linux-stable-rt/arch/sh/kernel/timers/timer-tmu.c

298 lines
7.0 KiB
C

/*
* arch/sh/kernel/timers/timer-tmu.c - TMU Timer Support
*
* Copyright (C) 2005 - 2007 Paul Mundt
*
* TMU handling code hacked out of arch/sh/kernel/time.c
*
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 2002, 2003, 2004 Paul Mundt
* Copyright (C) 2002 M. R. Brown <mrbrown@linux-sh.org>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/seqlock.h>
#include <linux/clockchips.h>
#include <asm/timer.h>
#include <asm/rtc.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/clock.h>
#define TMU_TOCR_INIT 0x00
#define TMU_TCR_INIT 0x0020
#define TMU0 (0)
#define TMU1 (1)
static inline void _tmu_start(int tmu_num)
{
ctrl_outb(ctrl_inb(TMU_012_TSTR) | (0x1<<tmu_num), TMU_012_TSTR);
}
static inline void _tmu_set_irq(int tmu_num, int enabled)
{
register unsigned long tmu_tcr = TMU0_TCR + (0xc*tmu_num);
ctrl_outw( (enabled ? ctrl_inw(tmu_tcr) | (1<<5) : ctrl_inw(tmu_tcr) & ~(1<<5)), tmu_tcr);
}
static inline void _tmu_stop(int tmu_num)
{
ctrl_outb(ctrl_inb(TMU_012_TSTR) & ~(0x1<<tmu_num), TMU_012_TSTR);
}
static inline void _tmu_clear_status(int tmu_num)
{
register unsigned long tmu_tcr = TMU0_TCR + (0xc*tmu_num);
/* Clear UNF bit */
ctrl_outw(ctrl_inw(tmu_tcr) & ~0x100, tmu_tcr);
}
static inline unsigned long _tmu_read(int tmu_num)
{
return ctrl_inl(TMU0_TCNT+0xC*tmu_num);
}
static int tmu_timer_start(void)
{
_tmu_start(TMU0);
_tmu_start(TMU1);
_tmu_set_irq(TMU0,1);
return 0;
}
static int tmu_timer_stop(void)
{
_tmu_stop(TMU0);
_tmu_stop(TMU1);
_tmu_clear_status(TMU0);
return 0;
}
/*
* also when the module_clk is scaled the TMU1
* will show the same frequency
*/
static int tmus_are_scaled;
static cycle_t tmu_timer_read(void)
{
return ((cycle_t)(~_tmu_read(TMU1)))<<tmus_are_scaled;
}
static unsigned long tmu_latest_interval[3];
static void tmu_timer_set_interval(int tmu_num, unsigned long interval, unsigned int reload)
{
unsigned long tmu_tcnt = TMU0_TCNT + tmu_num*0xC;
unsigned long tmu_tcor = TMU0_TCOR + tmu_num*0xC;
_tmu_stop(tmu_num);
ctrl_outl(interval, tmu_tcnt);
tmu_latest_interval[tmu_num] = interval;
/*
* TCNT reloads from TCOR on underflow, clear it if we don't
* intend to auto-reload
*/
ctrl_outl( reload ? interval : 0 , tmu_tcor);
_tmu_start(tmu_num);
}
static int tmu_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
tmu_timer_set_interval(TMU0,cycles, evt->mode == CLOCK_EVT_MODE_PERIODIC);
_tmu_set_irq(TMU0,1);
return 0;
}
static void tmu_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
ctrl_outl(tmu_latest_interval[TMU0], TMU0_TCOR);
break;
case CLOCK_EVT_MODE_ONESHOT:
ctrl_outl(0, TMU0_TCOR);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
}
static struct clock_event_device tmu0_clockevent = {
.name = "tmu0",
.shift = 32,
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = tmu_set_mode,
.set_next_event = tmu_set_next_event,
};
static irqreturn_t tmu_timer_interrupt(int irq, void *dummy)
{
struct clock_event_device *evt = &tmu0_clockevent;
_tmu_clear_status(TMU0);
_tmu_set_irq(TMU0,tmu0_clockevent.mode != CLOCK_EVT_MODE_ONESHOT);
switch (tmu0_clockevent.mode) {
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_PERIODIC:
evt->event_handler(evt);
break;
default:
break;
