From 3e3144ab84b14191e0b61848d4928765d6049137 Mon Sep 17 00:00:00 2001
From: Nidan <nidan@ghostdub.de>
Date: Fri, 10 Dec 2010 21:57:08 +0000
Subject: [PATCH] implemented i2c_read_write

---
 firmware/slavechip/i2c_simple.c | 12 +++++++++---
 firmware/slavechip/i2c_simple.h |  2 ++
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/firmware/slavechip/i2c_simple.c b/firmware/slavechip/i2c_simple.c
index 8c5772e..9b3f795 100644
--- a/firmware/slavechip/i2c_simple.c
+++ b/firmware/slavechip/i2c_simple.c
@@ -55,7 +55,7 @@ uint8_t i2c_read(uint8_t addr, uint8_t len, uint8_t *data)
 	return done;
 }
 
-uint8_t i2c_write(uint8_t addr, uint8_t len, uint8_t *data)
+uint8_t i2c_write_i(uint8_t addr, uint8_t len, uint8_t *data, uint8_t stop)
 {
 	TWCR &= ~TWSTO;
 	TWCR |= TWINT | TWSTA;
@@ -90,11 +90,17 @@ uint8_t i2c_write(uint8_t addr, uint8_t len, uint8_t *data)
 		done++;
 	}
 	
-	TWCR |= TWINT | TWSTO;
+	if(stop) {TWCR |= TWINT | TWSTO;}
 	return done;
 }
 
+inline uint8_t i2c_write(uint8_t addr, uint8_t len, uint8_t *data)
+{
+	return i2c_write(addr, len, data, 1);
+}
+
 uint8_t i2c_write_read(uint8_t addr, uint8_t writelen, uint8_t *writedata, uint8_t readlen, uint8_t *readdata)
 {
-	return 0; //TODO: implement
+	if(writelen == i2c_write_i(addr, writelen, writedata, 0)) {return i2c_read(addr, readlen, readdata);}
+	return 0;
 }
diff --git a/firmware/slavechip/i2c_simple.h b/firmware/slavechip/i2c_simple.h
index 2e76444..2f05186 100644
--- a/firmware/slavechip/i2c_simple.h
+++ b/firmware/slavechip/i2c_simple.h
@@ -5,9 +5,11 @@
 void i2c_init();
 
 /* reads len bytes from the i2c device addr into data */
+/* returns the number of bytes read */
 uint8_t i2c_read(uint8_t addr, uint8_t len, uint8_t *data);
 
 /* writes to an i2c device */
+/* returns the number of bytes written. if abitration was lost within a byte or it was followed by a NAK that byte is NOT counted */
 uint8_t i2c_write(uint8_t addr, uint8_t len, uint8_t *data);
 
 /* writes, followed by a repeated start and a read */