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RIOT/cpu/stm32/stmclk/stmclk_u5.c
2023-07-05 09:40:24 +02:00

320 lines
12 KiB
C

/*
* Copyright (C) 2021 Inria
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup cpu_stm32
* @{
*
* @file
* @brief Implementation of STM32 clock configuration for U5 family
*
* @author Alexandre Abadie <alexandre.abadie@inria.fr>
* @}
*/
#include "cpu.h"
#include "stmclk.h"
#include "periph_conf.h"
#define RCC_CFGR1_SW_MSI (0x00000000U)
#define RCC_CFGR1_SW_HSI (RCC_CFGR1_SW_0)
#define RCC_CFGR1_SW_HSE (RCC_CFGR1_SW_1)
#define RCC_CFGR1_SW_PLL (RCC_CFGR1_SW_1 | RCC_CFGR1_SW_0)
#define RCC_CFGR1_SWS_MSI (0x00000000U)
#define RCC_CFGR1_SWS_HSI (RCC_CFGR1_SWS_0)
#define RCC_CFGR1_SWS_HSE (RCC_CFGR1_SWS_1)
#define RCC_CFGR1_SWS_PLL (RCC_CFGR1_SWS_1 | RCC_CFGR1_SWS_0)
/* PLL configuration */
/* figure out which input to use */
#if IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_MSI)
#define PLL_SRC (RCC_PLL1CFGR_PLL1SRC_0)
#elif IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_HSE) && IS_ACTIVE(CONFIG_BOARD_HAS_HSE)
#define PLL_SRC (RCC_PLL1CFGR_PLL1SRC_1 | RCC_PLL1CFGR_PLL1SRC_0)
#elif IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_HSI)
#define PLL_SRC (RCC_PLL1CFGR_PLL1SRC_1)
#else
#define PLL_SRC 0
#endif
/* check configuration and get the corresponding bitfields */
#if (CONFIG_CLOCK_PLL_M < 1 || CONFIG_CLOCK_PLL_M > 16)
#error "PLL configuration: PLL M value is out of range"
#endif
#define PLL_M ((CONFIG_CLOCK_PLL_M - 1) << RCC_PLL1CFGR_PLL1M_Pos)
#if (CONFIG_CLOCK_PLL_N < 4 || CONFIG_CLOCK_PLL_N > 512)
#error "PLL configuration: PLL N value is out of range"
#endif
#define PLL_N ((CONFIG_CLOCK_PLL_N - 1) << RCC_PLL1DIVR_PLL1N_Pos)
#if (CONFIG_CLOCK_PLL_R < 1 || CONFIG_CLOCK_PLL_R > 128)
#error "PLL configuration: PLL R value is out of range"
#endif
#define PLL_R ((CONFIG_CLOCK_PLL_R - 1) << RCC_PLL1DIVR_PLL1R_Pos)
#if (CONFIG_CLOCK_PLL_Q < 1 || CONFIG_CLOCK_PLL_Q > 128)
#error "PLL configuration: PLL Q value is out of range"
#endif
#define PLL_Q ((CONFIG_CLOCK_PLL_Q - 1) << RCC_PLL1DIVR_PLL1Q_Pos)
/* Define MSI range bitfields */
#if CONFIG_CLOCK_MSI == KHZ(100)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_2 | RCC_ICSCR1_MSISRANGE_1 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == KHZ(133)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_2 | RCC_ICSCR1_MSISRANGE_1)
#elif CONFIG_CLOCK_MSI == KHZ(200)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_2 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == KHZ(400)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_2)
#elif CONFIG_CLOCK_MSI == KHZ(768)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_1 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == MHZ(1)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_2 | RCC_ICSCR1_MSISRANGE_1 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == KHZ(1024)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_1)
