Diff: targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/i2c_api.c

Revision:

56:99eb381a3269

Child:

57:c7e83bc5e387

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_NUCLEO_F103RB/i2c_api.c	Thu Dec 12 10:45:05 2013 +0000
@@ -0,0 +1,321 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "i2c_api.h"
+
+#if DEVICE_I2C
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "error.h"
+
+/* Timeout values for flags and events waiting loops. These timeouts are
+   not based on accurate values, they just guarantee that the application will 
+   not remain stuck if the I2C communication is corrupted. */   
+#define FLAG_TIMEOUT ((int)0x1000)
+#define LONG_TIMEOUT ((int)0x8000)
+
+// Functions exit codes
+#define EXIT_OK      (0)
+#define EXIT_FAIL    (1)
+#define EXIT_TIMEOUT (0xFFFFFFFF)
+
+static const PinMap PinMap_I2C_SDA[] = {
+    //{PB_7,  I2C_1, STM_PIN_DATA(GPIO_Mode_AF_OD, 0)}, // Cannot be used due to TIM4
+    {PB_9,  I2C_1, STM_PIN_DATA(GPIO_Mode_AF_OD, 7)}, // GPIO_Remap_I2C1
+    {NC,    NC,    0}
+};
+
+static const PinMap PinMap_I2C_SCL[] = {
+    //{PB_6,  I2C_1, STM_PIN_DATA(GPIO_Mode_AF_OD, 0)}, // // Cannot be used due to TIM4
+    {PB_8,  I2C_1, STM_PIN_DATA(GPIO_Mode_AF_OD, 7)}, // GPIO_Remap_I2C1
+    {NC,    NC,    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);
+
+    obj->i2c = (I2CName)pinmap_merge(i2c_sda, i2c_scl);
+    
+    if (obj->i2c == (I2CName)NC) {
+        error("I2C pin mapping failed");
+    }
+
+    // Enable I2C clock
+    if (obj->i2c == I2C_1) {    
+        RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
+    }
+    if (obj->i2c == I2C_2) {
+        RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, 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);
+    
+    // I2C configuration
+    i2c_frequency(obj, 100000); // 100 kHz per default    
+}
+
+void i2c_frequency(i2c_t *obj, int hz) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    I2C_InitTypeDef I2C_InitStructure;
+  
+    if ((hz != 0) && (hz <= 400000)) {
+        // I2C configuration
+        I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
+        I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
+        I2C_InitStructure.I2C_OwnAddress1 = 0;
+        I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
+        I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
+        I2C_InitStructure.I2C_ClockSpeed = hz;
+        I2C_Cmd(i2c, ENABLE);
+        I2C_Init(i2c, &I2C_InitStructure);  
+    }
+}
+
+inline int i2c_start(i2c_t *obj) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+  
+    I2C_ClearFlag(i2c, I2C_FLAG_AF); // Clear Acknowledge failure flag
+  
+    // Generate the START condition
+    I2C_GenerateSTART(i2c, ENABLE);  
+  
+    // Wait the START condition has been correctly sent
+    timeout = FLAG_TIMEOUT;
+    //while (I2C_CheckEvent(i2c, I2C_EVENT_MASTER_MODE_SELECT) == ERROR) {
+    while (I2C_GetFlagStatus(i2c, I2C_FLAG_SB) == RESET) {
+      if ((timeout--) == 0) {
+          return EXIT_TIMEOUT;
+      }
+    }
+    
+    return EXIT_OK;
+}
+
+inline int i2c_stop(i2c_t *obj) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    I2C_GenerateSTOP(i2c, ENABLE);
+    return EXIT_OK;
+}
+
+int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+    int count;
+    int value;
+  
+    if (length == 0) return 0;
+
+/*
+    // Wait until the bus is not busy anymore
+    timeout = LONG_TIMEOUT;
+    while (I2C_GetFlagStatus(i2c, I2C_FLAG_BUSY) == SET) {
+        if ((timeout--) == 0) {
+            return EXIT_TIMEOUT;
+        }
+    }
+*/
+  
+    i2c_start(obj);
+
+    // Send slave address for read
+    I2C_Send7bitAddress(i2c, address, I2C_Direction_Receiver);  
+
+    // Wait address is acknowledged
+    timeout = FLAG_TIMEOUT;
+    while (I2C_CheckEvent(i2c, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED) == ERROR) {
+      if ((timeout--) == 0) {
+          return EXIT_TIMEOUT;
+      }
+    }
+    
+    // Read all bytes except last one
+    for (count = 0; count < (length - 1); count++) {
+        value = i2c_byte_read(obj, 0);
