/*
 * Copyright (C) 2014 Loci Controls Inc.
 *
 * This file is subject to the terms and conditions of the GNU Lesser General
 * Public License v2.1. See the file LICENSE in the top level directory for more
 * details.
 */

/**
 * @ingroup     driver_periph
 * @{
 *
 * @file
 * @brief       Low-level GPIO driver implementation
 *
 * @author      Ian Martin <ian@locicontrols.com>
 *
 * @}
 */

#include <stdint.h>

#include "cpu.h"
#include "periph/gpio.h"
#include "periph_conf.h"

/**
 * @brief Generate a bit mask in which only the specified bit is high.
 *
 * @param[in] n Number of the bit to set high in the mask.
 *
 * @return A bit mask in which bit n is high.
*/
#define BIT(n) ( 1 << (n) )

/**
 * @brief Checks a bit in enable_lut to determine if a GPIO is enabled
 *
 * @param[in] dev RIOT GPIO device number
 *
 * @return 0 or 1 indicating if the specified GPIO is enabled
*/
#define gpio_enabled(dev) ( (enable_lut >> (dev)) & 1 )

static gpio_isr_ctx_t gpio_config[GPIO_NUMOF];

const uint32_t enable_lut = 0
#if GPIO_0_EN
    | BIT(0)
#endif
#if GPIO_1_EN
    | BIT(1)
#endif
#if GPIO_2_EN
    | BIT(2)
#endif
#if GPIO_3_EN
    | BIT(3)
#endif
#if GPIO_4_EN
    | BIT(4)
#endif
#if GPIO_5_EN
    | BIT(5)
#endif
#if GPIO_6_EN
    | BIT(6)
#endif
#if GPIO_7_EN
    | BIT(7)
#endif
#if GPIO_8_EN
    | BIT(8)
#endif
#if GPIO_9_EN
    | BIT(9)
#endif
#if GPIO_10_EN
    | BIT(10)
#endif
#if GPIO_11_EN
    | BIT(11)
#endif
#if GPIO_12_EN
    | BIT(12)
#endif
#if GPIO_13_EN
    | BIT(13)
#endif
#if GPIO_14_EN
    | BIT(14)
#endif
#if GPIO_15_EN
    | BIT(15)
#endif
#if GPIO_16_EN
    | BIT(16)
#endif
#if GPIO_17_EN
    | BIT(17)
#endif
#if GPIO_18_EN
    | BIT(18)
#endif
#if GPIO_19_EN
    | BIT(19)
#endif
#if GPIO_20_EN
    | BIT(20)
#endif
#if GPIO_21_EN
    | BIT(21)
#endif
#if GPIO_22_EN
    | BIT(22)
#endif
#if GPIO_23_EN
    | BIT(23)
#endif
#if GPIO_24_EN
    | BIT(24)
#endif
#if GPIO_25_EN
    | BIT(25)
#endif
#if GPIO_26_EN
    | BIT(26)
#endif
#if GPIO_27_EN
    | BIT(27)
#endif
#if GPIO_28_EN
    | BIT(28)
#endif
#if GPIO_29_EN
    | BIT(29)
#endif
#if GPIO_30_EN
    | BIT(30)
#endif
#if GPIO_31_EN
    | BIT(31)
#endif
;

