From 93a0ea501e1eca1ae5d7d2624906b656c765e5e8 Mon Sep 17 00:00:00 2001 From: Andrew Ruder Date: Tue, 12 Aug 2014 09:26:00 -0500 Subject: arm: mx31: use common timer functions This patch moves mx31 to the common timer functions added in commit 8dfafdd - Introduce common timer functions 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 Cc: Marek Vasut Cc: Linus Walleij Cc: Wolfgang Denk Cc: Fabio Estevam Cc: Helmut Raiger --- 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(-) (limited to 'arch') diff --git a/arch/arm/cpu/arm1136/mx31/timer.c b/arch/arm/cpu/arm1136/mx31/timer.c index f111242e53..3a81ce427c 100644 --- a/arch/arm/cpu/arm1136/mx31/timer.c +++ b/arch/arm/cpu/arm1136/mx31/timer.c @@ -7,9 +7,6 @@ #include #include -#include -#include -#include #include #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 f23350e5c2..71ebd243d7 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 */ -- cgit v1.2.1