Implementing Write_ReadInto for Raspberry Pi (#19)

Adding an implementation for write_readinto to the Raspberry Pi's spi.py class.

diff --git a/src/adafruit_blinka/microcontroller/raspi_23/spi.py b/src/adafruit_blinka/microcontroller/raspi_23/spi.py
old mode 100644 (file)
new mode 100755 (executable)
index 7e3eec5..d862e01
--- a/src/adafruit_blinka/microcontroller/raspi_23/spi.py
+++ b/src/adafruit_blinka/microcontroller/raspi_23/spi.py
@@ -64,6 +64,28 @@ class SPI:
             for i in range(len(buf)):  # 'readinto' the given buffer
               buf[i] = data[i]
             self._spi.close()
+        except FileNotFoundError as not_found:
+            print("Could not open SPI device - check if SPI is enabled in kernel!")
+            raise
+
+    def write_readinto(self, buffer_out, buffer_in, out_start=0, out_end=None, in_start=0, in_end=None):
+        if not buffer_out or not buffer_in:
+            return
+        if out_end - out_start != in_end - in_start:
+            raise RuntimeError
+        try:
+            self._spi.open(self._port, 0)
+            try:
+                self._spi.no_cs = True  # this doesn't work but try anyways
+            except AttributeError:
+                pass
+            self._spi.max_speed_hz = self.baudrate
+            self._spi.mode = self.mode
+            self._spi.bits_per_word = self.bits
+            data = self._spi.xfer(list(buffer_out))
+            for i in range(len(buffer_in)): # 'readinto' the given buffer
+                buffer_in[i] = data[i]
+            self._spi.close()
         except FileNotFoundError as not_found:
             print("Could not open SPI device - check if SPI is enabled in kernel!")
             raise
\ No newline at end of file

diff --git a/src/busio.py b/src/busio.py
index 302eb882dc813c41da72cb3f3db7d8600cb104da..3523acd7289e172357725233f5a55439558f35a4 100755 (executable)
--- a/src/busio.py
+++ b/src/busio.py
@@ -112,8 +112,8 @@ class SPI(Lockable):
     def readinto(self, buf):
         return self._spi.readinto(buf)
 
-    def write_readinto(self, buffer_out, buffer_in):
-        return self._spi.write_readinto(buffer_out, buffer_in)
+    def write_readinto(self, buffer_out, buffer_in,  out_start=0, out_end=None, in_start=0, in_end=None):
+        return self._spi.write_readinto(buffer_out, buffer_in, out_start, out_end, in_start, in_end)
 
 
 class UART(Lockable):