const unsigned int pin_lut[] = {
#if GPIO_0_EN
    [ 0] = GPIO_0_PIN,
#endif
#if GPIO_1_EN
    [ 1] = GPIO_1_PIN,
#endif
#if GPIO_2_EN
    [ 2] = GPIO_2_PIN,
#endif
#if GPIO_3_EN
    [ 3] = GPIO_3_PIN,
#endif
#if GPIO_4_EN
    [ 4] = GPIO_4_PIN,
#endif
#if GPIO_5_EN
    [ 5] = GPIO_5_PIN,
#endif
#if GPIO_6_EN
    [ 6] = GPIO_6_PIN,
#endif
#if GPIO_7_EN
    [ 7] = GPIO_7_PIN,
#endif
#if GPIO_8_EN
    [ 8] = GPIO_8_PIN,
#endif
#if GPIO_9_EN
    [ 9] = GPIO_9_PIN,
#endif
#if GPIO_10_EN
    [10] = GPIO_10_PIN,
#endif
#if GPIO_11_EN
    [11] = GPIO_11_PIN,
#endif
#if GPIO_12_EN
    [12] = GPIO_12_PIN,
#endif
#if GPIO_13_EN
    [13] = GPIO_13_PIN,
#endif
#if GPIO_14_EN
    [14] = GPIO_14_PIN,
#endif
#if GPIO_15_EN
    [15] = GPIO_15_PIN,
#endif
#if GPIO_16_EN
    [16] = GPIO_16_PIN,
#endif
#if GPIO_17_EN
    [17] = GPIO_17_PIN,
#endif
#if GPIO_18_EN
    [18] = GPIO_18_PIN,
#endif
#if GPIO_19_EN
    [19] = GPIO_19_PIN,
#endif
#if GPIO_20_EN
    [20] = GPIO_20_PIN,
#endif
#if GPIO_21_EN
    [21] = GPIO_21_PIN,
#endif
#if GPIO_22_EN
    [22] = GPIO_22_PIN,
#endif
#if GPIO_23_EN
    [23] = GPIO_23_PIN,
#endif
#if GPIO_24_EN
    [24] = GPIO_24_PIN,
#endif
#if GPIO_25_EN
    [25] = GPIO_25_PIN,
#endif
#if GPIO_26_EN
    [26] = GPIO_26_PIN,
#endif
#if GPIO_27_EN
    [27] = GPIO_27_PIN,
#endif
#if GPIO_28_EN
    [28] = GPIO_28_PIN,
#endif
#if GPIO_29_EN
    [29] = GPIO_29_PIN,
#endif
#if GPIO_30_EN
    [30] = GPIO_30_PIN,
#endif
#if GPIO_31_EN
    [31] = GPIO_31_PIN,
#endif
};

static const uint8_t reverse_pin_lut[] = {
#if GPIO_0_EN
    [GPIO_0_PIN] = 0,
#endif
#if GPIO_1_EN
    [GPIO_1_PIN] = 1,
#endif
#if GPIO_2_EN
    [GPIO_2_PIN] = 2,
#endif
#if GPIO_3_EN
    [GPIO_3_PIN] = 3,
#endif
#if GPIO_4_EN
    [GPIO_4_PIN] = 4,
#endif
#if GPIO_5_EN
    [GPIO_5_PIN] = 5,
#endif
#if GPIO_6_EN
    [GPIO_6_PIN] = 6,
#endif
#if GPIO_7_EN
    [GPIO_7_PIN] = 7,
#endif
#if GPIO_8_EN
    [GPIO_8_PIN] = 8,
#endif
#if GPIO_9_EN
    [GPIO_9_PIN] = 9,
#endif
#if GPIO_10_EN
    [GPIO_10_PIN] = 10,
#endif
#if GPIO_11_EN
    [GPIO_11_PIN] = 11,
#endif
#if GPIO_12_EN
    [GPIO_12_PIN] = 12,
#endif
#if GPIO_13_EN
    [GPIO_13_PIN] = 13,
#endif
#if GPIO_14_EN
    [GPIO_14_PIN] = 14,
#endif
#if GPIO_15_EN
    [GPIO_15_PIN] = 15,
#endif
#if GPIO_16_EN
    [GPIO_16_PIN] = 16,
#endif
#if GPIO_17_EN
    [GPIO_17_PIN] = 17,
#endif
#if GPIO_18_EN
    [GPIO_18_PIN] = 18,
#endif
#if GPIO_19_EN
    [GPIO_19_PIN] = 19,
#endif
#if GPIO_20_EN
    [GPIO_20_PIN] = 20,
#endif
#if GPIO_21_EN
    [GPIO_21_PIN] = 21,
#endif
#if GPIO_22_EN
    [GPIO_22_PIN] = 22,
#endif
#if GPIO_23_EN
    [GPIO_23_PIN] = 23,
#endif
#if GPIO_24_EN
    [GPIO_24_PIN] = 24,
#endif
#if GPIO_25_EN
    [GPIO_25_PIN] = 25,
#endif
#if GPIO_26_EN
    [GPIO_26_PIN] = 26,
#endif
#if GPIO_27_EN
    [GPIO_27_PIN] = 27,
#endif
#if GPIO_28_EN
    [GPIO_28_PIN] = 28,
#endif
#if GPIO_29_EN
    [GPIO_29_PIN] = 29,
#endif
#if GPIO_30_EN
    [GPIO_30_PIN] = 30,
#endif
#if GPIO_31_EN
    [GPIO_31_PIN] = 31,
#endif
};

