incubator-nuttx/drivers/i2c/i2c_write.c

75 lines
2.6 KiB
C

/****************************************************************************
* drivers/i2c/i2c_write.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <nuttx/i2c/i2c_master.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: i2c_write
*
* Description:
* Send a block of data on I2C. Each write operation will be an 'atomic'
* operation in the sense that any other I2C actions will be serialized
* and pend until this write completes.
*
* Input Parameters:
* dev - Device-specific state data
* config - Described the I2C configuration
* 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
*
****************************************************************************/
int i2c_write(FAR struct i2c_master_s *dev,
FAR const struct i2c_config_s *config,
FAR const uint8_t *buffer, int buflen)
{
struct i2c_msg_s msg;
int ret;
/* Setup for the transfer */
msg.frequency = config->frequency,
msg.addr = config->address;
msg.flags = (config->addrlen == 10) ? I2C_M_TEN : 0;
msg.buffer = (FAR uint8_t *)buffer; /* Override const */
msg.length = buflen;
/* Then perform the transfer. */
ret = I2C_TRANSFER(dev, &msg, 1);
return (ret >= 0) ? OK : ret;
}