linux/arch/arm/plat-samsung/samsung-time.c

395 lines
8.9 KiB
C

/*
* Copyright (c) 2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* samsung - Common hr-timer support (s3c and s5p)
*
* 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/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 <asm/mach/time.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/sched_clock.h>
#include <mach/map.h>
#include <plat/devs.h>
#include <plat/regs-timer.h>
#include <plat/samsung-time.h>
static struct clk *tin_event;
static struct clk *tin_source;
static struct clk *tdiv_event;
static struct clk *tdiv_source;
static struct clk *timerclk;
static struct samsung_timer_source timer_source;
static unsigned long clock_count_per_tick;
static void samsung_timer_resume(void);
static void samsung_time_stop(enum samsung_timer_mode mode)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
switch (mode) {
case SAMSUNG_PWM0:
tcon &= ~S3C2410_TCON_T0START;
break;
case SAMSUNG_PWM1:
tcon &= ~S3C2410_TCON_T1START;
break;
case SAMSUNG_PWM2:
tcon &= ~S3C2410_TCON_T2START;
break;
case SAMSUNG_PWM3:
tcon &= ~S3C2410_TCON_T3START;
break;
case SAMSUNG_PWM4:
tcon &= ~S3C2410_TCON_T4START;
break;
default:
printk(KERN_ERR "Invalid Timer %d\n", mode);
break;
}
__raw_writel(tcon, S3C2410_TCON);
}
static void samsung_time_setup(enum samsung_timer_mode mode, unsigned long tcnt)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
tcnt--;
switch (mode) {
case SAMSUNG_PWM0:
tcon &= ~(0x0f << 0);
tcon |= S3C2410_TCON_T0MANUALUPD;
break;
case SAMSUNG_PWM1:
tcon &= ~(0x0f << 8);
tcon |= S3C2410_TCON_T1MANUALUPD;
break;
case SAMSUNG_PWM2:
tcon &= ~(0x0f << 12);
tcon |= S3C2410_TCON_T2MANUALUPD;
break;
case SAMSUNG_PWM3:
tcon &= ~(0x0f << 16);
tcon |= S3C2410_TCON_T3MANUALUPD;
break;
case SAMSUNG_PWM4:
tcon &= ~(0x07 << 20);
tcon |= S3C2410_TCON_T4MANUALUPD;
break;
default:
printk(KERN_ERR "Invalid Timer %d\n", mode);
break;
}
__raw_writel(tcnt, S3C2410_TCNTB(mode));
__raw_writel(tcnt, S3C2410_TCMPB(mode));
__raw_writel(tcon, S3C2410_TCON);
}
static void samsung_time_start(enum samsung_timer_mode mode, bool periodic)
{
unsigned long tcon;
tcon = __raw_readl(S3C2410_TCON);
switch (mode) {
case SAMSUNG_PWM0:
tcon |= S3C2410_TCON_T0START;
tcon &= ~S3C2410_TCON_T0MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T0RELOAD;
else
tcon &= ~S3C2410_TCON_T0RELOAD;
break;
case SAMSUNG_PWM1:
tcon |= S3C2410_TCON_T1START;
tcon &= ~S3C2410_TCON_T1MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T1RELOAD;
else
tcon &= ~S3C2410_TCON_T1RELOAD;
break;
case SAMSUNG_PWM2:
tcon |= S3C2410_TCON_T2START;
tcon &= ~S3C2410_TCON_T2MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T2RELOAD;
else
tcon &= ~S3C2410_TCON_T2RELOAD;
break;
case SAMSUNG_PWM3:
tcon |= S3C2410_TCON_T3START;
tcon &= ~S3C2410_TCON_T3MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T3RELOAD;
else
tcon &= ~S3C2410_TCON_T3RELOAD;
break;
case SAMSUNG_PWM4:
tcon |= S3C2410_TCON_T4START;
tcon &= ~S3C2410_TCON_T4MANUALUPD;
if (periodic)
tcon |= S3C2410_TCON_T4RELOAD;
else
tcon &= ~S3C2410_TCON_T4RELOAD;
break;
default:
printk(KERN_ERR "Invalid Timer %d\n", mode);
break;
}
__raw_writel(tcon, S3C2410_TCON);
}
static int samsung_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
samsung_time_setup(timer_source.event_id, cycles);
samsung_time_start(timer_source.event_id, NON_PERIODIC);
return 0;
}
static void samsung_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
samsung_time_stop(timer_source.event_id);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
samsung_time_setup(timer_source.event_id, clock_count_per_tick);
samsung_time_start(timer_source.event_id, PERIODIC);
break;
case CLOCK_EVT_MODE_ONESHOT:
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
break;
case CLOCK_EVT_MODE_RESUME:
samsung_timer_resume();
break;
}
}
static void samsung_timer_resume(void)
{
/* event timer restart */
samsung_time_setup(timer_source.event_id, clock_count_per_tick);
samsung_time_start(timer_source.event_id, PERIODIC);
/* source timer restart */
samsung_time_setup(timer_source.source_id, TCNT_MAX);
samsung_time_start(timer_source.source_id, PERIODIC);
