u-boot/arch/arm/cpu/arm926ejs/mx27/timer.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

161 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* (C) Copyright 2002
* Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
*
* (C) Copyright 2009
* Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com>
*/
#include <common.h>
#include <div64.h>
#include <asm/io.h>
#include <asm/arch/imx-regs.h>
/* General purpose timers bitfields */
#define GPTCR_SWR (1 << 15) /* Software reset */
#define GPTCR_FRR (1 << 8) /* Freerun / restart */
#define GPTCR_CLKSOURCE_32 (4 << 1) /* Clock source */
#define GPTCR_TEN 1 /* Timer enable */
DECLARE_GLOBAL_DATA_PTR;
#define timestamp (gd->arch.tbl)
#define lastinc (gd->arch.lastinc)
/*
* "time" is measured in 1 / CONFIG_SYS_HZ seconds,
* "tick" is internal timer period
*/
#ifdef CONFIG_MX27_TIMER_HIGH_PRECISION
/* ~0.4% error - measured with stop-watch on 100s boot-delay */
static inline unsigned long long tick_to_time(unsigned long long tick)
{
tick *= CONFIG_SYS_HZ;
do_div(tick, CONFIG_MX27_CLK32);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
time *= CONFIG_MX27_CLK32;
do_div(time, CONFIG_SYS_HZ);
return time;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
us = us * CONFIG_MX27_CLK32 + 999999;
do_div(us, 1000000);
return us;
}
#else
/* ~2% error */
#define TICK_PER_TIME ((CONFIG_MX27_CLK32 + CONFIG_SYS_HZ / 2) / \
CONFIG_SYS_HZ)
#define US_PER_TICK (1000000 / CONFIG_MX27_CLK32)
static inline unsigned long long tick_to_time(unsigned long long tick)
{
do_div(tick, TICK_PER_TIME);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
return time * TICK_PER_TIME;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
us += US_PER_TICK - 1;
do_div(us, US_PER_TICK);
return us;
}
#endif
/* nothing really to do with interrupts, just starts up a counter. */
/* The 32768Hz 32-bit timer overruns in 131072 seconds */
int timer_init(void)
{
int i;
struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
struct pll_regs *pll = (struct pll_regs *)IMX_PLL_BASE;
/* setup GP Timer 1 */
writel(GPTCR_SWR, &regs->gpt_tctl);
writel(readl(&pll->pccr0) | PCCR0_GPT1_EN, &pll->pccr0);
writel(readl(&pll->pccr1) | PCCR1_PERCLK1_EN, &pll->pccr1);
for (i = 0; i < 100; i++)
writel(0, &regs->gpt_tctl); /* We have no udelay by now */
writel(0, &regs->gpt_tprer); /* 32Khz */
/* Freerun Mode, PERCLK1 input */
writel(readl(&regs->gpt_tctl) | GPTCR_CLKSOURCE_32 | GPTCR_FRR,
&regs->gpt_tctl);
writel(readl(&regs->gpt_tctl) | GPTCR_TEN, &regs->gpt_tctl);
return 0;
}
unsigned long long get_ticks(void)
{
struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
ulong now = readl(&regs->gpt_tcn); /* current tick value */
if (now >= lastinc) {
/*
* normal mode (non roll)
* move stamp forward with absolut diff ticks
*/
timestamp += (now - lastinc);
} else {
/* we have rollover of incrementer */
timestamp += (0xFFFFFFFF - lastinc) + now;
}
lastinc = now;
return timestamp;
}
ulong get_timer_masked(void)
{
/*
* get_ticks() returns a long long (64 bit), it wraps in
* 2^64 / CONFIG_MX27_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
* 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
* 5 * 10^6 days - long enough.
*/
return tick_to_time(get_ticks());
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
/* delay x useconds AND preserve advance timstamp value */
void __udelay(unsigned long usec)
{
unsigned long long tmp;
ulong tmo;
tmo = us_to_tick(usec);
tmp = get_ticks() + tmo; /* get current timestamp */
while (get_ticks() < tmp) /* loop till event */
/*NOP*/;
}
ulong get_tbclk(void)
{
return CONFIG_MX27_CLK32;
}