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rt-thread/bsp/efm32/Libraries/efm32lib/inc/efm32_i2c.h

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/***************************************************************************//**
* @file
* @brief Inter-intergrated circuit (I2C) peripheral API for EFM32.
* @author Energy Micro AS
* @version 2.3.2
*******************************************************************************
* @section License
* <b>(C) Copyright 2010 Energy Micro AS, http://www.energymicro.com</b>
*******************************************************************************
*
* This source code is the property of Energy Micro AS. The source and compiled
* code may only be used on Energy Micro "EFM32" microcontrollers.
*
* This copyright notice may not be removed from the source code nor changed.
*
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
* obligation to support this Software. Energy Micro AS is providing the
* Software "AS IS", with no express or implied warranties of any kind,
* including, but not limited to, any implied warranties of merchantability
* or fitness for any particular purpose or warranties against infringement
* of any proprietary rights of a third party.
*
* Energy Micro AS will not be liable for any consequential, incidental, or
* special damages, or any other relief, or for any claim by any third party,
* arising from your use of this Software.
*
******************************************************************************/
#ifndef __EFM32_I2C_H
#define __EFM32_I2C_H
#include <stdbool.h>
#include "efm32.h"
#ifdef __cplusplus
extern "C" {
#endif
/***************************************************************************//**
* @addtogroup EFM32_Library
* @{
******************************************************************************/
/***************************************************************************//**
* @addtogroup I2C
* @{
******************************************************************************/
/*******************************************************************************
******************************* DEFINES ***********************************
******************************************************************************/
/**
* @brief
* Standard mode max frequency assuming using 4:4 ratio for Nlow:Nhigh.
* @details
* From I2C specification: Min Tlow = 4.7us, min Thigh = 4.0us,
* max Trise=1.0us, max Tfall=0.3us. Since ratio is 4:4, have to use
* worst case value of Tlow or Thigh as base.
*
* 1/(Tlow + Thigh + 1us + 0.3us) = 1/(4.7 + 4.7 + 1.3)us = 93458Hz
*/
#define I2C_FREQ_STANDARD_MAX 93500
/**
* @brief
* Fast mode max frequency assuming using 6:3 ratio for Nlow:Nhigh.
* @details
* From I2C specification: Min Tlow = 1.3us, min Thigh = 0.6us,
* max Trise=0.3us, max Tfall=0.3us. Since ratio is 6:3, have to use
* worst case value of Tlow or 2xThigh as base.
*
* 1/(Tlow + Thigh + 0.3us + 0.3us) = 1/(1.3 + 0.65 + 0.6)us = 392157Hz
*/
#define I2C_FREQ_FAST_MAX 392500
/**
* @brief
* Fast mode+ max frequency assuming using 11:6 ratio for Nlow:Nhigh.
* @details
* From I2C specification: Min Tlow = 0.5us, min Thigh = 0.26us,
* max Trise=0.012us, max Tfall=0.12us. Since ratio is 11:6, have to use
* worst case value of Tlow or (11/6)xThigh as base.
*
* 1/(Tlow + Thigh + 0.12us + 0.12us) = 1/(0.5 + 0.273 + 0.24)us = 987167Hz
*/
#define I2C_FREQ_FASTPLUS_MAX 987500
/**
* @brief
* Indicate plain write sequence: S+ADDR(W)+DATA0+P.
* @details
* @li S - Start
* @li ADDR(W) - address with W/R bit cleared
* @li DATA0 - Data taken from buffer with index 0
* @li P - Stop
*/
#define I2C_FLAG_WRITE 0x0001
/**
* @brief
* Indicate plain read sequence: S+ADDR(R)+DATA0+P.
* @details
* @li S - Start
* @li ADDR(R) - address with W/R bit set
* @li DATA0 - Data read into buffer with index 0
* @li P - Stop
*/
#define I2C_FLAG_READ 0x0002
/**
* @brief
* Indicate combined write/read sequence: S+ADDR(W)+DATA0+Sr+ADDR(R)+DATA1+P.
* @details
* @li S - Start
* @li Sr - Repeated start
* @li ADDR(W) - address with W/R bit cleared
* @li ADDR(R) - address with W/R bit set
* @li DATAn - Data written from/read into buffer with index n
* @li P - Stop
*/
#define I2C_FLAG_WRITE_READ 0x0004
/**
* @brief
* Indicate write sequence using two buffers: S+ADDR(W)+DATA0+DATA1+P.