#elif CONFIG_CLOCK_MSI == KHZ(1330)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_2 | RCC_ICSCR1_MSISRANGE_1)
#elif CONFIG_CLOCK_MSI == KHZ(1536)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == MHZ(2)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_2 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == KHZ(3072)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_3)
#elif CONFIG_CLOCK_MSI == MHZ(4)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_2)
#elif CONFIG_CLOCK_MSI == MHZ(12)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_1 | RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == MHZ(16)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_1)
#elif CONFIG_CLOCK_MSI == MHZ(24)
#define CLOCK_MSIRANGE (RCC_ICSCR1_MSISRANGE_0)
#elif CONFIG_CLOCK_MSI == MHZ(48)
#define CLOCK_MSIRANGE (0)
#else
#error "Invalid MSI clock"
#endif
/* Configure the AHB and APB buses prescalers */
#define CLOCK_AHB_DIV (0)
#if CONFIG_CLOCK_APB1_DIV == 1
#define CLOCK_APB1_DIV (0)
#elif CONFIG_CLOCK_APB1_DIV == 2
#define CLOCK_APB1_DIV (RCC_CFGR2_PPRE1_2)
#elif CONFIG_CLOCK_APB1_DIV == 4
#define CLOCK_APB1_DIV (RCC_CFGR2_PPRE1_2 | RCC_CFGR2_PPRE1_0)
#elif CONFIG_CLOCK_APB1_DIV == 8
#define CLOCK_APB1_DIV (RCC_CFGR2_PPRE1_2 | RCC_CFGR2_PPRE1_1)
#elif CONFIG_CLOCK_APB1_DIV == 16
#define CLOCK_APB1_DIV (RCC_CFGR2_PPRE1_2 | RCC_CFGR2_PPRE1_1 | RCC_CFGR2_PPRE1_0)
#endif
#if CONFIG_CLOCK_APB2_DIV == 1
#define CLOCK_APB2_DIV (0)
#elif CONFIG_CLOCK_APB2_DIV == 2
#define CLOCK_APB2_DIV (RCC_CFGR2_PPRE2_2)
#elif CONFIG_CLOCK_APB2_DIV == 4
#define CLOCK_APB2_DIV (RCC_CFGR2_PPRE2_2 | RCC_CFGR2_PPRE2_0)
#elif CONFIG_CLOCK_APB2_DIV == 8
#define CLOCK_APB2_DIV (RCC_CFGR2_PPRE2_2 | RCC_CFGR2_PPRE2_1)
#elif CONFIG_CLOCK_APB2_DIV == 16
#define CLOCK_APB2_DIV (RCC_CFGR2_PPRE2_2 | RCC_CFGR2_PPRE2_1 | RCC_CFGR2_PPRE2_0)
#endif
/* Only periph_hwrng and periph_usbdev require HSI RC with 48MHz for the moment */
#if IS_USED(MODULE_PERIPH_HWRNG) || IS_USED(MODULE_PERIPH_USBDEV_CLK)
#define CLOCK_ENABLE_HSI48 1
#else
#define CLOCK_ENABLE_HSI48 0
#endif
/* Check if PLL is required
- When PLLQ is used as 48MHz clock source
*/
#if IS_ACTIVE(CONFIG_USE_CLOCK_PLL)
#define CLOCK_ENABLE_PLL 1
#else
#define CLOCK_ENABLE_PLL 0
#endif
/* Check if HSE is required:
- When used as system clock
- When used as PLL input clock
*/
#if IS_ACTIVE(CONFIG_USE_CLOCK_HSE) || \
(IS_ACTIVE(CLOCK_ENABLE_PLL) && IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_HSE))
#define CLOCK_ENABLE_HSE 1
#else
#define CLOCK_ENABLE_HSE 0
#endif
/* HSE cannot be enabled if not provided by the board */
#if IS_ACTIVE(CLOCK_ENABLE_HSE) && !IS_ACTIVE(CONFIG_BOARD_HAS_HSE)
#error "HSE is required by the clock configuration but is not provided by the board."
