/****************************************************************************
* include/nuttx/i2c.h
*
* Copyright(C) 2009-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 NuttX 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 OWNER 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_I2C_H
#define __INCLUDE_NUTTX_I2C_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* If a dynamic timeout is selected, then a non-negative, non-zero micro-
* seconds per byte value must be provided as well.
*/
#ifdef CONFIG_STM32_I2C_DYNTIMEO
# if CONFIG_STM32_I2C_DYNTIMEO_USECPERBYTE < 1
# warning "Ignoring CONFIG_STM32_I2C_DYNTIMEO because of CONFIG_STM32_I2C_DYNTIMEO_USECPERBYTE"
# undef CONFIG_STM32_I2C_DYNTIMEO
# endif
#endif
/* I2C address calculation. Convert 7- and 10-bit address to 8-bit and
* 16-bit read/write address
*/
#define I2C_READBIT 0x01
/* Convert 7- to 8-bit address */
#define I2C_ADDR8(a) ((a) << 1)
#define I2C_WRITEADDR8(a) I2C_ADDR8(a)
#define I2C_READADDR8(a) (I2C_ADDR8(a) | I2C_READBIT)
/* Convert 10- to 16-bit address */
#define I2C_ADDR10H(a) (0xf0 | (((a) >> 7) & 0x06))
#define I2C_ADDR10L(a) ((a) & 0xff)
#define I2C_WRITEADDR10H(a) I2C_ADDR10H(a)
#define I2C_WRITEADDR10L(a) I2C_ADDR10L(a)
#define I2C_READADDR10H(a) (I2C_ADDR10H(a) | I2C_READBIT)
#define I2C_READADDR10L(a) I2C_ADDR10L(a)
/* Bit definitions for the flags field in struct i2c_msg_s */
#define I2C_M_READ 0x0001 /* Read data, from slave to master */
#define I2C_M_TEN 0x0002 /* Ten bit address */
#define I2C_M_NORESTART 0x0080 /* Message should not begin with
* (re-)start of transfer */
/* Access macros ************************************************************/
/****************************************************************************
* Name: I2C_SETFREQUENCY
*
* Description:
* Set the I2C frequency. This frequency will be retained in the struct
* i2c_dev_s instance and will be used with all transfers. Required.
*
* Input Parameters:
* dev - Device-specific state data
* frequency - The I2C frequency requested
*
* Returned Value:
* Returns the actual frequency selected
*
****************************************************************************/
#define I2C_SETFREQUENCY(d,f) ((d)->ops->setfrequency(d,f))
/****************************************************************************
* Name: I2C_SETADDRESS
*
* Description:
* Set the I2C slave address. This frequency will be retained in the struct
* i2c_dev_s instance and will be used with all transfers. Required.
*
* Input Parameters:
* dev - Device-specific state data
* address - The I2C slave address
* nbits - The number of address bits provided (7 or 10)
*
* Returned Value:
* Returns OK on success; a negated errno on failure.
*
****************************************************************************/
#define I2C_SETADDRESS(d,a,n) ((d)->ops->setaddress(d,a,n))
/****************************************************************************
* Name: I2C_SETOWNADDRESS
*
* Description:
* Set our own I2C address. Calling this function enables Slave mode and
* disables Master mode on given instance (note that I2C is a bus, where
* multiple masters and slave may be handled by one device driver).
*
* One may register a callback to be notified about reception. During the
* slave mode reception, the function READ and WRITE must be used to
* to handle reads and writes from a master.
*
* Input Parameters:
* dev - Device-specific state data
* address - Our own slave address; If it is 0x00, then the device driver
* listens to general call
* nbits - The number of address bits provided (7 or 10)
*
* Returned Value:
* OK on valid address and if the same address has not been assigned
* to another instance sharing the same port. Otherwise ERROR is returned.
*
****************************************************************************/
#define I2C_SETOWNADDRESS(d,a,n) ((d)->ops->setownaddress(d,a,n))
/****************************************************************************
* Name: I2C_WRITE
*
* Description:
* Send a block of data on I2C using the previously selected I2C
* frequency and slave address. Each write operational will be an 'atomic'
* operation in the sense that any other I2C actions will be serialized
* and pend until this write completes. Required.
*
* Input Parameters:
* dev - Device-specific state data
* buffer - A pointer to the read-only buffer of data to be written to device
* buflen - The number of bytes to send from the buffer
*
* Returned Value:
* 0: success, <0: A negated errno
*
****************************************************************************/
#define I2C_WRITE(d,b,l) ((d)->ops->write(d,b,l))
/****************************************************************************
* Name: I2C_READ
*
* Description:
* Receive a block of data from I2C using the previously selected I2C
* frequency and slave address. Each read operational will be an 'atomic'
* operation in the sense that any other I2C actions will be serialized
* and pend until this read completes. Required.
