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/*
* (C) Copyright 2009
* Vipin Kumar, ST Micoelectronics, vipin.kumar@st.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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <asm/arch/spr_gpt.h>
#include <asm/arch/spr_misc.h>
#define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ)
#define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING)
static struct gpt_regs *const gpt_regs_p =
(struct gpt_regs *)CONFIG_SPEAR_TIMERBASE;
static struct misc_regs *const misc_regs_p =
(struct misc_regs *)CONFIG_SPEAR_MISCBASE;
DECLARE_GLOBAL_DATA_PTR;
#define timestamp gd->tbl
#define lastdec gd->lastinc
int timer_init(void)
{
u32 synth;
/* Prescaler setting */
#if defined(CONFIG_SPEAR3XX)
writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg);
synth = MISC_GPT4SYNTH;
#elif defined(CONFIG_SPEAR600)
writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg);
synth = MISC_GPT3SYNTH;
#else
# error Incorrect config. Can only be spear{600|300|310|320}
#endif
writel(readl(&misc_regs_p->periph_clk_cfg) | synth,
&misc_regs_p->periph_clk_cfg);
/* disable timers */
writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control);
/* load value for free running */
writel(GPT_FREE_RUNNING, &gpt_regs_p->compare);
/* auto reload, start timer */
writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control);
/* Reset the timer */
lastdec = READ_TIMER();
timestamp = 0;
return 0;
}
/*
* timer without interrupts
*/
ulong get_timer(ulong base)
{
return (get_timer_masked() / GPT_RESOLUTION) - base;
}
void __udelay(unsigned long usec)
{
ulong tmo;
ulong start = get_timer_masked();
ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100);
ulong rndoff;
rndoff = (usec % 10) ? 1 : 0;
/* tenudelcnt timer tick gives 10 microsecconds delay */
tmo = ((usec / 10) + rndoff) * tenudelcnt;
while ((ulong) (get_timer_masked() - start) < tmo)
;
}
ulong get_timer_masked(void)
{
ulong now = READ_TIMER();
if (now >= lastdec) {
/* normal mode */
timestamp += now - lastdec;
} else {
/* we have an overflow ... */
timestamp += now + GPT_FREE_RUNNING - lastdec;
}
lastdec = now;
return timestamp;
}
void udelay_masked(unsigned long usec)
{
return udelay(usec);
}
/*
* 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_SPEAR_HZ;
}
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