diff options
Diffstat (limited to 'arch/arm/cpu/arm926ejs/davinci/timer.c')
| -rw-r--r-- | arch/arm/cpu/arm926ejs/davinci/timer.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm926ejs/davinci/timer.c b/arch/arm/cpu/arm926ejs/davinci/timer.c new file mode 100644 index 0000000..9da7443 --- /dev/null +++ b/arch/arm/cpu/arm926ejs/davinci/timer.c @@ -0,0 +1,149 @@ +/* + * (C) Copyright 2003 + * Texas Instruments <www.ti.com> + * + * (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 2002-2004 + * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de> + * + * (C) Copyright 2004 + * Philippe Robin, ARM Ltd. <philippe.robin@arm.com> + * + * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net> + * + * 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 <asm/io.h> + +struct davinci_timer { + u_int32_t pid12; + u_int32_t emumgt; + u_int32_t na1; + u_int32_t na2; + u_int32_t tim12; + u_int32_t tim34; + u_int32_t prd12; + u_int32_t prd34; + u_int32_t tcr; + u_int32_t tgcr; + u_int32_t wdtcr; +}; + +static struct davinci_timer * const timer = + (struct davinci_timer *)CONFIG_SYS_TIMERBASE; + +#define TIMER_LOAD_VAL (CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ) +#define TIM_CLK_DIV 16 + +static ulong timestamp; +static ulong lastinc; + +int timer_init(void) +{ + /* We are using timer34 in unchained 32-bit mode, full speed */ + writel(0x0, &timer->tcr); + writel(0x0, &timer->tgcr); + writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &timer->tgcr); + writel(0x0, &timer->tim34); + writel(TIMER_LOAD_VAL, &timer->prd34); + lastinc = 0; + timestamp = 0; + writel(2 << 22, &timer->tcr); + + return(0); +} + +void reset_timer(void) +{ + writel(0x0, &timer->tcr); + writel(0x0, &timer->tim34); + lastinc = 0; + timestamp = 0; + writel(2 << 22, &timer->tcr); +} + +static ulong get_timer_raw(void) +{ + ulong now = readl(&timer->tim34); + + if (now >= lastinc) { + /* normal mode */ + timestamp += now - lastinc; + } else { + /* overflow ... */ + timestamp += now + TIMER_LOAD_VAL - lastinc; + } + lastinc = now; + return timestamp; +} + +ulong get_timer(ulong base) +{ + return((get_timer_raw() / (TIMER_LOAD_VAL / TIM_CLK_DIV)) - base); +} + +void set_timer(ulong t) +{ + timestamp = t; +} + +void __udelay(unsigned long usec) +{ + ulong tmo; + ulong endtime; + signed long diff; + + tmo = CONFIG_SYS_HZ_CLOCK / 1000; + tmo *= usec; + tmo /= (1000 * TIM_CLK_DIV); + + endtime = get_timer_raw() + tmo; + + do { + ulong now = get_timer_raw(); + diff = endtime - now; + } while (diff >= 0); +} + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On ARM it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return(get_timer(0)); +} + +/* + * 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) +{ + return CONFIG_SYS_HZ; +} |