spi_s {
Expand Down