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/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Perry Hung.
*
* 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 rcc.c
* @brief Implements pretty much only the basic clock setup on the
* stm32, clock enable/disable and peripheral reset commands.
*/
#include <libmaple/libmaple.h>
#include <libmaple/flash.h>
#include <libmaple/rcc.h>
#include <libmaple/bitband.h>
#define APB1 RCC_APB1
#define APB2 RCC_APB2
#define AHB RCC_AHB
struct rcc_dev_info {
const rcc_clk_domain clk_domain;
const uint8 line_num;
};
/* Device descriptor table, maps rcc_clk_id onto bus and enable/reset
* register bit numbers. */
static const struct rcc_dev_info rcc_dev_table[] = {
[RCC_GPIOA] = { .clk_domain = APB2, .line_num = 2 },
[RCC_GPIOB] = { .clk_domain = APB2, .line_num = 3 },
[RCC_GPIOC] = { .clk_domain = APB2, .line_num = 4 },
[RCC_GPIOD] = { .clk_domain = APB2, .line_num = 5 },
[RCC_AFIO] = { .clk_domain = APB2, .line_num = 0 },
[RCC_ADC1] = { .clk_domain = APB2, .line_num = 9 },
[RCC_ADC2] = { .clk_domain = APB2, .line_num = 10 },
[RCC_ADC3] = { .clk_domain = APB2, .line_num = 15 },
[RCC_USART1] = { .clk_domain = APB2, .line_num = 14 },
[RCC_USART2] = { .clk_domain = APB1, .line_num = 17 },
[RCC_USART3] = { .clk_domain = APB1, .line_num = 18 },
[RCC_TIMER1] = { .clk_domain = APB2, .line_num = 11 },
[RCC_TIMER2] = { .clk_domain = APB1, .line_num = 0 },
[RCC_TIMER3] = { .clk_domain = APB1, .line_num = 1 },
[RCC_TIMER4] = { .clk_domain = APB1, .line_num = 2 },
[RCC_SPI1] = { .clk_domain = APB2, .line_num = 12 },
[RCC_SPI2] = { .clk_domain = APB1, .line_num = 14 },
[RCC_DMA1] = { .clk_domain = AHB, .line_num = 0 },
[RCC_PWR] = { .clk_domain = APB1, .line_num = 28},
[RCC_BKP] = { .clk_domain = APB1, .line_num = 27},
[RCC_I2C1] = { .clk_domain = APB1, .line_num = 21 },
[RCC_I2C2] = { .clk_domain = APB1, .line_num = 22 },
[RCC_CRC] = { .clk_domain = AHB, .line_num = 6},
[RCC_FLITF] = { .clk_domain = AHB, .line_num = 4},
[RCC_SRAM] = { .clk_domain = AHB, .line_num = 2},
[RCC_USB] = { .clk_domain = APB1, .line_num = 23},
#if defined(STM32_HIGH_DENSITY) || defined(STM32_XL_DENSITY)
[RCC_GPIOE] = { .clk_domain = APB2, .line_num = 6 },
[RCC_GPIOF] = { .clk_domain = APB2, .line_num = 7 },
[RCC_GPIOG] = { .clk_domain = APB2, .line_num = 8 },
[RCC_UART4] = { .clk_domain = APB1, .line_num = 19 },
[RCC_UART5] = { .clk_domain = APB1, .line_num = 20 },
[RCC_TIMER5] = { .clk_domain = APB1, .line_num = 3 },
[RCC_TIMER6] = { .clk_domain = APB1, .line_num = 4 },
[RCC_TIMER7] = { .clk_domain = APB1, .line_num = 5 },
[RCC_TIMER8] = { .clk_domain = APB2, .line_num = 13 },
[RCC_FSMC] = { .clk_domain = AHB, .line_num = 8 },
[RCC_DAC] = { .clk_domain = APB1, .line_num = 29 },
[RCC_DMA2] = { .clk_domain = AHB, .line_num = 1 },
[RCC_SDIO] = { .clk_domain = AHB, .line_num = 10 },
[RCC_SPI3] = { .clk_domain = APB1, .line_num = 15 },
#endif
#ifdef STM32_XL_DENSITY
[RCC_TIMER9] = { .clk_domain = APB2, .line_num = 19 },