+        data[count] = (char)value;
+    }
+    
+    // If not repeated start, send stop.
+    // Warning: must be done BEFORE the data is read.
+    if (stop) {
+        i2c_stop(obj);
+    }
+
+    // Read the last byte
+    value = i2c_byte_read(obj, 1);
+    data[count] = (char)value;
+    
+    return length;
+}
+
+int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+    int count;
+  
+    if (length == 0) return 0;
+
+/*
+    // Wait until the bus is not busy anymore
+    timeout = LONG_TIMEOUT;
+    while (I2C_GetFlagStatus(i2c, I2C_FLAG_BUSY) == SET) {
+        if ((timeout--) == 0) {
+            return EXIT_TIMEOUT;
+        }
+    }
+*/
+
+    i2c_start(obj);
+
+    // Send slave address for write
+    I2C_Send7bitAddress(i2c, address, I2C_Direction_Transmitter);
+  
+    // Wait address is acknowledged
+    timeout = FLAG_TIMEOUT;
+    while (I2C_CheckEvent(i2c, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED) == ERROR) {
+      if ((timeout--) == 0) {
+          return EXIT_TIMEOUT;
+      }
+    }
+
+    for (count = 0; count < length; count++) {
+        if (i2c_byte_write(obj, data[count]) != EXIT_OK) {
+            return EXIT_FAIL;
+        }
+    }
+
+    // If not repeated start, send stop.
+    if (stop) {
+        i2c_stop(obj);
+    }
+
+    return count;
+}
+
+int i2c_byte_read(i2c_t *obj, int last) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    uint8_t data;
+    int timeout;
+  
+    if (last) {
+        // Don't acknowledge the last byte
+        I2C_AcknowledgeConfig(i2c, DISABLE);
+    } else {
+        // Acknowledge the byte
+        I2C_AcknowledgeConfig(i2c, ENABLE);
+    }
+
+    // Wait until the byte is received
+    timeout = FLAG_TIMEOUT;
+    while (I2C_GetFlagStatus(i2c, I2C_FLAG_RXNE) == RESET) {
+      if ((timeout--) == 0) {
+          return EXIT_TIMEOUT;
+      }
+    }
+
+    data = I2C_ReceiveData(i2c);
+    
+    return (int)data;
+}
+
+int i2c_byte_write(i2c_t *obj, int data) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+
+    I2C_SendData(i2c, (uint8_t)data);
+
+    // Wait until the byte is transmitted
+    timeout = FLAG_TIMEOUT;  
+    //while (I2C_CheckEvent(i2c, I2C_EVENT_MASTER_BYTE_TRANSMITTED) == ERROR) {
+    while ((I2C_GetFlagStatus(i2c, I2C_FLAG_TXE) == RESET) &&
+           (I2C_GetFlagStatus(i2c, I2C_FLAG_BTF) == RESET)) {
+        if ((timeout--) == 0) {
+            return EXIT_TIMEOUT;
+        }
+    }
+    
+    return EXIT_OK;
+}
+
+void i2c_reset(i2c_t *obj) {
+    if (obj->i2c == I2C_1) {    
+        RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, ENABLE);
+        RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, DISABLE);
+    }
+    if (obj->i2c == I2C_2) {
+        RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, ENABLE);
+        RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C2, DISABLE);      
+    }
+}
+
+#if DEVICE_I2CSLAVE
+
+void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask) {
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    uint16_t tmpreg;
+  
+    // Get the old register value
+    tmpreg = i2c->OAR1;
+    // Reset address bits
+    tmpreg &= 0xFC00;
+    // Set new address
+    tmpreg |= (uint16_t)((uint16_t)address & (uint16_t)0x00FE); // 7-bits
+    // Store the new register value
+    i2c->OAR1 = tmpreg;
+}
+
+void i2c_slave_mode(i2c_t *obj, int enable_slave) {
+    // Nothing to do
+}
+
+#define        NoData         0
+#define        ReadAddressed  1
+#define        WriteGeneral   2
+#define        WriteAddressed 3
+
+int i2c_slave_receive(i2c_t *obj) {
+    //I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int retval = NoData;
+    //int status;
+  
+    //if (I2C_GetFlagStatus(i2c, I2C_FLAG_GENCALL) == SET) retval = WriteGeneral;
+    
+    //status = I2C_GetLastEvent(i2c);
+  
+    return(retval);
+}
+
+int i2c_slave_read(i2c_t *obj, char *data, int length) {
+    return 0;
+}
+
+int i2c_slave_write(i2c_t *obj, const char *data, int length) {
+    return 0;
+}
+
+
+#endif // DEVICE_I2CSLAVE
+
+#endif // DEVICE_I2C