* @details
* @li S - Start
* @li ADDR(W) - address with W/R bit cleared
* @li DATAn - Data written from buffer with index n
* @li P - Stop
*/
#define I2C_FLAG_WRITE_WRITE 0x0008
/** Use 10 bit address. */
#define I2C_FLAG_10BIT_ADDR 0x0010
/*******************************************************************************
******************************** ENUMS ************************************
******************************************************************************/
/** Clock low to high ratio settings. */
typedef enum
{
i2cClockHLRStandard = _I2C_CTRL_CLHR_STANDARD, /**< Ratio is 4:4 */
i2cClockHLRAsymetric = _I2C_CTRL_CLHR_ASYMMETRIC, /**< Ratio is 6:3 */
i2cClockHLRFast = _I2C_CTRL_CLHR_FAST /**< Ratio is 11:3 */
} I2C_ClockHLR_TypeDef;
/** Return codes for single master mode transfer function. */
typedef enum
{
/* In progress code (>0) */
i2cTransferInProgress = 1, /**< Transfer in progress. */
/* Complete code (=0) */
i2cTransferDone = 0, /**< Transfer completed successfully. */
/* Transfer error codes (<0) */
i2cTransferNack = -1, /**< NACK received during transfer. */
i2cTransferBusErr = -2, /**< Bus error during transfer (misplaced START/STOP). */
i2cTransferArbLost = -3, /**< Arbitration lost during transfer. */
i2cTransferUsageFault = -4, /**< Usage fault. */
i2cTransferSwFault = -5 /**< SW fault. */
} I2C_TransferReturn_TypeDef;
/*******************************************************************************
******************************* STRUCTS ***********************************
******************************************************************************/
/** I2C initialization structure. */
typedef struct
{
/** Enable I2C peripheral when init completed. */
bool enable;
/** Set to master (true) or slave (false) mode */
bool master;
/**
* I2C reference clock assumed when configuring bus frequency setup.
* Set it to 0 if currently configurated reference clock shall be used
* This parameter is only applicable if operating in master mode.
*/
uint32_t refFreq;
/**
* (Max) I2C bus frequency to use. This parameter is only applicable
* if operating in master mode.
*/
uint32_t freq;
/** Clock low/high ratio control. */
I2C_ClockHLR_TypeDef clhr;
} I2C_Init_TypeDef;
/** Suggested default config for I2C init structure. */
#define I2C_INIT_DEFAULT \
{ true, /* Enable when init done */ \
true, /* Set to master mode */ \
0, /* Use currently configured reference clock */ \
I2C_FREQ_STANDARD_MAX, /* Set to standard rate assuring being */ \
/* within I2C spec */ \
i2cClockHLRStandard /* Set to use 4:4 low/high duty cycle */ \
}
/**
* @brief
* Master mode transfer message structure used to define a complete
* I2C transfer sequence (from start to stop).
* @details
* The structure allows for defining the following types of sequences,
* please refer to defines for sequence details.
* @li #I2C_FLAG_READ - data read into buf[0].data
* @li #I2C_FLAG_WRITE - data written from buf[0].data
* @li #I2C_FLAG_WRITE_READ - data written from buf[0].data and read
* into buf[1].data
* @li #I2C_FLAG_WRITE_WRITE - data written from buf[0].data and
* buf[1].data
*/
typedef struct
{
/**
* @brief
* Address to use after (repeated) start.
* @details
* Layout details, A = address bit, X = don't care bit (set to 0):
* @li 7 bit address - use format AAAA AAAX.
* @li 10 bit address - use format XXXX XAAX AAAA AAAA
*/
uint16_t addr;
/** Flags defining sequence type and details, see I2C_FLAG_... defines. */
uint16_t flags;
/**
* Buffers used to hold data to send from or receive into depending
* on sequence type.
*/
struct
{
/** Buffer used for data to transmit/receive, must be @p len long. */
uint8_t *data;
/**
* Number of bytes in @p data to send or receive. Notice that when
* receiving data to this buffer, at least 1 byte must be received.
* Setting @p len to 0 in the receive case is considered a usage fault.
* Transmitting 0 bytes is legal, in which case only the address
* is transmitted after the start condition.
*/
uint16_t len;
} buf[2];
} I2C_TransferSeq_TypeDef;
/*******************************************************************************
***************************** PROTOTYPES **********************************
******************************************************************************/
uint32_t I2C_BusFreqGet(I2C_TypeDef *i2c);
void I2C_BusFreqSet(I2C_TypeDef *i2c,
uint32_t refFreq,
uint32_t freq,
I2C_ClockHLR_TypeDef type);
void I2C_Enable(I2C_TypeDef *i2c, bool enable);
void I2C_Init(I2C_TypeDef *i2c, const I2C_Init_TypeDef *init);
/***************************************************************************//**
* @brief
* Clear one or more pending I2C interrupts.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @param[in] flags
* Pending I2C interrupt source to clear. Use a bitwse logic OR combination of
* valid interrupt flags for the I2C module (I2C_IF_nnn).
******************************************************************************/
static __INLINE void I2C_IntClear(I2C_TypeDef *i2c, uint32_t flags)
{
i2c->IFC = flags;
}
/***************************************************************************//**
* @brief
* Disable one or more I2C interrupts.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @param[in] flags
* I2C interrupt sources to disable. Use a bitwise logic OR combination of
* valid interrupt flags for the I2C module (I2C_IF_nnn).
******************************************************************************/
static __INLINE void I2C_IntDisable(I2C_TypeDef *i2c, uint32_t flags)
{
i2c->IEN &= ~(flags);
}
/***************************************************************************//**
* @brief
* Enable one or more I2C interrupts.
