/*
* System timer for Freescale STMP37XX/STMP378X
*
* Embedded Alley Solutions, Inc <source@embeddedalley.com>
*
* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <asm/mach/time.h>
#include <mach/stmp3xxx.h>
#include <mach/platform.h>
#include <mach/regs-timrot.h>
static irqreturn_t
stmp3xxx_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *c = dev_id;
/* timer 0 */
if (__raw_readl(REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL0) &
BM_TIMROT_TIMCTRLn_IRQ) {
stmp3xxx_clearl(BM_TIMROT_TIMCTRLn_IRQ,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL0);
c->event_handler(c);
}
/* timer 1 */
else if (__raw_readl(REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL1)
& BM_TIMROT_TIMCTRLn_IRQ) {
stmp3xxx_clearl(BM_TIMROT_TIMCTRLn_IRQ,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL1);
stmp3xxx_clearl(BM_TIMROT_TIMCTRLn_IRQ_EN,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL1);
__raw_writel(0xFFFF, REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT1);
}
return IRQ_HANDLED;
}
static cycle_t stmp3xxx_clock_read(struct clocksource *cs)
{
return ~((__raw_readl(REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT1)
& 0xFFFF0000) >> 16);
}
static int
stmp3xxx_timrot_set_next_event(unsigned long delta,
struct clock_event_device *dev)
{
/* reload the timer */
__raw_writel(delta, REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT0);
return 0;
}
static void
stmp3xxx_timrot_set_mode(enum clock_event_mode mode,
struct clock_event_device *dev)
{
}
static struct clock_event_device ckevt_timrot = {
.name = "timrot",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.set_next_event = stmp3xxx_timrot_set_next_event,
.set_mode = stmp3xxx_timrot_set_mode,
};
static struct clocksource cksrc_stmp3xxx = {
.name = "cksrc_stmp3xxx",
.rating = 250,
.read = stmp3xxx_clock_read,
.mask = CLOCKSOURCE_MASK(16),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct irqaction stmp3xxx_timer_irq = {
.name = "stmp3xxx_timer",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = stmp3xxx_timer_interrupt,
.dev_id = &ckevt_timrot,
};
/*
* Set up timer interrupt, and return the current time in seconds.
*/
static void __init stmp3xxx_init_timer(void)
{
ckevt_timrot.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC,
ckevt_timrot.shift);
ckevt_timrot.min_delta_ns = clockevent_delta2ns(2, &ckevt_timrot);
ckevt_timrot.max_delta_ns = clockevent_delta2ns(0xFFF, &ckevt_timrot);
ckevt_timrot.cpumask = cpumask_of(0);
stmp3xxx_reset_block(REGS_TIMROT_BASE, false);
/* clear two timers */
__raw_writel(0, REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT0);
__raw_writel(0, REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT1);
/* configure them */
__raw_writel(
(8 << BP_TIMROT_TIMCTRLn_SELECT) | /* 32 kHz */
BM_TIMROT_TIMCTRLn_RELOAD |
BM_TIMROT_TIMCTRLn_UPDATE |
BM_TIMROT_TIMCTRLn_IRQ_EN,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL0);
__raw_writel(
(8 << BP_TIMROT_TIMCTRLn_SELECT) | /* 32 kHz */
BM_TIMROT_TIMCTRLn_RELOAD |
BM_TIMROT_TIMCTRLn_UPDATE |
BM_TIMROT_TIMCTRLn_IRQ_EN,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL1);
__raw_writel(CLOCK_TICK_RATE / HZ - 1,
REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT0);
__raw_writel(0xFFFF, REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT1);
setup_irq(IRQ_TIMER0, &stmp3xxx_timer_irq);
clocksource_register_hz(&cksrc_stmp3xxx, CLOCK_TICK_RATE);
clockevents_register_device(&ckevt_timrot);
}
#ifdef CONFIG_PM
void stmp3xxx_suspend_timer(void)
{
stmp3xxx_clearl(BM_TIMROT_TIMCTRLn_IRQ_EN | BM_TIMROT_TIMCTRLn_IRQ,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL0);
stmp3xxx_setl(BM_TIMROT_ROTCTRL_CLKGATE,
REGS_TIMROT_BASE + HW_TIMROT_ROTCTRL);
}
void stmp3xxx_resume_timer(void)
{
stmp3xxx_clearl(BM_TIMROT_ROTCTRL_SFTRST | BM_TIMROT_ROTCTRL_CLKGATE,
REGS_TIMROT_BASE + HW_TIMROT_ROTCTRL);
__raw_writel(
8 << BP_TIMROT_TIMCTRLn_SELECT | /* 32 kHz */
BM_TIMROT_TIMCTRLn_RELOAD |
BM_TIMROT_TIMCTRLn_UPDATE |
BM_TIMROT_TIMCTRLn_IRQ_EN,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL0);
__raw_writel(
8 << BP_TIMROT_TIMCTRLn_SELECT | /* 32 kHz */
BM_TIMROT_TIMCTRLn_RELOAD |
BM_TIMROT_TIMCTRLn_UPDATE |
BM_TIMROT_TIMCTRLn_IRQ_EN,
REGS_TIMROT_BASE + HW_TIMROT_TIMCTRL1);
__raw_writel(CLOCK_TICK_RATE / HZ - 1,
REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT0);
__raw_writel(0xFFFF, REGS_TIMROT_BASE + HW_TIMROT_TIMCOUNT1);
}
#else
#define stmp3xxx_suspend_timer NULL
#define stmp3xxx_resume_timer NULL
#endif /* CONFIG_PM */
struct sys_timer stmp3xxx_timer = {
.init = stmp3xxx_init_timer,
.suspend = stmp3xxx_suspend_timer,
.resume = stmp3xxx_resume_timer,
};
