From: Andrew Ruder andrew.ruder@elecsyscorp.com
This patch moves mx35 to the common timer functions added in commit
8dfafdd - Introduce common timer functions <Rob Herring>
The (removed) mx35 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 mx35 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: Stefano Babic sbabic@denx.de ---
This patch has been COMPILE tested only. The situation isn't quite as bad on mx35 as 32-bit rollover occurs in about a day and a half.
Before patch: Configuring for woodburn board... 308 -rw-r--r-- 1 andy andy 314232 Aug 12 08:36 u-boot.bin
After patch: Configuring for woodburn board... 308 -rw-r--r-- 1 andy andy 314208 Aug 12 08:37 u-boot.bin
arch/arm/cpu/arm1136/mx35/timer.c | 83 ------------------------------- arch/arm/include/asm/arch-mx35/imx-regs.h | 12 +++++ 2 files changed, 12 insertions(+), 83 deletions(-)
diff --git a/arch/arm/cpu/arm1136/mx35/timer.c b/arch/arm/cpu/arm1136/mx35/timer.c index cc6166f..4edf533 100644 --- a/arch/arm/cpu/arm1136/mx35/timer.c +++ b/arch/arm/cpu/arm1136/mx35/timer.c @@ -9,16 +9,11 @@
#include <common.h> #include <asm/io.h> -#include <div64.h> #include <asm/arch/imx-regs.h> #include <asm/arch/crm_regs.h> -#include <asm/arch/clock.h>
DECLARE_GLOBAL_DATA_PTR;
-#define timestamp (gd->arch.tbl) -#define lastinc (gd->arch.lastinc) - /* General purpose timers bitfields */ #define GPTCR_SWR (1<<15) /* Software reset */ #define GPTCR_FRR (1<<9) /* Freerun / restart */ @@ -26,27 +21,6 @@ DECLARE_GLOBAL_DATA_PTR; #define GPTCR_TEN (1) /* Timer enable */
/* - * "time" is measured in 1 / CONFIG_SYS_HZ seconds, - * "tick" is internal timer period - */ -/* ~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 us_to_tick(unsigned long long us) -{ - us = us * MXC_CLK32 + 999999; - do_div(us, 1000000); - - return us; -} - -/* * nothing really to do with interrupts, just starts up a counter. * The 32KHz 32-bit timer overruns in 134217 seconds */ @@ -71,60 +45,3 @@ int timer_init(void)
return 0; } - -unsigned long long get_ticks(void) -{ - struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR; - ulong now = readl(&gpt->counter); /* 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 / 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 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*/; -} - -/* - * 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; -} diff --git a/arch/arm/include/asm/arch-mx35/imx-regs.h b/arch/arm/include/asm/arch-mx35/imx-regs.h index b530029..28a47ed 100644 --- a/arch/arm/include/asm/arch-mx35/imx-regs.h +++ b/arch/arm/include/asm/arch-mx35/imx-regs.h @@ -372,4 +372,16 @@ struct aips_regs { #define CCM_RCSR_NF_16BIT_SEL (1 << 14)
#endif + +/* + * Generic timer support + */ +#ifdef CONFIG_MX35_CLK32 +#define CONFIG_SYS_TIMER_RATE CONFIG_MX35_CLK32 +#else +#define CONFIG_SYS_TIMER_RATE 32768 +#endif + +#define CONFIG_SYS_TIMER_COUNTER (GPT1_BASE_ADDR+36) + #endif /* __ASM_ARCH_MX35_H */