49 lines
1.0 KiB
C
49 lines
1.0 KiB
C
#include <stdio.h>
|
|
|
|
#include <ec/smbus.h>
|
|
|
|
void i2c_write(unsigned char value) {
|
|
for (;;) {
|
|
// Wait for last command
|
|
while (HOSTAA & 1) {}
|
|
|
|
// Clear result
|
|
HOSTAA = HOSTAA;
|
|
|
|
// Clock down to 50 KHz
|
|
SCLKTSA = 1;
|
|
|
|
// Enable host interface with i2c compatibility
|
|
HOCTL2A = (1 << 1) | (1 << 0);
|
|
|
|
// Write value to 0x76
|
|
TRASLAA = (0x76 << 1) | (0 << 1);
|
|
HOCMDA = value;
|
|
|
|
// Start command
|
|
HOCTLA = (1 << 6) | (0b001 << 2);
|
|
|
|
// Wait for command to start
|
|
while (!(HOSTAA & 1)) {}
|
|
|
|
// Wait for command to finish
|
|
while (HOSTAA & 1) {}
|
|
|
|
// Read and clear status
|
|
uint8_t status = HOSTAA;
|
|
HOSTAA = status;
|
|
|
|
// If there were no errors, return
|
|
uint8_t error = (1 << 6) | (1 << 5) | (1 << 4) | (1 << 3) | (1 << 2);
|
|
if (!(status & error)) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
int putchar(int c) {
|
|
unsigned char byte = (unsigned char)c;
|
|
i2c_write(byte);
|
|
return (int)byte;
|
|
}
|