1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2008 4 * Texas Instruments 5 * 6 * Richard Woodruff <r-woodruff2@ti.com> 7 * Syed Moahmmed Khasim <khasim@ti.com> 8 * 9 * (C) Copyright 2002 10 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 11 * Marius Groeger <mgroeger@sysgo.de> 12 * Alex Zuepke <azu@sysgo.de> 13 * 14 * (C) Copyright 2002 15 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de> 16 */ 17 18 #include <common.h> 19 #include <asm/io.h> 20 #include <asm/arch/cpu.h> 21 #include <asm/arch/clock.h> 22 23 DECLARE_GLOBAL_DATA_PTR; 24 25 static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE; 26 27 /* 28 * Nothing really to do with interrupts, just starts up a counter. 29 */ 30 31 #define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV)) 32 #define TIMER_OVERFLOW_VAL 0xffffffff 33 #define TIMER_LOAD_VAL 0 34 35 int timer_init(void) 36 { 37 /* start the counter ticking up, reload value on overflow */ 38 writel(TIMER_LOAD_VAL, &timer_base->tldr); 39 /* enable timer */ 40 writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST, 41 &timer_base->tclr); 42 43 return 0; 44 } 45 46 /* 47 * timer without interrupts 48 */ 49 ulong get_timer(ulong base) 50 { 51 return get_timer_masked() - base; 52 } 53 54 /* delay x useconds */ 55 void __udelay(unsigned long usec) 56 { 57 long tmo = usec * (TIMER_CLOCK / 1000) / 1000; 58 unsigned long now, last = readl(&timer_base->tcrr); 59 60 while (tmo > 0) { 61 now = readl(&timer_base->tcrr); 62 if (last > now) /* count up timer overflow */ 63 tmo -= TIMER_OVERFLOW_VAL - last + now + 1; 64 else 65 tmo -= now - last; 66 last = now; 67 } 68 } 69 70 ulong get_timer_masked(void) 71 { 72 /* current tick value */ 73 ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ); 74 75 if (now >= gd->arch.lastinc) { /* normal mode (non roll) */ 76 /* move stamp fordward with absoulte diff ticks */ 77 gd->arch.tbl += (now - gd->arch.lastinc); 78 } else { /* we have rollover of incrementer */ 79 gd->arch.tbl += ((TIMER_OVERFLOW_VAL / (TIMER_CLOCK / 80 CONFIG_SYS_HZ)) - gd->arch.lastinc) + now; 81 } 82 gd->arch.lastinc = now; 83 return gd->arch.tbl; 84 } 85 86 /* 87 * This function is derived from PowerPC code (read timebase as long long). 88 * On ARM it just returns the timer value. 89 */ 90 unsigned long long get_ticks(void) 91 { 92 return get_timer(0); 93 } 94 95 /* 96 * This function is derived from PowerPC code (timebase clock frequency). 97 * On ARM it returns the number of timer ticks per second. 98 */ 99 ulong get_tbclk(void) 100 { 101 return CONFIG_SYS_HZ; 102 } 103