hal_lld.c
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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
---
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes ChibiOS/RT, without being obliged to provide
the source code for any proprietary components. See the file exception.txt
for full details of how and when the exception can be applied.
*/
/**
* @file STM8L/hal_lld.c
* @brief STM8L HAL subsystem low level driver source.
*
* @addtogroup HAL
* @{
*/
#include "ch.h"
#include "hal.h"
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level HAL driver initialization.
* @details Clock sources initialization, HSI is assumed to be already
* started after reset.
* @note If the @p STM8L_CLOCK_INIT option is set to @p FALSE then the
* initialization is not performed and is left to the application.
*
* @notapi
*/
void hal_lld_init(void) {
#if !STM8L_NO_CLOCK_INIT
/* Makes sure that HSI is stable before proceeding.*/
CLK->ICKCR |= CLK_ICKCR_HSION;
while ((CLK->ICKCR & CLK_ICKCR_HSIRDY) == 0)
;
/* LSI startup and stabilization if required.*/
#if STM8L_LSI_ENABLED
CLK->ICKCR |= CLK_ICKCR_LSION;
while ((CLK->ICKCR & CLK_ICKCR_LSIRDY) == 0)
;
#endif
/* HSE startup and stabilization if required.*/
#if STM8L_HSE_ENABLED
#if HSEBYPASS
CLK->ECKCR |= CLK_ECKCR_HSEON | CLK_ECKCR_HSEBYP;
#else
CLK->ECKCR |= CLK_ECKCR_HSEON;
#endif
while ((CLK->ECKCR & CLK_ECKCR_HSERDY) == 0)
;
#endif
/* LSE startup and stabilization if required.*/
#if STM8L_LSE_ENABLED
#if LSEBYPASS
CLK->ECKCR |= CLK_ECKCR_LSEON | CLK_ECKCR_LSEBYP;
#else
CLK->ECKCR |= CLK_ECKCR_LSEON;
#endif
while ((CLK->ECKCR & CLK_ECKCR_LSERDY) == 0)
;
#endif
/* Setting up clock dividers.*/
CLK->CKDIVR = STM8L_SYSCLK_DIVIDER << 0;
/* SYSCLK switch to the selected source, not necessary if it is HSI.*/
#if STM8L_SYSCLK_SOURCE != CLK_SYSSEL_HSI
/* Switching clock (manual switch mode).*/
CLK->SWR = STM8L_SYSCLK_SOURCE;
while ((CLK->SWCR & CLK_SWCR_SWIF) == 0)
;
CLK->SWCR = CLK_SWCR_SWEN;
#endif
/* Clocks initially all disabled, note the boot ROM clock is disabled
because the boot loader is no more required and it draws precious uAs.*/
CLK->PCKENR1 = 0;
CLK->PCKENR2 = 0;
CLK->PCKENR3 = 0;
/* Other clock related initializations.*/
CLK->CSSR = 0;
CLK->CCOR = 0;
/* HSI disabled if it is no more required.*/
#if !STM8L_HSI_ENABLED
CLK->ICKCR &= ~CLK_ICKCR_HSION;
#endif
#endif /* !STM8L_NO_CLOCK_INIT */
}
/** @} */