Lee Kai Xuan
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Diff: targets/TARGET_STM/TARGET_STM32F1/i2c_api.c
- Revision:
- 0:f269e3021894
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32F1/i2c_api.c Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,468 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2014, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *******************************************************************************
+ */
+#include "mbed_assert.h"
+#include "i2c_api.h"
+
+#if DEVICE_I2C
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "PeripheralPins.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)
+
+I2C_HandleTypeDef I2cHandle;
+
+void i2c_init(i2c_t *obj, PinName sda, PinName scl)
+{
+ static int i2c1_inited = 0;
+ static int i2c2_inited = 0;
+
+ // 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);
+ MBED_ASSERT(obj->i2c != (I2CName)NC);
+
+ // Check if I2C peripherals are already configured
+ if ((obj->i2c == I2C_1) && i2c1_inited) return;
+ if ((obj->i2c == I2C_2) && i2c2_inited) return;
+
+ // Set I2C clock
+ if (obj->i2c == I2C_1) {
+ i2c1_inited = 1;
+ __I2C1_CLK_ENABLE();
+ }
+
+ if (obj->i2c == I2C_2) {
+ i2c2_inited = 1;
+ __I2C2_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);
+
+ // I2C configuration
+ i2c_frequency(obj, 100000); // 100 kHz per default
+
+ // I2C master by default
+ obj->slave = 0;
+}
+
+void i2c_frequency(i2c_t *obj, int hz)
+{
+ MBED_ASSERT((hz != 0) && (hz <= 400000));
+ 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));
+
+ // I2C configuration
+ I2cHandle.Init.ClockSpeed = hz;
+ I2cHandle.Init.DutyCycle = I2C_DUTYCYCLE_2;
+ I2cHandle.Init.OwnAddress1 = 0;
+ I2cHandle.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
+ I2cHandle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLED;
+ I2cHandle.Init.OwnAddress2 = 0;
+ I2cHandle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLED;
+ I2cHandle.Init.NoStretchMode = I2C_NOSTRETCH_DISABLED;
+ HAL_I2C_Init(&I2cHandle);
+
+ if (obj->slave) {
+ // Enable Address Acknowledge
+ I2cHandle.Instance->CR1 |= I2C_CR1_ACK;
+ }
+}
+
+inline int i2c_start(i2c_t *obj)
+{
+ I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+ int timeout;
+
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+
+ // Clear Acknowledge failure flag
+ __HAL_I2C_CLEAR_FLAG(&I2cHandle, I2C_FLAG_AF);
+
+ // Wait the STOP condition has been previously correctly sent
+ // This timeout can be avoid in some specific cases by simply clearing the STOP bit
+ timeout = FLAG_TIMEOUT;
+ while ((i2c->CR1 & I2C_CR1_STOP) == I2C_CR1_STOP) {
+ if ((timeout--) == 0) {
+ return 1;
+ }
+ }
+
+ // Generate the START condition
+ i2c->CR1 |= I2C_CR1_START;
+
+ // Wait the START condition has been correctly sent
+ timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_SB) == RESET) {
+ if ((timeout--) == 0) {
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+inline int i2c_stop(i2c_t *obj)
+{
+ I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+
+ // Generate the STOP condition
+ i2c->CR1 |= I2C_CR1_STOP;
+
+ return 0;
+}
+
+int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
+{
+ I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+ int timeout;
+ int count;
+ int value;
+
+ // Generate start condition
+ i2c_start(obj);
+
+ // Send address for read
+ i2c->DR = __HAL_I2C_7BIT_ADD_READ(address);
+
+ // Wait address is acknowledged
+ timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_ADDR) == RESET) {
+ timeout--;
+ if (timeout == 0) {
+ return -1;
+ }
+ }
+ __HAL_I2C_CLEAR_ADDRFLAG(&I2cHandle);
+
+ // 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);
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+ int timeout;
+ int count;
+
+ // Generate start condition
+ i2c_start(obj);
+
+ // Send address for write
+ i2c->DR = __HAL_I2C_7BIT_ADD_WRITE(address);
+
+ // Wait address is acknowledged
+ timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_ADDR) == RESET) {
+ timeout--;
+ if (timeout == 0) {
+ return -1;
+ }
+ }
+ __HAL_I2C_CLEAR_ADDRFLAG(&I2cHandle);
+
+ // Write all bytes
+ for (count = 0; count < length; count++) {
+ if (i2c_byte_write(obj, data[count]) != 1) {
+ i2c_stop(obj);
+ return -1;
+ }
+ }
+
+ // 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);
+ int timeout;
+
+ if (last) {
