130 lines
3.8 KiB
C
130 lines
3.8 KiB
C
/******************************************************************************
|
|
* The MIT License
|
|
*
|
|
* Copyright (c) 2010 LeafLabs, LLC.
|
|
*
|
|
* 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 libmaple/stm32f1/bkp.c
|
|
* @brief STM32F1 Backup register support.
|
|
*/
|
|
|
|
#include <libmaple/bkp.h>
|
|
#include <libmaple/pwr.h>
|
|
#include <libmaple/rcc.h>
|
|
#include <libmaple/bitband.h>
|
|
|
|
static inline __IO uint32* data_register(uint8 reg);
|
|
|
|
bkp_dev bkp = {
|
|
.regs = BKP_BASE,
|
|
};
|
|
/** Backup device. */
|
|
const bkp_dev *BKP = &bkp;
|
|
|
|
/**
|
|
* @brief Initialize backup interface.
|
|
*
|
|
* Enables the power and backup interface clocks, and resets the
|
|
* backup device.
|
|
*/
|
|
void bkp_init(void) {
|
|
/* Don't call pwr_init(), or you'll reset the device. We just
|
|
* need the clock. */
|
|
rcc_clk_enable(RCC_PWR);
|
|
rcc_clk_enable(RCC_BKP);
|
|
rcc_reset_dev(RCC_BKP);
|
|
}
|
|
|
|
/**
|
|
* Enable write access to the backup registers. Backup interface must
|
|
* be initialized for subsequent register writes to work.
|
|
* @see bkp_init()
|
|
*/
|
|
void bkp_enable_writes(void) {
|
|
*bb_perip(&PWR_BASE->CR, PWR_CR_DBP_BIT) = 1;
|
|
}
|
|
|
|
/**
|
|
* Disable write access to the backup registers.
|
|
*/
|
|
void bkp_disable_writes(void) {
|
|
*bb_perip(&PWR_BASE->CR, PWR_CR_DBP_BIT) = 0;
|
|
}
|
|
|
|
/**
|
|
* Read a value from given backup data register.
|
|
* @param reg Data register to read, from 1 to BKP_NR_DATA_REGS (10 on
|
|
* medium-density devices, 42 on high-density devices).
|
|
*/
|
|
uint16 bkp_read(uint8 reg) {
|
|
__IO uint32* dr = data_register(reg);
|
|
if (!dr) {
|
|
ASSERT(0); /* nonexistent register */
|
|
return 0;
|
|
}
|
|
return (uint16)*dr;
|
|
}
|
|
|
|
/**
|
|
* @brief Write a value to given data register.
|
|
*
|
|
* Write access to backup registers must be enabled.
|
|
*
|
|
* @param reg Data register to write, from 1 to BKP_NR_DATA_REGS (10
|
|
* on medium-density devices, 42 on high-density devices).
|
|
* @param val Value to write into the register.
|
|
* @see bkp_enable_writes()
|
|
*/
|
|
void bkp_write(uint8 reg, uint16 val) {
|
|
__IO uint32* dr = data_register(reg);
|
|
if (!dr) {
|
|
ASSERT(0); /* nonexistent register */
|
|
return;
|
|
}
|
|
*dr = (uint32)val;
|
|
}
|
|
|
|
/*
|
|
* Data register memory layout is not contiguous. It's split up from
|
|
* 1--NR_LOW_DRS, beginning at BKP_BASE->DR1, through to
|
|
* (NR_LOW_DRS+1)--BKP_NR_DATA_REGS, beginning at BKP_BASE->DR11.
|
|
*/
|
|
#define NR_LOW_DRS 10
|
|
|
|
static inline __IO uint32* data_register(uint8 reg) {
|
|
if (reg < 1 || reg > BKP_NR_DATA_REGS) {
|
|
return 0;
|
|
}
|
|
|
|
#if BKP_NR_DATA_REGS == NR_LOW_DRS
|
|
return (uint32*)BKP_BASE + reg;
|
|
#else
|
|
if (reg <= NR_LOW_DRS) {
|
|
return (uint32*)BKP_BASE + reg;
|
|
} else {
|
|
return (uint32*)&(BKP_BASE->DR11) + (reg - NR_LOW_DRS - 1);
|
|
}
|
|
#endif
|
|
}
|