Added support for I2C

targets/TARGET_STM/TARGET_STM32G4/i2c_device.h

@@ -0,0 +1,63 @@
+/* mbed Microcontroller Library
+ * SPDX-License-Identifier: BSD-3-Clause
+ ******************************************************************************
+ *
+ * Copyright (c) 2015 STMicroelectronics.
+ * All rights reserved.
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *                        opensource.org/licenses/BSD-3-Clause
+ *
+ ******************************************************************************
+ */
+#ifndef MBED_I2C_DEVICE_H
+#define MBED_I2C_DEVICE_H
+
+#include "cmsis.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if DEVICE_I2C
+
+#define I2C_IP_VERSION_V2
+
+#define I2C_IT_ALL (I2C_IT_ERRI|I2C_IT_TCI|I2C_IT_STOPI|I2C_IT_NACKI|I2C_IT_ADDRI|I2C_IT_RXI|I2C_IT_TXI)
+
+/*  Family specifc settings for clock source */
+#define I2CAPI_I2C1_CLKSRC RCC_I2C1CLKSOURCE_SYSCLK
+#define I2CAPI_I2C2_CLKSRC RCC_I2C2CLKSOURCE_SYSCLK
+#define I2CAPI_I2C3_CLKSRC RCC_I2C3CLKSOURCE_SYSCLK
+#define I2CAPI_I2C4_CLKSRC RCC_I2C4CLKSOURCE_SYSCLK
+
+/*  Provide the suitable timing depending on requested frequencie */
+static inline uint32_t get_i2c_timing(int hz)
+{
+    uint32_t tim = 0;
+    // Common settings: I2C clock = 64 MHz, Analog filter = ON, Digital filter coefficient = 0
+    switch (hz) {
+        case 100000:
+            tim = 0xC0311319; // Standard mode with Rise Time = 400ns and Fall Time = 100ns
+            break;
+        case 400000:
+            tim = 0x10B1102E; // Fast mode with Rise Time = 250ns and Fall Time = 100ns
+            break;
+        case 1000000:
+            tim = 0x00710B1E; // Fast mode Plus with Rise Time = 60ns and Fall Time = 100ns
+            break;
+        default:
+            break;
+    }
+    return tim;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // DEVICE_I2C
+
+#endif

targets/TARGET_STM/TARGET_STM32G4/objects.h

@@ -63,6 +63,37 @@ struct serial_s {
 #endif
 };
 
+struct i2c_s {
+    /*  The 1st 2 members I2CName i2c
+     *  and I2C_HandleTypeDef handle should
+     *  be kept as the first members of this struct
+     *  to ensure i2c_get_obj to work as expected
+     */
+    I2CName  i2c;
+    I2C_HandleTypeDef handle;
+    uint8_t index;
+    int hz;
+    PinName sda;
+    PinName scl;
+    int sda_func;
+    int scl_func;
+    IRQn_Type event_i2cIRQ;
+    IRQn_Type error_i2cIRQ;
+    uint32_t XferOperation;
+    volatile uint8_t event;
+    volatile int pending_start;
+#if DEVICE_I2CSLAVE
+    uint8_t slave;
+    volatile uint8_t pending_slave_tx_master_rx;
+    volatile uint8_t pending_slave_rx_maxter_tx;
+#endif
+#if DEVICE_I2C_ASYNCH
+    uint32_t address;
+    uint8_t stop;
+    uint8_t available_events;
+#endif
+};
+
 struct analogin_s {
     ADC_HandleTypeDef handle;
     PinName pin;

targets/targets.json

@@ -7562,7 +7562,6 @@
             "MPU"
         ],
         "device_has_remove": [
-            "I2C",
             "I2CSLAVE",
             "I2C_ASYNCH",
             "INTERRUPTIN",