diff options
Diffstat (limited to 'arch/arm/cpu/armv7m/stm32f4/clock.c')
| -rw-r--r-- | arch/arm/cpu/armv7m/stm32f4/clock.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7m/stm32f4/clock.c b/arch/arm/cpu/armv7m/stm32f4/clock.c new file mode 100644 index 0000000000..2eded1f52e --- /dev/null +++ b/arch/arm/cpu/armv7m/stm32f4/clock.c @@ -0,0 +1,209 @@ +/* + * (C) Copyright 2015 + * Kamil Lulko, <rev13@wp.pl> + * + * (C) Copyright 2014 + * STMicroelectronics + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/stm32.h> + +#define RCC_CR_HSION (1 << 0) +#define RCC_CR_HSEON (1 << 16) +#define RCC_CR_HSERDY (1 << 17) +#define RCC_CR_HSEBYP (1 << 18) +#define RCC_CR_CSSON (1 << 19) +#define RCC_CR_PLLON (1 << 24) +#define RCC_CR_PLLRDY (1 << 25) + +#define RCC_PLLCFGR_PLLM_MASK 0x3F +#define RCC_PLLCFGR_PLLN_MASK 0x7FC0 +#define RCC_PLLCFGR_PLLP_MASK 0x30000 +#define RCC_PLLCFGR_PLLQ_MASK 0xF000000 +#define RCC_PLLCFGR_PLLSRC (1 << 22) +#define RCC_PLLCFGR_PLLN_SHIFT 6 +#define RCC_PLLCFGR_PLLP_SHIFT 16 +#define RCC_PLLCFGR_PLLQ_SHIFT 24 + +#define RCC_CFGR_AHB_PSC_MASK 0xF0 +#define RCC_CFGR_APB1_PSC_MASK 0x1C00 +#define RCC_CFGR_APB2_PSC_MASK 0xE000 +#define RCC_CFGR_SW0 (1 << 0) +#define RCC_CFGR_SW1 (1 << 1) +#define RCC_CFGR_SW_MASK 0x3 +#define RCC_CFGR_SW_HSI 0 +#define RCC_CFGR_SW_HSE RCC_CFGR_SW0 +#define RCC_CFGR_SW_PLL RCC_CFGR_SW1 +#define RCC_CFGR_SWS0 (1 << 2) +#define RCC_CFGR_SWS1 (1 << 3) +#define RCC_CFGR_SWS_MASK 0xC +#define RCC_CFGR_SWS_HSI 0 +#define RCC_CFGR_SWS_HSE RCC_CFGR_SWS0 +#define RCC_CFGR_SWS_PLL RCC_CFGR_SWS1 +#define RCC_CFGR_HPRE_SHIFT 4 +#define RCC_CFGR_PPRE1_SHIFT 10 +#define RCC_CFGR_PPRE2_SHIFT 13 + +#define RCC_APB1ENR_PWREN (1 << 28) + +#define PWR_CR_VOS0 (1 << 14) +#define PWR_CR_VOS1 (1 << 15) +#define PWR_CR_VOS_MASK 0xC000 +#define PWR_CR_VOS_SCALE_MODE_1 (PWR_CR_VOS0 | PWR_CR_VOS1) +#define PWR_CR_VOS_SCALE_MODE_2 (PWR_CR_VOS1) +#define PWR_CR_VOS_SCALE_MODE_3 (PWR_CR_VOS0) + +#define FLASH_ACR_WS(n) n +#define FLASH_ACR_PRFTEN (1 << 8) +#define FLASH_ACR_ICEN (1 << 9) +#define FLASH_ACR_DCEN (1 << 10) + +struct pll_psc { + u8 pll_m; + u16 pll_n; + u8 pll_p; + u8 pll_q; + u8 ahb_psc; + u8 apb1_psc; + u8 apb2_psc; +}; + +#define AHB_PSC_1 0 +#define AHB_PSC_2 0x8 +#define AHB_PSC_4 0x9 +#define AHB_PSC_8 0xA +#define AHB_PSC_16 0xB +#define AHB_PSC_64 0xC +#define AHB_PSC_128 0xD +#define AHB_PSC_256 0xE +#define AHB_PSC_512 0xF + +#define APB_PSC_1 0 +#define APB_PSC_2 0x4 +#define APB_PSC_4 0x5 +#define APB_PSC_8 0x6 +#define APB_PSC_16 0x7 + +#if !defined(CONFIG_STM32_HSE_HZ) +#error "CONFIG_STM32_HSE_HZ not defined!" +#else +#if (CONFIG_STM32_HSE_HZ == 8000000) +struct pll_psc pll_psc_168 = { + .pll_m = 8, + .pll_n = 336, + .pll_p = 2, + .pll_q = 7, + .ahb_psc = AHB_PSC_1, + .apb1_psc = APB_PSC_4, + .apb2_psc = APB_PSC_2 +}; +#else +#error "No PLL/Prescaler configuration for given CONFIG_STM32_HSE_HZ exists" +#endif +#endif + +int configure_clocks(void) +{ + /* Reset