}
void __init samsung_set_timer_source(enum samsung_timer_mode event,
enum samsung_timer_mode source)
{
s3c_device_timer[event].dev.bus = &platform_bus_type;
s3c_device_timer[source].dev.bus = &platform_bus_type;
timer_source.event_id = event;
timer_source.source_id = source;
}
static struct clock_event_device time_event_device = {
.name = "samsung_event_timer",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.rating = 200,
.set_next_event = samsung_set_next_event,
.set_mode = samsung_set_mode,
};
static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction samsung_clock_event_irq = {
.name = "samsung_time_irq",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = samsung_clock_event_isr,
.dev_id = &time_event_device,
};
static void __init samsung_clockevent_init(void)
{
unsigned long pclk;
unsigned long clock_rate;
unsigned int irq_number;
struct clk *tscaler;
pclk = clk_get_rate(timerclk);
tscaler = clk_get_parent(tdiv_event);
clk_set_rate(tscaler, pclk / TSCALER_DIV);
clk_set_rate(tdiv_event, pclk / TDIV);
clk_set_parent(tin_event, tdiv_event);
clock_rate = clk_get_rate(tin_event);
clock_count_per_tick = clock_rate / HZ;
time_event_device.cpumask = cpumask_of(0);
clockevents_config_and_register(&time_event_device, clock_rate, 1, -1);
irq_number = timer_source.event_id + IRQ_TIMER0;
setup_irq(irq_number, &samsung_clock_event_irq);
}
static void __iomem *samsung_timer_reg(void)
{
unsigned long offset = 0;
switch (timer_source.source_id) {
case SAMSUNG_PWM0:
case SAMSUNG_PWM1:
case SAMSUNG_PWM2:
case SAMSUNG_PWM3:
offset = (timer_source.source_id * 0x0c) + 0x14;
break;
case SAMSUNG_PWM4:
offset = 0x40;
break;
default:
printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
return NULL;
}
return S3C_TIMERREG(offset);
}
/*
* Override the global weak sched_clock symbol with this
* local implementation which uses the clocksource to get some
* better resolution when scheduling the kernel. We accept that
* this wraps around for now, since it is just a relative time
* stamp. (Inspired by U300 implementation.)
*/
static u32 notrace samsung_read_sched_clock(void)
{
void __iomem *reg = samsung_timer_reg();
if (!reg)
return 0;
return ~__raw_readl(reg);
}
static void __init samsung_clocksource_init(void)
{
unsigned long pclk;
unsigned long clock_rate;
pclk = clk_get_rate(timerclk);
clk_set_rate(tdiv_source, pclk / TDIV);
clk_set_parent(tin_source, tdiv_source);
clock_rate = clk_get_rate(tin_source);
samsung_time_setup(timer_source.source_id, TCNT_MAX);
samsung_time_start(timer_source.source_id, PERIODIC);
setup_sched_clock(samsung_read_sched_clock, TSIZE, clock_rate);
if (clocksource_mmio_init(samsung_timer_reg(), "samsung_clocksource_timer",
clock_rate, 250, TSIZE, clocksource_mmio_readl_down))
panic("samsung_clocksource_timer: can't register clocksource\n");
}
static void __init samsung_timer_resources(void)
{
unsigned long event_id = timer_source.event_id;
unsigned long source_id = timer_source.source_id;
char devname[15];
timerclk = clk_get(NULL, "timers");
if (IS_ERR(timerclk))
panic("failed to get timers clock for timer");
clk_enable(timerclk);
sprintf(devname, "s3c24xx-pwm.%lu", event_id);
s3c_device_timer[event_id].id = event_id;
s3c_device_timer[event_id].dev.init_name = devname;
tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
if (IS_ERR(tin_event))
panic("failed to get pwm-tin clock for event timer");
tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
if (IS_ERR(tdiv_event))
panic("failed to get pwm-tdiv clock for event timer");
clk_enable(tin_event);
sprintf(devname, "s3c24xx-pwm.%lu", source_id);
s3c_device_timer[source_id].id = source_id;
s3c_device_timer[source_id].dev.init_name = devname;
tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
if (IS_ERR(tin_source))
panic("failed to get pwm-tin clock for source timer");
tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
if (IS_ERR(tdiv_source))
panic("failed to get pwm-tdiv clock for source timer");
clk_enable(tin_source);
}
void __init samsung_timer_init(void)
{
samsung_timer_resources();
samsung_clockevent_init();
samsung_clocksource_init();
}