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arm: mx31: use common timer functions

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This patch moves mx31 to the common timer functions added in commit

  8dfafdd - Introduce common timer functions <Rob Herring>

The (removed) mx31 timer code (specifically __udelay()) could deadlock at
the 32-bit boundary of get_ticks().  get_ticks() returned a 32-bit value
cast up to a 64-bit value.  If get_ticks() + tmo in __udelay() crossed
the 32-bit boundary, the while condition became unconditionally true and
locks the processor.  Rather than patch the specific mx31 issues, simply
move everything over to the common code.

Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Helmut Raiger <helmut.raiger@hale.at>
This commit is contained in:
Andrew Ruder 2014-08-12 09:26:00 -05:00 • committed by Stefano Babic
parent 4c97f16911
commit 93a0ea501e
2 changed files with 12 additions and 102 deletions
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104
arch/arm/cpu/arm1136/mx31/timer.c
View file

@ -7,9 +7,6 @@
#include <common.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#include <div64.h>
#include <watchdog.h>
#include <asm/io.h>
#define TIMER_BASE 0x53f90000 /* General purpose timer 1 */
@ -28,57 +25,6 @@
DECLARE_GLOBAL_DATA_PTR;
/*
* "time" is measured in 1 / CONFIG_SYS_HZ seconds,
* "tick" is internal timer period
*/
#ifdef CONFIG_MX31_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, MXC_CLK32);
return tick;
}
static inline unsigned long long time_to_tick(unsigned long long time)
{
time *= MXC_CLK32;
do_div(time, CONFIG_SYS_HZ);
return time;
}
static inline unsigned long long us_to_tick(unsigned long long us)
{
us = us * MXC_CLK32 + 999999;
do_div(us, 1000000);
return us;
}
#else
/* ~2% error */
#define TICK_PER_TIME ((MXC_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ)
#define US_PER_TICK (1000000 / MXC_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
/* The 32768Hz 32-bit timer overruns in 131072 seconds */
int timer_init(void)
{
@ -95,53 +41,7 @@ int timer_init(void)
return 0;
}
unsigned long long get_ticks(void)
unsigned long timer_read_counter(void)
{
ulong now = GPTCNT; /* current tick value */
if (now >= gd->arch.lastinc) /* normal mode (non roll) */
/* move stamp forward with absolut diff ticks */
gd->arch.tbl += (now - gd->arch.lastinc);
else /* we have rollover of incrementer */
gd->arch.tbl += (0xFFFFFFFF - gd->arch.lastinc) + now;
gd->arch.lastinc = now;
return gd->arch.tbl;
}
ulong get_timer_masked(void)
{
/*
* get_ticks() returns a long long (64 bit), it wraps in
* 2^64 / MXC_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 timestamp 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*/;
}
/*
* 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 MXC_CLK32;
return GPTCNT;
}

10
arch/arm/include/asm/arch-mx31/imx-regs.h
View file

@ -909,9 +909,19 @@ struct esdc_regs {
#define MXC_CSPIPERIOD_32KHZ (1 << 15)
#define MAX_SPI_BYTES 4
#define MXC_SPI_BASE_ADDRESSES \
0x43fa4000, \
0x50010000, \
0x53f84000,
/*
* Generic timer support
*/
#ifdef CONFIG_MX31_CLK32
#define CONFIG_SYS_TIMER_RATE CONFIG_MX31_CLK32
#else
#define CONFIG_SYS_TIMER_RATE 32768
#endif
#endif /* __ASM_ARCH_MX31_IMX_REGS_H */