Diff: targets/hal/TARGET_STM/TARGET_STM32L4/i2c_api.c

Revision:

610:813dcc80987e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_STM32L4/i2c_api.c	Fri Aug 14 13:15:17 2015 +0100
@@ -0,0 +1,413 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2015, 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 "mbed_error.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;
+#if defined(I2C3_BASE)
+    static int i2c3_inited = 0;
+#endif
+
+    // 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;
+        __HAL_RCC_I2C1_CONFIG(RCC_I2C1CLKSOURCE_SYSCLK);
+        __HAL_RCC_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;
+        __HAL_RCC_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);
+    }
+
+#if defined(I2C3_BASE)
+    // Enable I2C3 clock and pinout if not done
+    if ((obj->i2c == I2C_3) && !i2c3_inited) {
+        i2c3_inited = 1;
+        __HAL_RCC_I2C3_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);
+    }
+#endif
+
+    // 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)
+{
+    MBED_ASSERT((hz == 100000) || (hz == 400000) || (hz == 1000000));
+    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));
+
+    // Common settings: I2C clock = 32 MHz, Analog filter = ON, Digital filter coefficient = 0
+    switch (hz) {
+        case 100000:
+            I2cHandle.Init.Timing = 0x20602938; // Standard mode with Rise Time = 400ns and Fall Time = 100ns
+            break;
+        case 400000:
+            I2cHandle.Init.Timing = 0x00B0122A; // Fast mode with Rise Time = 250ns and Fall Time = 100ns
+            break;
+        case 1000000:
+            I2cHandle.Init.Timing = 0x0030040E; // Fast mode Plus with Rise Time = 60ns and Fall Time = 100ns
+            break;
+        default:
+            break;
+    }
+
+    // I2C configuration
+    I2cHandle.Init.AddressingMode   = I2C_ADDRESSINGMODE_7BIT;
+    I2cHandle.Init.DualAddressMode  = I2C_DUALADDRESS_DISABLE;
+    I2cHandle.Init.GeneralCallMode  = I2C_GENERALCALL_DISABLE;
+    I2cHandle.Init.NoStretchMode    = I2C_NOSTRETCH_DISABLE;
+    I2cHandle.Init.OwnAddress1      = 0;
+    I2cHandle.Init.OwnAddress2      = 0;
+    I2cHandle.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
+
+    if (HAL_I2C_Init(&I2cHandle) != HAL_OK) {
+        error("Cannot initialize I2C\n");
+    }
+}
+
+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);
+
+    // Generate the START condition
+    i2c->CR2 |= I2C_CR2_START;
+
+    // Wait the START condition has been correctly sent
+    timeout = FLAG_TIMEOUT;
+    while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_BUSY) == 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->CR2 |= I2C_CR2_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;
+
+    /* update CR2 register */
+    i2c->CR2 = (i2c->CR2 & (uint32_t)~((uint32_t)(I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN | I2C_CR2_START | I2C_CR2_STOP)))
+               | (uint32_t)(((uint32_t)address & I2C_CR2_SADD) | (((uint32_t)length << 16) & I2C_CR2_NBYTES) | (uint32_t)I2C_SOFTEND_MODE | (uint32_t)I2C_GENERATE_START_READ);
+
+    // Read all bytes
+    for (count = 0; count < length; count++) {
+        value = i2c_byte_read(obj, 0);
+        data[count] = (char)value;
+    }
+
+    // Wait transfer complete
+    timeout = FLAG_TIMEOUT;
+    while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_TC) == RESET) {
+        timeout--;
+        if (timeout == 0) {
+            return -1;
+        }
+    }
+
+    __HAL_I2C_CLEAR_FLAG(&I2cHandle, I2C_FLAG_TC);
+
+    // If not repeated start, send stop.
+    if (stop) {
+        i2c_stop(obj);
+        /* Wait until STOPF 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_FLAG(&I2cHandle, I2C_FLAG_STOPF);
+    }
+
+    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;
+
+    /* update CR2 register */
+    i2c->CR2 = (i2c->CR2 & (uint32_t)~((uint32_t)(I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD | I2C_CR2_AUTOEND | I2C_CR2_RD_WRN | I2C_CR2_START | I2C_CR2_STOP)))
+               | (uint32_t)(((uint32_t)address & I2C_CR2_SADD) | (((uint32_t)length << 16) & I2C_CR2_NBYTES) | (uint32_t)I2C_SOFTEND_MODE | (uint32_t)I2C_GENERATE_START_WRITE);
+
+    for (count = 0; count < length; count++) {
+        i2c_byte_write(obj, data[count]);
+    }
+
+    // Wait transfer complete
+    timeout = FLAG_TIMEOUT;
+    while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_TC) == RESET) {
+        timeout--;
+        if (timeout == 0) {
+            return -1;
+        }
+    }
+
+    __HAL_I2C_CLEAR_FLAG(&I2cHandle, I2C_FLAG_TC);
+
+    // If not repeated start, send stop.
+    if (stop) {
+        i2c_stop(obj);
+        /* Wait until STOPF 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_FLAG(&I2cHandle, I2C_FLAG_STOPF);
+    }
+
+    return count;
+}
+
+int i2c_byte_read(i2c_t *obj, int last)
+{
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+
+    // 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->RXDR;
+}
+
+int i2c_byte_write(i2c_t *obj, int data)
+{
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    int timeout;
+
+    // Wait until the previous byte is transmitted
+    timeout = FLAG_TIMEOUT;
+    while (__HAL_I2C_GET_FLAG(&I2cHandle, I2C_FLAG_TXIS) == RESET) {
+        if ((timeout--) == 0) {
+            return 0;
+        }
+    }
+
+    i2c->TXDR = (uint8_t)data;
+
+    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) {
+        __HAL_RCC_I2C1_FORCE_RESET();
+        __HAL_RCC_I2C1_RELEASE_RESET();
+    }
+    if (obj->i2c == I2C_2) {
+        __HAL_RCC_I2C2_FORCE_RESET();
+        __HAL_RCC_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;
+
+    // disable
+    i2c->OAR1 &= (uint32_t)(~I2C_OAR1_OA1EN);
+    // 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;
+    // enable
+    i2c->OAR1 |= I2C_OAR1_OA1EN;
+}
+
+void i2c_slave_mode(i2c_t *obj, int enable_slave)
+{
+
+    I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c);
+    uint16_t tmpreg;
+
+    // Get the old register value
+    tmpreg = i2c->OAR1;
+
+    // Enable / disable slave
+    if (enable_slave == 1) {
+        tmpreg |= I2C_OAR1_OA1EN;
+    } else {
+        tmpreg &= (uint32_t)(~I2C_OAR1_OA1EN);
+    }
+
+    // Set new mode
+    i2c->OAR1 = tmpreg;
+
+}
+
+// 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_DIR) == 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)
+{
+    char size = 0;
+
+    while (size < length) data[size++] = (char)i2c_byte_read(obj, 0);
+
+    return size;
+}
+
+int i2c_slave_write(i2c_t *obj, const char *data, int length)
+{
+    char size = 0;
+    I2cHandle.Instance = (I2C_TypeDef *)(obj->i2c);
+
+    do {
+        i2c_byte_write(obj, data[size]);
+        size++;
+    } while (size < length);
+
+    return size;
+}
+
+
+#endif // DEVICE_I2CSLAVE
+
+#endif // DEVICE_I2C