277d358eda
This driver does debouncing and best lradc usage and only requires a sorted table of values to work, this factoring code as much as possible. Change-Id: I84b46f4b08094634e1c5deb5ca9ba20763389e66
56 lines
2.2 KiB
C
56 lines
2.2 KiB
C
/***************************************************************************
|
|
* __________ __ ___.
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
|
* \/ \/ \/ \/ \/
|
|
* $Id$
|
|
*
|
|
* Copyright (C) 2013 by Amaury Pouly
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
* KIND, either express or implied.
|
|
*
|
|
****************************************************************************/
|
|
#ifndef __button_lradc_imx233__
|
|
#define __button_lradc_imx233__
|
|
|
|
#include "button.h"
|
|
#include "button-target.h"
|
|
|
|
/** This driver implements button sensing with lradc. It does debouncing
|
|
* and can handle hold sensing too. It can be tweaked using the following defines
|
|
* and variables:
|
|
* - imx233_button_lradc_mapping: target-defined table of adc values and mapping
|
|
* - IMX233_BUTTON_LRADC_CHANNEL: lradc channel to use
|
|
*/
|
|
|
|
/* special value for btn to handle HOLD */
|
|
#define IMX233_BUTTON_LRADC_END -1
|
|
#define IMX233_BUTTON_LRADC_HOLD -2
|
|
|
|
struct imx233_button_lradc_mapping_t
|
|
{
|
|
int adc_val;
|
|
int btn;
|
|
};
|
|
|
|
/* target-defined
|
|
* NOTE for proper operation, the table should contain entries for all states, including:
|
|
* - one with adc_val set to default value when no button is pressed
|
|
* - one with adc_val set to value when hold is selected (if hold is sensed using adc)
|
|
* - a dummy entry with btn set to IMX233_BUTTON_LRADC_END as the last entry
|
|
* The table must be sorted by increasing values of adc_val */
|
|
extern struct imx233_button_lradc_mapping_t imx233_button_lradc_mapping[];
|
|
|
|
void imx233_button_lradc_init(void);
|
|
int imx233_button_lradc_read(void);
|
|
bool imx233_button_lradc_hold(void);
|
|
|
|
#endif /* __button_lradc_imx233__ */
|