u-boot/arch/arm/cpu/arm926ejs/kirkwood/timer.c

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/*
* Copyright (C) Marvell International Ltd. and its affiliates
* Written-by: Prafulla Wadaskar <prafulla@marvell.com>
*
* 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/kirkwood.h>
#define UBOOT_CNTR 0 /* counter to use for uboot timer */
/* Timer reload and current value registers */
struct kwtmr_val {
u32 reload; /* Timer reload reg */
u32 val; /* Timer value reg */
};
/* Timer registers */
struct kwtmr_registers {
u32 ctrl; /* Timer control reg */
u32 pad[3];
struct kwtmr_val tmr[2];
u32 wdt_reload;
u32 wdt_val;
};
struct kwtmr_registers *kwtmr_regs = (struct kwtmr_registers *)KW_TIMER_BASE;
/*
* ARM Timers Registers Map
*/
#define CNTMR_CTRL_REG &kwtmr_regs->ctrl
#define CNTMR_RELOAD_REG(tmrnum) &kwtmr_regs->tmr[tmrnum].reload
#define CNTMR_VAL_REG(tmrnum) &kwtmr_regs->tmr[tmrnum].val
/*
* ARM Timers Control Register
* CPU_TIMERS_CTRL_REG (CTCR)
*/
#define CTCR_ARM_TIMER_EN_OFFS(cntr) (cntr * 2)
#define CTCR_ARM_TIMER_EN_MASK(cntr) (1 << CTCR_ARM_TIMER_EN_OFFS)
#define CTCR_ARM_TIMER_EN(cntr) (1 << CTCR_ARM_TIMER_EN_OFFS(cntr))
#define CTCR_ARM_TIMER_DIS(cntr) (0 << CTCR_ARM_TIMER_EN_OFFS(cntr))
#define CTCR_ARM_TIMER_AUTO_OFFS(cntr) ((cntr * 2) + 1)
#define CTCR_ARM_TIMER_AUTO_MASK(cntr) (1 << 1)
#define CTCR_ARM_TIMER_AUTO_EN(cntr) (1 << CTCR_ARM_TIMER_AUTO_OFFS(cntr))
#define CTCR_ARM_TIMER_AUTO_DIS(cntr) (0 << CTCR_ARM_TIMER_AUTO_OFFS(cntr))
/*
* ARM Timer\Watchdog Reload Register
* CNTMR_RELOAD_REG (TRR)
*/
#define TRG_ARM_TIMER_REL_OFFS 0
#define TRG_ARM_TIMER_REL_MASK 0xffffffff
/*
* ARM Timer\Watchdog Register
* CNTMR_VAL_REG (TVRG)
*/
#define TVR_ARM_TIMER_OFFS 0
#define TVR_ARM_TIMER_MASK 0xffffffff
#define TVR_ARM_TIMER_MAX 0xffffffff
#define TIMER_LOAD_VAL 0xffffffff
#define READ_TIMER (readl(CNTMR_VAL_REG(UBOOT_CNTR)) / \
(CONFIG_SYS_TCLK / 1000))
DECLARE_GLOBAL_DATA_PTR;
#define timestamp gd->arch.tbl
#define lastdec gd->arch.lastinc
ulong get_timer_masked(void)
{
ulong now = READ_TIMER;
if (lastdec >= now) {
/* normal mode */
timestamp += lastdec - now;
} else {
/* we have an overflow ... */
timestamp += lastdec +
(TIMER_LOAD_VAL / (CONFIG_SYS_TCLK / 1000)) - now;
}
lastdec = now;
return timestamp;
}
ulong get_timer(ulong base)
{
return get_timer_masked() - base;
}
void __udelay(unsigned long usec)
{
uint current;
ulong delayticks;
current = readl(CNTMR_VAL_REG(UBOOT_CNTR));
delayticks = (usec * (CONFIG_SYS_TCLK / 1000000));
if (current < delayticks) {
delayticks -= current;
while (readl(CNTMR_VAL_REG(UBOOT_CNTR)) < current) ;
while ((TIMER_LOAD_VAL - delayticks) <
readl(CNTMR_VAL_REG(UBOOT_CNTR))) ;
} else {
while (readl(CNTMR_VAL_REG(UBOOT_CNTR)) >
(current - delayticks)) ;
}
}
/*
* init the counter
*/
int timer_init(void)
{
unsigned int cntmrctrl;
/* load value into timer */
writel(TIMER_LOAD_VAL, CNTMR_RELOAD_REG(UBOOT_CNTR));
writel(TIMER_LOAD_VAL, CNTMR_VAL_REG(UBOOT_CNTR));
/* enable timer in auto reload mode */
cntmrctrl = readl(CNTMR_CTRL_REG);
cntmrctrl |= CTCR_ARM_TIMER_EN(UBOOT_CNTR);
cntmrctrl |= CTCR_ARM_TIMER_AUTO_EN(UBOOT_CNTR);
writel(cntmrctrl, CNTMR_CTRL_REG);
/* init the timestamp and lastdec value */
lastdec = READ_TIMER;
timestamp = 0;
return 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 (ulong)CONFIG_SYS_HZ;
}