From 816264fc6672dbb7c7b22ad9e67b8d0056873394 Mon Sep 17 00:00:00 2001 From: Andrew Ruder Date: Tue, 12 Aug 2014 09:26:01 -0500 Subject: [PATCH] arm: mx35: use common timer functions This patch moves mx35 to the common timer functions added in commit 8dfafdd - Introduce common timer functions 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 Cc: Marek Vasut Cc: Stefano Babic --- 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 cc6166f938..4edf533e2a 100644 --- a/arch/arm/cpu/arm1136/mx35/timer.c +++ b/arch/arm/cpu/arm1136/mx35/timer.c @@ -9,43 +9,17 @@ #include #include -#include #include #include -#include 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 */ #define GPTCR_CLKSOURCE_32 (4<<6) /* Clock source */ #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 b5300291a9..28a47ed44d 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 */ -- 2.25.1