ft232h: Fix SPI.readinto's write_value= argument

Before, this argument was ignored.  This prevented adafruit_sdcard from
functioning, as it relies on being able to send out the value 0xff.

diff --git a/src/adafruit_blinka/microcontroller/ft232h/spi.py b/src/adafruit_blinka/microcontroller/ft232h/spi.py
index 81797b3557397d85ab7ccef30b2a576cc3c42f01..af164e97b92929ea86550af0f3b321092271acc8 100644 (file)
--- a/src/adafruit_blinka/microcontroller/ft232h/spi.py
+++ b/src/adafruit_blinka/microcontroller/ft232h/spi.py
@@ -67,7 +67,10 @@ class SPI:
     def readinto(self, buf, start=0, end=None, write_value=0):
         """Read data from SPI and into the buffer"""
         end = end if end else len(buf)
     def readinto(self, buf, start=0, end=None, write_value=0):
         """Read data from SPI and into the buffer"""
         end = end if end else len(buf)

-        result = self._port.read(end - start)
+        buffer_out = [write_value] * (end-start)
+        result = self._port.exchange(
+            buffer_out, end - start, duplex=True
+        )

         for i, b in enumerate(result):
             buf[start + i] = b
 
         for i, b in enumerate(result):
             buf[start + i] = b