On Tuesday, August 12, 2014 at 04:26:00 PM, andrew.ruder@elecsyscorp.com wrote:
From: Andrew Ruder andrew.ruder@elecsyscorp.com
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
+CC Stefano
This patch has been COMPILE tested only. The situation isn't quite as bad on mx31 as 32-bit rollover occurs in about a day and a half.
Before patch: Configuring for qong board... 456 -rw-r--r-- 1 andy andy 463236 Aug 12 08:36 u-boot.bin
After patch: Configuring for qong board... 456 -rw-r--r-- 1 andy andy 463248 Aug 12 08:38 u-boot.bin
arch/arm/cpu/arm1136/mx31/timer.c | 104 +----------------------------- arch/arm/include/asm/arch-mx31/imx-regs.h | 10 +++ 2 files changed, 12 insertions(+), 102 deletions(-)
diff --git a/arch/arm/cpu/arm1136/mx31/timer.c b/arch/arm/cpu/arm1136/mx31/timer.c index f111242..3a81ce4 100644 --- a/arch/arm/cpu/arm1136/mx31/timer.c +++ b/arch/arm/cpu/arm1136/mx31/timer.c @@ -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) -{
- 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) +unsigned long timer_read_counter(void) {
- return MXC_CLK32;
- return GPTCNT;
} diff --git a/arch/arm/include/asm/arch-mx31/imx-regs.h b/arch/arm/include/asm/arch-mx31/imx-regs.h index f23350e..71ebd24 100644 --- a/arch/arm/include/asm/arch-mx31/imx-regs.h +++ b/arch/arm/include/asm/arch-mx31/imx-regs.h @@ -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 */