181 lines
6.5 KiB
C
181 lines
6.5 KiB
C
/****************************************************************************
|
|
* include/nuttx/qencoder.h
|
|
*
|
|
* Copyright (C) 2012, 2015 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* 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 __NUTTX_SENSORS_QENCODER_H
|
|
#define __NUTTX_SENSORS_QENCODER_H
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
#include <nuttx/fs/ioctl.h>
|
|
|
|
#ifdef CONFIG_QENCODER
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
/* Configuration ************************************************************
|
|
* CONFIG_QENCODER - Enables support for the quadrature encoder upper half
|
|
*/
|
|
|
|
/* IOCTL Commands ***********************************************************/
|
|
/* The Quadrature Encode module uses a standard character driver framework.
|
|
* However, since the driver is a devices control interface and not a data
|
|
* transfer interface, the majority of the functionality is implemented in
|
|
* driver ioctl calls. The PWM ioctl commands are listed below:
|
|
*
|
|
* QEIOC_POSITION - Get the current position from the encoder.
|
|
* Argument: int32_t pointer to the location to return the position.
|
|
* QEIOC_RESET - Reset the position to zero.
|
|
* Argument: None
|
|
*/
|
|
|
|
#define QEIOC_POSITION _QEIOC(0x0001) /* Arg: int32_t* pointer */
|
|
#define QEIOC_RESET _QEIOC(0x0002) /* Arg: None */
|
|
|
|
/* User defined ioctl cms should use QEIOC_USER like this:
|
|
*
|
|
* #define QEIOC_MYCMD1 _QEIOC(QEIOC_USER)
|
|
* #define QEIOC_MYCMD2 _QEIOC(QEIOC_USER+1)
|
|
* ...
|
|
*/
|
|
|
|
#define QEIOC_USER 0x0003
|
|
|
|
/****************************************************************************
|
|
* Public Types
|
|
****************************************************************************/
|
|
/* This is the vtable that is used to by the upper half quadrature encoder
|
|
* to call back into the lower half quadrature encoder.
|
|
*/
|
|
|
|
struct qe_lowerhalf_s;
|
|
struct qe_ops_s
|
|
{
|
|
/* This method is called when the driver is opened. The lower half driver
|
|
* should configure and initialize the device so that it is ready for use.
|
|
* The initial position value should be zero.
|
|
*/
|
|
|
|
CODE int (*setup)(FAR struct qe_lowerhalf_s *lower);
|
|
|
|
/* This method is called when the driver is closed. The lower half driver
|
|
* should stop data collection, free any resources, disable timer hardware,
|
|
* and put the system into the lowest possible power usage state
|
|
*/
|
|
|
|
CODE int (*shutdown)(FAR struct qe_lowerhalf_s *lower);
|
|
|
|
/* Return the current position measurement. */
|
|
|
|
CODE int (*position)(FAR struct qe_lowerhalf_s *lower, FAR int32_t *pos);
|
|
|
|
/* Reset the position measurement to zero. */
|
|
|
|
CODE int (*reset)(FAR struct qe_lowerhalf_s *lower);
|
|
|
|
/* Lower-half logic may support platform-specific ioctl commands */
|
|
|
|
CODE int (*ioctl)(FAR struct qe_lowerhalf_s *lower,
|
|
int cmd, unsigned long arg);
|
|
};
|
|
|
|
/* This is the interface between the lower half quadrature encoder driver
|
|
* and the upper half quadrature encoder driver. A (device-specific)
|
|
* instance of this structure is passed to the upper-half driver when the
|
|
* quadrature encoder driver is registered.
|
|
*
|
|
* Normally that lower half logic will have its own, custom state structure
|
|
* that is simply cast to struct qe_lowerhalf_s. In order to perform such
|
|
* casts, the initial fields of the custom state structure match the initial
|
|
* fields of the following generic lower half state structure.
|
|
*/
|
|
|
|
struct qe_lowerhalf_s
|
|
{
|
|
/* The first field of this state structure must be a pointer to the lower-
|
|
* half callback structure:
|
|
*/
|
|
|
|
FAR const struct qe_ops_s *ops;
|
|
|
|
/* The custom timer state structure may include additional fields after
|
|
* the pointer to the callback structure.
|
|
*/
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Public Data
|
|
****************************************************************************/
|
|
|
|
#ifdef __cplusplus
|
|
#define EXTERN extern "C"
|
|
extern "C"
|
|
{
|
|
#else
|
|
#define EXTERN extern
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: qe_register
|
|
*
|
|
* Description:
|
|
* Register the Quadrature Encoder lower half device as 'devpath'
|
|
*
|
|
* Input Parameters:
|
|
* devpath - The full path to the driver to register. E.g., "/dev/qe0"
|
|
* lower - An instance of the lower half interface
|
|
*
|
|
* Returned Value:
|
|
* Zero (OK) on success; a negated errno value on failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int qe_register(FAR const char *devpath, FAR struct qe_lowerhalf_s *lower);
|
|
|
|
#undef EXTERN
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* CONFIG_QENCODER */
|
|
#endif /* __NUTTX_SENSORS_QENCODER_H */
|