+ // Don't acknowledge the last byte
+ i2c->CR1 &= ~I2C_CR1_ACK;
+ } else {
+ // Acknowledge the byte
+ i2c->CR1 |= I2C_CR1_ACK;
+ }
+
+ // Wait until the byte is received
+ timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_RXNE) == RESET) {
+ if ((timeout--) == 0) {
+ return -1;
+ }
+ }
+
+ return (int)i2c->DR;
+}
+
+int i2c_byte_write(i2c_t *obj, int data)
+{
+ I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+ int timeout;
+
+ i2c->DR = (uint8_t)data;
+
+ // Wait until the byte is transmitted
+ timeout = FLAG_TIMEOUT;
+ while ((__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_TXE) == RESET) &&
+ (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BTF) == RESET)) {
+ if ((timeout--) == 0) {
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+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));
+
+ if (obj->i2c == I2C_1) {
+ __I2C1_FORCE_RESET();
+ __I2C1_RELEASE_RESET();
+ }
+
+ if (obj->i2c == I2C_2) {
+ __I2C2_FORCE_RESET();
+ __I2C2_RELEASE_RESET();
+ }
+}
+
+#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 = 0;
+
+ // 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)
+{
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+ if (enable_slave) {
+ obj->slave = 1;
+ /* Enable Address Acknowledge */
+ I2cHandle.Instance->CR1 |= I2C_CR1_ACK;
+ }
+}
+
+// See I2CSlave.h
+#define NoData 0 // the slave has not been addressed
+#define ReadAddressed 1 // the master has requested a read from this slave (slave = transmitter)
+#define WriteGeneral 2 // the master is writing to all slave
+#define WriteAddressed 3 // the master is writing to this slave (slave = receiver)
+
+int i2c_slave_receive(i2c_t *obj)
+{
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+ int retValue = NoData;
+
+ if (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BUSY) == 1) {
+ if (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_ADDR) == 1) {
+ if (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_TRA) == 1) {
+ retValue = ReadAddressed;
+ } else {
+ retValue = WriteAddressed;
+ }
+ __HAL_I2C_CLEAR_FLAG(&I2cHandle, I2C_FLAG_ADDR);
+ }
+ }
+
+ return (retValue);
+}
+
+int i2c_slave_read(i2c_t *obj, char *data, int length)
+{
+ uint32_t Timeout;
+ int size = 0;
+
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+
+ while (length > 0) {
+ // Wait until RXNE flag is set
+ // Wait until the byte is received
+ Timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_RXNE) == RESET) {
+ Timeout--;
+ if (Timeout == 0) {
+ return -1;
+ }
+ }
+
+ // Read data
+ (*data++) = I2cHandle.Instance->DR;
+ length--;
+ size++;
+
+ if ((__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BTF) == SET) && (length != 0)) {
+ // Read data
+ (*data++) = I2cHandle.Instance->DR;
+ length--;
+ size++;
+ }
+ }
+
+ // Wait until STOP flag is set
+ Timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_STOPF) == RESET) {
+ Timeout--;
+ if (Timeout == 0) {
+ return -1;
+ }
+ }
+
+ // Clear STOP flag
+ __HAL_I2C_CLEAR_STOPFLAG(&I2cHandle);
+
+ // Wait until BUSY flag is reset
+ Timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BUSY) == SET) {
+ Timeout--;
+ if (Timeout == 0) {
+ return -1;
+ }
+ }
+
+ return size;
+}
+
+int i2c_slave_write(i2c_t *obj, const char *data, int length)
+{
+ uint32_t Timeout;
+ int size = 0;
+
+ I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+
+ while (length > 0) {
+ // Wait until TXE flag is set
+ Timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_TXE) == RESET) {
+ Timeout--;
+ if (Timeout == 0) {
+ return -1;
+ }
+ }
+
+ // Write data
+ I2cHandle.Instance->DR = (*data++);
+ length--;
+ size++;
+
+ if ((__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BTF) == SET) && (length != 0)) {
+ // Write data to DR
+ I2cHandle.Instance->DR = (*data++);
+ length--;
+ size++;
+ }
+ }
+
+ // Wait until AF flag is set
+ Timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_AF) == RESET) {
+ Timeout--;
+ if (Timeout == 0) {
+ return -1;
+ }
+ }
+
+ // Clear AF flag
+ __HAL_I2C_CLEAR_FLAG(&I2cHandle, I2C_FLAG_AF);
+
+ // Wait until BUSY flag is reset
+ Timeout = FLAG_TIMEOUT;
+ while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BUSY) == SET) {
+ Timeout--;
+ if (Timeout == 0) {
+ return -1;
+ }
+ }
+
+ return size;
+}
+
+
+#endif // DEVICE_I2CSLAVE
+
+#endif // DEVICE_I2C