diff options
Diffstat (limited to 'arch/arm/mach-omap2/timer.c')
-rw-r--r-- | arch/arm/mach-omap2/timer.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c new file mode 100644 index 0000000000..49e3a971d9 --- /dev/null +++ b/arch/arm/mach-omap2/timer.c @@ -0,0 +1,103 @@ +/* + * (C) Copyright 2008 + * Texas Instruments + * + * Richard Woodruff <r-woodruff2@ti.com> + * Syed Moahmmed Khasim <khasim@ti.com> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * Alex Zuepke <azu@sysgo.de> + * + * (C) Copyright 2002 + * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/cpu.h> +#include <asm/arch/clock.h> + +DECLARE_GLOBAL_DATA_PTR; + +static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE; + +/* + * Nothing really to do with interrupts, just starts up a counter. + */ + +#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV)) +#define TIMER_OVERFLOW_VAL 0xffffffff +#define TIMER_LOAD_VAL 0 + +int timer_init(void) +{ + /* start the counter ticking up, reload value on overflow */ + writel(TIMER_LOAD_VAL, &timer_base->tldr); + /* enable timer */ + writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST, + &timer_base->tclr); + + return 0; +} + +/* + * timer without interrupts + */ +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +/* delay x useconds */ +void __udelay(unsigned long usec) +{ + long tmo = usec * (TIMER_CLOCK / 1000) / 1000; + unsigned long now, last = readl(&timer_base->tcrr); + + while (tmo > 0) { + now = readl(&timer_base->tcrr); + if (last > now) /* count up timer overflow */ + tmo -= TIMER_OVERFLOW_VAL - last + now + 1; + else + tmo -= now - last; + last = now; + } +} + +ulong get_timer_masked(void) +{ + /* current tick value */ + ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ); + + if (now >= gd->arch.lastinc) { /* normal mode (non roll) */ + /* move stamp fordward with absoulte diff ticks */ + gd->arch.tbl += (now - gd->arch.lastinc); + } else { /* we have rollover of incrementer */ + gd->arch.tbl += ((TIMER_OVERFLOW_VAL / (TIMER_CLOCK / + CONFIG_SYS_HZ)) - gd->arch.lastinc) + now; + } + gd->arch.lastinc = now; + return gd->arch.tbl; +} + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On ARM it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +/* + * 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 CONFIG_SYS_HZ; +} |