/* mbed Microcontroller Library
 *******************************************************************************
 * Copyright (c) 2014, STMicroelectronics
 * All rights reserved.
 *
 * 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 of STMicroelectronics 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 <stddef.h>
#include "cmsis.h"
#include "gpio_irq_api.h"
#include "pinmap.h"
#include "mbed_error.h"

#define EDGE_NONE (0)
#define EDGE_RISE (1)
#define EDGE_FALL (2)
#define EDGE_BOTH (3)

// Number of EXTI irq vectors (EXTI0_1, EXTI2_3, EXTI4_15)
#define CHANNEL_NUM (3)

// Max pins for one line (max with EXTI4_15)
#define MAX_PIN_LINE (12)

typedef struct gpio_channel {
    uint32_t pin_mask;                   // bitmask representing which pins are configured for receiving interrupts
    uint32_t channel_ids[MAX_PIN_LINE];  // mbed "gpio_irq_t gpio_irq" field of instance
    uint32_t channel_gpio[MAX_PIN_LINE]; // base address of gpio port group
    uint32_t channel_pin[MAX_PIN_LINE];  // pin number in port group
} gpio_channel_t;

static gpio_channel_t channels[CHANNEL_NUM] = {
    {.pin_mask = 0},
    {.pin_mask = 0},
    {.pin_mask = 0}
};

// Used to return the index for channels array.
static uint32_t pin_base_nr[16] = {
    // EXTI0_1
    0, // pin 0
    1, // pin 1
    // EXTI2_3
    0, // pin 2
    1, // pin 3
    // EXTI4_15
    0, // pin 4
    1, // pin 5
    2, // pin 6
    3, // pin 7
    4, // pin 8
    5, // pin 9
    6, // pin 10
    7, // pin 11
    8, // pin 12
    9, // pin 13
   10, // pin 14
   11  // pin 15
};

static gpio_irq_handler irq_handler;

static void handle_interrupt_in(uint32_t irq_index, uint32_t max_num_pin_line) {
    gpio_channel_t *gpio_channel = &channels[irq_index];
    uint32_t gpio_idx;

    for (gpio_idx = 0; gpio_idx < max_num_pin_line; gpio_idx++) {
        uint32_t current_mask = (1 << gpio_idx);

        if (gpio_channel->pin_mask & current_mask) {
            // Retrieve the gpio and pin that generate the irq
            GPIO_TypeDef *gpio = (GPIO_TypeDef *)(gpio_channel->channel_gpio[gpio_idx]);
            uint32_t pin = (uint32_t)(1 << (gpio_channel->channel_pin[gpio_idx]));

            // Clear interrupt flag
            if (__HAL_GPIO_EXTI_GET_FLAG(pin) != RESET) {
                __HAL_GPIO_EXTI_CLEAR_FLAG(pin);

                if (gpio_channel->channel_ids[gpio_idx] == 0) continue;

                // Check which edge has generated the irq
                if ((gpio->IDR & pin) == 0) {
                    irq_handler(gpio_channel->channel_ids[gpio_idx], IRQ_FALL);
                } else  {
                    irq_handler(gpio_channel->channel_ids[gpio_idx], IRQ_RISE);
                }
            }
        }
    }
}

// EXTI lines 0 to 1
static void gpio_irq0(void) {
    handle_interrupt_in(0, 2);
}

// EXTI lines 2 to 3
static void gpio_irq1(void) {
    handle_interrupt_in(1, 2);
}

// EXTI lines 4 to 15
static void gpio_irq2(void) {
    handle_interrupt_in(2, 12);
}

extern uint32_t Set_GPIO_Clock(uint32_t port_idx);
extern void pin_function_gpiomode(PinName pin, uint32_t gpiomode);

int gpio_irq_init(gpio_irq_t *obj, PinName pin, gpio_irq_handler handler, uint32_t id) {
    IRQn_Type irq_n = (IRQn_Type)0;
    uint32_t vector = 0;
    uint32_t irq_index;
    gpio_channel_t *gpio_channel;
    uint32_t gpio_idx;

    if (pin == NC) return -1;

    uint32_t port_index = STM_PORT(pin);
    uint32_t pin_index  = STM_PIN(pin);

