incubator-nuttx/include/nuttx/sensors/qencoder.h

222 lines
7.8 KiB
C

/****************************************************************************
* include/nuttx/sensors/qencoder.h
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_SENSORS_QENCODER_H
#define __INCLUDE_NUTTX_SENSORS_QENCODER_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/fs/ioctl.h>
#ifdef CONFIG_SENSORS_QENCODER
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************
* CONFIG_SENSORS_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 device control interface rather than 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
* QEIOC_SETPOSMAX - Set the maximum position for the encoder.
* Argument: uint32_t maximum position
* QEIOC_SETINDEX - Set the index position for the encoder.
* Argument: uint32_t index position
* QEIOC_GETINDEX - Get the index position and count of the encoder.
* The structure also contains current position so QEIOC_POSITION
* is not required when QEIOC_GETINDEX is used.
* Argment: qe_index_s structure (refer below)
*/
#define QEIOC_POSITION _QEIOC(0x0001) /* Arg: int32_t* pointer */
#define QEIOC_RESET _QEIOC(0x0002) /* Arg: None */
#define QEIOC_SETPOSMAX _QEIOC(0x0003) /* Arg: uint32_t */
#define QEIOC_SETINDEX _QEIOC(0x0004) /* Arg: uint32_t */
#define QEIOC_GETINDEX _QEIOC(0x0005) /* Arg: qe_index_s struct */
#define QE_FIRST 0x0001 /* First required command */
#define QE_NCMDS 5 /* 5 required commands */
/* User defined ioctl commands are also supported. These will be forwarded
* by the upper-half QE driver to the lower-half QE driver via the ioctl()
* method of the QE lower-half interface. However, the lower-half driver
* must reserve a block of commands as follows in order prevent IOCTL
* command numbers from overlapping.
*/
/* See arch/arm/src/tiva/tiva_qencoder.h (Not usable at that location) */
#define QE_TIVA_FIRST (QE_FIRST + QE_NCMDS)
#define QE_TIVA_NCMDS 5
/* See include/nuttx/sensors/as5048b.h */
#define QE_AS5048B_FIRST (QE_TIVA_FIRST + QE_TIVA_NCMDS)
#define QE_AS5048B_NCMDS 4
/* See arch/arm/src/imxrt/imxrt_enc.h */
#define QE_IMXRT_FIRST (QE_AS5048B_FIRST + QE_AS5048B_NCMDS)
#define QE_IMXRT_NCMDS 7
/* See include/nuttx/sensors/as5048a.h */
#define QE_AS5048A_FIRST (QE_IMXRT_FIRST + QE_IMXRT_NCMDS)
#define QE_AS5048A_NCMDS 4
/****************************************************************************
* 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);
/* Set the maximum encoder position. */
CODE int (*setposmax)(FAR struct qe_lowerhalf_s *lower, uint32_t pos);
/* Reset the position measurement to zero. */
CODE int (*reset)(FAR struct qe_lowerhalf_s *lower);
/* Set the index pin position */
CODE int (*setindex)(FAR struct qe_lowerhalf_s *lower, uint32_t pos);
/* Lower-half logic may support platform-specific ioctl commands */
CODE int (*ioctl)(FAR struct qe_lowerhalf_s *lower,
int cmd, unsigned long arg);
};
/* Structure qe_index_s is used for QEIOC_GETINDEX call. This call returns
* current encoder position, the last index position and number of index
* occurances.
*/
struct qe_index_s
{
int32_t qenc_pos; /* Qencoder actual position */
int32_t indx_pos; /* Index last position */
int16_t indx_cnt; /* Number of index occurances */
};
/* 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_SENSORS_QENCODER */
#endif /* __INCLUDE_NUTTX_SENSORS_QENCODER_H */