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ARM: gemini: convert to GENERIC_CLOCKEVENTS 

This converts the gemini machine to use generic clockevents
by rewriting the timer driver.

Cc: arm@kernel.org
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
This commit is contained in:
Linus Walleij 2013-10-01 12:57:20 +02:00 committed by Olof Johansson
parent 43d93947a5
commit f3372c0181
2 changed files with 91 additions and 9 deletions
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3
arch/arm/Kconfig
View File

@ -384,8 +384,9 @@ config ARCH_CLPS711X
config ARCH_GEMINI
bool "Cortina Systems Gemini"
select ARCH_REQUIRE_GPIOLIB
select ARCH_USES_GETTIMEOFFSET
select CLKSRC_MMIO
select CPU_FA526
select GENERIC_CLOCKEVENTS
select NEED_MACH_GPIO_H
help
Support for the Cortina Systems Gemini family SoCs

97
arch/arm/mach-gemini/time.c
View File

@ -13,6 +13,8 @@
#include <mach/hardware.h>
#include <mach/global_reg.h>
#include <asm/mach/time.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
/*
* Register definitions for the timers
@ -33,19 +35,89 @@
#define TIMER_3_CR_CLOCK (1 << 7)
#define TIMER_3_CR_INT (1 << 8)
static unsigned int tick_rate;
static int gemini_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
u32 cr;
cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
/* This may be overdoing it, feel free to test without this */
cr &= ~TIMER_2_CR_ENABLE;
cr &= ~TIMER_2_CR_INT;
writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
/* Set next event */
writel(cycles, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
writel(cycles, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
cr |= TIMER_2_CR_ENABLE;
cr |= TIMER_2_CR_INT;
writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
return 0;
}
static void gemini_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ);
u32 cr;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* Start the timer */
writel(period,
TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
writel(period,
TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
cr |= TIMER_2_CR_ENABLE;
cr |= TIMER_2_CR_INT;
writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
break;
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
/*
* Disable also for oneshot: the set_next() call will
* arm the timer instead.
*/
cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
cr &= ~TIMER_2_CR_ENABLE;
cr &= ~TIMER_2_CR_INT;
writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
break;
default:
break;
}
}
/* Use TIMER2 as clock event */
static struct clock_event_device gemini_clockevent = {
.name = "TIMER2",
.rating = 300, /* Reasonably fast and accurate clock event */
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = gemini_timer_set_next_event,
.set_mode = gemini_timer_set_mode,
};
/*
* IRQ handler for the timer
*/
static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id)
{
timer_tick();
struct clock_event_device *evt = &gemini_clockevent;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction gemini_timer_irq = {
.name = "Gemini Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER,
.flags = IRQF_TIMER,
.handler = gemini_timer_interrupt,
};
@ -54,9 +126,9 @@ static struct irqaction gemini_timer_irq = {
*/
void __init gemini_timer_init(void)
{
unsigned int tick_rate, reg_v;
u32 reg_v;
reg_v = __raw_readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS));
reg_v = readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS));
tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000;
printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000);
@ -82,8 +154,17 @@ void __init gemini_timer_init(void)
* Make irqs happen for the system timer
*/
setup_irq(IRQ_TIMER2, &gemini_timer_irq);
/* Start the timer */
__raw_writel(tick_rate / HZ, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
__raw_writel(tick_rate / HZ, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
__raw_writel(TIMER_2_CR_ENABLE | TIMER_2_CR_INT, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
/* Enable and use TIMER1 as clock source */
writel(0xffffffff, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER1_BASE)));
writel(0xffffffff, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER1_BASE)));
writel(TIMER_1_CR_ENABLE, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
if (clocksource_mmio_init(TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER1_BASE)),
"TIMER1", tick_rate, 300, 32,
clocksource_mmio_readl_up))
pr_err("timer: failed to initialize gemini clock source\n");
/* Configure and register the clockevent */
clockevents_config_and_register(&gemini_clockevent, tick_rate,
1, 0xffffffff);
}