/* Function Description: Send the address for a read access.
* Return : 0 if not acknowledged, otherwise acknowledged.
*/
static int envctrl_i2c_read_addr(unsigned char addr)
{
envctrl_i2c_test_bb();
/* Load address. */
envctrl_writeb(addr + 1, &i2c->data);
envctrl_i2c_test_bb();
envctrl_writeb(OBD_SEND_START, &i2c->csr);
/* Wait for PIN. */
envtrl_i2c_test_pin();
/* CSR 0 means acknowledged. */
if (!(envctrl_readb(&i2c->csr) & STATUS_LRB)) {
return envctrl_readb(&i2c->data);
} else {
envctrl_writeb(OBD_SEND_STOP, &i2c->csr);
return 0;
}
}
/* Function Description: Send the address for a read access.
* Return : 0 if not acknowledged, otherwise acknowledged.
*/
static int envctrl_i2c_read_addr(unsigned char addr)
{
envctrl_i2c_test_bb();
/* Load address. */
writeb(addr + 1, i2c + PCF8584_DATA);
envctrl_i2c_test_bb();
writeb(OBD_SEND_START, i2c + PCF8584_CSR);
/* Wait for PIN. */
envtrl_i2c_test_pin();
/* CSR 0 means acknowledged. */
if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
return readb(i2c + PCF8584_DATA);
} else {
writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
return 0;
}
}
/* Function Description: Generate Stop condition after last byte is sent.
* Return : None.
*/
static void envctrl_i2c_stop(void)
{
envtrl_i2c_test_pin();
envctrl_writeb(OBD_SEND_STOP, &i2c->csr);
}
/* Function Description: Instruct the device which port to read data from.
* Return : None.
*/
static void envctrl_i2c_write_data(unsigned char port)
{
envtrl_i2c_test_pin();
envctrl_writeb(port, &i2c->data);
}
/* Function Description: Read 1 byte of data from addr
* set by envctrl_i2c_read_addr()
* Return : Data from address set by envctrl_i2c_read_addr().
*/
static unsigned char envctrl_i2c_read_data(void)
{
envtrl_i2c_test_pin();
envctrl_writeb(CONTROL_ES0, &i2c->csr); /* Send neg ack. */
return envctrl_readb(&i2c->data);
}
/* Function Description: Generate Stop condition after last byte is sent.
* Return : None.
*/
static void envctrl_i2c_stop(void)
{
envtrl_i2c_test_pin();
writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
}
/* Function Description: Instruct the device which port to read data from.
* Return : None.
*/
static void envctrl_i2c_write_data(unsigned char port)
{
envtrl_i2c_test_pin();
writeb(port, i2c + PCF8584_DATA);
}
/* Function Description: Read 1 byte of data from addr
* set by envctrl_i2c_read_addr()
* Return : Data from address set by envctrl_i2c_read_addr().
*/
static unsigned char envctrl_i2c_read_data(void)
{
envtrl_i2c_test_pin();
writeb(CONTROL_ES0, i2c + PCF8584_CSR); /* Send neg ack. */
return readb(i2c + PCF8584_DATA);
}
