334 lines
12 KiB
C
334 lines
12 KiB
C
/****************************************************************************
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* include/nuttx/i2c/i2c.h
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*
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* Copyright(C) 2009-2011 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES(INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#ifndef __INCLUDE_NUTTX_I2C_I2C_H
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#define __INCLUDE_NUTTX_I2C_I2C_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <stdint.h>
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* I2C address calculation. Convert 7- and 10-bit address to 8-bit and
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* 16-bit read/write address
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*/
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#define I2C_READBIT 0x01
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/* Conver 7- to 8-bit address */
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#define I2C_ADDR8(a) ((a) << 1)
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#define I2C_WRITEADDR8(a) I2C_ADDR8(a)
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#define I2C_READADDR8(a) (I2C_ADDR8(a) | I2C_READBIT)
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/* Convert 10- to 16-bit address */
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#define I2C_ADDR10H(a) (0xf0 | (((a) >> 7) & 0x06))
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#define I2C_ADDR10L(a) ((a) & 0xff)
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#define I2C_WRITEADDR10H(a) I2C_ADDR10H(a)
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#define I2C_WRITEADDR10L(a) I2C_ADDR10L(a)
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#define I2C_READADDR10H(a) (I2C_ADDR10H(a) | I2C_READBIT)
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#define I2C_READADDR10L(a) I2C_ADDR10L(a)
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/* Bit definitions for the flags field in struct i2c_ops_s */
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#define I2C_M_READ 0x0001 /* read data, from slave to master */
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#define I2C_M_TEN 0x0002 /* ten bit address */
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#define I2C_M_NORESTART 0x0080 /* message should not begin with (re-)start of transfer */
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/* Access macros */
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/****************************************************************************
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* Name: I2C_SETFREQUENCY
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*
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* Description:
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* Set the I2C frequency. This frequency will be retained in the struct
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* i2c_dev_s instance and will be used with all transfers. Required.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* frequency - The I2C frequency requested
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*
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* Returned Value:
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* Returns the actual frequency selected
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*
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****************************************************************************/
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#define I2C_SETFREQUENCY(d,f) ((d)->ops->setfrequency(d,f))
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/****************************************************************************
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* Name: I2C_SETADDRESS
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*
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* Description:
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* Set the I2C slave address. This frequency will be retained in the struct
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* i2c_dev_s instance and will be used with all transfers. Required.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* address - The I2C slave address
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* nbits - The number of address bits provided (7 or 10)
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*
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* Returned Value:
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* Returns OK on success; a negated errno on failure.
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*
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****************************************************************************/
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#define I2C_SETADDRESS(d,f,b) ((d)->ops->setaddress(d,f,b))
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/****************************************************************************
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* Name: I2C_SETOWNADDRESS
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*
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* Description:
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* Set our own I2C address. Calling this function enables Slave mode and
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* disables Master mode on given instance (note that I2C is a bus, where
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* multiple masters and slave may be handled by one device driver).
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*
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* One may register callback to be notifyed about reception. During the
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* slave mode reception, the function READ and WRITE must be used to
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* to handle reads and writes from a master.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* address - Our own slave address; If it is 0x00, then the device driver
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* listens to general call
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* nbits - The number of address bits provided (7 or 10)
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*
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* Returned Value:
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* OK on valid address and if the same address has not been assigned
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* to other existance sharing the same port. Otherwise ERROR is returned.
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*
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****************************************************************************/
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#define I2C_SETOWNADDRESS(d,f,b) ((d)->ops->setownaddress(d,f,b))
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/****************************************************************************
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* Name: I2C_WRITE
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*
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* Description:
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* Send a block of data on I2C using the previously selected I2C
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* frequency and slave address. Each write operational will be an 'atomic'
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* operation in the sense that any other I2C actions will be serialized
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* and pend until this write completes. Required.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* buffer - A pointer to the read-only buffer of data to be written to device
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* buflen - The number of bytes to send from the buffer
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*
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* Returned Value:
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* 0: success, <0: A negated errno
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*
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****************************************************************************/
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#define I2C_WRITE(d,b,l) ((d)->ops->write(d,b,l))
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/****************************************************************************
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* Name: I2C_READ
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*
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* Description:
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* Receive a block of data from I2C using the previously selected I2C
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* frequency and slave address. Each read operational will be an 'atomic'
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* operation in the sense that any other I2C actions will be serialized
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* and pend until this read completes. Required.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* buffer - A pointer to a buffer of data to receive the data from the device
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* buflen - The requested number of bytes to be read
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*
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* Returned Value:
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* 0: success, <0: A negated errno
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*
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****************************************************************************/
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#define I2C_READ(d,b,l) ((d)->ops->read(d,b,l))
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/****************************************************************************
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* Name: I2C_WRITEREAD
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*
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* Description:
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* Send a block of data on I2C using the previously selected I2C
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* frequency and slave address, followed by restarted read access.
