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