/****************************************************************************
* include/nuttx/i2c.h
*
* Copyright(C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 __NUTTX_I2C_H
#define __NUTTX_I2C_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
/****************************************************************************
* Definitions
****************************************************************************/
/* I2C address calculation. Convert 7-bit address to 8-bit read/write address */
#define I2C_READADDR(a) (((a) << 1) | 1)
#define I2C_WRITEADDR(a) ((a) << 1)
/* 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
*
* Returned Value:
* Returns the actual frequency selected
*
****************************************************************************/
#define I2C_SETADDRESS(d,f) ((d)->ops->setaddress(d,f))
/****************************************************************************
* 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))
/****************************************************************************
* Public Types
****************************************************************************/
/* The I2C vtable */
struct i2c_dev_s;
struct i2c_ops_s
{
uint32 (*setfrequency)(FAR struct i2c_dev_s *dev, uint32 frequency);
int (*setaddress)(FAR struct i2c_dev_s *dev, int addr);
int (*write)(FAR struct i2c_dev_s *dev, const ubyte *buffer, int buflen);
int (*read)(FAR struct i2c_dev_s *dev, ubyte *buffer, int buflen);
};
/* 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 mutiple I2C interfaces)
*
* Returned Value:
* Valid I2C device structre reference on succcess; a NULL on failure
*
****************************************************************************/
EXTERN FAR struct i2c_dev_s *up_i2cinitialize(int port);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __NUTTX_I2C_H */
