unsigned char i2c_transmit(com_state_t type) {
switch (type) {
case START:
status_reg = ADDR_MATCH;
i2c_interrupt();
break;
case DATA:
case DATA_NACK:
if (!dir_cpy) {
if (gc) {
status_reg = DATA_RXGC;
i2c_interrupt();
} else {
status_reg = DATA_RX;
i2c_interrupt();
}
} else {
status_reg = DATA_TX;
i2c_interrupt();
}
break;
case STOP:
status_reg = STOP_CATCHED;
i2c_interrupt();
return 0;
}
// TODO(NR) Timeout
return (0);
}
void intc_cpu_int_group_6(void)
{
/* Determine interrupt number. */
int intc_group_6 = intc_get_ec_int();
switch (intc_group_6) {
#ifdef CONFIG_I2C
case IT83XX_IRQ_SMB_A:
i2c_interrupt(IT83XX_I2C_CH_A);
break;
case IT83XX_IRQ_SMB_B:
i2c_interrupt(IT83XX_I2C_CH_B);
break;
case IT83XX_IRQ_SMB_C:
i2c_interrupt(IT83XX_I2C_CH_C);
break;
case IT83XX_IRQ_SMB_D:
i2c_interrupt(IT83XX_I2C_CH_D);
break;
case IT83XX_IRQ_SMB_E:
i2c_interrupt(IT83XX_I2C_CH_E);
break;
case IT83XX_IRQ_SMB_F:
i2c_interrupt(IT83XX_I2C_CH_F);
break;
#endif
default:
break;
}
}
void intc_cpu_int_group_6(void)
{
/* Determine interrupt number. */
int intc_group_6 = intc_get_ec_int();
switch (intc_group_6) {
case IT83XX_IRQ_SMB_A:
i2c_interrupt(0);
break;
case IT83XX_IRQ_SMB_B:
i2c_interrupt(1);
break;
case IT83XX_IRQ_SMB_C:
i2c_interrupt(2);
break;
default:
break;
}
}
void interrupt_func(void)
{
// I2C interrupt handler
i2c_interrupt();
if (INTCONbits.TMR0IF == 1) {
TMR0 = T0CNT;
INTCONbits.TMR0IF = 0;
gcounter++;
if (gcounter > 8000) {
gcounter = 0;
}
}
if (INTCONbits.RABIF == 1) {
unsigned short now = TMR3;
//TMR3 = 0;
//PIR2bits.TMR3IF = 0;
INTCONbits.RABIF = 0;
debug_counter++;
}
}
int chip_i2c_xfer(int port, int slave_addr, const uint8_t *out, int out_size,
uint8_t *in, int in_size, int flags)
{
int ctrl = i2c_port_to_controller(port);
volatile struct i2c_status *p_status = i2c_stsobjs + ctrl;
if (out_size == 0 && in_size == 0)
return EC_SUCCESS;
interrupt_disable();
/* make sure bus is not occupied by the other task */
if (p_status->task_waiting != TASK_ID_INVALID) {
interrupt_enable();
return EC_ERROR_BUSY;
}
/* Assign current task ID */
p_status->task_waiting = task_get_current();
interrupt_enable();
/* Select port for multi-ports i2c controller */
i2c_select_port(port);
/* Copy data to controller struct */
p_status->flags = flags;
p_status->tx_buf = out;
p_status->sz_txbuf = out_size;
p_status->rx_buf = in;
p_status->sz_rxbuf = in_size;
#if I2C_7BITS_ADDR
/* Set slave address from 7-bits to 8-bits */
p_status->slave_addr = (slave_addr<<1);
#else
/* Set slave address (8-bits) */
p_status->slave_addr = slave_addr;
#endif
/* Reset index & error */
p_status->idx_buf = 0;
p_status->err_code = SMB_OK;
/* Make sure we're in a good state to start */
if ((flags & I2C_XFER_START) && (i2c_bus_busy(ctrl)
|| (i2c_get_line_levels(port) != I2C_LINE_IDLE))) {
/* Attempt to unwedge the controller. */
i2c_unwedge(ctrl);
/* recovery i2c controller */
i2c_recovery(ctrl);
/* Select port again for recovery */
i2c_select_port(port);
}
CPUTS("\n");
/* Start master transaction */
i2c_master_transaction(ctrl);
/* Reset task ID */
p_status->task_waiting = TASK_ID_INVALID;
/* Disable SMB interrupt and New Address Match interrupt source */
i2c_interrupt(ctrl, 0);
CPRINTS("-Err:0x%02x\n", p_status->err_code);
return (p_status->err_code == SMB_OK) ? EC_SUCCESS : EC_ERROR_UNKNOWN;
}
