Diff: targets/TARGET_STM/TARGET_STM32L1/i2c_api.c

Revision:

0:f269e3021894

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32L1/i2c_api.c	Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,489 @@
+/* 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;
+
+int i2c1_inited = 0;
+int i2c2_inited = 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);
+    MBED_ASSERT(obj->i2c != (I2CName)NC);
+
+    // Enable I2C1 clock and pinout if not done
+    if ((obj->i2c == I2C_1) && !i2c1_inited) {
+        i2c1_inited = 1;
+        __I2C1_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);
+    }
+    // Enable I2C2 clock and pinout if not done
+    if ((obj->i2c == I2C_2) && !i2c2_inited) {
+        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.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
+    I2cHandle.Init.ClockSpeed      = hz;
+    I2cHandle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLED;
+    I2cHandle.Init.DutyCycle       = I2C_DUTYCYCLE_2;
+    I2cHandle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLED;
+    I2cHandle.Init.NoStretchMode   = I2C_NOSTRETCH_DISABLED;
+    I2cHandle.Init.OwnAddress1     = 0;
+    I2cHandle.Init.OwnAddress2     = 0;
+    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;
+
+    i2c_start(obj);
+
+    // Wait until SB flag is set
+    timeout = FLAG_TIMEOUT;
+    while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_SB) == RESET) {
+        timeout--;
+        if (timeout == 0) {
+            return -1;
+        }
+    }
+
+    i2c->DR = 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;
+
+    i2c_start(obj);
+
+    // Wait until SB flag is set
+    timeout = FLAG_TIMEOUT;
+    while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_SB) == RESET) {
+        timeout--;
+        if (timeout == 0) {
+            return -1;
+        }
+    }
+
+    i2c->DR = 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);
+
+    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)
+{
+    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 from DR */
+        (*data++) = I2cHandle.Instance->DR;
+        length--;
+        size++;
+
+        if ((__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BTF) == SET) && (length != 0)) {
+            /* Read data from DR */
+            (*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 to DR */
+        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;
+        }
+    }
+
+    I2cHandle.State = HAL_I2C_STATE_READY;
+
+    /* Process Unlocked */
+    __HAL_UNLOCK(&I2cHandle);
+
+    return size;
+}
+
+
+#endif // DEVICE_I2CSLAVE
+
+#endif // DEVICE_I2C