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* It provides a convenient wrapper to the transfer function.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* wbuffer - A pointer to the read-only buffer of data to be written to device
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* wbuflen - The number of bytes to send from the buffer
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* rbuffer - A pointer to a buffer of data to receive the data from the device
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* rbuflen - The requested number of bytes to be read
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*
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* Returned Value:
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* 0: success, <0: A negated errno
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*
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****************************************************************************/
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#define I2C_WRITEREAD(d,wb,wl,rb,rl) ((d)->ops->writeread(d,wb,wl,rb,rl))
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/****************************************************************************
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* Name: I2C_TRANSFER
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*
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* Description:
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* Perform a sequence of I2C transfers, each transfer is started with a
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* START and the final transfer is completed with a STOP. Each sequence
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* will be an 'atomic' operation in the sense that any other I2C actions
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* will be serialized and pend until this read completes. Optional.
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*
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* Input Parameters:
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* dev - Device-specific state data
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* msgs - A pointer to a set of message descriptors
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* msgcount - The number of transfers to perform
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*
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* Returned Value:
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* The number of transfers completed
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*
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****************************************************************************/
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#define I2C_TRANSFER(d,m,c) ((d)->ops->transfer(d,m,c))
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/****************************************************************************
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* Public Types
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****************************************************************************/
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/* The I2C vtable */
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struct i2c_dev_s;
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struct i2c_msg_s;
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struct i2c_ops_s
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{
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uint32_t (*setfrequency)(FAR struct i2c_dev_s *dev, uint32_t frequency);
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int (*setaddress)(FAR struct i2c_dev_s *dev, int addr, int nbits);
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int (*write)(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen);
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int (*read)(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen);
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#ifdef CONFIG_I2C_WRITEREAD
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int (*writeread)(FAR struct i2c_dev_s *inst, const uint8_t *wbuffer, int wbuflen,
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uint8_t *rbuffer, int rbuflen);
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#endif
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#ifdef CONFIG_I2C_TRANSFER
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int (*transfer)(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int count);
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#endif
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#ifdef CONFIG_I2C_SLAVE
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int (*setownaddress)(FAR struct i2c_dev_s *dev, int addr, int nbits);
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int (*registercallback)(FAR struct i2c_dev_s *dev, int (*callback)(void) );
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#endif
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};
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/* I2C transaction segment beginning with a START. A number of these can
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* be transfered together to form an arbitrary sequence of write/read transfer
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* to an I2C slave device.
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*/
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struct i2c_msg_s
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{
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uint16_t addr; /* Slave address */
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uint16_t flags; /* See I2C_M_* definitions */
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uint8_t *buffer;
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int length;
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};
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/* I2C private data. This structure only defines the initial fields of the
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* structure visible to the I2C client. The specific implementation may
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* add additional, device specific fields after the vtable.
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*/
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struct i2c_dev_s
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{
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const struct i2c_ops_s *ops; /* I2C vtable */
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};
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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#undef EXTERN
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#if defined(__cplusplus)
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#define EXTERN extern "C"
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extern "C" {
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#else
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#define EXTERN extern
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#endif
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/****************************************************************************
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* Name: up_i2cinitialize
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*
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* Description:
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* Initialize the selected I2C port. And return a unique instance of struct
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* struct i2c_dev_s. This function may be called to obtain multiple
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* instances of the interface, each of which may be set up with a
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* different frequency and slave address.
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*
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* Input Parameter:
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* Port number (for hardware that has mutiple I2C interfaces)
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*
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* Returned Value:
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* Valid I2C device structre reference on succcess; a NULL on failure
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*
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****************************************************************************/
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EXTERN FAR struct i2c_dev_s *up_i2cinitialize(int port);
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/****************************************************************************
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* Name: up_i2cuninitialize
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*
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* Description:
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* De-initialize the selected I2C port, and power down the device.
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*
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* Input Parameter:
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* Device structure as returned by the up_i2cinitalize()
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*
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* Returned Value:
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* OK on success, ERROR when internal reference count missmatch or dev
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* points to invalid hardware device.
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*
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****************************************************************************/
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EXTERN int up_i2cuninitialize(FAR struct i2c_dev_s * dev);
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#undef EXTERN
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#if defined(__cplusplus)
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}
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#endif
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#endif /* __INCLUDE_NUTTX_I2C_I2C_H */
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