inline void i2c_handle_sda_irq(int controller)
{
volatile struct i2c_status *p_status = i2c_stsobjs + controller;
/* 1 Issue Start is successful ie. write address byte */
if (p_status->oper_state == SMB_MASTER_START
|| p_status->oper_state == SMB_REPEAT_START) {
uint8_t addr = p_status->slave_addr;
/* Prepare address byte */
if (p_status->sz_txbuf == 0) {/* Receive mode */
p_status->oper_state = SMB_READ_OPER;
/*
* Receiving one byte only - set nack just
* before writing address byte
*/
if (p_status->sz_rxbuf == 1)
I2C_NACK(controller);
/* Write the address to the bus R bit*/
I2C_WRITE_BYTE(controller, (addr | 0x1));
CPRINTS("-ARR-0x%02x", addr);
} else {/* Transmit mode */
p_status->oper_state = SMB_WRITE_OPER;
/* Write the address to the bus W bit*/
I2C_WRITE_BYTE(controller, addr);
CPRINTS("-ARW-0x%02x", addr);
}
/* Completed handling START condition */
return;
}
/* 2 Handle master write operation */
else if (p_status->oper_state == SMB_WRITE_OPER) {
/* all bytes have been written, in a pure write operation */
if (p_status->idx_buf == p_status->sz_txbuf) {
/* no more message */
if (p_status->sz_rxbuf == 0) {
/* need to STOP or not */
if (p_status->flags & I2C_XFER_STOP) {
/* Issue a STOP condition on the bus */
I2C_STOP(controller);
CPUTS("-SP");
/* Clear SDAST by writing dummy byte */
I2C_WRITE_BYTE(controller, 0xFF);
}
/* Set error code */
p_status->err_code = SMB_OK;
/* Set SMB status if we need stall bus */
p_status->oper_state
= (p_status->flags & I2C_XFER_STOP)
? SMB_IDLE : SMB_WRITE_SUSPEND;
/*
* Disable interrupt for i2c master stall SCL
* and forbid SDAST generate interrupt
* until common layer start other transactions
*/
if (p_status->oper_state == SMB_WRITE_SUSPEND)
i2c_interrupt(controller, 0);
/* Notify upper layer */
task_set_event(p_status->task_waiting,
TASK_EVENT_I2C_IDLE, 0);
CPUTS("-END");
}
/* need to restart & send slave address immediately */
else {
uint8_t addr_byte = p_status->slave_addr;
/*
* Prepare address byte
* and start to receive bytes
*/
p_status->oper_state = SMB_READ_OPER;
/* Reset index of buffer */
p_status->idx_buf = 0;
/*
* Generate (Repeated) Start
* upon next write to SDA
*/
I2C_START(controller);
CPUTS("-RST");
/*
* Receiving one byte only - set nack just
* before writing address byte
*/
if (p_status->sz_rxbuf == 1) {
I2C_NACK(controller);
CPUTS("-GNA");
}
/* Write the address to the bus R bit*/
I2C_WRITE_BYTE(controller, (addr_byte | 0x1));
CPUTS("-ARR");
}
}
/* write next byte (not last byte and not slave address */
else {
I2C_WRITE_BYTE(controller,
p_status->tx_buf[p_status->idx_buf++]);
CPRINTS("-W(%02x)",
p_status->tx_buf[p_status->idx_buf-1]);
}
}
/* 3 Handle master read operation (read or after a write operation) */
else if (p_status->oper_state == SMB_READ_OPER) {
uint8_t data;
/* last byte is about to be read - end of transaction */
if (p_status->idx_buf == (p_status->sz_rxbuf - 1)) {
/* need to STOP or not */
if (p_status->flags & I2C_XFER_STOP) {
/* Stop should set before reading last byte */
I2C_STOP(controller);
CPUTS("-SP");
}
}
/* Check if byte-before-last is about to be read */
else if (p_status->idx_buf == (p_status->sz_rxbuf - 2)) {
/*
* Set nack before reading byte-before-last,
* so that nack will be generated after receive
* of last byte
*/
if (p_status->flags & I2C_XFER_STOP) {
