STM32: driver/Added I2C timing calculation algorithm

targets/TARGET_STM/TARGET_STM32F0/CMakeLists.txt

@@ -21,6 +21,7 @@ target_sources(mbed-stm32f0
         cmsis_nvic.c
         flash_api.c
         gpio_irq_device.c
+        i2c_device.c
         pwmout_device.c
         serial_device.c
         spi_api.c

targets/TARGET_STM/TARGET_STM32F0/i2c_device.c

@@ -0,0 +1,90 @@
+/* mbed Microcontroller Library
+ * SPDX-License-Identifier: BSD-3-Clause
+ ******************************************************************************
+ *
+ * Copyright (c) 2021 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
+ *
+ ******************************************************************************
+ */
+
+#include "i2c_device.h"
+#include "mbed_assert.h"
+#include "mbed_error.h"
+#include "stm32f0xx_ll_rcc.h"
+
+/*  Define I2C Device */
+#if DEVICE_I2C
+
+/**
+  * @brief  Get I2C clock source frequency according I2C instance used.
+  * @param  i2c I2C instance name.
+  * @retval I2C clock source frequency in Hz.
+  */
+uint32_t i2c_get_pclk(I2CName i2c)
+{
+    uint32_t clocksource;
+    uint32_t pclk = 0;
+    if (i2c == I2C_1) {
+        clocksource = __HAL_RCC_GET_I2C1_SOURCE();
+        switch (clocksource) {
+            case RCC_I2C1CLKSOURCE_SYSCLK:
+                pclk = HAL_RCC_GetSysClockFreq();
+                break;
+
+            case RCC_I2C1CLKSOURCE_HSI:
+                pclk = HSI_VALUE;
+                break;
+        }
+    } else {
+        // should not happend
+        error("I2C: unknown instance");
+    }
+    return pclk;
+}
+
+/**
+ * @brief  Provide the suitable timing depending on requested frequency
+ * @param  hz Required I2C clock in Hz.
+ * @retval I2C timing or 0 in case of error.
+ */
+uint32_t i2c_get_timing(I2CName i2c, int hz)
+{
+    uint32_t tim;
+    uint32_t pclk;
+
+    pclk = i2c_get_pclk(i2c);
+
+    if (pclk == I2C_PCLK_DEF) {
+        switch (hz) {
+            case 100000:
+                tim = TIMING_VAL_DEFAULT_CLK_100KHZ;
+                break;
+            case 400000:
+                tim = TIMING_VAL_DEFAULT_CLK_400KHZ;
+                break;
+            case 1000000:
+                tim = TIMING_VAL_DEFAULT_CLK_1MHZ;
+                break;
+            default:
+                MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000));
+                break;
+        }
+    }
+
+    else {
+        tim = i2c_compute_timing(pclk, hz);
+    }
+    return tim;
+}
+
+/**
+  * @}
+  */
+
+#endif // DEVICE_I2C

targets/TARGET_STM/TARGET_STM32F0/i2c_device.h

@@ -2,7 +2,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  ******************************************************************************
  *
- * Copyright (c) 2015-2020 STMicroelectronics.
+ * Copyright (c) 2015-2021 STMicroelectronics.
  * All rights reserved.
  *
  * This software component is licensed by ST under BSD 3-Clause license,
@@ -16,12 +16,13 @@
 #ifndef MBED_I2C_DEVICE_H
 #define MBED_I2C_DEVICE_H
 
-#include "cmsis.h"
+#include "PeripheralNames.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/*  Define I2C Device */
 #if DEVICE_I2C
 
 #if defined I2C1_BASE
@@ -32,41 +33,28 @@ extern "C" {
 #define I2C2_EV_IRQn I2C2_IRQn
 #define I2C2_ER_IRQn I2C2_IRQn
 #endif
-#if defined I2C3_BASE
-#define I2C3_EV_IRQn I2C3_IRQn
-#define I2C3_ER_IRQn I2C3_IRQn
-#endif
-
-#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)
-
 
 /*  Define IP version */
 #define I2C_IP_VERSION_V2
 
+#define TIMING_VAL_DEFAULT_CLK_100KHZ  0x10805E89  // Standard mode with Rise Time = 400ns and Fall Time = 100ns
+#define TIMING_VAL_DEFAULT_CLK_400KHZ  0x00901850  // Fast mode with Rise Time = 250ns and Fall Time = 100ns
+#define TIMING_VAL_DEFAULT_CLK_1MHZ    0x00700818  // Fast mode Plus with Rise Time = 60ns and Fall Time = 100ns
+#define I2C_PCLK_DEF                   48000000    // 48 MHz    
+
+#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
 
