Merge pull request #257 from facchinm/i2c_patch_unor4

UNOR4: rebuild libfsp with I2C patch

Author: facchinm

extras/fsp

@@ -405,6 +405,19 @@ void TwoWire::_begin(void) {
          init_ok = false;
       }
   }
+
+  if (init_ok) {
+    // inspired by https://community.element14.com/products/roadtest/b/blog/posts/using-i2c-spi-and-dma-on-renesas-ra2l1-part-1
+    // abort previous transactions
+    if (!is_sci) {
+      for (int i = 0; i < 20; i++) {
+        m_i2c_ctrl.p_reg->ICCR1_b.CLO = 1;
+        while (m_i2c_ctrl.p_reg->ICCR1_b.CLO) {
+        }
+      }
+    }
+    m_abort(&m_i2c_ctrl);
+  }
 }
 
 /* -------------------------------------------------------------------------- */
@@ -486,6 +499,10 @@ uint8_t TwoWire::read_from(uint8_t address, uint8_t* data, uint8_t length, unsig
   if(bus_status == WIRE_STATUS_RX_COMPLETED) {
     return length;
   }
+
+  if(bus_status == WIRE_STATUS_UNSET) {
+    m_abort(&m_i2c_ctrl);
+  }
 
   return 0; /* ???????? return value ??????? */
 }
@@ -518,6 +535,7 @@ uint8_t TwoWire::write_to(uint8_t address, uint8_t* data, uint8_t length, unsign
     }
     else if(bus_status == WIRE_STATUS_UNSET) {
       rv = END_TX_TIMEOUT;
+      m_abort(&m_i2c_ctrl);
     }
     /* as far as I know is impossible to distinguish between NACK on ADDRESS and
       NACK on DATA */