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ARM/imx/epit: Migrate to new 'set-state' interface 

Migrate imx driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Also drop 'clockevent_mode': It was caching the last state of the
clockevent device. The same behavior can be achieved by using
clockevents state helpers. These helpers are only required for oneshot
mode as shutdown/resume wouldn't be done twice by the core.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Viresh Kumar 2015-02-27 13:39:52 +05:30
parent e2efda2480
commit 3200579faf
1 changed files with 35 additions and 32 deletions
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67
arch/arm/mach-imx/epit.c
View File

@ -57,7 +57,6 @@
#include "hardware.h"
static struct clock_event_device clockevent_epit;
static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_UNUSED;
static void __iomem *timer_base;
@ -106,8 +105,8 @@ static int epit_set_next_event(unsigned long evt,
return 0;
}
static void epit_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
/* Left event sources disabled, no more interrupts appear */
static int epit_shutdown(struct clock_event_device *evt)
{
unsigned long flags;
@ -120,39 +119,41 @@ static void epit_set_mode(enum clock_event_mode mode,
/* Disable interrupt in GPT module */
epit_irq_disable();
if (mode != clockevent_mode) {
/* Set event time into far-far future */
/* Clear pending interrupt */
epit_irq_acknowledge();
/* Clear pending interrupt */
epit_irq_acknowledge();
}
/* Remember timer mode */
clockevent_mode = mode;
local_irq_restore(flags);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
printk(KERN_ERR "epit_set_mode: Periodic mode is not "
"supported for i.MX EPIT\n");
break;
case CLOCK_EVT_MODE_ONESHOT:
return 0;
}
static int epit_set_oneshot(struct clock_event_device *evt)
{
unsigned long flags;
/*
* The timer interrupt generation is disabled at least
* for enough time to call epit_set_next_event()
*/
local_irq_save(flags);
/* Disable interrupt in GPT module */
epit_irq_disable();
/* Clear pending interrupt, only while switching mode */
if (!clockevent_state_oneshot(evt))
epit_irq_acknowledge();
/*
* Do not put overhead of interrupt enable/disable into
* epit_set_next_event(), the core has about 4 minutes
* to call epit_set_next_event() or shutdown clock after
* mode switching
*/
local_irq_save(flags);
epit_irq_enable();
local_irq_restore(flags);
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_RESUME:
/* Left event sources disabled, no more interrupts appear */
break;
}
epit_irq_enable();
local_irq_restore(flags);
return 0;
}
/*
@ -176,11 +177,13 @@ static struct irqaction epit_timer_irq = {
};
static struct clock_event_device clockevent_epit = {
.name = "epit",
.features = CLOCK_EVT_FEAT_ONESHOT,
.set_mode = epit_set_mode,
.set_next_event = epit_set_next_event,
.rating = 200,
.name = "epit",
.features = CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = epit_shutdown,
.tick_resume = epit_shutdown,
.set_state_oneshot = epit_set_oneshot,
.set_next_event = epit_set_next_event,
.rating = 200,
};
static int __init epit_clockevent_init(struct clk *timer_clk)