1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * (C) Copyright 2007-2011 4 * Allwinner Technology Co., Ltd. <www.allwinnertech.com> 5 * Tom Cubie <tangliang@allwinnertech.com> 6 */ 7 8#include <init.h> 9#include <time.h> 10#include <asm/global_data.h> 11#include <asm/io.h> 12#include <asm/arch/cpu.h> 13#include <asm/arch/timer.h> 14#include <linux/delay.h> 15 16DECLARE_GLOBAL_DATA_PTR; 17 18#define TIMER_MODE (0x0 << 7) /* continuous mode */ 19#define TIMER_DIV (0x0 << 4) /* pre scale 1 */ 20#define TIMER_SRC (0x1 << 2) /* osc24m */ 21#define TIMER_RELOAD (0x1 << 1) /* reload internal value */ 22#define TIMER_EN (0x1 << 0) /* enable timer */ 23 24#define TIMER_CLOCK (24 * 1000 * 1000) 25#define COUNT_TO_USEC(x) ((x) / 24) 26#define USEC_TO_COUNT(x) ((x) * 24) 27#define TICKS_PER_HZ (TIMER_CLOCK / CONFIG_SYS_HZ) 28#define TICKS_TO_HZ(x) ((x) / TICKS_PER_HZ) 29 30#define TIMER_LOAD_VAL 0xffffffff 31 32#define TIMER_NUM 0 /* we use timer 0 */ 33 34/* read the 32-bit timer */ 35static ulong read_timer(void) 36{ 37 struct sunxi_timer_reg *timers = 38 (struct sunxi_timer_reg *)SUNXI_TIMER_BASE; 39 struct sunxi_timer *timer = &timers->timer[TIMER_NUM]; 40 41 /* 42 * The hardware timer counts down, therefore we invert to 43 * produce an incrementing timer. 44 */ 45 return ~readl(&timer->val); 46} 47 48/* init timer register */ 49int timer_init(void) 50{ 51 struct sunxi_timer_reg *timers = 52 (struct sunxi_timer_reg *)SUNXI_TIMER_BASE; 53 struct sunxi_timer *timer = &timers->timer[TIMER_NUM]; 54 55 writel(TIMER_LOAD_VAL, &timer->inter); 56 writel(TIMER_MODE | TIMER_DIV | TIMER_SRC | TIMER_RELOAD | TIMER_EN, 57 &timer->ctl); 58 59 return 0; 60} 61 62static ulong get_timer_masked(void) 63{ 64 /* current tick value */ 65 ulong now = TICKS_TO_HZ(read_timer()); 66 67 if (now >= gd->arch.lastinc) { /* normal (non rollover) */ 68 gd->arch.tbl += (now - gd->arch.lastinc); 69 } else { 70 /* rollover */ 71 gd->arch.tbl += (TICKS_TO_HZ(TIMER_LOAD_VAL) 72 - gd->arch.lastinc) + now; 73 } 74 gd->arch.lastinc = now; 75 76 return gd->arch.tbl; 77} 78 79/* timer without interrupts */ 80ulong get_timer(ulong base) 81{ 82 return get_timer_masked() - base; 83} 84 85/* delay x useconds */ 86void __udelay(unsigned long usec) 87{ 88 long tmo = USEC_TO_COUNT(usec); 89 ulong now, last = read_timer(); 90 91 while (tmo > 0) { 92 now = read_timer(); 93 if (now > last) /* normal (non rollover) */ 94 tmo -= now - last; 95 else /* rollover */ 96 tmo -= TIMER_LOAD_VAL - last + now; 97 last = now; 98 } 99} 100 101/* 102 * This function is derived from PowerPC code (read timebase as long long). 103 * On ARM it just returns the timer value. 104 */ 105unsigned long long get_ticks(void) 106{ 107 return get_timer(0); 108} 109 110/* 111 * This function is derived from PowerPC code (timebase clock frequency). 112 * On ARM it returns the number of timer ticks per second. 113 */ 114ulong get_tbclk(void) 115{ 116 return CONFIG_SYS_HZ; 117} 118