I2C_NACK(controller);
CPUTS("-GNA");
}
}
/* Read last byte but flag don't include I2C_XFER_STOP */
if (p_status->idx_buf == p_status->sz_rxbuf-1) {
/*
* Disable interrupt before i2c master read SDA reg
* (stall SCL) and forbid SDAST generate interrupt
* until common layer start other transactions
*/
if (!(p_status->flags & I2C_XFER_STOP))
i2c_interrupt(controller, 0);
}
/* Read data for SMBSDA */
I2C_READ_BYTE(controller, data);
CPRINTS("-R(%02x)", data);
/* Read to buffer */
p_status->rx_buf[p_status->idx_buf++] = data;
/* last byte is read - end of transaction */
if (p_status->idx_buf == p_status->sz_rxbuf) {
/* Set current status */
p_status->oper_state = (p_status->flags & I2C_XFER_STOP)
? SMB_IDLE : SMB_READ_SUSPEND;
/* Set error code */
p_status->err_code = SMB_OK;
/* Notify upper layer of missing data */
task_set_event(p_status->task_waiting,
TASK_EVENT_I2C_IDLE, 0);
CPUTS("-END");
}
}
}
enum smb_error i2c_master_transaction(int controller)
{
/* Set i2c mode to object */
int events = 0;
volatile struct i2c_status *p_status = i2c_stsobjs + controller;
/* Assign current SMB status of controller */
if (p_status->oper_state == SMB_IDLE) {
/* New transaction */
p_status->oper_state = SMB_MASTER_START;
} else if (p_status->oper_state == SMB_WRITE_SUSPEND) {
if (p_status->sz_txbuf == 0) {
/* Read bytes from next transaction */
p_status->oper_state = SMB_REPEAT_START;
CPUTS("R");
} else {
/* Continue to write the other bytes */
p_status->oper_state = SMB_WRITE_OPER;
I2C_WRITE_BYTE(controller,
p_status->tx_buf[p_status->idx_buf++]);
CPRINTS("-W(%02x)",
p_status->tx_buf[p_status->idx_buf-1]);
}
} else if (p_status->oper_state == SMB_READ_SUSPEND) {
/* Need to read the other bytes from next transaction */
uint8_t data;
uint8_t timeout = 10; /* unit: us */
p_status->oper_state = SMB_READ_OPER;
/* wait for SDAST issue */
while (timeout > 0) {
if (IS_BIT_SET(NPCX_SMBST(controller),
NPCX_SMBST_SDAST))
break;
if (--timeout > 0)
usleep(10);
}
if (timeout == 0)
return EC_ERROR_TIMEOUT;
/*
* Read first byte from SMBSDA in case SDAST interrupt occurs
* immediately before task_wait_event_mask() func
*/
I2C_READ_BYTE(controller, data);
CPRINTS("-R(%02x)", data);
/* Read to buffer */
p_status->rx_buf[p_status->idx_buf++] = data;
}
/* Generate a START condition */
if (p_status->oper_state == SMB_MASTER_START ||
p_status->oper_state == SMB_REPEAT_START) {
I2C_START(controller);
CPUTS("ST");
}
/* Enable SMB interrupt and New Address Match interrupt source */
i2c_interrupt(controller, 1);
/* Wait for transfer complete or timeout */
events = task_wait_event_mask(TASK_EVENT_I2C_IDLE,
p_status->timeout_us);
/* Handle bus timeout */
if ((events & TASK_EVENT_I2C_IDLE) == 0) {
/* Recovery I2C controller */
i2c_recovery(controller);
p_status->err_code = SMB_TIMEOUT_ERROR;
}
/*
* In slave write operation, NACK is OK, otherwise it is a problem
*/
else if (p_status->err_code == SMB_BUS_ERROR ||
p_status->err_code == SMB_MASTER_NO_ADDRESS_MATCH){
i2c_recovery(controller);
}
/* Wait till STOP condition is generated */
if (p_status->err_code == SMB_OK && i2c_wait_stop_completed(controller,
I2C_MIN_TIMEOUT) != EC_SUCCESS) {
cprints(CC_I2C, "STOP fail! scl %02x is held by slave device!",
controller);
p_status->err_code = SMB_TIMEOUT_ERROR;
}
return p_status->err_code;
}
