From df4c0014f65705c19d5dcc8d8cd649e7f141a2c4 Mon Sep 17 00:00:00 2001
From: Chris <herrmann1001@gmail.com>
Date: Sun, 8 Jul 2018 13:52:30 +0200
Subject: [PATCH] chg: i2c fixes

---
 client/cmdsmartcard.c |  2 ++
 common/i2c.c          | 37 ++++++++++++++++++++-----------------
 2 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/client/cmdsmartcard.c b/client/cmdsmartcard.c
index 207a8e951..37b85741d 100644
--- a/client/cmdsmartcard.c
+++ b/client/cmdsmartcard.c
@@ -89,6 +89,8 @@ int CmdSmartRaw(const char *Cmd) {
 	//Validations
 	if (errors || cmdp == 0 ) return usage_sm_raw();			
 
+	// arg0 = RFU flags
+	// arg1 = length
 	UsbCommand c = {CMD_SMART_RAW, {0, hexlen, 0}};	
 	memcpy(c.d.asBytes, data, hexlen );
 	clearCommandBuffer();
diff --git a/common/i2c.c b/common/i2c.c
index 128dca7ee..b2d90bd59 100644
--- a/common/i2c.c
+++ b/common/i2c.c
@@ -356,6 +356,9 @@ bool I2C_BufferWrite(uint8_t *data, uint8_t len, uint8_t device_cmd, uint8_t dev
 // len = uint8 (max buffer to read 256bytes)
 uint8_t I2C_BufferRead(uint8_t *data, uint8_t len, uint8_t device_cmd, uint8_t device_address) {
 
+	if ( !data || len == 0 )
+		return 0;
+
 	// extra wait  500us (514us measured)
 	// 200us  (xx measured)
 	SpinDelayUs(200);	
@@ -406,7 +409,7 @@ uint8_t I2C_BufferRead(uint8_t *data, uint8_t len, uint8_t device_cmd, uint8_t d
 			data++;			
 		}
 		readcount++;
-
+		
 		// acknowledgements. After last byte send NACK.
 		if (len == 0)
 			I2C_NoAck();
@@ -415,7 +418,8 @@ uint8_t I2C_BufferRead(uint8_t *data, uint8_t len, uint8_t device_cmd, uint8_t d
 	}
 	
 	I2C_Stop();
-	return readcount;
+	// return bytecount - first byte (which is length byte)
+	return (readcount) ? readcount-- : 0;
 }
 
 uint8_t I2C_ReadFW(uint8_t *data, uint8_t len, uint8_t msb, uint8_t lsb, uint8_t device_address) {
@@ -522,12 +526,12 @@ bool I2C_WriteFW(uint8_t *data, uint8_t len, uint8_t msb, uint8_t lsb, uint8_t d
 }
 
 void I2C_print_status(void) {
+
+	DbpString("Smart card module (ISO 7816)");
+	uint8_t resp[] = {0,0,0};
 	I2C_init();
 	I2C_Reset_EnterMainProgram();
-	uint8_t resp[4] = {0};
-	uint8_t len = I2C_BufferRead(resp, 4, I2C_DEVICE_CMD_GETVERSION, I2C_DEVICE_ADDRESS_MAIN);
-	DbpString("Smart card module (ISO 7816)");
-	if ( len )
+	if ( I2C_BufferRead(resp, sizeof(resp), I2C_DEVICE_CMD_GETVERSION, I2C_DEVICE_ADDRESS_MAIN) )
 		Dbprintf("  FW version................v%x.%02x", resp[0], resp[1]);
 	else
 		DbpString("  FW version................FAILED");
@@ -535,6 +539,7 @@ void I2C_print_status(void) {
 
 bool GetATR(smart_card_atr_t *card_ptr) {
 	
+	// clear 
 	if ( card_ptr ) {
 		card_ptr->atr_len = 0;
 		memset(card_ptr->atr, 0, sizeof(card_ptr->atr));
@@ -551,14 +556,13 @@ bool GetATR(smart_card_atr_t *card_ptr) {
 	// read answer
 	uint8_t len = I2C_BufferRead(card_ptr->atr, sizeof(card_ptr->atr), I2C_DEVICE_CMD_READ, I2C_DEVICE_ADDRESS_MAIN);
 	
-	if ( len == 0)
+	if ( len == 0 )
 		return false;
-	
-	// remove length byte from the read bytes.
-	if ( card_ptr )
-		card_ptr->atr_len = (len == 0) ? 0 : len--;
-	
-	LogTrace(card_ptr->atr, card_ptr->atr_len, 0, 0, NULL, false);
+
+	if ( card_ptr ) {
+		card_ptr->atr_len = len;
+		LogTrace(card_ptr->atr, card_ptr->atr_len, 0, 0, NULL, false);
+	}
 	return true;
 }
 
@@ -607,12 +611,11 @@ void SmartCardRaw( uint64_t arg0, uint64_t arg1, uint8_t *data ) {
 	// read response
 	// start [C0 03 start C1 len aa bb cc stop]
 	len = I2C_BufferRead(resp, ISO7618_MAX_FRAME, I2C_DEVICE_CMD_READ, I2C_DEVICE_ADDRESS_MAIN);
-
-	// remove length byte from the read bytes.
-	if ( len > 0 ) len--;
 	
 	// log answer
-	LogTrace(resp, len, 0, 0, NULL, false);
+	if ( len )	
+		LogTrace(resp, len, 0, 0, NULL, false);
+	
 out:	
 	cmd_send(CMD_ACK, isOK, len, 0, resp, len);
 	LED_D_OFF();