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- /****************************************************************************
- * drivers/i2c/i2c_read.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_read
- *
- * Description:
- * Receive a block of data from I2C. Each read operation will be an
- * 'atomic' operation in the sense that any other I2C actions will be
- * serialized and pend until this read completes.
- *
- * 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
- *
- ****************************************************************************/
- int i2c_read(FAR struct i2c_master_s *dev,
- FAR const struct i2c_config_s *config,
- FAR uint8_t *buffer, int buflen)
- {
- struct i2c_msg_s msg;
- unsigned int flags;
- int ret;
- /* 7- or 10-bit? */
- flags = (config->addrlen == 10) ? I2C_M_TEN : 0;
- /* Setup for the transfer */
- msg.frequency = config->frequency,
- msg.addr = config->address,
- msg.flags = (flags | I2C_M_READ);
- msg.buffer = buffer;
- msg.length = buflen;
- /* Then perform the transfer. */
- ret = I2C_TRANSFER(dev, &msg, 1);
- return (ret >= 0) ? OK : ret;
- }
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