/****************************************************************************
* include/nuttx/input/mxt.h
*
* Copyright (C) 2014 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 __INCLUDE_NUTTX_INPUT_MXT_H
#define __INCLUDE_NUTTX_INPUT_MXT_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <nuttx/i2c.h>
#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_MXT)
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Maximum number of threads than can be waiting for POLL events */
#ifndef CONFIG_MXT_NPOLLWAITERS
# define CONFIG_MXT_NPOLLWAITERS 2
#endif
/* Thresholding
*
* New touch positions will only be reported when the X or Y data
* changes by these thresholds. This trades reduced data rates for some
* loss in dragging accuracy. For 12-bit values the raw ranges are
* 0-4095. So for example, if your display is 800x480, then THRESHX=5
* and THRESHY=8 would correspond to a one pixel change.
*
* NOTE: This does nothing to reduce the interrupt rate. It only
* reduces the rate at which touch events are reports.
*/
#ifndef CONFIG_MXT_MXT_THRESHX
# define CONFIG_MXT_MXT_THRESHX 5
#endif
#ifndef CONFIG_MXT_MXT_THRESHY
# define CONFIG_MXT_MXT_THRESHY 8
#endif
/* Buttons are not supported */
#undef CONFIG_MXT_BUTTONS
/* Check for some required settings. This can save the user a lot of time
* in getting the right configuration.
*/
#ifndef CONFIG_I2C_TRANSFER
# error "CONFIG_I2C_TRANSFER is required in the I2C configuration"
#endif
#ifdef CONFIG_DISABLE_SIGNALS
# error "Signals are required. CONFIG_DISABLE_SIGNALS must not be selected."
#endif
#ifndef CONFIG_SCHED_WORKQUEUE
# error "Work queue support required. CONFIG_SCHED_WORKQUEUE must be selected."
#endif
/* Helper macros ************************************************************/
#define MXT_ATTACH(s,isr,arg) ((s)->attach(s,isr,arg))
#define MXT_DETACH(s) ((s)->attach(s,NULL,NULL))
#define MXT_ENABLE(s) ((s)->enable(s,true))
#define MXT_DISABLE(s) ((s)->enable(s,false))
#define MXT_CLEAR(s) ((s)->clear(s))
/****************************************************************************
* Public Types
****************************************************************************/
/* This is the type of the MXT interrupt handler. The lower level code will
* intercept the interrupt and provide the upper level with the private data
* that was provided when the interrupt was attached.
*/
struct mxt_lower_s;
typedef CODE int (*mxt_handler_t)(FAR const struct mxt_lower_s *lower,
FAR void *arg);
/* A reference to a structure of this type must be passed to the MXT
* driver. This structure provides information about the configuration
* of the MXT and provides some board-specific hooks.
*
* Memory for this structure is provided by the caller. It is not copied
* by the driver and is presumed to persist while the driver is active.
*/
struct mxt_lower_s
{
/* Device characterization */
uint32_t frequency; /* Initial I2C frequency */
uint8_t address; /* 7-bit I2C address (only bits 0-6 used) */
/* True: Swap X and Y values */
bool swapxy;
#ifdef CONFIG_MXT_BUTTONS
/* Buttons are not currently supported. But if they were we
* would need to know which which.
*/
uint8_t bmask; /* Bit encoded, see MXT_GPIOn_MASK */
#endif
/* IRQ/GPIO access callbacks. These operations all hidden behind
* callbacks to isolate the MXT driver from differences in GPIO
* interrupt handling by varying boards and MCUs. If possible,
* interrupts should be configured on both rising and falling edges
* so that contact and loss-of-contact events can be detected.
*
* attach - Attach the MXT interrupt handler to the GPIO interrupt
* enable - Enable or disable the GPIO interrupt
* clear - Acknowledge/clear any pending GPIO interrupt
*/
int (*attach)(FAR const struct mxt_lower_s *lower, mxt_handler_t isr,
FAR void *arg);
void (*enable)(FAR const struct mxt_lower_s *lower, bool enable);
void (*clear)(FAR const struct mxt_lower_s *lower);
};
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: mxt_register
*
* Description:
* Configure the maXTouch to use the provided I2C device instance. This
* will register the driver as /dev/inputN where N is the minor device
* number
*
* Input Parameters:
* i2c - An I2C driver instance
* lower - Persistent board configuration data
* minor - The input device minor number
*
* Returned Value:
* Zero is returned on success. Otherwise, a negated errno value is
* returned to indicate the nature of the failure.
*
****************************************************************************/
int mxt_register(FAR struct i2c_dev_s *i2c,
FAR const struct mxt_lower_s *lower, int minor);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_INPUT && CONFIG_INPUT_MXT */
#endif /* __INCLUDE_NUTTX_INPUT_MXT_H */
