Added functions for exclusive I2C access

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

2 files changed, 14 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;
diff --git a/firmware/drivers/i2c.h b/firmware/drivers/i2c.h
index a16077428c..ed9a5e678d 100644
--- a/firmware/drivers/i2c.h
+++ b/firmware/drivers/i2c.h
@@ -20,6 +20,8 @@
 #define I2C_H
 
 extern void i2c_init(void);
+extern void i2c_begin(void);
+extern void i2c_end(void);
 extern int i2c_write(int device, unsigned char* buf, int count );
 extern int i2c_read(int device, unsigned char* buf, int count );
 extern int i2c_readmem(int device, int address, unsigned char* buf, int count );