esp32: port support for I2C_M_NOSTART and I2C_M_NOSTOP

Signed-off-by: Robert-Ionut Alexa <[email protected]>

Author: robertalexa2000

arch/xtensa/src/esp32/esp32_i2c.c

@@ -895,16 +895,39 @@ static int esp32_i2c_transfer(struct i2c_master_s *dev,
 
       esp32_i2c_init_clock(priv, msgs[i].frequency);
 
-      /* Reset I2C trace logic */
+      if ((msgs[i].flags & I2C_M_NOSTART) != 0)
+        {
+          esp32_i2c_traceevent(priv, I2CEVENT_SENDBYTE, priv->bytes,
+                               esp32_i2c_get_reg(priv, I2C_SR_OFFSET));
+          esp32_i2c_senddata(priv);
+
+          if (priv->bytes == msgs[i].length)
+            {
+              if ((msgs[i].flags & I2C_M_NOSTOP) == 0)
+                {
+                  priv->i2cstate = I2CSTATE_STOP;
+                }
+#ifndef CONFIG_I2C_POLLED
+              else
+                {
+                  priv->i2cstate = I2CSTATE_FINISH;
+                }
+#endif
+            }
+        }
+      else
+        {
+          /* Reset I2C trace logic */
 
-      esp32_i2c_tracereset(priv);
+          esp32_i2c_tracereset(priv);
 
-      esp32_i2c_traceevent(priv, I2CEVENT_SENDADDR, msgs[i].addr,
-                           esp32_i2c_get_reg(priv, I2C_SR_OFFSET));
+          esp32_i2c_traceevent(priv, I2CEVENT_SENDADDR, msgs[i].addr,
+                               esp32_i2c_get_reg(priv, I2C_SR_OFFSET));
 
-      /* Send the start cmd */
+          /* Send the start cmd */
 
-      esp32_i2c_sendstart(priv);
+          esp32_i2c_sendstart(priv);
+        }
 
 #ifndef CONFIG_I2C_POLLED
       if (esp32_i2c_sem_waitdone(priv) < 0)
@@ -1391,7 +1414,16 @@ static inline void esp32_i2c_process(struct esp32_i2c_priv_s *priv,
 
               if (priv->bytes == msg->length)
                 {
-                  priv->i2cstate = I2CSTATE_STOP;
+                  if ((msg->flags & I2C_M_NOSTOP) == 0)
+                    {
+                      priv->i2cstate = I2CSTATE_STOP;
+                    }
+#ifndef CONFIG_I2C_POLLED
+                  else
+                    {
+                      priv->i2cstate = I2CSTATE_FINISH;
+                    }
+#endif
                 }
             }
         }