STM32 I2C changes from Mike Smith

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5532 42af7a65-404d-4744-a932-0658087f49c3

nuttx/arch/arm/src/stm32/stm32_i2c.c

@@ -1245,11 +1245,11 @@ static int stm32_i2c_isr(struct stm32_i2c_priv_s *priv)
 
           /* Disable acknowledge when last byte is to be received */
 
+          priv->dcnt--;
           if (priv->dcnt == 1)
             {
               stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_ACK, 0);  
             }
-          priv->dcnt--;
 
 #ifdef CONFIG_I2C_POLLED
           irqrestore(state);
@@ -1985,7 +1985,6 @@ int up_i2creset(FAR struct i2c_dev_s * dev)
   unit32_ scl_gpio;
   unit32_ sda_gpio;
   int ret = ERROR;
-  irqstate_t state;
 
   ASSERT(dev);
 
@@ -2010,6 +2009,10 @@ int up_i2creset(FAR struct i2c_dev_s * dev)
   scl_gpio = MKI2C_OUTPUT(priv->config->scl_pin);
   sda_gpio = MKI2C_OUTPUT(priv->config->sda_pin);
 
+  /* Let SDA go high */
+
+  stm32_gpiowrite(sda_gpio, 1);
+
   /* Clock the bus until any slaves currently driving it let it go. */
 
   clock_count = 0;
@@ -2017,7 +2020,7 @@ int up_i2creset(FAR struct i2c_dev_s * dev)
     {
       /* Give up if we have tried too hard */
 
-      if (clock_count++ > 1000)
+      if (clock_count++ > 10)
         { 
           goto out;
         }
@@ -2032,7 +2035,7 @@ int up_i2creset(FAR struct i2c_dev_s * dev)
         { 
           /* Give up if we have tried too hard */
 
-          if (stretch_count++ > 1000)
+          if (stretch_count++ > 10)
             { 
               goto out;
             }