From d51930558a73dd1083b924159971d4c77df411e6 Mon Sep 17 00:00:00 2001
From: Michael Gernoth <michael@gernoth.net>
Date: Sun, 22 Aug 2010 21:42:37 +0200
Subject: [PATCH] I2C master mode implemented and more decoding

---
 bmc/Makefile |  2 +-
 bmc/bmc.c    | 36 ---------------------------------
 bmc/bmc.h    |  1 -
 bmc/i2c.c    | 45 +++++++++++++++++++++++++++++++++++++++--
 bmc/i2c.h    |  1 +
 bmc/ipmb.c   | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 bmc/ipmb.h   | 13 ++++++++++++
 7 files changed, 114 insertions(+), 40 deletions(-)
 create mode 100644 bmc/ipmb.c
 create mode 100644 bmc/ipmb.h

diff --git a/bmc/Makefile b/bmc/Makefile
index 6f8b4dd..d9ad589 100644
--- a/bmc/Makefile
+++ b/bmc/Makefile
@@ -11,7 +11,7 @@ OBJCOPY=avr-objcopy
 
 all: bmc.bin
 
-bmc: bmc.o usart.o i2c.o
+bmc: bmc.o usart.o i2c.o ipmb.o
 
 bmc.bin: bmc
 	$(OBJCOPY) -j .text -j .data -O binary $^ $@
diff --git a/bmc/bmc.c b/bmc/bmc.c
index 4db28a6..525785e 100644
--- a/bmc/bmc.c
+++ b/bmc/bmc.c
@@ -6,42 +6,6 @@
 #include "i2c.h"
 #include "bmc.h"
 
-uint8_t ipmb_csum(unsigned char *buf, int len)
-{
-	uint8_t csum = 0x00;
-	int i;
-
-	for(i = 0; i < len; i++) {
-		csum += buf[i];
-	}
-
-	return -csum;
-}
-
-void decode_bmc_cmd(unsigned char *buf, int len)
-{
-	int i;
-
-	printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
-	printf("Connection Header:\n");
-	printf("\trs Slave Addr.: 0x%02x\n", buf[0]);
-	printf("\tnetFn: 0x%02x, LUN: 0x%02x\n", (buf[1]>>2)&0x3f, (buf[1] & 0x03));
-	printf("\tChecksum: 0x%02x (%s)\n", buf[2],
-		(buf[2] == ipmb_csum(buf, 2)) ? "OK" : "Wrong");
-	printf("Data:\n");
-	printf("\trq Slave Addr.: 0x%02x\n", buf[3]);
-	printf("\trqSeq: 0x%02x, rqLUN: 0x%02x\n", (buf[4]>>2)&0x3f, (buf[4] & 0x03));
-	printf("\tcmd: 0x%02x\n", buf[5]);
-	printf("\tData: ");
-	for(i = 6; i < (len - 1); i++) {
-		printf("0x%02x ", buf[i]);
-	}
-	printf("\n");
-	printf("\tChecksum: 0x%02x (%s)\n", buf[len-1],
-		(buf[len-1] == ipmb_csum(buf+3, len-4)) ? "OK" : "Wrong");
-	printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
-}
-
 int main(void)
 {
 	DDRB = 0xff;
diff --git a/bmc/bmc.h b/bmc/bmc.h
index 99d5810..e69de29 100644
--- a/bmc/bmc.h
+++ b/bmc/bmc.h
@@ -1 +0,0 @@
-void decode_bmc_cmd(unsigned char *buf, int len);
diff --git a/bmc/i2c.c b/bmc/i2c.c
index 4ada02e..6550c92 100644
--- a/bmc/i2c.c
+++ b/bmc/i2c.c
@@ -2,7 +2,7 @@
 #include <avr/interrupt.h>
 #include <stdio.h>
 #include "i2c.h"
-#include "bmc.h"
+#include "ipmb.h"
 
 #define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC);  
 #define TWCR_NACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC);
@@ -21,6 +21,47 @@ void i2c_init()
 	PORTC = 0x03;
 }
 