*
* @note
* Depending on the use, a pending interrupt may already be set prior to
* enabling the interrupt. Consider using I2C_IntClear() prior to enabling
* if such a pending interrupt should be ignored.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @param[in] flags
* I2C interrupt sources to enable. Use a bitwise logic OR combination of
* valid interrupt flags for the I2C module (I2C_IF_nnn).
******************************************************************************/
static __INLINE void I2C_IntEnable(I2C_TypeDef *i2c, uint32_t flags)
{
i2c->IEN |= flags;
}
/***************************************************************************//**
* @brief
* Get pending I2C interrupt flags.
*
* @note
* The event bits are not cleared by the use of this function.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @return
* I2C interrupt sources pending. A bitwise logic OR combination of valid
* interrupt flags for the I2C module (I2C_IF_nnn).
******************************************************************************/
static __INLINE uint32_t I2C_IntGet(I2C_TypeDef *i2c)
{
return(i2c->IF);
}
/***************************************************************************//**
* @brief
* Set one or more pending I2C interrupts from SW.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @param[in] flags
* I2C interrupt sources to set to pending. Use a bitwise logic OR combination
* of valid interrupt flags for the I2C module (I2C_IF_nnn).
******************************************************************************/
static __INLINE void I2C_IntSet(I2C_TypeDef *i2c, uint32_t flags)
{
i2c->IFS = flags;
}
void I2C_Reset(I2C_TypeDef *i2c);
/***************************************************************************//**
* @brief
* Get slave address used for I2C peripheral (when operating in slave mode).
*
* @details
* For 10 bit addressing mode, the address is split in two bytes, and only
* the first byte setting is fetched, effectively only controlling the 2 most
* significant bits of the 10 bit address. Full handling of 10 bit addressing
* in slave mode requires additional SW handling.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @return
* I2C slave address in use. The 7 most significant bits define the actual
* address, the least significant bit is reserved and always returned as 0.
******************************************************************************/
static __INLINE uint8_t I2C_SlaveAddressGet(I2C_TypeDef *i2c)
{
return((uint8_t)(i2c->SADDR));
}
/***************************************************************************//**
* @brief
* Set slave address to use for I2C peripheral (when operating in slave mode).
*
* @details
* For 10 bit addressing mode, the address is split in two bytes, and only
* the first byte is set, effectively only controlling the 2 most significant
* bits of the 10 bit address. Full handling of 10 bit addressing in slave
* mode requires additional SW handling.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @param[in] addr
* I2C slave address to use. The 7 most significant bits define the actual
* address, the least significant bit is reserved and always set to 0.
******************************************************************************/
static __INLINE void I2C_SlaveAddressSet(I2C_TypeDef *i2c, uint8_t addr)
{
i2c->SADDR = (uint32_t)addr & 0xfe;
}
/***************************************************************************//**
* @brief
* Get slave address mask used for I2C peripheral (when operating in slave
* mode).
*
* @details
* The address mask defines how the comparator works. A bit position with
* value 0 means that the corresponding slave address bit is ignored during
* comparison (don't care). A bit position with value 1 means that the
* corresponding slave address bit must match.
*
* For 10 bit addressing mode, the address is split in two bytes, and only
* the mask for the first address byte is fetched, effectively only
* controlling the 2 most significant bits of the 10 bit address.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @return
* I2C slave address mask in use. The 7 most significant bits define the
* actual address mask, the least significant bit is reserved and always
* returned as 0.
******************************************************************************/
static __INLINE uint8_t I2C_SlaveAddressMaskGet(I2C_TypeDef *i2c)
{
return((uint8_t)(i2c->SADDRMASK));
}
/***************************************************************************//**
* @brief
* Set slave address mask used for I2C peripheral (when operating in slave
* mode).
*
* @details
* The address mask defines how the comparator works. A bit position with
* value 0 means that the corresponding slave address bit is ignored during
* comparison (don't care). A bit position with value 1 means that the
* corresponding slave address bit must match.
*
* For 10 bit addressing mode, the address is split in two bytes, and only
* the mask for the first address byte is set, effectively only controlling
* the 2 most significant bits of the 10 bit address.
*
* @param[in] i2c
* Pointer to I2C peripheral register block.
*
* @param[in] mask
* I2C slave address mask to use. The 7 most significant bits define the
* actual address mask, the least significant bit is reserved and should
* be 0.
******************************************************************************/
static __INLINE void I2C_SlaveAddressMaskSet(I2C_TypeDef *i2c, uint8_t mask)
{
i2c->SADDRMASK = (uint32_t)mask & 0xfe;
}
I2C_TransferReturn_TypeDef I2C_Transfer(I2C_TypeDef *i2c);
I2C_TransferReturn_TypeDef I2C_TransferInit(I2C_TypeDef *i2c,
I2C_TransferSeq_TypeDef *seq);
/** @} (end addtogroup I2C) */
/** @} (end addtogroup EFM32_Library) */
#ifdef __cplusplus
}
#endif
#endif /* __EFM32_I2C_H */
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