/*
* This implements the state machine defined in the IPMI manual, see
* that for details on how this works. Divide that flowchart into
* sections delimited by "Wait for IBF" and this will become clear.
*/
static enum si_sm_result kcs_event(struct si_sm_data *kcs, long time)
{
unsigned char status;
unsigned char state;
status = read_status(kcs);
if (kcs_debug & KCS_DEBUG_STATES)
printk(KERN_DEBUG "KCS: State = %d, %x\n", kcs->state, status);
/* All states wait for ibf, so just do it here. */
if (!check_ibf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
/* Just about everything looks at the KCS state, so grab that, too. */
state = GET_STATUS_STATE(status);
switch (kcs->state) {
case KCS_IDLE:
/* If there's and interrupt source, turn it off. */
clear_obf(kcs, status);
if (GET_STATUS_ATN(status))
return SI_SM_ATTN;
else
return SI_SM_IDLE;
case KCS_START_OP:
if (state != KCS_IDLE_STATE) {
start_error_recovery(kcs,
"State machine not idle at start");
break;
}
clear_obf(kcs, status);
write_cmd(kcs, KCS_WRITE_START);
kcs->state = KCS_WAIT_WRITE_START;
break;
case KCS_WAIT_WRITE_START:
if (state != KCS_WRITE_STATE) {
start_error_recovery(
kcs,
"Not in write state at write start");
break;
}
read_data(kcs);
if (kcs->write_count == 1) {
write_cmd(kcs, KCS_WRITE_END);
kcs->state = KCS_WAIT_WRITE_END;
} else {
write_next_byte(kcs);
kcs->state = KCS_WAIT_WRITE;
}
break;
case KCS_WAIT_WRITE:
if (state != KCS_WRITE_STATE) {
start_error_recovery(kcs,
"Not in write state for write");
break;
}
clear_obf(kcs, status);
if (kcs->write_count == 1) {
write_cmd(kcs, KCS_WRITE_END);
kcs->state = KCS_WAIT_WRITE_END;
} else {
write_next_byte(kcs);
}
break;
case KCS_WAIT_WRITE_END:
if (state != KCS_WRITE_STATE) {
start_error_recovery(kcs,
"Not in write state"
" for write end");
break;
}
clear_obf(kcs, status);
write_next_byte(kcs);
kcs->state = KCS_WAIT_READ;
break;
case KCS_WAIT_READ:
if ((state != KCS_READ_STATE) && (state != KCS_IDLE_STATE)) {
start_error_recovery(
kcs,
"Not in read or idle in read state");
break;
}
if (state == KCS_READ_STATE) {
if (!check_obf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
read_next_byte(kcs);
} else {
/*
* We don't implement this exactly like the state
* machine in the spec. Some broken hardware
* does not write the final dummy byte to the
* read register. Thus obf will never go high
* here. We just go straight to idle, and we
* handle clearing out obf in idle state if it
* happens to come in.
*/
clear_obf(kcs, status);
kcs->orig_write_count = 0;
kcs->state = KCS_IDLE;
return SI_SM_TRANSACTION_COMPLETE;
}
break;
case KCS_ERROR0:
clear_obf(kcs, status);
status = read_status(kcs);
if (GET_STATUS_OBF(status))
/* controller isn't responding */
if (time_before(jiffies, kcs->error0_timeout))
return SI_SM_CALL_WITH_TICK_DELAY;
write_cmd(kcs, KCS_GET_STATUS_ABORT);
kcs->state = KCS_ERROR1;
break;
case KCS_ERROR1:
clear_obf(kcs, status);
write_data(kcs, 0);
kcs->state = KCS_ERROR2;
break;
case KCS_ERROR2:
if (state != KCS_READ_STATE) {
start_error_recovery(kcs,
"Not in read state for error2");
break;
}
if (!check_obf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
clear_obf(kcs, status);
write_data(kcs, KCS_READ_BYTE);
kcs->state = KCS_ERROR3;
break;
case KCS_ERROR3:
if (state != KCS_IDLE_STATE) {
start_error_recovery(kcs,
"Not in idle state for error3");
break;
}
