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 static ulong get_timer_masked(void); 27 28 /* 29 * Nothing really to do with interrupts, just starts up a counter. 30 */ 31 32 #define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV)) 33 #define TIMER_OVERFLOW_VAL 0xffffffff 34 #define TIMER_LOAD_VAL 0 35 36 int timer_init(void) 37 { 38 /* start the counter ticking up, reload value on overflow */ 39 writel(TIMER_LOAD_VAL, &timer_base->tldr); 40 /* enable timer */ 41 writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST, 42 &timer_base->tclr); 43 44 return 0; 45 } 46 47 /* 48 * timer without interrupts 49 */ 50 ulong get_timer(ulong base) 51 { 52 return get_timer_masked() - base; 53 } 54 55 /* delay x useconds */ 56 void __udelay(unsigned long usec) 57 { 58 long tmo = usec * (TIMER_CLOCK / 1000) / 1000; 59 unsigned long now, last = readl(&timer_base->tcrr); 60 61 while (tmo > 0) { 62 now = readl(&timer_base->tcrr); 63 if (last > now) /* count up timer overflow */ 64 tmo -= TIMER_OVERFLOW_VAL - last + now + 1; 65 else 66 tmo -= now - last; 67 last = now; 68 } 69 } 70 71 static ulong get_timer_masked(void) 72 { 73 /* current tick value */ 74 ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ); 75 76 if (now >= gd->arch.lastinc) { /* normal mode (non roll) */ 77 /* move stamp fordward with absoulte diff ticks */ 78 gd->arch.tbl += (now - gd->arch.lastinc); 79 } else { /* we have rollover of incrementer */ 80 gd->arch.tbl += ((TIMER_OVERFLOW_VAL / (TIMER_CLOCK / 81 CONFIG_SYS_HZ)) - gd->arch.lastinc) + now; 82 } 83 gd->arch.lastinc = now; 84 return gd->arch.tbl; 85 } 86 87 /* 88 * This function is derived from PowerPC code (read timebase as long long). 89 * On ARM it just returns the timer value. 90 */ 91 unsigned long long get_ticks(void) 92 { 93 return get_timer(0); 94 } 95 96 /* 97 * This function is derived from PowerPC code (timebase clock frequency). 98 * On ARM it returns the number of timer ticks per second. 99 */ 100 ulong get_tbclk(void) 101 { 102 return CONFIG_SYS_HZ; 103 } 104