#endif
/* Check if HSI RC with 16 MHz is required:
- When used as system clock
- When used as PLL input clock
*/
#if IS_ACTIVE(CONFIG_USE_CLOCK_HSI) || \
(IS_ACTIVE(CLOCK_ENABLE_PLL) && IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_HSI))
#define CLOCK_ENABLE_HSI 1
#else
#define CLOCK_ENABLE_HSI 0
#endif
/* Check if MSI is required
- When used as system clock
- When used as PLL input clock
*/
#if IS_ACTIVE(CONFIG_USE_CLOCK_MSI) || \
(IS_ACTIVE(CLOCK_ENABLE_PLL) && IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_MSI)) || \
(IS_ACTIVE(CLOCK_ENABLE_48MHZ) && IS_ACTIVE(CLOCK48MHZ_USE_MSI))
#define CLOCK_ENABLE_MSI 1
#else
#define CLOCK_ENABLE_MSI 0
#endif
/* Deduct the needed flash wait states from the core clock frequency */
#if CLOCK_AHB <= MHZ(32)
#define FLASH_WAITSTATES FLASH_ACR_LATENCY_0WS
#elif CLOCK_AHB <= MHZ(64)
#define FLASH_WAITSTATES FLASH_ACR_LATENCY_1WS
#elif CLOCK_AHB <= MHZ(96)
#define FLASH_WAITSTATES FLASH_ACR_LATENCY_2WS
#elif CLOCK_AHB <= MHZ(128)
#define FLASH_WAITSTATES FLASH_ACR_LATENCY_3WS
#elif CLOCK_AHB <= MHZ(160)
#define FLASH_WAITSTATES FLASH_ACR_LATENCY_4WS
#endif
void stmclk_init_sysclk(void)
{
/* disable any interrupts. Global interrupts could be enabled if this is
* called from some kind of bootloader... */
unsigned is = irq_disable();
RCC->CIER = 0;
/* select 1-way cache */
ICACHE->CR &= ~ICACHE_CR_WAYSEL;
ICACHE->CR |= ICACHE_CR_EN;
/* enable HSI clock for the duration of initialization */
stmclk_enable_hsi();
/* use HSI as system clock while we do any further configuration and
* configure the AHB and APB clock dividers as configured by the board */
RCC->CFGR1 = RCC_CFGR1_SW_HSI;
while ((RCC->CFGR1 & RCC_CFGR1_SWS) != RCC_CFGR1_SWS_HSI) {}
RCC->CFGR2 = (CLOCK_AHB_DIV | CLOCK_APB1_DIV | CLOCK_APB2_DIV);
/* Select the Voltage Range 1 */
PWR->VOSR = (PWR_VOSR_VOS_1 | PWR_VOSR_VOS_0);
/* Wait Until the Voltage Regulator is ready */
while (!(PWR->VOSR & PWR_VOSR_VOSRDY)) {}
/* Backup RAM retention in Standby and VBAT modes:
This bit can be written only when the regulator is LDO,
which must be configured before switching to SMPS */
PWR->BDCR1 |= PWR_BDCR1_BREN;
/* Switch to SMPS regulator instead of LDO */
PWR->CR3 |= PWR_CR3_REGSEL;
while (!(PWR->SVMSR & PWR_SVMSR_REGS)) {}
/* configure flash wait states */
FLASH->ACR = FLASH_WAITSTATES;
/* disable all active clocks except HSI -> resets the clk configuration */
RCC->CR = RCC_CR_HSION;
