gf_i2c_writeread()

Perform an I2C master write/read transaction

Synopsis:

#include <gf/gf.h>

int gf_i2c_writeread ( gf_dev_t     gdev,
                       int          busno,
                       int          slaveaddr,
                       uint8_t *    odata,
                       int          obytes,
                       uint8_t *    idata,
                       int          ibytes );

Arguments:

gdev

The handle for the graphics device to perform the transaction on. This is the handle acquired by gf_dev_attach().

busno

Index of the I2C bus, on which this device is capable of being a master.

slaveaddr

The address of the I2C slave device.

odata

A pointer to a buffer where the outgoing data is stored.

obytes

The number of bytes to write. The maximum is 128 bytes.

idata

A pointer to a buffer where the function can store the incoming data.

ibytes

The number of bytes to read. The maximum is 128 bytes.

Library:

gf

Description:

This function performs an I2C master write/read transaction. The transaction performed is what the I2C specification refers to as a combined transfer format. This is typically used to write a register or memory subaddress to the device, followed by a read transfer from that register/memory.

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Threads should not call this function between calls to gf_draw_begin() and gf_draw_end(), or a deadlock will occur.

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Returns:

GF_ERR_OK

Success.

GF_ERR_PARM

The busno index is out of range for the specified device.

GF_ERR_IODISPLAY

Error communicating with io-display. Check to ensure that io-display is still running. The sloginfo utility may provide more information.

GF_ERR_IO

Hardware error reading from the slave device. The sloginfo utility may provide more information.

GF_ERR_TOOBIG

The number of bytes requested to be read (ibytes) or written (obytes) is larger than the maximum of 128.

Classification:

QNX Graphics Framework

See also:

gf_i2c_read(), gf_i2c_write()