u-boot/arch/arm/mach-stm32/stm32f4/timer.c

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/*
* (C) Copyright 2015
* Kamil Lulko, <kamil.lulko@gmail.com>
*
* 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;
}