*
* Input Parameters:
* dev - Device-specific state data
* buffer - A pointer to a buffer of data to receive the data from the device
* buflen - The requested number of bytes to be read
*
* Returned Value:
* 0: success, <0: A negated errno
*
****************************************************************************/
#define I2C_READ(d,b,l) ((d)->ops->read(d,b,l))
/****************************************************************************
* Name: I2C_WRITEREAD
*
* Description:
* Send a block of data on I2C using the previously selected I2C
* frequency and slave address, followed by restarted read access.
* It provides a convenient wrapper to the transfer function.
*
* Input Parameters:
* dev - Device-specific state data
* wbuffer - A pointer to the read-only buffer of data to be written to device
* wbuflen - The number of bytes to send from the buffer
* rbuffer - A pointer to a buffer of data to receive the data from the device
* rbuflen - The requested number of bytes to be read
*
* Returned Value:
* 0: success, <0: A negated errno
*
****************************************************************************/
#define I2C_WRITEREAD(d,wb,wl,rb,rl) ((d)->ops->writeread(d,wb,wl,rb,rl))
/****************************************************************************
* Name: I2C_TRANSFER
*
* Description:
* Perform a sequence of I2C transfers, each transfer is started with a
* START and the final transfer is completed with a STOP. Each sequence
* will be an 'atomic' operation in the sense that any other I2C actions
* will be serialized and pend until this read completes. Optional.
*
* Input Parameters:
* dev - Device-specific state data
* msgs - A pointer to a set of message descriptors
* msgcount - The number of transfers to perform
*
* Returned Value:
* The number of transfers completed
*
****************************************************************************/
#define I2C_TRANSFER(d,m,c) ((d)->ops->transfer(d,m,c))
/****************************************************************************
* Public Types
****************************************************************************/
/* The I2C vtable */
struct i2c_dev_s;
struct i2c_msg_s;
struct i2c_ops_s
{
uint32_t (*setfrequency)(FAR struct i2c_dev_s *dev, uint32_t frequency);
int (*setaddress)(FAR struct i2c_dev_s *dev, int addr, int nbits);
int (*write)(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen);
int (*read)(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen);
#ifdef CONFIG_I2C_WRITEREAD
int (*writeread)(FAR struct i2c_dev_s *inst, const uint8_t *wbuffer, int wbuflen,
uint8_t *rbuffer, int rbuflen);
#endif
#ifdef CONFIG_I2C_TRANSFER
int (*transfer)(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int count);
#endif
#ifdef CONFIG_I2C_SLAVE
int (*setownaddress)(FAR struct i2c_dev_s *dev, int addr, int nbits);
int (*registercallback)(FAR struct i2c_dev_s *dev, int (*callback)(void) );
#endif
};
/* I2C transaction segment beginning with a START. A number of these can
* be transferred together to form an arbitrary sequence of write/read transfer
* to an I2C slave device.
*/
struct i2c_msg_s
{
uint16_t addr; /* Slave address */
uint16_t flags; /* See I2C_M_* definitions */
uint8_t *buffer;
int length;
};
/* I2C private data. This structure only defines the initial fields of the
* structure visible to the I2C client. The specific implementation may
* add additional, device specific fields after the vtable.
*/
struct i2c_dev_s
{
const struct i2c_ops_s *ops; /* I2C vtable */
};
/****************************************************************************
* Public Functions
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: up_i2cinitialize
*
* Description:
* Initialize the selected I2C port. And return a unique instance of struct
* struct i2c_dev_s. This function may be called to obtain multiple
* instances of the interface, each of which may be set up with a
* different frequency and slave address.
*
* Input Parameter:
* Port number (for hardware that has multiple I2C interfaces)
*
* Returned Value:
* Valid I2C device structure reference on succcess; a NULL on failure
*
****************************************************************************/
EXTERN FAR struct i2c_dev_s *up_i2cinitialize(int port);
/****************************************************************************
* Name: up_i2cuninitialize
*
* Description:
* De-initialize the selected I2C port, and power down the device.
*
* Input Parameter:
* Device structure as returned by the up_i2cinitialize()
*
* Returned Value:
* OK on success, ERROR when internal reference count mismatch or dev
* points to invalid hardware device.
*
****************************************************************************/
EXTERN int up_i2cuninitialize(FAR struct i2c_dev_s *dev);
/************************************************************************************
* Name: up_i2creset
*
* Description:
* Reset an I2C bus
*
************************************************************************************/
#ifdef CONFIG_I2C_RESET
EXTERN int up_i2creset(FAR struct i2c_dev_s *dev);
#endif
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_NUTTX_I2C_H */