[RCC_TIMER10] = { .clk_domain = APB2, .line_num = 20 },
[RCC_TIMER11] = { .clk_domain = APB2, .line_num = 21 },
[RCC_TIMER12] = { .clk_domain = APB1, .line_num = 6 },
[RCC_TIMER13] = { .clk_domain = APB1, .line_num = 7 },
[RCC_TIMER14] = { .clk_domain = APB1, .line_num = 8 },
#endif
};
/**
* @brief Initialize the clock control system. Initializes the system
* clock source to use the PLL driven by an external oscillator
* @param sysclk_src system clock source, must be PLL
* @param pll_src pll clock source, must be HSE
* @param pll_mul pll multiplier
*/
void rcc_clk_init(rcc_sysclk_src sysclk_src,
rcc_pllsrc pll_src,
rcc_pll_multiplier pll_mul) {
uint32 cfgr = 0;
uint32 cr;
/* Assume that we're going to clock the chip off the PLL, fed by
* the HSE */
ASSERT(sysclk_src == RCC_CLKSRC_PLL &&
pll_src == RCC_PLLSRC_HSE);
RCC_BASE->CFGR = pll_src | pll_mul;
/* Turn on the HSE */
cr = RCC_BASE->CR;
cr |= RCC_CR_HSEON;
RCC_BASE->CR = cr;
while (!(RCC_BASE->CR & RCC_CR_HSERDY))
;
/* Now the PLL */
cr |= RCC_CR_PLLON;
RCC_BASE->CR = cr;
while (!(RCC_BASE->CR & RCC_CR_PLLRDY))
;
/* Finally, let's switch over to the PLL */
cfgr &= ~RCC_CFGR_SW;
cfgr |= RCC_CFGR_SW_PLL;
RCC_BASE->CFGR = cfgr;
while ((RCC_BASE->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL)
;
}
/**
* @brief Turn on the clock line on a peripheral
* @param id Clock ID of the peripheral to turn on.
*/
void rcc_clk_enable(rcc_clk_id id) {
static const __io uint32* enable_regs[] = {
[APB1] = &RCC_BASE->APB1ENR,
[APB2] = &RCC_BASE->APB2ENR,
[AHB] = &RCC_BASE->AHBENR,
};
rcc_clk_domain clk_domain = rcc_dev_clk(id);
__io uint32* enr = (__io uint32*)enable_regs[clk_domain];
uint8 lnum = rcc_dev_table[id].line_num;
bb_peri_set_bit(enr, lnum, 1);
}
/**
* @brief Reset a peripheral.
* @param id Clock ID of the peripheral to reset.
*/
void rcc_reset_dev(rcc_clk_id id) {
static const __io uint32* reset_regs[] = {
[APB1] = &RCC_BASE->APB1RSTR,
[APB2] = &RCC_BASE->APB2RSTR,
};
rcc_clk_domain clk_domain = rcc_dev_clk(id);
__io void* addr = (__io void*)reset_regs[clk_domain];
uint8 lnum = rcc_dev_table[id].line_num;
bb_peri_set_bit(addr, lnum, 1);
bb_peri_set_bit(addr, lnum, 0);
}
/**
* @brief Get a peripheral's clock domain
* @param id Clock ID of the peripheral whose clock domain to return
* @return Clock source for the given clock ID
*/
rcc_clk_domain rcc_dev_clk(rcc_clk_id id) {
return rcc_dev_table[id].clk_domain;
}
/**
* @brief Set the divider on a peripheral prescaler
* @param prescaler prescaler to set
* @param divider prescaler divider
*/
void rcc_set_prescaler(rcc_prescaler prescaler, uint32 divider) {
static const uint32 masks[] = {
[RCC_PRESCALER_AHB] = RCC_CFGR_HPRE,
[RCC_PRESCALER_APB1] = RCC_CFGR_PPRE1,
[RCC_PRESCALER_APB2] = RCC_CFGR_PPRE2,
[RCC_PRESCALER_USB] = RCC_CFGR_USBPRE,
[RCC_PRESCALER_ADC] = RCC_CFGR_ADCPRE,
};
uint32 cfgr = RCC_BASE->CFGR;
cfgr &= ~masks[prescaler];
cfgr |= divider;
RCC_BASE->CFGR = cfgr;
}
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