RCC configuration */ + setbits_le32(&STM32_RCC->cr, RCC_CR_HSION); + writel(0, &STM32_RCC->cfgr); /* Reset CFGR */ + clrbits_le32(&STM32_RCC->cr, (RCC_CR_HSEON | RCC_CR_CSSON + | RCC_CR_PLLON)); + writel(0x24003010, &STM32_RCC->pllcfgr); /* Reset value from RM */ + clrbits_le32(&STM32_RCC->cr, RCC_CR_HSEBYP); + writel(0, &STM32_RCC->cir); /* Disable all interrupts */ + + /* Configure for HSE+PLL operation */ + setbits_le32(&STM32_RCC->cr, RCC_CR_HSEON); + while (!(readl(&STM32_RCC->cr) & RCC_CR_HSERDY)) + ; + + /* Enable high performance mode, System frequency up to 168 MHz */ + setbits_le32(&STM32_RCC->apb1enr, RCC_APB1ENR_PWREN); + writel(PWR_CR_VOS_SCALE_MODE_1, &STM32_PWR->cr); + + setbits_le32(&STM32_RCC->cfgr, (( + pll_psc_168.ahb_psc << RCC_CFGR_HPRE_SHIFT) + | (pll_psc_168.apb1_psc << RCC_CFGR_PPRE1_SHIFT) + | (pll_psc_168.apb2_psc << RCC_CFGR_PPRE2_SHIFT))); + + writel(pll_psc_168.pll_m + | (pll_psc_168.pll_n << RCC_PLLCFGR_PLLN_SHIFT) + | (((pll_psc_168.pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT) + | (pll_psc_168.pll_q << RCC_PLLCFGR_PLLQ_SHIFT), + &STM32_RCC->pllcfgr); + setbits_le32(&STM32_RCC->pllcfgr, RCC_PLLCFGR_PLLSRC); + + setbits_le32(&STM32_RCC->cr, RCC_CR_PLLON); + + while (!(readl(&STM32_RCC->cr) & RCC_CR_PLLRDY)) + ; + + /* 5 wait states, Prefetch enabled, D-Cache enabled, I-Cache enabled */ + writel(FLASH_ACR_WS(5) | FLASH_ACR_PRFTEN | FLASH_ACR_ICEN + | FLASH_ACR_DCEN, &STM32_FLASH->acr); + + clrbits_le32(&STM32_RCC->cfgr, (RCC_CFGR_SW0 | RCC_CFGR_SW1)); + setbits_le32(&STM32_RCC->cfgr, RCC_CFGR_SW_PLL); + + while ((readl(&STM32_RCC->cfgr) & RCC_CFGR_SWS_MASK) != + RCC_CFGR_SWS_PLL) + ; + + return 0; +} + +unsigned long clock_get(enum clock clck) +{ + u32 sysclk = 0; + u32 shift = 0; + /* Prescaler table lookups for clock computation */ + u8 ahb_psc_table[16] = { + 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9 + }; + u8 apb_psc_table[8] = { + 0, 0, 0, 0, 1, 2, 3, 4 + }; + + if ((readl(&STM32_RCC->cfgr) & RCC_CFGR_SWS_MASK) == + RCC_CFGR_SWS_PLL) { + u16 pllm, plln, pllp; + pllm = (readl(&STM32_RCC->pllcfgr) & RCC_PLLCFGR_PLLM_MASK); + plln = ((readl(&STM32_RCC->pllcfgr) & RCC_PLLCFGR_PLLN_MASK) + >> RCC_PLLCFGR_PLLN_SHIFT); + pllp = ((((readl(&STM32_RCC->pllcfgr) & RCC_PLLCFGR_PLLP_MASK) + >> RCC_PLLCFGR_PLLP_SHIFT) + 1) << 1); + sysclk = ((CONFIG_STM32_HSE_HZ / pllm) * plln) / pllp; + } + + switch (clck) { + case CLOCK_CORE: + return sysclk; + break; + case CLOCK_AHB: + shift = ahb_psc_table[( + (readl(&STM32_RCC->cfgr) & RCC_CFGR_AHB_PSC_MASK) + >> RCC_CFGR_HPRE_SHIFT)]; + return sysclk >>= shift; + break; + case CLOCK_APB1: + shift = apb_psc_table[( + (readl(&STM32_RCC->cfgr) & RCC_CFGR_APB1_PSC_MASK) + >> RCC_CFGR_PPRE1_SHIFT)]; + return sysclk >>= shift; + break; + case CLOCK_APB2: + shift = apb_psc_table[( + (readl(&STM32_RCC->cfgr) & RCC_CFGR_APB2_PSC_MASK) + >> RCC_CFGR_PPRE2_SHIFT)]; + return sysclk >>= shift; + break; + default: + return 0; + break; + } +} |
