renamed spi/i2c to generic linux since they're not platform specific

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

diff --git a/src/adafruit_blinka/microcontroller/generic_linux/spi.py b/src/adafruit_blinka/microcontroller/generic_linux/spi.py
new file mode 100755 (executable)
index 0000000..b905873
--- /dev/null
+++ b/src/adafruit_blinka/microcontroller/generic_linux/spi.py
@@ -0,0 +1,100 @@
+import spidev
+import time
+
+class SPI:
+    MSB = 0
+    LSB = 1
+    CPHA = 1
+    CPOL = 2
+
+    baudrate = 100000
+    mode = 0
+    bits = 8
+
+    def __init__(self, portid):
+        self._port = portid
+        self._spi = spidev.SpiDev()
+
+    def init(self, baudrate=100000, polarity=0, phase=0, bits=8,
+                  firstbit=MSB, sck=None, mosi=None, miso=None):
+        mode = 0
+        if polarity:
+            mode |= self.CPOL
+        if phase:
+            mode |= self.CPHA
+
+        self.clock_pin = sck
+        self.mosi_pin = mosi
+        self.miso_pin = miso
+        self.baudrate = baudrate
+        self.mode = mode
+        self.bits = bits
+
+    def write(self, buf, start=0, end=None):
+        if not buf:
+            return
+        if end is None:
+            end = len(buf)
+        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
+            self._spi.writebytes([x for x in buf[start:end]])
+            self._spi.close()
+        except FileNotFoundError as not_found:
+            print("Could not open SPI device - check if SPI is enabled in kernel!")
+            raise
+
+    def readinto(self, buf, start=0, end=None):
+        if not buf:
+            return
+        if end is None:
+            end = len(buf)
+        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(end-start)
+            for i in range(end-start):  # 'readinto' the given buffer
+              buf[start+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 is None:
+            out_end = len(buffer_out)        
+        if in_end is None:
+            in_end = len(buffer_in)
+        if out_end - out_start != in_end - in_start:
+            raise RuntimeError('Buffer slices must be of equal length.')
+        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[out_start:out_end+1]))
+            for i in range((in_end - in_start)):
+                buffer_in[i+in_start] = data[i]
+            self._spi.close()
+        except FileNotFoundError as not_found:
+            print("Could not open SPI device - check if SPI is enabled in kernel!")
+            raise