soft_i2c: Add CFG_I2C_INIT_BOARD option

This patch adds the option for a boardspecific
I2C deblocking mechanism for the soft i2c driver.

Signed-off-by: Heiko Schocher <hs@denx.de>

diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c
index 19c364b136e5c196f5f70d15885ab7b23cf98927..63e6a7b0d110e898c0a4dfbd6f5b0f0229209d89 100644 (file)
--- a/drivers/i2c/soft_i2c.c
+++ b/drivers/i2c/soft_i2c.c
@@ -75,13 +75,16 @@ static unsigned int i2c_bus_num __attribute__ ((section ("data"))) = 0;
 /*-----------------------------------------------------------------------
  * Local functions
  */
+#if !defined(CFG_I2C_INIT_BOARD)
 static void  send_reset        (void);
+#endif
 static void  send_start        (void);
 static void  send_stop (void);
 static void  send_ack  (int);
 static int   write_byte        (uchar byte);
 static uchar read_byte (int);
 
+#if !defined(CFG_I2C_INIT_BOARD)
 /*-----------------------------------------------------------------------
  * Send a reset sequence consisting of 9 clocks with the data signal high
  * to clock any confused device back into an idle state.  Also send a
@@ -109,6 +112,7 @@ static void send_reset(void)
        send_stop();
        I2C_TRISTATE;
 }
+#endif
 
 /*-----------------------------------------------------------------------
  * START: High -> Low on SDA while SCL is High
@@ -280,6 +284,12 @@ static uchar read_byte(int ack)
  */
 void i2c_init (int speed, int slaveaddr)
 {
+#if defined(CFG_I2C_INIT_BOARD)
+       /* call board specific i2c bus reset routine before accessing the   */
+       /* environment, which might be in a chip on that bus. For details   */
+       /* about this problem see doc/I2C_Edge_Conditions.                  */
+       i2c_init_board();
+#else
        /*
         * WARNING: Do NOT save speed in a static variable: if the
         * I2C routines are called before RAM is initialized (to read
@@ -287,6 +297,7 @@ void i2c_init (int speed, int slaveaddr)
         * system will crash.
         */
        send_reset ();
+#endif
 }
 
 /*-----------------------------------------------------------------------