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