int gpio_init(gpio_t dev, gpio_mode_t mode)
{
    int pin;

    if (!gpio_enabled(dev)) {
        return -1;
    }

    pin = pin_lut[dev];
    gpio_software_control(pin);

    switch (mode) {
        case GPIO_IN:
            gpio_dir_input(pin);
            /* configure the pin's pull resistor state */
            IOC_PXX_OVER[pin] = (IOC_OVERRIDE_DIS);
            break;
        case GPIO_IN_PD:
            gpio_dir_input(pin);
            /* configure the pin's pull resistor state */
            IOC_PXX_OVER[pin] = (IOC_OVERRIDE_PDE);
            break;
        case GPIO_IN_PU:
            gpio_dir_input(pin);
            /* configure the pin's pull resistor state */
            IOC_PXX_OVER[pin] = (IOC_OVERRIDE_PUE);
            break;
        case GPIO_OUT:
            gpio_dir_output(pin);
            /* configure the pin's pull resistor state */
            IOC_PXX_OVER[pin] = (IOC_OVERRIDE_OE);
            break;
        default:
            return -1;
    }

    return 0;
}

int gpio_init_int(gpio_t dev, gpio_mode_t mode, gpio_flank_t flank,
                  gpio_cb_t cb, void *arg)
{
    int res, pin, irq_num;
    uint32_t mask;
    cc2538_gpio_t* instance;

    /* Note: gpio_init() also checks if the gpio is enabled. */
    res = gpio_init(dev, mode);
    if (res < 0) {
        return res;
    }

    /* Store the callback information for later: */
    gpio_config[dev].cb  = cb;
    gpio_config[dev].arg = arg;

    pin = pin_lut[dev];
    mask = GPIO_PIN_MASK(GPIO_BIT_NUM(pin));

    instance = GPIO_NUM_TO_DEV(pin);

    /* Enable power-up interrupts for this GPIO port: */
    SYS_CTRL_IWE |= BIT(GPIO_NUM_TO_PORT_NUM(pin));

    switch(flank) {
        case GPIO_FALLING:
            instance->IBE         &= ~mask;     /**< Not both edges */
            instance->IEV         &= ~mask;     /**< Falling edge */
            instance->P_EDGE_CTRL |=  BIT(pin); /**< Falling edge power-up interrupt */
            break;

        case GPIO_RISING:
            instance->IBE         &= ~mask;     /**< Not both edges */
            instance->IEV         |=  mask;     /**< Rising edge */
            instance->P_EDGE_CTRL &= ~BIT(pin); /**< Rising edge power-up interrupt */
            break;

        case GPIO_BOTH:
            instance->IBE = mask;               /**< Both edges */
            break;
    }

    instance->IS     &= ~mask;                  /**< Edge triggered (as opposed to level-triggered) */
    instance->IC     |=  mask;                  /**< Clear any preexisting interrupt state */
    instance->PI_IEN |= BIT(pin);               /**< Enable power-up interrupts for this pin */

    /* Set interrupt priority for the whole GPIO port: */
    irq_num = GPIO_PORT_A_IRQn + GPIO_NUM_TO_PORT_NUM(pin);
    NVIC_SetPriority(irq_num, GPIO_IRQ_PRIO);

    /* Enable interrupts for the whole GPIO port: */
    NVIC_EnableIRQ(irq_num);