if (!check_obf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
clear_obf(kcs, status);
if (kcs->orig_write_count) {
restart_kcs_transaction(kcs);
} else {
kcs->state = KCS_IDLE;
return SI_SM_TRANSACTION_COMPLETE;
}
break;
case KCS_HOSED:
break;
}
if (kcs->state == KCS_HOSED) {
init_kcs_data(kcs, kcs->io);
return SI_SM_HOSED;
}
return SI_SM_CALL_WITHOUT_DELAY;
}
static enum si_sm_result kcs_event(struct si_sm_data *kcs, long time)
{
unsigned char status;
unsigned char state;
status = read_status(kcs);
if (kcs_debug & KCS_DEBUG_STATES)
printk(KERN_DEBUG "KCS: State = %d, %x\n", kcs->state, status);
if (!check_ibf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
state = GET_STATUS_STATE(status);
switch (kcs->state) {
case KCS_IDLE:
clear_obf(kcs, status);
if (GET_STATUS_ATN(status))
return SI_SM_ATTN;
else
return SI_SM_IDLE;
case KCS_START_OP:
if (state != KCS_IDLE_STATE) {
start_error_recovery(kcs,
"State machine not idle at start");
break;
}
clear_obf(kcs, status);
write_cmd(kcs, KCS_WRITE_START);
kcs->state = KCS_WAIT_WRITE_START;
break;
case KCS_WAIT_WRITE_START:
if (state != KCS_WRITE_STATE) {
start_error_recovery(
kcs,
"Not in write state at write start");
break;
}
read_data(kcs);
if (kcs->write_count == 1) {
write_cmd(kcs, KCS_WRITE_END);
kcs->state = KCS_WAIT_WRITE_END;
} else {
write_next_byte(kcs);
kcs->state = KCS_WAIT_WRITE;
}
break;
case KCS_WAIT_WRITE:
if (state != KCS_WRITE_STATE) {
start_error_recovery(kcs,
"Not in write state for write");
break;
}
clear_obf(kcs, status);
if (kcs->write_count == 1) {
write_cmd(kcs, KCS_WRITE_END);
kcs->state = KCS_WAIT_WRITE_END;
} else {
write_next_byte(kcs);
}
break;
case KCS_WAIT_WRITE_END:
if (state != KCS_WRITE_STATE) {
start_error_recovery(kcs,
"Not in write state"
" for write end");
break;
}
clear_obf(kcs, status);
write_next_byte(kcs);
kcs->state = KCS_WAIT_READ;
break;
case KCS_WAIT_READ:
if ((state != KCS_READ_STATE) && (state != KCS_IDLE_STATE)) {
start_error_recovery(
kcs,
"Not in read or idle in read state");
break;
}
if (state == KCS_READ_STATE) {
if (!check_obf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
read_next_byte(kcs);
} else {
clear_obf(kcs, status);
kcs->orig_write_count = 0;
kcs->state = KCS_IDLE;
return SI_SM_TRANSACTION_COMPLETE;
}
break;
case KCS_ERROR0:
clear_obf(kcs, status);
status = read_status(kcs);
if (GET_STATUS_OBF(status))
if (time_before(jiffies, kcs->error0_timeout))
return SI_SM_CALL_WITH_TICK_DELAY;
write_cmd(kcs, KCS_GET_STATUS_ABORT);
kcs->state = KCS_ERROR1;
break;
case KCS_ERROR1:
clear_obf(kcs, status);
write_data(kcs, 0);
kcs->state = KCS_ERROR2;
break;
case KCS_ERROR2:
if (state != KCS_READ_STATE) {
start_error_recovery(kcs,
"Not in read state for error2");
break;
}
if (!check_obf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
clear_obf(kcs, status);
write_data(kcs, KCS_READ_BYTE);
kcs->state = KCS_ERROR3;
break;
case KCS_ERROR3:
if (state != KCS_IDLE_STATE) {
start_error_recovery(kcs,
"Not in idle state for error3");
break;
}
if (!check_obf(kcs, status, time))
return SI_SM_CALL_WITH_DELAY;
clear_obf(kcs, status);
if (kcs->orig_write_count) {
restart_kcs_transaction(kcs);
} else {
kcs->state = KCS_IDLE;
return SI_SM_TRANSACTION_COMPLETE;
}
break;
case KCS_HOSED:
break;
}
if (kcs->state == KCS_HOSED) {
init_kcs_data(kcs, kcs->io);
return SI_SM_HOSED;
}
return SI_SM_CALL_WITHOUT_DELAY;
}