From: Erik Andresen <erik@vontaene.de>
Date: Tue, 27 Dec 2016 15:27:45 +0000 (+0100)
Subject: updated i2c.py
X-Git-Url: https://defiant.homedns.org/gitweb/?a=commitdiff_plain;h=44c7f3645d8839dbc49a54bf1481dd2f75199a7a;p=pyshared.git

updated i2c.py
---

diff --git a/i2c.py b/i2c.py
index 2e9a109..2bb9f94 100755
--- a/i2c.py
+++ b/i2c.py
@@ -5,10 +5,13 @@ import threading
 import inspect
 import os
 import logging
+import struct
+import fcntl
 from ctypes import *
 from time import sleep
 
 DEBUG=0
+I2C_FILENAME = "/dev/i2c-2"
 logger = logging.getLogger(__name__)
 
 class i2c:
@@ -31,9 +34,10 @@ 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("/dev/i2c-2", os.O_RDWR)
+		self.dev = i2c.libc.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")
@@ -62,6 +66,23 @@ class i2c:
 	def __del__(self):
 		self.close()
 
+
+def i2c_write_reg(addr, reg, buf):
+	dev = i2c(addr)
+	s = struct.pack(">B", reg) + buf
+	dev.write(s)
+	dev.close()
+
+
+def i2c_read_reg(addr, reg, num=1):
+	dev = i2c(addr)
+	s = struct.pack(">B", reg)
+	dev.write(s)
+	s = dev.read(num)
+	dev.close()
+	return s
+
+
 if __name__ == "__main__":
 	import struct
 	import sys