-/*  Provide the suitable timing depending on requested frequencie */
-static inline uint32_t get_i2c_timing(int hz)
-{
-    uint32_t tim = 0;
+uint32_t i2c_get_pclk(I2CName i2c);
+uint32_t i2c_compute_timing(uint32_t clock_src_freq, uint32_t i2c_freq);
+uint32_t i2c_get_timing(I2CName i2c, int hz);
+void i2c_compute_presc_scldel_sdadel(uint32_t clock_src_freq, uint32_t I2C_speed);
+uint32_t i2c_compute_scll_sclh(uint32_t clock_src_freq, uint32_t I2C_speed);
 
-    switch (hz) {
-        case 100000:
-            tim = 0x10805E89; // Standard mode with Rise Time = 400ns and Fall Time = 100ns
-            break;
-        case 400000:
-            tim = 0x00901850; // Fast mode with Rise Time = 250ns and Fall Time = 100ns
-            break;
-        case 1000000:
-            tim = 0x00700818; // 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_STM32F3/CMakeLists.txt

@@ -21,6 +21,7 @@ target_sources(mbed-stm32f3
         analogout_device.c
         flash_api.c
         gpio_irq_device.c
+        i2c_device.c
         pwmout_device.c
         serial_device.c
         spi_api.c

targets/TARGET_STM/TARGET_STM32F3/i2c_device.c

@@ -0,0 +1,134 @@
+/* mbed Microcontroller Library
+ * SPDX-License-Identifier: BSD-3-Clause
+ ******************************************************************************
+ *
+ * Copyright (c) 2021 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
+ *
+ ******************************************************************************
+ */
+
+#include "i2c_device.h"
+#include "mbed_assert.h"
+#include "mbed_error.h"
+#include "stm32f3xx_ll_rcc.h"
+
+/*  Define I2C Device */
+#if DEVICE_I2C
+
+/**
+  * @brief  Get I2C clock source frequency according I2C instance used.
+  * @param  i2c I2C instance name.
+  * @retval I2C clock source frequency in Hz.
+  */
+uint32_t i2c_get_pclk(I2CName i2c)
+{
+    uint32_t clocksource;
+    uint32_t pclk = 0;
+    if (i2c == I2C_1) {
+        clocksource = __HAL_RCC_GET_I2C1_SOURCE();
+        switch (clocksource) {
+            case RCC_I2C1CLKSOURCE_SYSCLK:
+                pclk = HAL_RCC_GetSysClockFreq();
+                break;
+
+            case RCC_I2C1CLKSOURCE_HSI:
+                pclk = HSI_VALUE;
+                break;
+        }
+    }
+#if defined I2C2_BASE
+    else if (i2c == I2C_2) {
+        clocksource = __HAL_RCC_GET_I2C2_SOURCE();
+        switch (clocksource) {
+            case RCC_I2C2CLKSOURCE_SYSCLK:
+                pclk = HAL_RCC_GetSysClockFreq();
+                break;
+
+            case RCC_I2C2CLKSOURCE_HSI:
+                pclk = HSI_VALUE;
+                break;
+        }
+    }
+#endif
+#if defined I2C3_BASE
+    else if (i2c == I2C_3) {
+        clocksource = __HAL_RCC_GET_I2C3_SOURCE();
+        switch (clocksource) {
+            case RCC_I2C3CLKSOURCE_SYSCLK:
+                pclk = HAL_RCC_GetSysClockFreq();
+                break;
+
+            case RCC_I2C3CLKSOURCE_HSI:
+                pclk = HSI_VALUE;
+                break;
+        }
+    }
+#endif
+    else {
+        // should not happend
+        error("I2C: unknown instance");
+    }
+    return pclk;
+}
+
+/**
+ * @brief  Provide the suitable timing depending on requested frequency
+ * @param  hz Required I2C clock in Hz.
+ * @retval I2C timing or 0 in case of error.
+ */
+uint32_t i2c_get_timing(I2CName i2c, int hz)
+{
+    uint32_t tim;
+    uint32_t pclk;
+
+    pclk = i2c_get_pclk(i2c);
+
+    if (pclk == I2C_PCLK_HSI) {
+        switch (hz) {
+            case 100000:
+                tim = TIMING_VAL_64M_CLK_100KHZ;
+                break;
+            case 400000:
+                tim = TIMING_VAL_64M_CLK_400KHZ;
+                break;
+            case 1000000:
+                tim = TIMING_VAL_64M_CLK_1MHZ;
+                break;
+            default:
+                MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000));
+                break;
+        }
+    } else if (pclk == I2C_PCLK_HSE) {
+        switch (hz) {
+            case 100000:
+                tim = TIMING_VAL_72M_CLK_100KHZ;
+                break;
+            case 400000:
+                tim = TIMING_VAL_72M_CLK_400KHZ;
+                break;
+            case 1000000:
+                tim = TIMING_VAL_72M_CLK_1MHZ;
+                break;
+            default:
+                MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000));
+                break;
+        }
+    }
+
+    else {
+        tim = i2c_compute_timing(pclk, hz);
+    }
+    return tim;
+}
+
+/**
+  * @}
+  */
+
+#endif // DEVICE_I2C