    /* Enable interrupts for the specific pin: */
    instance->IE |= mask;

    return 0;
}

void gpio_irq_enable(gpio_t dev)
{
    if (gpio_enabled(dev)) {
        int pin = pin_lut[dev];
        GPIO_NUM_TO_DEV(pin)->IE |= GPIO_PIN_MASK(GPIO_BIT_NUM(pin));
    }
}

void gpio_irq_disable(gpio_t dev)
{
    if (gpio_enabled(dev)) {
        int pin = pin_lut[dev];
        GPIO_NUM_TO_DEV(pin)->IE &= ~GPIO_PIN_MASK(GPIO_BIT_NUM(pin));
    }
}

int gpio_read(gpio_t dev)
{
    int pin;

    if (!gpio_enabled(dev)) {
        return -1;
    }

    pin = pin_lut[dev];
    return (GPIO_NUM_TO_DEV(pin)->DATA >> GPIO_BIT_NUM(pin)) & 1;
}

void gpio_set(gpio_t dev)
{
    int pin;

    if (!gpio_enabled(dev)) {
        return;
    }

    pin = pin_lut[dev];
    GPIO_NUM_TO_DEV(pin)->DATA |= GPIO_PIN_MASK(GPIO_BIT_NUM(pin));
}

void gpio_clear(gpio_t dev)
{
    int pin;

    if (!gpio_enabled(dev)) {
        return;
    }

    pin = pin_lut[dev];
    GPIO_NUM_TO_DEV(pin)->DATA &= ~GPIO_PIN_MASK(GPIO_BIT_NUM(pin));
}

void gpio_toggle(gpio_t dev)
{
    if (gpio_read(dev)) {
        gpio_clear(dev);
    }
    else {
        gpio_set(dev);
    }
}

void gpio_write(gpio_t dev, int value)
{
    if (value) {
        gpio_set(dev);
    }
    else {
        gpio_clear(dev);
    }
}

/** @brief Interrupt service routine for Port A */
void isr_gpioa(void)
{
    int mis, bit;
    gpio_isr_ctx_t* state;

    /* Latch and clear the interrupt status early on: */
    mis = GPIO_A->MIS;
    GPIO_A->IC             = 0x000000ff;
    GPIO_A->IRQ_DETECT_ACK = 0x000000ff;

    for (bit = 0; bit < GPIO_BITS_PER_PORT; bit++) {
        if (mis & 1) {
            state = gpio_config + reverse_pin_lut[GPIO_PXX_TO_NUM(PORT_A, bit)];
            state->cb(state->arg);
        }

        mis >>= 1;
    }

    cortexm_isr_end();
}

/** @brief Interrupt service routine for Port B */
void isr_gpiob(void)
{
    int mis, bit;
    gpio_isr_ctx_t* state;

    /* Latch and clear the interrupt status early on: */
    mis = GPIO_B->MIS;
    GPIO_B->IC             = 0x000000ff;
    GPIO_B->IRQ_DETECT_ACK = 0x0000ff00;

    for (bit = 0; bit < GPIO_BITS_PER_PORT; bit++) {
        if (mis & 1) {
            state = gpio_config + reverse_pin_lut[GPIO_PXX_TO_NUM(PORT_B, bit)];
            state->cb(state->arg);
        }

        mis >>= 1;
    }

    cortexm_isr_end();
}

/** @brief Interrupt service routine for Port C */
void isr_gpioc(void)
{
    int mis, bit;
    gpio_isr_ctx_t* state;

    /* Latch and clear the interrupt status early on: */
    mis = GPIO_C->MIS;
    GPIO_C->IC             = 0x000000ff;
    GPIO_C->IRQ_DETECT_ACK = 0x00ff0000;

    for (bit = 0; bit < GPIO_BITS_PER_PORT; bit++) {
        if (mis & 1) {
            state = gpio_config + reverse_pin_lut[GPIO_PXX_TO_NUM(PORT_C, bit)];
            state->cb(state->arg);
        }

        mis >>= 1;
    }

    cortexm_isr_end();
}

/** @brief Interrupt service routine for Port D */
void isr_gpiod(void)
{
    int mis, bit;
    gpio_isr_ctx_t* state;

    /* Latch and clear the interrupt status early on: */
    mis = GPIO_D->MIS;
    GPIO_D->IC             = 0x000000ff;
    GPIO_D->IRQ_DETECT_ACK = 0xff000000;

    for (bit = 0; bit < GPIO_BITS_PER_PORT; bit++) {
        if (mis & 1) {
            state = gpio_config + reverse_pin_lut[GPIO_PXX_TO_NUM(PORT_D, bit)];
            state->cb(state->arg);
        }

        mis >>= 1;
    }

    cortexm_isr_end();
}