fsl_kpp.c

/*
 * Copyright 2017 NXP
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * o Redistributions of source code must retain the above copyright notice, this list
 *   of conditions and the following disclaimer.
 *
 * o 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.
 *
 * o Neither the name of the copyright holder 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 HOLDER 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.
 */

#include "fsl_kpp.h"

/*******************************************************************************
 * Definitions
 ******************************************************************************/
#define KPP_KEYPAD_SCAN_TIMES (3U)
/*******************************************************************************
 * Prototypes
 ******************************************************************************/

/*******************************************************************************
 * Variables
 ******************************************************************************/

#if !(defined(FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL) && FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL)
/*! @brief Pointers to SEMC clocks for each instance. */
static const clock_ip_name_t s_kppClock[FSL_FEATURE_SOC_KPP_COUNT] = KPP_CLOCKS;
#endif /* FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL */

/*! @brief Pointers to SEMC bases for each instance. */
static KPP_Type *const s_kppBases[] = KPP_BASE_PTRS;

/*! @brief Pointers to KPP IRQ number for each instance. */
static const IRQn_Type s_kppIrqs[] = KPP_IRQS;
/*******************************************************************************
 * Code
 ******************************************************************************/
static uint32_t KPP_GetInstance(KPP_Type *base)
{
    uint32_t instance;

    /* Find the instance index from base address mappings. */
    for (instance = 0; instance < ARRAY_SIZE(s_kppBases); instance++)
    {
        if (s_kppBases[instance] == base)
        {
            break;
        }
    }

    assert(instance < ARRAY_SIZE(s_kppBases));

    return instance;
}
static void KPP_Mdelay(uint64_t tickets)
{
    while (tickets--)
    {
        __NOP();
    }
}

void KPP_Init(KPP_Type *base, kpp_config_t *configure)
{
    assert(configure);

    uint32_t instance = KPP_GetInstance(base);

#if !(defined(FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL) && FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL)
    /* Un-gate sdram controller clock. */
    CLOCK_EnableClock(s_kppClock[KPP_GetInstance(base)]);
#endif /* FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL */

    /* Clear all. */
    base->KPSR &= ~(KPP_KPSR_KRIE_MASK | KPP_KPSR_KDIE_MASK);

    /* Enable the keypad row and set the column strobe output to open drain. */
    base->KPCR = KPP_KPCR_KRE(configure->activeRow);
    base->KPDR = KPP_KPDR_KCD((uint8_t)~(configure->activeColumn));
    base->KPCR |= KPP_KPCR_KCO(configure->activeColumn);

    /* Set the input direction for row and output direction for column. */
    base->KDDR = KPP_KDDR_KCDD(configure->activeColumn) | KPP_KDDR_KRDD((uint8_t)~(configure->activeRow));

    /* Clear the status flag and enable the interrupt. */
    base->KPSR =
        KPP_KPSR_KPKR_MASK | KPP_KPSR_KPKD_MASK | KPP_KPSR_KDSC_MASK | configure->interrupt;

    if (configure->interrupt)
    {
        /* Enable at the Interrupt */
        EnableIRQ(s_kppIrqs[instance]);
    }
}

void KPP_Deinit(KPP_Type *base)
{
    /* Disable interrupts and disable all rows. */
    base->KPSR &= ~(KPP_KPSR_KRIE_MASK | KPP_KPSR_KDIE_MASK);
    base->KPCR = 0;

#if !(defined(FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL) && FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL)
    /* Disable KPP clock. */
    CLOCK_DisableClock(s_kppClock[KPP_GetInstance(base)]);
#endif /* FSL_SDK_DISABLE_DRIVER_CLOCK_CONTROL */
}

void KPP_keyPressScanning(KPP_Type *base, uint8_t *data, uint32_t clockSrc_Hz)
{
    assert(data);

    uint16_t kppKCO = base->KPCR & KPP_KPCR_KCO_MASK;
    uint8_t columIndex = 0;
    uint8_t activeColumn = (base->KPCR & KPP_KPCR_KCO_MASK) >> KPP_KPCR_KCO_SHIFT;
    uint8_t times;
    uint8_t rowData[KPP_KEYPAD_SCAN_TIMES][KPP_KEYPAD_COLUMNNUM_MAX];
    bool press = false;
    uint8_t column;

    /* Initialize row data to zero. */
    memset(&rowData[0][0], 0, sizeof(rowData));

    /* Scanning. */
    /* Configure the column data to 1 according to column numbers. */
    base->KPDR = KPP_KPDR_KCD_MASK;
    /* Configure column to totem pole for quick discharge of keypad capacitance. */
    base->KPCR &= (uint16_t)(((uint16_t)~kppKCO) | KPP_KPCR_KRE_MASK);
    /* Recover. */
    base->KPCR |= kppKCO;
    /* Three times scanning. */
    for (times = 0; times < KPP_KEYPAD_SCAN_TIMES; times++)
    {
        for (columIndex = 0; columIndex < KPP_KEYPAD_COLUMNNUM_MAX; columIndex++)
        {
            column = activeColumn & (1U << columIndex);
            if (column)
            {
                /* Set the single column line to 0. */
                base->KPDR = KPP_KPDR_KCD(~(uint16_t)column);
                /* Take 100us delays. */
                KPP_Mdelay(clockSrc_Hz / 10000000);
                /* Read row data. */
                rowData[times][columIndex] = ~(base->KPDR & KPP_KPDR_KRD_MASK);
            }
            else
            {
                /* Read row data. */
                rowData[times][columIndex] = 0;
            }
        }
    }
    
    /* Return all columns to 0 in preparation for standby mode. */
    base->KPDR &= ~KPP_KPDR_KCD_MASK;

    /* Check if three time scan data is the same. */
    for (columIndex = 0; columIndex < KPP_KEYPAD_COLUMNNUM_MAX; columIndex++)
    {
        if ((uint8_t)(rowData[0][columIndex] & rowData[1][columIndex]) & rowData[2][columIndex])
        {
            press = true;
        }
    }

    if (press)
    {
        memcpy((void *)data, &rowData[0][0], sizeof(rowData[0]));
    }
    else
    {
        memset((void *)data, 0, sizeof(rowData[0]));
    }
}