How to set MSI clock

Dear friends,

I am working with STM32L152VD. my problem is that after setting system clock to MSI and setting PWM on TIM4 I see that system clock is much lower than expected.

void SetHSICLKToMSI(uint32_t freq,bool div2,bool With_RTC)
{

  /* RCC system reset */
  RCC_DeInit();

  /* Flash 1 wait state */
  FLASH_SetLatency(FLASH_Latency_0);

  /* Disable Prefetch Buffer */
  FLASH_PrefetchBufferCmd(DISABLE);

  /* Disable 64-bit access */
  FLASH_ReadAccess64Cmd(DISABLE);

  /* Disable FLASH during SLeep  */
  FLASH_SLEEPPowerDownCmd(ENABLE);

  /* Enable the PWR APB1 Clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  /* Select the Voltage Range 3 (1.2V) */
  PWR_VoltageScalingConfig(PWR_VoltageScaling_Range3);

  /* Wait Until the Voltage Regulator is ready */
  while (PWR_GetFlagStatus(PWR_FLAG_VOS) != RESET)
  {}

  /* To configure the MSI frequency */
  RCC_MSIRangeConfig(freq);

  /* Select MSI as system clock source */
  RCC_SYSCLKConfig(RCC_SYSCLKSource_MSI);

  /* Wait till MSI is used as system clock source */
  while (RCC_GetSYSCLKSource() != 0x00)
  {}

  if (div2)
  {
    RCC_HCLKConfig(RCC_SYSCLK_Div2);
  }

  RCC_HSICmd(DISABLE);

  /* Disable HSE clock */
  RCC_HSEConfig(RCC_HSE_OFF);

  /* Disable LSE clock */
  if (! With_RTC)
    RCC_LSEConfig(RCC_LSE_OFF);

  /* Disable LSI clock */
  RCC_LSICmd(DISABLE);

}

I use below command but I get 5KHz insted of 32.5Khz !!

#define RCC_MSIRange_0                   RCC_ICSCR_MSIRANGE_0 /*!< MSI = 65.536 KHz  */
SetHSICLKToMSI(RCC_MSIRange_0,DIV2,RTC);