}
return IRQ_HANDLED;
}
static struct irqaction tmu0_irq = {
.name = "periodic/oneshot timer",
.handler = tmu_timer_interrupt,
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
};
static void __init tmu_clk_init(struct clk *clk)
{
u8 divisor = TMU_TCR_INIT & 0x7;
int tmu_num = clk->name[3]-'0';
ctrl_outw(TMU_TCR_INIT, TMU0_TCR+(tmu_num*0xC));
clk->rate = clk_get_rate(clk->parent) / (4 << (divisor << 1));
}
static void tmu_clk_recalc(struct clk *clk)
{
int tmu_num = clk->name[3]-'0';
unsigned long prev_rate = clk_get_rate(clk);
unsigned long flags;
u8 divisor = ctrl_inw(TMU0_TCR+tmu_num*0xC) & 0x7;
clk->rate = clk_get_rate(clk->parent) / (4 << (divisor << 1));
if(prev_rate==clk_get_rate(clk))
return;
if(tmu_num)
return; /* No more work on TMU1 */
local_irq_save(flags);
tmus_are_scaled = (prev_rate > clk->rate);
_tmu_stop(TMU0);
tmu0_clockevent.mult = div_sc(clk->rate, NSEC_PER_SEC,
tmu0_clockevent.shift);
tmu0_clockevent.max_delta_ns =
clockevent_delta2ns(-1, &tmu0_clockevent);
tmu0_clockevent.min_delta_ns =
clockevent_delta2ns(1, &tmu0_clockevent);
if (tmus_are_scaled)
tmu_latest_interval[TMU0] >>= 1;
else
tmu_latest_interval[TMU0] <<= 1;
tmu_timer_set_interval(TMU0,
tmu_latest_interval[TMU0],
tmu0_clockevent.mode == CLOCK_EVT_MODE_PERIODIC);
_tmu_start(TMU0);
local_irq_restore(flags);
}
static struct clk_ops tmu_clk_ops = {
.init = tmu_clk_init,
.recalc = tmu_clk_recalc,
};
static struct clk tmu0_clk = {
.name = "tmu0_clk",
.ops = &tmu_clk_ops,
};
static struct clk tmu1_clk = {
.name = "tmu1_clk",
.ops = &tmu_clk_ops,
};
static int tmu_timer_init(void)
{
unsigned long interval;
unsigned long frequency;
setup_irq(CONFIG_SH_TIMER_IRQ, &tmu0_irq);
tmu0_clk.parent = clk_get(NULL, "module_clk");
tmu1_clk.parent = clk_get(NULL, "module_clk");
tmu_timer_stop();
#if !defined(CONFIG_CPU_SUBTYPE_SH7720) && \
!defined(CONFIG_CPU_SUBTYPE_SH7721) && \
!defined(CONFIG_CPU_SUBTYPE_SH7760) && \
!defined(CONFIG_CPU_SUBTYPE_SH7785) && \
!defined(CONFIG_CPU_SUBTYPE_SH7786) && \
!defined(CONFIG_CPU_SUBTYPE_SHX3)
ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
#endif
clk_register(&tmu0_clk);
clk_register(&tmu1_clk);
clk_enable(&tmu0_clk);
clk_enable(&tmu1_clk);
frequency = clk_get_rate(&tmu0_clk);
interval = (frequency + HZ / 2) / HZ;
tmu_timer_set_interval(TMU0,interval, 1);
tmu_timer_set_interval(TMU1,~0,1);
_tmu_start(TMU1);
clocksource_sh.rating = 200;
clocksource_sh.mask = CLOCKSOURCE_MASK(32);
clocksource_sh.read = tmu_timer_read;
clocksource_sh.shift = 10;
clocksource_sh.mult = clocksource_hz2mult(clk_get_rate(&tmu1_clk),
clocksource_sh.shift);
clocksource_sh.flags = CLOCK_SOURCE_IS_CONTINUOUS;
clocksource_register(&clocksource_sh);
tmu0_clockevent.mult = div_sc(frequency, NSEC_PER_SEC,
tmu0_clockevent.shift);
tmu0_clockevent.max_delta_ns =
clockevent_delta2ns(-1, &tmu0_clockevent);
tmu0_clockevent.min_delta_ns =
clockevent_delta2ns(1, &tmu0_clockevent);
tmu0_clockevent.cpumask = cpumask_of(0);
tmu0_clockevent.rating = 100;
clockevents_register_device(&tmu0_clockevent);
return 0;
}
static struct sys_timer_ops tmu_timer_ops = {
.init = tmu_timer_init,
.start = tmu_timer_start,
.stop = tmu_timer_stop,
};
struct sys_timer tmu_timer = {
.name = "tmu",
.ops = &tmu_timer_ops,
};