sys_timer.cpp

/** @defgroup 06 sys_timer System Timer and smooth typing
 *
 * @ingroup infrastructure_apis
 *
 * @file sys_timer.cpp System Timer and smooth typing routines.
 *
 * @brief <b>System Timer and smooth typing routines.</b>
 *
 * @version 1.0.0
 *
 * @author @htmlonly &copy; @endhtmlonly 2022
 * Evandro Souza <evandro.r.souza@gmail.com>
 *
 * @date 25 September 2022
 *
 * This library executes functions to interface and control a PS/2 keyboard, like:
 * power control of a PS/2 key, general interface to read events and write commands to PS/2
 * keyboard, including interrupt service routines on the STM32F4 and STM32F1 series of ARM
 * Cortex Microcontrollers by ST Microelectronics.
 *
 * LGPL License Terms ref lgpl_license
 */

/*
 * This file was part of the libopencm3 project, but highly modifyed.
 *
 * Copyright (C) 2021 Evandro Souza <evandro.r.souza@gmail.com>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "sys_timer.h"
//Use Tab width=2


//Global vars
volatile uint32_t systicks, ticks;
volatile uint16_t ticks_keys;
volatile uint16_t last_ps2_fails=0;
volatile uint16_t fail_count;
extern bool ps2_keyb_detected;                    //Declared on ps2handl.c
extern bool update_ps2_leds, ps2numlockstate;     //Declared on msxmap.cpp


void systick_setup(void)
{
  //Make sure systick doesn't interrupt PS/2 protocol bitbang action
  nvic_set_priority(NVIC_SYSTICK_IRQ, IRQ_PRI_SYSTICK);

  /* 84MHz / 8 => 10500000 counts per second */
  /* 10500000 / 30(ints per second) = 350000 systick reload - every 33,3ms one interrupt */
  /* SysTick interrupt every N clock pulses: set reload to N-1 */
  systick_set_reload(((rcc_apb2_frequency * 2) / FREQ_INT_SYSTICK) - 1);
  systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
  
  systicks = 0; //systick_clear
  ticks = 0;
  ticks_keys = 0;

  /* Start counting. */
  systick_counter_enable();

  systick_interrupt_enable();

  // GPIO C13 is the onboard LED
#if MCU == STM32F103
  gpio_set_mode(EMBEDDED_LED_PORT, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, EMBEDDED_LED_PIN);
  // Enable the led. It is active LOW, but the instruction was omitted, since 0 is the default.
#endif//#if MCU == STM32F103
#if MCU == STM32F401
  gpio_mode_setup(EMBEDDED_LED_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, EMBEDDED_LED_PIN);
  gpio_set_output_options(EMBEDDED_LED_PORT, GPIO_OTYPE_OD, GPIO_OSPEED_100MHZ, EMBEDDED_LED_PIN);
  // Enable the led. It is active LOW, but the instruction was omitted, since 0 is the default.
#endif//#if MCU == STM32F401
}

/*************************************************************************************************/
/*************************************************************************************************/
/******************************************* ISR's ***********************************************/
/*************************************************************************************************/
/*************************************************************************************************/
void sys_tick_handler(void) // f=30Hz (Each 33,33ms)
{
  iwdg_reset(); //Prevent from reset

  systicks++;

  ticks++;
  if( (ps2_keyb_detected == true) && (ticks >= (10*3)) )
  { /*C13 LED blinks each 2s (2*1 s) on keyboard detected */
    gpio_toggle(EMBEDDED_LED_PORT, EMBEDDED_LED_PIN);
    ticks=0;
  } else if( (ps2_keyb_detected == false) && (ticks >= 7) )
  { /*C13 LED blinks each 467 ms (2*233.3 ms) on keyboard absence*/
    gpio_toggle(EMBEDDED_LED_PORT, EMBEDDED_LED_PIN);
    ticks=0;
  }

  if(ps2_keyb_detected == true)
  {
    //Queue keys processing:
    ticks_keys = (ticks_keys++ & (MAX_TICKS_KEYS - 1));
    if (!ticks_keys)
    {
      msxmap objeto;
      objeto.msxqueuekeys();
    }
  }

  if(fail_count!=last_ps2_fails)
  {
    // printf("PS/2 failure count: %03d\r\n", fail_count);
    /*uint8_t mountstring[3];
    usart_send_string((uint8_t*)"PS/2 failure count: ");
    conv_uint8_to_2a_hex(fail_count, mountstring);
    usart_send_string(mountstring);
    usart_send_string((uint8_t*)"\r\n");*/

    last_ps2_fails=fail_count;
  }
}