mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
Diff: targets/hal/TARGET_STM/TARGET_DISCO_F051R8/i2c_api.c
- Revision:
- 130:1dec54e4aec3
- Child:
- 142:7f2b6c44bbe3
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_STM/TARGET_DISCO_F051R8/i2c_api.c Fri Mar 21 11:45:09 2014 +0000 @@ -0,0 +1,313 @@ +/* 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 "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) + +static const PinMap PinMap_I2C_SDA[] = { + {PB_9, I2C_1, STM_PIN_DATA(GPIO_Mode_AF, GPIO_OType_OD, GPIO_PuPd_UP, GPIO_AF_1)}, + {NC, NC, 0} +}; + +static const PinMap PinMap_I2C_SCL[] = { + {PB_8, I2C_1, STM_PIN_DATA(GPIO_Mode_AF, GPIO_OType_OD, GPIO_PuPd_UP, GPIO_AF_1)}, + {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(scl, PinMap_I2C_SCL); + pin_mode(scl, OpenDrain); + pinmap_pinout(sda, PinMap_I2C_SDA); + pin_mode(sda, 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; + uint32_t tim; + + // Values calculated with I2C_Timing_Configuration_V1.0.1.xls file (see AN4235) + // with Rise time = 100ns and Fall time = 10ns + switch (hz) { + case 100000: + tim = 0x00201D2B; // Standard mode + break; + case 200000: + tim = 0x0010021E; // Fast mode + break; + case 400000: + tim = 0x0010020A; // Fast mode + break; + default: + error("Only 100kHz, 200kHz and 400kHz I2C frequencies are supported."); + break; + } + + // I2C configuration + I2C_InitStructure.I2C_Mode = I2C_Mode_I2C; + I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable; + I2C_InitStructure.I2C_DigitalFilter = 0x00; + I2C_InitStructure.I2C_OwnAddress1 = 0x00; + I2C_InitStructure.I2C_Ack = I2C_Ack_Enable; + I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; + I2C_InitStructure.I2C_Timing = tim; + I2C_Init(i2c, &I2C_InitStructure); + + I2C_Cmd(i2c, ENABLE); +} + +inline int i2c_start(i2c_t *obj) { + I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c); + int timeout; + + // Test BUSY Flag + timeout = LONG_TIMEOUT; + while (I2C_GetFlagStatus(i2c, I2C_ISR_BUSY) != RESET) { + timeout--; + if (timeout == 0) { + return 0; + } + } + + I2C_GenerateSTART(i2c, ENABLE); + + return 0; +} + +inline int i2c_stop(i2c_t *obj) { + I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c); + + I2C_GenerateSTOP(i2c, ENABLE); + + return 0; +} + +int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) { + I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c); + int count; + int value; + + if (length == 0) return 0; + + // Configure slave address, nbytes, reload, end mode and start or stop generation + I2C_TransferHandling(i2c, address, length, I2C_AutoEnd_Mode, I2C_Generate_Start_Read); + + // Read all bytes + for (count = 0; count < length; count++) { + value = i2c_byte_read(obj, 0); + 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; + + // TODO: the stop is always sent even with I2C_SoftEnd_Mode. To be corrected. + + // Configure slave address, nbytes, reload, end mode and start or stop generation + //if (stop) { + I2C_TransferHandling(i2c, address, length, I2C_AutoEnd_Mode, I2C_Generate_Start_Write); + //} + //else { + // I2C_TransferHandling(i2c, address, length, I2C_SoftEnd_Mode, I2C_Generate_Start_Write); + //} + + // Write all bytes + for (count = 0; count < length; count++) { + if (i2c_byte_write(obj, data[count]) != 1) { + i2c_stop(obj); + return 0; + } + } + + /* + if (stop) { + // Wait until STOPF flag is set + timeout = LONG_TIMEOUT; + while (I2C_GetFlagStatus(i2c, I2C_ISR_STOPF) == RESET) { + timeout--; + if (timeout == 0) { + return 0; + } + } + // Clear STOPF flag + I2C_ClearFlag(i2c, I2C_ICR_STOPCF); + } + */ + + return count; +} + +int i2c_byte_read(i2c_t *obj, int last) { + I2C_TypeDef *i2c = (I2C_TypeDef *)(obj->i2c); + uint8_t data; + int timeout; + + // Wait until the byte is received + timeout = FLAG_TIMEOUT; + while (I2C_GetFlagStatus(i2c, I2C_ISR_RXNE) == RESET) { + timeout--; + if (timeout == 0) { + return 0; + } + } + + 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; + + // Wait until the previous byte is transmitted + timeout = FLAG_TIMEOUT; + while (I2C_GetFlagStatus(i2c, I2C_ISR_TXIS) == RESET) { + timeout--; + if (timeout == 0) { + return 0; + } + } + + I2C_SendData(i2c, (uint8_t)data); + + return 1; +} + +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 +} + +// 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) { + // TO BE DONE + return(0); +} + +int i2c_slave_read(i2c_t *obj, char *data, int length) { + int count = 0; + + // Read all bytes + for (count = 0; count < length; count++) { + data[count] = i2c_byte_read(obj, 0); + } + + return count; +} + +int i2c_slave_write(i2c_t *obj, const char *data, int length) { + int count = 0; + + // Write all bytes + for (count = 0; count < length; count++) { + i2c_byte_write(obj, data[count]); + } + + return count; +} + + +#endif // DEVICE_I2CSLAVE + +#endif // DEVICE_I2C