1 /* 2 * Copyright 2013 Freescale Semiconductor, Inc. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <asm/io.h> 9 #include <div64.h> 10 #include <asm/arch/imx-regs.h> 11 #include <asm/arch/clock.h> 12 13 static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR; 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 #define TIMER_LOAD_VAL 0xffffffff 18 19 static inline unsigned long long tick_to_time(unsigned long long tick) 20 { 21 tick *= CONFIG_SYS_HZ; 22 do_div(tick, mxc_get_clock(MXC_IPG_CLK)); 23 24 return tick; 25 } 26 27 static inline unsigned long long us_to_tick(unsigned long long usec) 28 { 29 usec = usec * mxc_get_clock(MXC_IPG_CLK) + 999999; 30 do_div(usec, 1000000); 31 32 return usec; 33 } 34 35 int timer_init(void) 36 { 37 __raw_writel(0, &cur_pit->mcr); 38 39 __raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1); 40 __raw_writel(0, &cur_pit->tctrl1); 41 __raw_writel(1, &cur_pit->tctrl1); 42 43 gd->arch.tbl = 0; 44 gd->arch.tbu = 0; 45 46 return 0; 47 } 48 49 unsigned long long get_ticks(void) 50 { 51 ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1); 52 53 /* increment tbu if tbl has rolled over */ 54 if (now < gd->arch.tbl) 55 gd->arch.tbu++; 56 gd->arch.tbl = now; 57 58 return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl; 59 } 60 61 ulong get_timer_masked(void) 62 { 63 return tick_to_time(get_ticks()); 64 } 65 66 ulong get_timer(ulong base) 67 { 68 return get_timer_masked() - base; 69 } 70 71 /* delay x useconds AND preserve advance timstamp value */ 72 void __udelay(unsigned long usec) 73 { 74 unsigned long long start; 75 ulong tmo; 76 77 start = get_ticks(); /* get current timestamp */ 78 tmo = us_to_tick(usec); /* convert usecs to ticks */ 79 while ((get_ticks() - start) < tmo) 80 ; /* loop till time has passed */ 81 } 82 83 /* 84 * This function is derived from PowerPC code (timebase clock frequency). 85 * On ARM it returns the number of timer ticks per second. 86 */ 87 ulong get_tbclk(void) 88 { 89 return mxc_get_clock(MXC_IPG_CLK); 90 } 91