diff options
Diffstat (limited to 'arch/arm/cpu/armv7/ls102xa/timer.c')
-rw-r--r-- | arch/arm/cpu/armv7/ls102xa/timer.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/ls102xa/timer.c b/arch/arm/cpu/armv7/ls102xa/timer.c new file mode 100644 index 0000000000..11b17b2c74 --- /dev/null +++ b/arch/arm/cpu/armv7/ls102xa/timer.c @@ -0,0 +1,127 @@ +/* + * Copyright 2014 Freescale Semiconductor, Inc. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <div64.h> +#include <asm/arch/immap_ls102xa.h> +#include <asm/arch/clock.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* + * This function is intended for SHORT delays only. + * It will overflow at around 10 seconds @ 400MHz, + * or 20 seconds @ 200MHz. + */ +unsigned long usec2ticks(unsigned long usec) +{ + ulong ticks; + + if (usec < 1000) + ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000; + else + ticks = ((usec / 10) * (get_tbclk() / 100000)); + + return ticks; +} + +static inline unsigned long long tick_to_time(unsigned long long tick) +{ + unsigned long freq; + + asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); + + tick *= CONFIG_SYS_HZ; + do_div(tick, freq); + + return tick; +} + +static inline unsigned long long us_to_tick(unsigned long long usec) +{ + unsigned long freq; + + asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); + + usec = usec * freq + 999999; + do_div(usec, 1000000); + + return usec; +} + +int timer_init(void) +{ + struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR; + unsigned long ctrl, val, freq; + + /* Enable System Counter */ + writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr); + + freq = GENERIC_TIMER_CLK; + asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq)); + + /* Set PL1 Physical Timer Ctrl */ + ctrl = ARCH_TIMER_CTRL_ENABLE; + asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl)); + + /* Set PL1 Physical Comp Value */ + val = TIMER_COMP_VAL; + asm("mcrr p15, 2, %Q0, %R0, c14" : : "r" (val)); + + gd->arch.tbl = 0; + gd->arch.tbu = 0; + + return 0; +} + +unsigned long long get_ticks(void) +{ + unsigned long long now; + + asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now)); + + gd->arch.tbl = (unsigned long)(now & 0xffffffff); + gd->arch.tbu = (unsigned long)(now >> 32); + + return now; +} + +unsigned long get_timer_masked(void) +{ + return tick_to_time(get_ticks()); +} + +unsigned long 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 start; + unsigned long tmo; + + start = get_ticks(); /* get current timestamp */ + tmo = us_to_tick(usec); /* convert usecs to ticks */ + + while ((get_ticks() - start) < tmo) + ; /* loop till time has passed */ +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +unsigned long get_tbclk(void) +{ + unsigned long freq; + + asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); + + return freq; +} |