1 // SPDX-License-Identifier: GPL-2.0+
6 * Richard Woodruff <r-woodruff2@ti.com>
7 * Syed Moahmmed Khasim <khasim@ti.com>
10 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
11 * Marius Groeger <mgroeger@sysgo.de>
12 * Alex Zuepke <azu@sysgo.de>
15 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
21 #include <asm/global_data.h>
23 #include <asm/arch/cpu.h>
24 #include <asm/arch/clock.h>
25 #include <asm/omap_common.h>
26 #include <linux/delay.h>
28 DECLARE_GLOBAL_DATA_PTR;
30 static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
31 static ulong get_timer_masked(void);
34 * Nothing really to do with interrupts, just starts up a counter.
37 #define TIMER_CLOCK (V_SCLK / (2 << SYS_PTV))
38 #define TIMER_OVERFLOW_VAL 0xffffffff
39 #define TIMER_LOAD_VAL 0
43 /* start the counter ticking up, reload value on overflow */
44 writel(TIMER_LOAD_VAL, &timer_base->tldr);
46 writel((SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
53 * timer without interrupts
55 ulong get_timer(ulong base)
57 return get_timer_masked() - base;
60 /* delay x useconds */
61 void __udelay(unsigned long usec)
63 long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
64 unsigned long now, last = readl(&timer_base->tcrr);
67 now = readl(&timer_base->tcrr);
68 if (last > now) /* count up timer overflow */
69 tmo -= TIMER_OVERFLOW_VAL - last + now + 1;
76 static ulong get_timer_masked(void)
78 /* current tick value */
79 ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
81 if (now >= gd->arch.lastinc) { /* normal mode (non roll) */
82 /* move stamp fordward with absoulte diff ticks */
83 gd->arch.tbl += (now - gd->arch.lastinc);
84 } else { /* we have rollover of incrementer */
85 gd->arch.tbl += ((TIMER_OVERFLOW_VAL / (TIMER_CLOCK /
86 CONFIG_SYS_HZ)) - gd->arch.lastinc) + now;
88 gd->arch.lastinc = now;
93 * This function is derived from PowerPC code (read timebase as long long).
94 * On ARM it just returns the timer value.
96 unsigned long long get_ticks(void)
102 * This function is derived from PowerPC code (timebase clock frequency).
103 * On ARM it returns the number of timer ticks per second.
105 ulong get_tbclk(void)
107 return CONFIG_SYS_HZ;