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/*
* (C) Copyright 2016
* Vikas Manocha, ST Micoelectronics, vikas.manocha@st.com.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/stm32.h>
#include <asm/arch/stm32_defs.h>
#include <asm/arch/gpt.h>
#define READ_TIMER() (readl(&gpt1_regs_ptr->cnt) & GPT_FREE_RUNNING)
#define GPT_RESOLUTION (CONFIG_SYS_HZ_CLOCK/CONFIG_STM32_HZ)
DECLARE_GLOBAL_DATA_PTR;
#define timestamp gd->arch.tbl
#define lastdec gd->arch.lastinc
int timer_init(void)
{
/* Timer2 clock configuration */
clock_setup(TIMER2_CLOCK_CFG);
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/* Stop the timer */
writel(readl(&gpt1_regs_ptr->cr1) & ~GPT_CR1_CEN, &gpt1_regs_ptr->cr1);
writel((CONFIG_SYS_CLK_FREQ/CONFIG_SYS_HZ_CLOCK) - 1,
&gpt1_regs_ptr->psc);
/* Configure timer for auto-reload */
writel(readl(&gpt1_regs_ptr->cr1) | GPT_MODE_AUTO_RELOAD,
&gpt1_regs_ptr->cr1);
/* load value for free running */
writel(GPT_FREE_RUNNING, &gpt1_regs_ptr->arr);
/* start timer */
writel(readl(&gpt1_regs_ptr->cr1) | GPT_CR1_CEN, &gpt1_regs_ptr->cr1);
writel(readl(&gpt1_regs_ptr->egr) | TIM_EGR_UG, &gpt1_regs_ptr->egr);
/* Reset the timer */
lastdec = READ_TIMER();
timestamp = 0;
return 0;
}
/*
* timer without interrupts
*/
ulong get_timer(ulong base)
{
return (get_timer_masked() / GPT_RESOLUTION) - base;
}
void __udelay(unsigned long usec)
{
ulong tmo;
ulong start = get_timer_masked();
ulong tenudelcnt = CONFIG_SYS_HZ_CLOCK / (1000 * 100);
ulong rndoff;
rndoff = (usec % 10) ? 1 : 0;
/* tenudelcnt timer tick gives 10 microsecconds delay */
tmo = ((usec / 10) + rndoff) * tenudelcnt;
while ((ulong) (get_timer_masked() - start) < tmo)
;
}
ulong get_timer_masked(void)
{
ulong now = READ_TIMER();
if (now >= lastdec) {
/* normal mode */
timestamp += now - lastdec;
} else {
/* we have an overflow ... */
timestamp += now + GPT_FREE_RUNNING - lastdec;
}
lastdec = now;
return timestamp;
}
void udelay_masked(unsigned long usec)
{
return udelay(usec);
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return get_timer(0);
}
/*
* 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_STM32_HZ;
}