| Alison Wang | 035260a | 2013-05-27 22:55:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2013 Freescale Semiconductor, Inc. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License as |
| 6 | * published by the Free Software Foundation; either version 2 of |
| 7 | * the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 17 | * MA 02111-1307 USA |
| 18 | */ |
| 19 | |
| 20 | #include <common.h> |
| 21 | #include <asm/io.h> |
| 22 | #include <div64.h> |
| 23 | #include <asm/arch/imx-regs.h> |
| 24 | #include <asm/arch/clock.h> |
| 25 | |
| 26 | static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR; |
| 27 | |
| 28 | DECLARE_GLOBAL_DATA_PTR; |
| 29 | |
| 30 | #define TIMER_LOAD_VAL 0xffffffff |
| 31 | |
| 32 | static inline unsigned long long tick_to_time(unsigned long long tick) |
| 33 | { |
| 34 | tick *= CONFIG_SYS_HZ; |
| 35 | do_div(tick, mxc_get_clock(MXC_IPG_CLK)); |
| 36 | |
| 37 | return tick; |
| 38 | } |
| 39 | |
| 40 | static inline unsigned long long us_to_tick(unsigned long long usec) |
| 41 | { |
| 42 | usec = usec * mxc_get_clock(MXC_IPG_CLK) + 999999; |
| 43 | do_div(usec, 1000000); |
| 44 | |
| 45 | return usec; |
| 46 | } |
| 47 | |
| 48 | int timer_init(void) |
| 49 | { |
| 50 | __raw_writel(0, &cur_pit->mcr); |
| 51 | |
| 52 | __raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1); |
| 53 | __raw_writel(0, &cur_pit->tctrl1); |
| 54 | __raw_writel(1, &cur_pit->tctrl1); |
| 55 | |
| 56 | gd->arch.tbl = 0; |
| 57 | gd->arch.tbu = 0; |
| 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | unsigned long long get_ticks(void) |
| 63 | { |
| 64 | ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1); |
| 65 | |
| 66 | /* increment tbu if tbl has rolled over */ |
| 67 | if (now < gd->arch.tbl) |
| 68 | gd->arch.tbu++; |
| 69 | gd->arch.tbl = now; |
| 70 | |
| 71 | return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl; |
| 72 | } |
| 73 | |
| 74 | ulong get_timer_masked(void) |
| 75 | { |
| 76 | return tick_to_time(get_ticks()); |
| 77 | } |
| 78 | |
| 79 | ulong get_timer(ulong base) |
| 80 | { |
| 81 | return get_timer_masked() - base; |
| 82 | } |
| 83 | |
| 84 | /* delay x useconds AND preserve advance timstamp value */ |
| 85 | void __udelay(unsigned long usec) |
| 86 | { |
| 87 | unsigned long long start; |
| 88 | ulong tmo; |
| 89 | |
| 90 | start = get_ticks(); /* get current timestamp */ |
| 91 | tmo = us_to_tick(usec); /* convert usecs to ticks */ |
| 92 | while ((get_ticks() - start) < tmo) |
| 93 | ; /* loop till time has passed */ |
| 94 | } |
| 95 | |
| 96 | /* |
| 97 | * This function is derived from PowerPC code (timebase clock frequency). |
| 98 | * On ARM it returns the number of timer ticks per second. |
| 99 | */ |
| 100 | ulong get_tbclk(void) |
| 101 | { |
| 102 | return mxc_get_clock(MXC_IPG_CLK); |
| 103 | } |