    // Select irq number and interrupt routine
    if ((pin_index == 0) || (pin_index == 1)) {
        irq_n = EXTI0_1_IRQn;
        vector = (uint32_t)&gpio_irq0;
        irq_index = 0;
    } else if ((pin_index == 2) || (pin_index == 3)) {
        irq_n = EXTI2_3_IRQn;
        vector = (uint32_t)&gpio_irq1;
        irq_index = 1;
    } else if ((pin_index > 3) && (pin_index < 16)) {
        irq_n = EXTI4_15_IRQn;
        vector = (uint32_t)&gpio_irq2;
        irq_index = 2;
    } else {
        error("InterruptIn error: pin not supported.\n");
        return -1;
    }

    // Enable GPIO clock
    uint32_t gpio_add = Set_GPIO_Clock(port_index);

    // Configure GPIO
    pin_function(pin, STM_PIN_DATA(STM_MODE_IT_FALLING, GPIO_NOPULL, 0));

    // Enable EXTI interrupt
    NVIC_SetVector(irq_n, vector);
    NVIC_EnableIRQ(irq_n);

    // Save informations for future use
    obj->irq_n = irq_n;
    obj->irq_index = irq_index;
    obj->event = EDGE_NONE;
    obj->pin = pin;

    gpio_channel = &channels[irq_index];
    gpio_idx = pin_base_nr[pin_index];
    gpio_channel->pin_mask |= (1 << gpio_idx);
    gpio_channel->channel_ids[gpio_idx] = id;
    gpio_channel->channel_gpio[gpio_idx] = gpio_add;
    gpio_channel->channel_pin[gpio_idx] = pin_index;

    irq_handler = handler;

    return 0;
}

void gpio_irq_free(gpio_irq_t *obj) {
    gpio_channel_t *gpio_channel = &channels[obj->irq_index];
    uint32_t pin_index  = STM_PIN(obj->pin);
    uint32_t gpio_idx = pin_base_nr[pin_index];

    gpio_channel->pin_mask &= ~(1 << gpio_idx);
    gpio_channel->channel_ids[gpio_idx] = 0;
    gpio_channel->channel_gpio[gpio_idx] = 0;
    gpio_channel->channel_pin[gpio_idx] = 0;

    // Disable EXTI line, but don't change pull-up config
    pin_function_gpiomode(obj->pin, STM_MODE_INPUT);
    obj->event = EDGE_NONE;
}

void gpio_irq_set(gpio_irq_t *obj, gpio_irq_event event, uint32_t enable) {
    uint32_t mode = STM_MODE_IT_EVT_RESET;
    uint32_t pull = GPIO_NOPULL;

    if (enable) {
        if (event == IRQ_RISE) {
            if ((obj->event == EDGE_FALL) || (obj->event == EDGE_BOTH)) {
                mode = STM_MODE_IT_RISING_FALLING;
                obj->event = EDGE_BOTH;
            } else { // NONE or RISE
                mode = STM_MODE_IT_RISING;
                obj->event = EDGE_RISE;
            }
        }
        if (event == IRQ_FALL) {
            if ((obj->event == EDGE_RISE) || (obj->event == EDGE_BOTH)) {
                mode = STM_MODE_IT_RISING_FALLING;
                obj->event = EDGE_BOTH;
            } else { // NONE or FALL
                mode = STM_MODE_IT_FALLING;
                obj->event = EDGE_FALL;
            }
        }
    } else { // Disable
        if (event == IRQ_RISE) {
            if ((obj->event == EDGE_FALL) || (obj->event == EDGE_BOTH)) {
                mode = STM_MODE_IT_FALLING;
                obj->event = EDGE_FALL;
            } else { // NONE or RISE
                mode = STM_MODE_IT_EVT_RESET;
                obj->event = EDGE_NONE;
            }
        }
        if (event == IRQ_FALL) {
            if ((obj->event == EDGE_RISE) || (obj->event == EDGE_BOTH)) {
                mode = STM_MODE_IT_RISING;
                obj->event = EDGE_RISE;
            } else { // NONE or FALL
                mode = STM_MODE_IT_EVT_RESET;
                obj->event = EDGE_NONE;
            }
        }
    }

    pin_function_gpiomode(obj->pin, mode);
}

void gpio_irq_enable(gpio_irq_t *obj) {
    NVIC_EnableIRQ(obj->irq_n);
}

void gpio_irq_disable(gpio_irq_t *obj) {
    NVIC_DisableIRQ(obj->irq_n);
    obj->event = EDGE_NONE;
}
