/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2022-03-28     shelton      first version
 */

#include "board.h"

void system_clock_config(void)
{
  /* enable pwc periph clock */
  crm_periph_clock_enable(CRM_PWC_PERIPH_CLOCK, TRUE);

  /* config ldo voltage */
  pwc_ldo_output_voltage_set(PWC_LDO_OUTPUT_1V3);

  /* set the flash clock divider */
  flash_clock_divider_set(FLASH_CLOCK_DIV_3);

  /* reset crm */
  crm_reset();

  crm_clock_source_enable(CRM_CLOCK_SOURCE_HEXT, TRUE);

  /* wait till hext is ready */
  while(crm_hext_stable_wait() == ERROR)
  {
  }

  /* config pll clock resource
  common frequency config list: pll source selected  hick or hext(8mhz)
  _______________________________________________________________________________________
  |        |         |         |         |         |         |         |        |        |
  |pll(mhz)|   288   |   252   |   216   |   180   |   144   |   108   |   72   |   36   |
  |________|_________|_________|_________|_________|_________|_________|_________________|
  |        |         |         |         |         |         |         |        |        |
  |pll_ns  |   72    |   63    |   108   |   90    |   72    |   108   |   72   |   72   |
  |        |         |         |         |         |         |         |        |        |
  |pll_ms  |   1     |   1     |   1     |   1     |   1     |   1     |   1    |   1    |
  |        |         |         |         |         |         |         |        |        |
  |pll_fr  |   FR_2  |   FR_2  |   FR_4  |   FR_4  |   FR_4  |   FR_8  |   FR_8 |   FR_16|
  |________|_________|_________|_________|_________|_________|_________|________|________|

  if pll clock source selects hext with other frequency values, or configure pll to other
  frequency values, please use the at32 new clock  configuration tool for configuration.  */
  crm_pll_config(CRM_PLL_SOURCE_HEXT, 125, 1, CRM_PLL_FR_4);

  /* enable pll */
  crm_clock_source_enable(CRM_CLOCK_SOURCE_PLL, TRUE);

  /* wait till pll is ready */
  while(crm_flag_get(CRM_PLL_STABLE_FLAG) != SET)
  {
  }

  /* config ahbclk */
  crm_ahb_div_set(CRM_AHB_DIV_1);

  /* config apb2clk */
  crm_apb2_div_set(CRM_APB2_DIV_2);

  /* config apb1clk */
  crm_apb1_div_set(CRM_APB1_DIV_2);

  /* enable auto step mode */
  crm_auto_step_mode_enable(TRUE);

  /* select pll as system clock source */
  crm_sysclk_switch(CRM_SCLK_PLL);

  /* wait till pll is used as system clock source */
  while(crm_sysclk_switch_status_get() != CRM_SCLK_PLL)
  {
  }

  /* disable auto step mode */
  crm_auto_step_mode_enable(FALSE);

  /* update system_core_clock global variable */
  system_core_clock_update();
}