incubator-nuttx/include/nuttx/rf/dat-31r5-sp.h

100 lines
3.9 KiB
C

/****************************************************************************
* include/nuttx/rf/dat-31r5-sp.h
* Character driver for the Mini-Circuits DAT-31R5-SP+ digital step
* attenuator.
*
* Copyright (C) 2019, Augusto Fraga Giachero. All rights reserved.
* Author: Augusto Fraga Giachero <afg@augustofg.net>
*
* 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 __INCLUDE_NUTTX_RF_DAT_31R5_SP_H_
#define __INCLUDE_NUTTX_RF_DAT_31R5_SP_H_
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/irq.h>
#include <nuttx/config.h>
#include <nuttx/rf/ioctl.h>
#include <nuttx/spi/spi.h>
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: dat31r5sp_register
*
* Description:
* Register the dat31r5sp character device as 'devpath'. WARNING:
* the DAT-31R5-SP+ is not spi compatible because it hasn't a proper
* chip-select input, but it can coexist with other devices on the
* spi bus assuming that the LE (Latch Enable) is always 0 when the
* device isn't selected. With LE=0 the internal shift-register will
* store the last 6 bits sent through the bus, but it will only
* change the attenuation level when LE=1. This driver sends the
* attenuation bitstream and gives a small positive pulse to LE.
*
* Remember when implementing the corresponding spi select function
* when selected == true LE should be 1, and when selected == false
* LE should be 0.
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/att0"
* spi - An instance of the SPI interface to use to communicate with
* spidev - Number of the spi device (used to drive the Latch Enable pin).
*
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int dat31r5sp_register(FAR const char *devpath,
FAR struct spi_dev_s *spi,
int spidev);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_RF_DAT_31R5_SP_H_ */