Added functions for exclusive I2C access

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1144 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 12 insertions, 0 deletions

diff --git a/firmware/drivers/i2c.c b/firmware/drivers/i2c.c
index 5aa822e83b..ccd11e01de 100644
--- a/firmware/drivers/i2c.c
+++ b/firmware/drivers/i2c.c
@@ -41,6 +41,18 @@
 /* arbitrary delay loop */
 #define DELAY   do { int _x; for(_x=0;_x<20;_x++);} while (0)
 
+static struct mutex i2c_mtx;
+
+void i2c_begin(void)
+{
+    mutex_lock(&i2c_mtx);
+}
+
+void i2c_end(void)
+{
+    mutex_unlock(&i2c_mtx);
+}
+
 void i2c_start(void)
 {
     SDA_OUTPUT;