i2c: use python low level api instead ob c calls

diff --git a/i2c.py b/i2c.py
index 2bb9f94026849106394d92e9f3210d7feff14de6..60d825dd2a7ad31a5d3e744a55227e05a0128254 100755 (executable)
--- a/i2c.py
+++ b/i2c.py
@@ -7,7 +7,6 @@ import os
 import logging
 import struct
 import fcntl
-from ctypes import *
 from time import sleep
 
 DEBUG=0
@@ -15,7 +14,6 @@ I2C_FILENAME = "/dev/i2c-2"
 logger = logging.getLogger(__name__)
 
 class i2c:
-       libc = CDLL("libc.so.6")
        I2C_SLAVE = 0x0703  # Use this slave address
        __single = None
        __lock = threading.Lock()
@@ -34,33 +32,29 @@ class i2c:
                                        logger.warning("Error: (%s) I2C blocked %fs by %s!", parent, count*0.001, parent_owner)
                                i2c.__parent_owner = inspect.stack()[1]
                        i2c.__single = True
-               self.dev = i2c.libc.open(I2C_FILENAME, os.O_RDWR)
+               self.dev = os.open(I2C_FILENAME, os.O_RDWR)
                if self.dev < 0:
                        raise IOError("open")
                fcntl.flock(self.dev, fcntl.LOCK_EX)
-               err = i2c.libc.ioctl(self.dev, i2c.I2C_SLAVE, addr>>1)
-               if err < 0:
-                       raise IOError("ioctl")
+               fcntl.ioctl(self.dev, i2c.I2C_SLAVE, addr>>1)
 
        def write(self, s):
-               num_write = i2c.libc.write(self.dev, s, len(s))
+               num_write = os.write(self.dev, s)
                if num_write != len(s):
                        self.close()
                        raise IOError("write: %d" % (num_write))
        
        def read(self, num):
-               buf = create_string_buffer(num)
-               num_read = i2c.libc.read(self.dev, buf, num)
-               if num_read != num:
+               buf = os.read(self.dev, num)
+               if len(buf) != num:
                        self.close()
-                       raise IOError("read: %d" % (num_read))
-               return buf.raw
+                       raise IOError("read: %d" % (len(buf)))
+               return buf
 
        def close(self):
                if self.dev:
-                       i2c.libc.close(self.dev)
+                       os.close(self.dev)
                        self.dev = None
-                       #i2c.__parent_owner = None
                        i2c.__single = None
 
        def __del__(self):
@@ -84,7 +78,6 @@ def i2c_read_reg(addr, reg, num=1):
 
 
 if __name__ == "__main__":
-       import struct
        import sys
 
        dev = i2c(0x50)