+void i2c_send(unsigned char *buf, int len)
+{
+	uint8_t old_TWCR = TWCR;
+	uint8_t old_SREG = SREG;
+	int i;
+
+	cli();
+
+	TWCR = ((1<<TWINT) | (1<<TWSTA) | (1<<TWEN)); /* Send start */
+
+	while(!(TWCR & (1<<TWINT))) {}
+	if ((TW_STATUS & 0xf8) != TW_START)
+		goto out;
+
+	TWDR = buf[0]; /* SLA_W */
+	TWCR = ((1<<TWINT) | (1<<TWEN));
+
+	while(!(TWCR & (1<<TWINT))) {}
+	if ((TW_STATUS & 0xf8) != TW_MT_SLA_ACK)
+		goto out;
+	
+	for(i = 1; i < len; i++) {
+		TWDR = buf[i]; /* Send Data */
+		TWCR = ((1<<TWINT) | (1<<TWEN));
+
+		while(!(TWCR & (1<<TWINT))) {}
+		if ((TW_STATUS & 0xf8) != TW_MT_DATA_ACK)
+			goto out;
+	}
+
+	TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO));
+
+	printf("I2C Data sent 0x%02x\n", TW_STATUS);
+
+
+out:	
+	TWDR = 0x00;
+	TWCR = old_TWCR;
+	SREG = old_SREG;
+}
+
 ISR (TWI_vect, ISR_BLOCK)
 {
 	switch (TW_STATUS) {
@@ -47,7 +88,7 @@ ISR (TWI_vect, ISR_BLOCK)
 #ifdef DEBUG
 			printf("I2C: STOP received\n");
 #endif
-			decode_bmc_cmd((unsigned char*)databuf, pos);
+			decode_ipmb_pkt((unsigned char*)databuf, pos);
 			pos = 0x00;
 			TWCR_RESET;
 			break;
diff --git a/bmc/i2c.h b/bmc/i2c.h
index d666669..c53ff03 100644
--- a/bmc/i2c.h
+++ b/bmc/i2c.h
@@ -1,3 +1,4 @@
 #define BMC_ADDR 0x24
 
 void i2c_init();
+void i2c_send(unsigned char *buf, int len);
diff --git a/bmc/ipmb.c b/bmc/ipmb.c
new file mode 100644
index 0000000..7d272fb
--- /dev/null
+++ b/bmc/ipmb.c
@@ -0,0 +1,56 @@
+#include <stdio.h>
+
+#include "ipmb.h"
+
+uint8_t ipmb_csum(unsigned char *buf, int len)
+{
+	uint8_t csum = 0x00;
+	int i;
+
+	for(i = 0; i < len; i++) {
+		csum += buf[i];
+	}
+
+	return -csum;
+}
+
+void decode_ipmb_pkt(unsigned char *buf, int len)
+{
+	int i;
+	struct ipmb_req req;
+
+	req.rsSA = buf[0];
+	req.netFn = (buf[1]>>2)&0x3f;
+	req.rsLUN = (buf[1] & 0x03);
+	req.rqSA = buf[3];
+	req.rqSEQ = (buf[4]>>2)&0x3f;
+	req.rqLUN = (buf[4] & 0x03);
+	req.cmd = buf[5];
+	req.data = buf+6;
+	req.datalen = len - 6 - 1;
+
+	printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+	printf("Connection Header:\n");
+	printf("\trs Slave Addr.: 0x%02x\n", req.rsSA);
+	printf("\tnetFn: 0x%02x, LUN: 0x%02x\n", req.netFn, req.rsLUN);
+	printf("\tChecksum: 0x%02x (%s)\n", buf[2],
+		(buf[2] == ipmb_csum(buf, 2)) ? "OK" : "Wrong");
+	printf("Data:\n");
+	printf("\trq Slave Addr.: 0x%02x\n", req.rqSA);
+	printf("\trqSeq: 0x%02x, rqLUN: 0x%02x\n", req.rqSEQ, req.rqLUN);
+	printf("\tcmd: 0x%02x\n", req.cmd);
+	printf("\tData: ");
+	for(i = 0; i < req.datalen; i++) {
+		printf("0x%02x ", req.data[i]);
+	}
+	printf("\n");
+	printf("\tChecksum: 0x%02x (%s)\n", buf[len-1],
+		(buf[len-1] == ipmb_csum(buf+3, len-4)) ? "OK" : "Wrong");
+	printf("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+
+	if ((buf[2] != ipmb_csum(buf, 2)) ||
+	    (buf[len-1] == ipmb_csum(buf+3, len-4)))
+		return; /* Checksum wrong */
+
+	//i2c_send((unsigned char*)"\x28\x00",1);
+}
diff --git a/bmc/ipmb.h b/bmc/ipmb.h
new file mode 100644
index 0000000..c48ad31
--- /dev/null
+++ b/bmc/ipmb.h
@@ -0,0 +1,13 @@
+struct ipmb_req {
+	uint8_t rsSA;
+	uint8_t netFn;
+	uint8_t rsLUN;
+	uint8_t rqSA;
+	uint8_t rqSEQ;
+	uint8_t rqLUN;
+	uint8_t cmd;
+	unsigned char *data;
+	uint8_t datalen;
+};
+
+void decode_ipmb_pkt(unsigned char *buf, int len);
-- 
2.39.5