1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2002 4 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 5 * Marius Groeger <mgroeger@sysgo.de> 6 * 7 * (C) Copyright 2002 8 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> 9 * Alex Zuepke <azu@sysgo.de> 10 * 11 * (C) Copyright 2002 12 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> 13 * 14 * (C) Copyright 2009 15 * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com> 16 */ 17 18 #include <common.h> 19 #include <div64.h> 20 #include <asm/io.h> 21 #include <asm/arch/imx-regs.h> 22 23 /* General purpose timers bitfields */ 24 #define GPTCR_SWR (1 << 15) /* Software reset */ 25 #define GPTCR_FRR (1 << 8) /* Freerun / restart */ 26 #define GPTCR_CLKSOURCE_32 (4 << 1) /* Clock source */ 27 #define GPTCR_TEN 1 /* Timer enable */ 28 29 DECLARE_GLOBAL_DATA_PTR; 30 31 #define timestamp (gd->arch.tbl) 32 #define lastinc (gd->arch.lastinc) 33 34 /* 35 * "time" is measured in 1 / CONFIG_SYS_HZ seconds, 36 * "tick" is internal timer period 37 */ 38 #ifdef CONFIG_MX27_TIMER_HIGH_PRECISION 39 /* ~0.4% error - measured with stop-watch on 100s boot-delay */ 40 static inline unsigned long long tick_to_time(unsigned long long tick) 41 { 42 tick *= CONFIG_SYS_HZ; 43 do_div(tick, CONFIG_MX27_CLK32); 44 return tick; 45 } 46 47 static inline unsigned long long time_to_tick(unsigned long long time) 48 { 49 time *= CONFIG_MX27_CLK32; 50 do_div(time, CONFIG_SYS_HZ); 51 return time; 52 } 53 54 static inline unsigned long long us_to_tick(unsigned long long us) 55 { 56 us = us * CONFIG_MX27_CLK32 + 999999; 57 do_div(us, 1000000); 58 return us; 59 } 60 #else 61 /* ~2% error */ 62 #define TICK_PER_TIME ((CONFIG_MX27_CLK32 + CONFIG_SYS_HZ / 2) / \ 63 CONFIG_SYS_HZ) 64 #define US_PER_TICK (1000000 / CONFIG_MX27_CLK32) 65 66 static inline unsigned long long tick_to_time(unsigned long long tick) 67 { 68 do_div(tick, TICK_PER_TIME); 69 return tick; 70 } 71 72 static inline unsigned long long time_to_tick(unsigned long long time) 73 { 74 return time * TICK_PER_TIME; 75 } 76 77 static inline unsigned long long us_to_tick(unsigned long long us) 78 { 79 us += US_PER_TICK - 1; 80 do_div(us, US_PER_TICK); 81 return us; 82 } 83 #endif 84 85 /* nothing really to do with interrupts, just starts up a counter. */ 86 /* The 32768Hz 32-bit timer overruns in 131072 seconds */ 87 int timer_init(void) 88 { 89 int i; 90 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE; 91 struct pll_regs *pll = (struct pll_regs *)IMX_PLL_BASE; 92 93 /* setup GP Timer 1 */ 94 writel(GPTCR_SWR, ®s->gpt_tctl); 95 96 writel(readl(&pll->pccr0) | PCCR0_GPT1_EN, &pll->pccr0); 97 writel(readl(&pll->pccr1) | PCCR1_PERCLK1_EN, &pll->pccr1); 98 99 for (i = 0; i < 100; i++) 100 writel(0, ®s->gpt_tctl); /* We have no udelay by now */ 101 writel(0, ®s->gpt_tprer); /* 32Khz */ 102 /* Freerun Mode, PERCLK1 input */ 103 writel(readl(®s->gpt_tctl) | GPTCR_CLKSOURCE_32 | GPTCR_FRR, 104 ®s->gpt_tctl); 105 writel(readl(®s->gpt_tctl) | GPTCR_TEN, ®s->gpt_tctl); 106 107 return 0; 108 } 109 110 unsigned long long get_ticks(void) 111 { 112 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE; 113 ulong now = readl(®s->gpt_tcn); /* current tick value */ 114 115 if (now >= lastinc) { 116 /* 117 * normal mode (non roll) 118 * move stamp forward with absolut diff ticks 119 */ 120 timestamp += (now - lastinc); 121 } else { 122 /* we have rollover of incrementer */ 123 timestamp += (0xFFFFFFFF - lastinc) + now; 124 } 125 lastinc = now; 126 return timestamp; 127 } 128 129 ulong get_timer_masked(void) 130 { 131 /* 132 * get_ticks() returns a long long (64 bit), it wraps in 133 * 2^64 / CONFIG_MX27_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~ 134 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in 135 * 5 * 10^6 days - long enough. 136 */ 137 return tick_to_time(get_ticks()); 138 } 139 140 ulong get_timer(ulong base) 141 { 142 return get_timer_masked() - base; 143 } 144 145 /* delay x useconds AND preserve advance timstamp value */ 146 void __udelay(unsigned long usec) 147 { 148 unsigned long long tmp; 149 ulong tmo; 150 151 tmo = us_to_tick(usec); 152 tmp = get_ticks() + tmo; /* get current timestamp */ 153 154 while (get_ticks() < tmp) /* loop till event */ 155 /*NOP*/; 156 } 157 158 ulong get_tbclk(void) 159 { 160 return CONFIG_MX27_CLK32; 161 } 162