/* Enable the HSE clock only when it's used */
if (IS_ACTIVE(CLOCK_ENABLE_HSE)) {
RCC->CR |= (RCC_CR_HSEON);
while (!(RCC->CR & RCC_CR_HSERDY)) {}
}
/* Enable the MSIS clock only when it's used */
if (IS_ACTIVE(CLOCK_ENABLE_MSI)) {
RCC->ICSCR1 = RCC_ICSCR1_MSIRGSEL;
RCC->ICSCR1 |= CLOCK_MSIRANGE;
RCC->CR |= (RCC_CR_MSISON | RCC_CR_MSIPLLSEL | RCC_CR_MSIPLLFAST);
while (!(RCC->CR & RCC_CR_MSISRDY)) {}
}
/* Enable the PLL clock only when it's used */
if (IS_ACTIVE(CLOCK_ENABLE_PLL)) {
if (IS_ACTIVE(CONFIG_CLOCK_PLL_SRC_MSI) && IS_ACTIVE(CONFIG_BOARD_HAS_LSE)) {
/* configure the low speed clock domain */
stmclk_enable_lfclk();
/* now we can enable the MSI PLL mode to enhance accuracy of the MSI */
RCC->CR |= RCC_CR_MSIPLLEN;
while (!(RCC->CR & RCC_CR_MSISRDY)) {}
}
/* configure and start the PLL */
RCC->PLL1CFGR = (PLL_SRC | PLL_M | RCC_PLL1CFGR_PLL1RGE_1 | RCC_PLL1CFGR_PLL1RGE_0);
if (IS_ACTIVE(CONFIG_USE_CLOCK_PLL)) {
/* Enable PLLCLK if PLL is used as system clock */
RCC->PLL1CFGR |= RCC_PLL1CFGR_PLL1REN;
}
if (IS_ACTIVE(CLOCK48MHZ_USE_PLLQ)) {
/* Enable PLLQ if PLL is used as 48MHz source clock */
RCC->PLL1CFGR |= RCC_PLL1CFGR_PLL1QEN;
}
RCC->PLL1DIVR = (PLL_N | PLL_R | PLL_Q);
RCC->PLL1FRACR = 0;
RCC->CR |= RCC_CR_PLL1ON;
while (!(RCC->CR & RCC_CR_PLL1RDY)) {}
}
/* Configure SYSCLK */
if (!IS_ACTIVE(CONFIG_USE_CLOCK_HSI)) {
RCC->CFGR1 &= ~RCC_CFGR1_SW;
}
if (IS_ACTIVE(CONFIG_USE_CLOCK_HSE)) {
/* Select HSE as system clock */
RCC->CFGR1 |= RCC_CFGR1_SW_HSE;
while ((RCC->CFGR1 & RCC_CFGR1_SWS) != RCC_CFGR1_SWS_HSE) {}
}
else if (IS_ACTIVE(CONFIG_USE_CLOCK_MSI)) {
/* Select MSI as system clock */
RCC->CFGR1 |= RCC_CFGR1_SW_MSI;
while ((RCC->CFGR1 & RCC_CFGR1_SWS) != RCC_CFGR1_SWS_MSI) {}
}
else if (IS_ACTIVE(CONFIG_USE_CLOCK_PLL)) {
/* Select main PLL as system clock */
RCC->CFGR1 |= RCC_CFGR1_SW_PLL;
while ((RCC->CFGR1 & RCC_CFGR1_SWS) != RCC_CFGR1_SWS_PLL) {}
}
if (!IS_ACTIVE(CLOCK_ENABLE_HSI)) {
/* Disable HSI only if not used */
stmclk_disable_hsi();
}
if (IS_ACTIVE(CLOCK_ENABLE_HSI48)) {
/* enable HSI48 clock for certain peripherals (RNG, OTG_FS, USB and SDMMC) */
RCC->CR |= RCC_CR_HSI48ON;
while (!(RCC->CR & RCC_CR_HSI48RDY)) {}
/* select HSI48 as clock for RNG (reset value) */
/* RCC->CCIPR2 &= ~(RCC_CCIPR2_RNGSEL_1 | RCC_CCIPR2_RNGSEL_0); */
/* select HSI48 as clock for OTG_FS, USB and SDMMC (reset value) */
/* RCC->CCIPR1 &= ~(RCC_CCIPR1_CLK48MSEL_1 | RCC_CCIPR1_CLK48MSEL_0); */
}
irq_restore(is);
}