Diff: targets/hal/TARGET_STM/TARGET_NUCLEO_F334R8/i2c_api.c

Revision:

306:1f0269907d8b

Parent:

272:949bd8bf133b

--- a/targets/hal/TARGET_STM/TARGET_NUCLEO_F334R8/i2c_api.c	Fri Aug 29 17:15:07 2014 +0100
+++ b/targets/hal/TARGET_STM/TARGET_NUCLEO_F334R8/i2c_api.c	Fri Aug 29 20:45:07 2014 +0100
@@ -57,8 +57,9 @@
 
 I2C_HandleTypeDef I2cHandle;
 
-void i2c_init(i2c_t *obj, PinName sda, PinName scl)
-{
+int i2c1_inited = 0;
+
+void i2c_init(i2c_t *obj, PinName sda, PinName scl) {
     // Determine the I2C to use
     I2CName i2c_sda = (I2CName)pinmap_peripheral(sda, PinMap_I2C_SDA);
     I2CName i2c_scl = (I2CName)pinmap_peripheral(scl, PinMap_I2C_SCL);
@@ -66,17 +67,17 @@
     obj->i2c = (I2CName)pinmap_merge(i2c_sda, i2c_scl);
     MBED_ASSERT(obj->i2c != (I2CName)NC);
 
-    // Enable I2C clock
-    __I2C1_CLK_ENABLE();
-
-    // Configure the I2C clock source
-    __HAL_RCC_I2C1_CONFIG(RCC_I2C1CLKSOURCE_SYSCLK);
-  
-    // Configure I2C pins
-    pinmap_pinout(sda, PinMap_I2C_SDA);
-    pinmap_pinout(scl, PinMap_I2C_SCL);
-    pin_mode(sda, OpenDrain);
-    pin_mode(scl, OpenDrain);
+    // Enable I2C1 clock and pinout if not done
+    if ((obj->i2c == I2C_1)&& !i2c1_inited) {
+        i2c1_inited = 1;
+        __HAL_RCC_I2C1_CONFIG(RCC_I2C1CLKSOURCE_SYSCLK);
+        __I2C1_CLK_ENABLE();
+        // Configure I2C pins
+        pinmap_pinout(sda, PinMap_I2C_SDA);
+        pinmap_pinout(scl, PinMap_I2C_SCL);
+        pin_mode(sda, OpenDrain);
+        pin_mode(scl, OpenDrain);
+    }
 
     // Reset to clear pending flags if any
     i2c_reset(obj);
@@ -92,6 +93,11 @@
     MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000));
 
     I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+
+    // wait before init
+    timeout = LONG_TIMEOUT;
+    while((__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BUSY)) && (timeout-- != 0));
 
     // Update the SystemCoreClock variable.
     SystemCoreClockUpdate();
@@ -313,6 +319,12 @@
 
 void i2c_reset(i2c_t *obj)
 {
+    int timeout;
+	
+    // wait before reset
+    timeout = LONG_TIMEOUT;
+    while((__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BUSY)) && (timeout-- != 0));
+
     __I2C1_FORCE_RESET();
     __I2C1_RELEASE_RESET();
 }