[NUCLEO_L152RE] add SPI slave and I2C slave

Author: dbestm

libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/device.h

@@ -42,10 +42,10 @@
 #define DEVICE_SERIAL           1
 
 #define DEVICE_I2C              1
-#define DEVICE_I2CSLAVE         0 // Not yet supported
+#define DEVICE_I2CSLAVE         1
 
 #define DEVICE_SPI              1
-#define DEVICE_SPISLAVE         0 // Not yet supported
+#define DEVICE_SPISLAVE         1
 
 #define DEVICE_RTC              1
 

libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/i2c_api.c

@@ -314,7 +314,44 @@ void i2c_slave_mode(i2c_t *obj, int enable_slave) {
 #define WriteAddressed 3 // the master is writing to this slave (slave = receiver)
 
 int i2c_slave_receive(i2c_t *obj) {
-    return(0);
+    int retValue = NoData;
+    uint32_t event;
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+
+    event = I2C_GetLastEvent( i2c );
+    if(event != 0)
+    {
+        switch(event){
+            case I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED:
+                retValue = WriteAddressed;
+                break;
+            case I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED:
+                retValue = ReadAddressed;
+                break;
+            case I2C_EVENT_SLAVE_GENERALCALLADDRESS_MATCHED:
+                retValue = WriteGeneral;
+                break;
+            default:
+                retValue = NoData;
+                break;
+        }
+
+        // clear ADDR 
+        if((retValue == WriteAddressed) || (retValue == ReadAddressed)){
+            i2c->SR1;// read status register 1
+            i2c->SR2;// read status register 2
+        }
+        // clear stopf
+        if(I2C_GetFlagStatus(i2c, I2C_FLAG_STOPF) == SET) {
+            i2c->SR1;// read status register 1
+            I2C_Cmd(i2c,  ENABLE);    
+        }
+        // clear AF
+        if(I2C_GetFlagStatus(i2c, I2C_FLAG_AF) == SET) {
+            I2C_ClearFlag(i2c, I2C_FLAG_AF);
+        }        
+    }
+    return(retValue);
 }
 
 int i2c_slave_read(i2c_t *obj, char *data, int length) {

libraries/mbed/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/spi_api.c

@@ -139,7 +139,7 @@ void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel
     else { // Slave
         pinmap_pinout(ssel, PinMap_SPI_SSEL);
         obj->mode = SPI_Mode_Slave;
-        obj->nss = SPI_NSS_Soft;
+        obj->nss = SPI_NSS_Hard;
     }
 
     init_spi(obj);
@@ -288,7 +288,8 @@ int spi_master_write(spi_t *obj, int value) {
 }
 
 int spi_slave_receive(spi_t *obj) {
-    return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
+    //return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0); // initial code
+    return (ssp_readable(obj)) ? (1) : (0); // works better like this
 };
 
 int spi_slave_read(spi_t *obj) {