Implementing Write_ReadInto for Raspberry Pi (#19)

[hackapet/Adafruit_Blinka.git] / src / adafruit_blinka / microcontroller / raspi_23 / spi.py

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 d6627c6..d862e01
--- a/src/adafruit_blinka/microcontroller/raspi_23/spi.py
+++ b/src/adafruit_blinka/microcontroller/raspi_23/spi.py
@@ -34,9 +34,11 @@ class SPI:
         if not buf:
             return
         try:
-
             self._spi.open(self._port, 0)
-            self._spi.no_cs = True
+            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
@@ -45,3 +47,45 @@ class SPI:
         except FileNotFoundError as not_found:
             print("Could not open SPI device - check if SPI is enabled in kernel!")
             raise
+
+    def readinto(self, buf):
+        if not buf:
+            return
+        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.readbytes(len(buf))
+            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
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