/* * (C) Copyright 2002 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> * Marius Groeger <mgroeger@sysgo.de> * * (C) Copyright 2002 * Sysgo Real-Time Solutions, GmbH <www.elinos.com> * Alex Zuepke <azu@sysgo.de> * * (C) Copyright 2002 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> * * (C) Copyright 2009 * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com> * * (C) Copyright 2009 DENX Software Engineering * Author: John Rigby <jrigby@gmail.com> * Add support for MX25 * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ #include <common.h> #include <div64.h> #include <asm/io.h> #include <asm/arch/imx-regs.h> #include <asm/arch/clock.h> DECLARE_GLOBAL_DATA_PTR; #define timestamp (gd->tbl) #define lastinc (gd->lastinc) /* * "time" is measured in 1 / CONFIG_SYS_HZ seconds, * "tick" is internal timer period */ #ifdef CONFIG_MX25_TIMER_HIGH_PRECISION /* ~0.4% error - measured with stop-watch on 100s boot-delay */ static inline unsigned long long tick_to_time(unsigned long long tick) { tick *= CONFIG_SYS_HZ; do_div(tick, MXC_CLK32); return tick; } static inline unsigned long long time_to_tick(unsigned long long time) { time *= MXC_CLK32; do_div(time, CONFIG_SYS_HZ); return time; } static inline unsigned long long us_to_tick(unsigned long long us) { us = us * MXC_CLK32 + 999999; do_div(us, 1000000); return us; } #else /* ~2% error */ #define TICK_PER_TIME ((MXC_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ) #define US_PER_TICK (1000000 / MXC_CLK32) static inline unsigned long long tick_to_time(unsigned long long tick) { do_div(tick, TICK_PER_TIME); return tick; } static inline unsigned long long time_to_tick(unsigned long long time) { return time * TICK_PER_TIME; } static inline unsigned long long us_to_tick(unsigned long long us) { us += US_PER_TICK - 1; do_div(us, US_PER_TICK); return us; } #endif /* nothing really to do with interrupts, just starts up a counter. */ /* The 32KHz 32-bit timer overruns in 134217 seconds */ int timer_init(void) { int i; struct gpt_regs *gpt = (struct gpt_regs *)IMX_GPT1_BASE; struct ccm_regs *ccm = (struct ccm_regs *)IMX_CCM_BASE; /* setup GP Timer 1 */ writel(GPT_CTRL_SWR, &gpt->ctrl); writel(readl(&ccm->cgr1) | CCM_CGR1_GPT1, &ccm->cgr1); for (i = 0; i < 100; i++) writel(0, &gpt->ctrl); /* We have no udelay by now */ writel(0, &gpt->pre); /* prescaler = 1 */ /* Freerun Mode, 32KHz input */ writel(readl(&gpt->ctrl) | GPT_CTRL_CLKSOURCE_32 | GPT_CTRL_FRR, &gpt->ctrl); writel(readl(&gpt->ctrl) | GPT_CTRL_TEN, &gpt->ctrl); return 0; } unsigned long long get_ticks(void) { struct gpt_regs *gpt = (struct gpt_regs *)IMX_GPT1_BASE; ulong now = readl(&gpt->counter); /* current tick value */ if (now >= lastinc) { /* * normal mode (non roll) * move stamp forward with absolut diff ticks */ timestamp += (now - lastinc); } else { /* we have rollover of incrementer */ timestamp += (0xFFFFFFFF - lastinc) + now; } lastinc = now; return timestamp; } ulong get_timer_masked(void) { /* * get_ticks() returns a long long (64 bit), it wraps in * 2^64 / MXC_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~ * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in * 5 * 10^6 days - long enough. */ return tick_to_time(get_ticks()); } ulong get_timer(ulong base) { return get_timer_masked() - base; } /* delay x useconds AND preserve advance timstamp value */ void __udelay(unsigned long usec) { unsigned long long tmp; ulong tmo; tmo = us_to_tick(usec); tmp = get_ticks() + tmo; /* get current timestamp */ while (get_ticks() < tmp) /* loop till event */ /*NOP*/; } /* * This function is derived from PowerPC code (timebase clock frequency). * On ARM it returns the number of timer ticks per second. */ ulong get_tbclk(void) { ulong tbclk; tbclk = MXC_CLK32; return tbclk; }