/* linux/arch/arm/mach-s5pv310/time.c
*
* Copyright (c) 2010 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* S5PV310 (and compatible) HRT support
* PWM 2/4 is used for this feature
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/platform_device.h>
#include <asm/smp_twd.h>
#include <mach/map.h>
#include <plat/regs-timer.h>
#include <asm/mach/time.h>
static unsigned long clock_count_per_tick;
static struct clk *tin2;
static struct clk *tin4;
static struct clk *tdiv2;
static struct clk *tdiv4;
static struct clk *timerclk;
static void s5pv310_pwm_stop(unsigned int pwm_id)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
switch (pwm_id) {
case 2:
tcon &= ~S3C2410_TCON_T2START;
break;
case 4:
tcon &= ~S3C2410_TCON_T4START;
break;
default:
break;
}
__raw_writel(tcon, S3C2410_TCON);
}
static void s5pv310_pwm_init(unsigned int pwm_id, unsigned long tcnt)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
/* timers reload after counting zero, so reduce the count by 1 */
tcnt--;
/* ensure timer is stopped... */
switch (pwm_id) {
case 2:
tcon &= ~(0xf<<12);
tcon |= S3C2410_TCON_T2MANUALUPD;
__raw_writel(tcnt, S3C2410_TCNTB(2));
__raw_writel(tcnt, S3C2410_TCMPB(2));
__raw_writel(tcon, S3C2410_TCON);
break;
case 4:
tcon &= ~(7<<20);
tcon |= S3C2410_TCON_T4MANUALUPD;
__raw_writel(tcnt, S3C2410_TCNTB(4));
__raw_writel(tcnt, S3C2410_TCMPB(4));
__raw_writel(tcon, S3C2410_TCON);
break;
default:
break;
}
}
static inline void s5pv310_pwm_start(unsigned int pwm_id, bool periodic)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
switch (pwm_id) {
case 2:
tcon |= S3C2410_TCON_T2START;
tcon &= ~S3C2410_TCON_T2MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T2RELOAD;
else
tcon &= ~S3C2410_TCON_T2RELOAD;
break;
case 4:
tcon |= S3C2410_TCON_T4START;
tcon &= ~S3C2410_TCON_T4MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T4RELOAD;
else
tcon &= ~S3C2410_TCON_T4RELOAD;
break;
default:
break;
}
__raw_writel(tcon, S3C2410_TCON);
}
static int s5pv310_pwm_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
s5pv310_pwm_init(2, cycles);
s5pv310_pwm_start(2, 0);
return 0;
}
static void s5pv310_pwm_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
s5pv310_pwm_stop(2);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
s5pv310_pwm_init(2, clock_count_per_tick);
s5pv310_pwm_start(2, 1);
break;
case CLOCK_EVT_MODE_ONESHOT:
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
}
static struct clock_event_device pwm_event_device = {
.name = "pwm_timer2",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.rating = 200,
.shift = 32,
.set_next_event = s5pv310_pwm_set_next_event,
.set_mode = s5pv310_pwm_set_mode,
};
irqreturn_t s5pv310_clock_event_isr(int irq, void *dev_id)
{
struct clock_event_device *evt = &pwm_event_device;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction s5pv310_clock_event_irq = {
.name = "pwm_timer2_irq",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = s5pv310_clock_event_isr,
};
static void __init s5pv310_clockevent_init(void)
{
unsigned long pclk;
unsigned long clock_rate;
struct clk *tscaler;
pclk = clk_get_rate(timerclk);
/* configure clock tick */
tscaler = clk_get_parent(tdiv2);
clk_set_rate(tscaler, pclk / 2);
clk_set_rate(tdiv2, pclk / 2);
clk_set_parent(tin2, tdiv2);
clock_rate = clk_get_rate(tin2);
clock_count_per_tick = clock_rate / HZ;
pwm_event_device.mult =
div_sc(clock_rate, NSEC_PER_SEC, pwm_event_device.shift);
pwm_event_device.max_delta_ns =
clockevent_delta2ns(-1, &pwm_event_device);
pwm_event_device.min_delta_ns =
clockevent_delta2ns(1, &pwm_event_device);
pwm_event_device.cpumask = cpumask_of(0);
clockevents_register_device(&pwm_event_device);
setup_irq(IRQ_TIMER2, &s5pv310_clock_event_irq);
}
static cycle_t s5pv310_pwm4_read(struct clocksource *cs)
{
return (cycle_t) ~__raw_readl(S3C_TIMERREG(0x40));
}
struct clocksource pwm_clocksource = {
.name = "pwm_timer4",
.rating = 250,
.read = s5pv310_pwm4_read,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.flags = CLOCK_SOURCE_IS_CONTINUOUS ,
};
static void __init s5pv310_clocksource_init(void)
{
unsigned long pclk;
unsigned long clock_rate;
pclk = clk_get_rate(timerclk);
clk_set_rate(tdiv4, pclk / 2);
clk_set_parent(tin4, tdiv4);
clock_rate = clk_get_rate(tin4);
s5pv310_pwm_init(4, ~0);
s5pv310_pwm_start(4, 1);
pwm_clocksource.mult =
clocksource_khz2mult(clock_rate/1000, pwm_clocksource.shift);
if (clocksource_register(&pwm_clocksource))
panic("%s: can't register clocksource\n", pwm_clocksource.name);
}
static void __init s5pv310_timer_resources(void)
{
struct platform_device tmpdev;
tmpdev.dev.bus = &platform_bus_type;
timerclk = clk_get(NULL, "timers");
if (IS_ERR(timerclk))
panic("failed to get timers clock for system timer");
clk_enable(timerclk);
tmpdev.id = 2;
tin2 = clk_get(&tmpdev.dev, "pwm-tin");
if (IS_ERR(tin2))
panic("failed to get pwm-tin2 clock for system timer");
tdiv2 = clk_get(&tmpdev.dev, "pwm-tdiv");
if (IS_ERR(tdiv2))
panic("failed to get pwm-tdiv2 clock for system timer");
clk_enable(tin2);
tmpdev.id = 4;
tin4 = clk_get(&tmpdev.dev, "pwm-tin");
if (IS_ERR(tin4))
panic("failed to get pwm-tin4 clock for system timer");
tdiv4 = clk_get(&tmpdev.dev, "pwm-tdiv");
if (IS_ERR(tdiv4))
panic("failed to get pwm-tdiv4 clock for system timer");
clk_enable(tin4);
}
static void __init s5pv310_timer_init(void)
{
#ifdef CONFIG_LOCAL_TIMERS
twd_base = S5P_VA_TWD;
#endif
s5pv310_timer_resources();
s5pv310_clockevent_init();
s5pv310_clocksource_init();
}
struct sys_timer s5pv310_timer = {
.init = s5pv310_timer_init,
};
