/******************************************************************************
 * The MIT License
 *
 * Copyright (c) 2010 Perry Hung.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *****************************************************************************/

/**
 * @file util.c
 * @brief Utility procedures for debugging, mostly an error LED fade
 * and messages dumped over a UART for failed asserts.
 */

#include "libmaple.h"
#include "usart.h"
#include "gpio.h"
#include "nvic.h"
#include "adc.h"
#include "timer.h"

/* Failed ASSERT()s send out a message using this USART config. */
#ifndef ERROR_USART
#define ERROR_USART            USART2
#define ERROR_USART_CLK_SPEED  STM32_PCLK1
#define ERROR_USART_BAUD       9600
#define ERROR_TX_PORT          GPIOA
#define ERROR_TX_PIN           2
#endif

/* If you define ERROR_LED_PORT and ERROR_LED_PIN, then a failed
 * ASSERT() will also throb() an LED connected to that port and pin.
 */
#if defined(ERROR_LED_PORT) && defined(ERROR_LED_PIN)
#define HAVE_ERROR_LED
#endif

/**
 * @brief Disables all peripheral interrupts except USB and fades the
 *        error LED.
 */
/* (Called from exc.S with global interrupts disabled.) */
void __error(void) {
    /* Turn off peripheral interrupts */
    nvic_irq_disable_all();

    /* Turn off timers */
    timer_disable_all();

    /* Turn off ADC */
    adc_disable_all();

    /* Turn off all USARTs */
    usart_disable_all();

    /* Turn the USB interrupt back on so the bootloader keeps on functioning */
    nvic_irq_enable(NVIC_USB_HP_CAN_TX);
    nvic_irq_enable(NVIC_USB_LP_CAN_RX0);

    /* Reenable global interrupts */
    nvic_globalirq_enable();
    throb();
}

/**
 * @brief Print an error message on a UART upon a failed assertion
 *        and throb the error LED, if there is one defined.
 * @param file Source file of failed assertion
 * @param line Source line of failed assertion
 * @param exp String representation of failed assertion
 * @sideeffect Turns of all peripheral interrupts except USB.
 */
void _fail(const char* file, int line, const char* exp) {
    /* Initialize the error USART */
    gpio_set_mode(ERROR_TX_PORT, ERROR_TX_PIN, GPIO_AF_OUTPUT_PP);
    usart_init(ERROR_USART);
    usart_set_baud_rate(ERROR_USART, ERROR_USART_CLK_SPEED, ERROR_USART_BAUD);

    /* Print failed assert message */
    usart_putstr(ERROR_USART, "ERROR: FAILED ASSERT(");
    usart_putstr(ERROR_USART, exp);
    usart_putstr(ERROR_USART, "): ");
    usart_putstr(ERROR_USART, file);
    usart_putstr(ERROR_USART, ": ");
    usart_putudec(ERROR_USART, line);
    usart_putc(ERROR_USART, '\n');
    usart_putc(ERROR_USART, '\r');

    /* Error fade */
    __error();
}

/**
 * @brief Provide an __assert_func handler to libc so that calls to assert() get
 * redirected to _fail.
 */
void __assert_func(const char* file, int line, const char* method,
                   const char* expression) {
    _fail(file, line, expression);
}

/**
 * @brief Fades the error LED on and off
 * @sideeffect Sets output push-pull on ERROR_LED_PIN.
 */
void throb(void) {
#ifdef HAVE_ERROR_LED
    int32  slope   = 1;
    uint32 CC      = 0x0000;
    uint32 TOP_CNT = 0x0200;
    uint32 i       = 0;

    gpio_set_mode(ERROR_LED_PORT, ERROR_LED_PIN, GPIO_OUTPUT_PP);
    /* Error fade. */
    while (1) {
        if (CC == TOP_CNT)  {
            slope = -1;
        } else if (CC == 0) {
            slope = 1;
        }

        if (i == TOP_CNT)  {
            CC += slope;
            i = 0;
        }

        if (i < CC) {
            gpio_write_bit(ERROR_LED_PORT, ERROR_LED_PIN, 1);
        } else {
            gpio_write_bit(ERROR_LED_PORT, ERROR_LED_PIN, 0);
        }
        i++;
    }
#else
    /* No error LED is defined; do nothing. */
    while (1)
        ;
#endif
}