diff options
Diffstat (limited to 'arch/arm/cpu/armv7m/stm32f4/timer.c')
-rw-r--r-- | arch/arm/cpu/armv7m/stm32f4/timer.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7m/stm32f4/timer.c b/arch/arm/cpu/armv7m/stm32f4/timer.c new file mode 100644 index 0000000000..102ae6d960 --- /dev/null +++ b/arch/arm/cpu/armv7m/stm32f4/timer.c @@ -0,0 +1,118 @@ +/* + * (C) Copyright 2015 + * Kamil Lulko, <rev13@wp.pl> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/armv7m.h> +#include <asm/arch/stm32.h> + +DECLARE_GLOBAL_DATA_PTR; + +#define STM32_TIM2_BASE (STM32_APB1PERIPH_BASE + 0x0000) + +#define RCC_APB1ENR_TIM2EN (1 << 0) + +struct stm32_tim2_5 { + u32 cr1; + u32 cr2; + u32 smcr; + u32 dier; + u32 sr; + u32 egr; + u32 ccmr1; + u32 ccmr2; + u32 ccer; + u32 cnt; + u32 psc; + u32 arr; + u32 reserved1; + u32 ccr1; + u32 ccr2; + u32 ccr3; + u32 ccr4; + u32 reserved2; + u32 dcr; + u32 dmar; + u32 or; +}; + +#define TIM_CR1_CEN (1 << 0) + +#define TIM_EGR_UG (1 << 0) + +int timer_init(void) +{ + struct stm32_tim2_5 *tim = (struct stm32_tim2_5 *)STM32_TIM2_BASE; + + setbits_le32(&STM32_RCC->apb1enr, RCC_APB1ENR_TIM2EN); + + if (clock_get(CLOCK_AHB) == clock_get(CLOCK_APB1)) + writel((clock_get(CLOCK_APB1) / CONFIG_SYS_HZ_CLOCK) - 1, + &tim->psc); + else + writel(((clock_get(CLOCK_APB1) * 2) / CONFIG_SYS_HZ_CLOCK) - 1, + &tim->psc); + + writel(0xFFFFFFFF, &tim->arr); + writel(TIM_CR1_CEN, &tim->cr1); + setbits_le32(&tim->egr, TIM_EGR_UG); + + gd->arch.tbl = 0; + gd->arch.tbu = 0; + gd->arch.lastinc = 0; + + return 0; +} + +ulong get_timer(ulong base) +{ + return (get_ticks() / (CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ)) - base; +} + +unsigned long long get_ticks(void) +{ + struct stm32_tim2_5 *tim = (struct stm32_tim2_5 *)STM32_TIM2_BASE; + u32 now; + + now = readl(&tim->cnt); + + if (now >= gd->arch.lastinc) + gd->arch.tbl += (now - gd->arch.lastinc); + else + gd->arch.tbl += (0xFFFFFFFF - gd->arch.lastinc) + now; + + gd->arch.lastinc = now; + + return gd->arch.tbl; +} + +void reset_timer(void) +{ + struct stm32_tim2_5 *tim = (struct stm32_tim2_5 *)STM32_TIM2_BASE; + + gd->arch.lastinc = readl(&tim->cnt); + gd->arch.tbl = 0; +} + +/* delay x useconds */ +void __udelay(ulong usec) +{ + unsigned long long start; + + start = get_ticks(); /* get current timestamp */ + while ((get_ticks() - start) < usec) + ; /* loop till time has passed */ +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +ulong get_tbclk(void) +{ + return CONFIG_SYS_HZ_CLOCK; +} |