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>

diff --git a/arch/arm/mach-imx/epit.c b/arch/arm/mach-imx/epit.c
index 074b1a81ba764aa2caeecf6f973c3807e2f5b4a2..08ce20771bb3f9e49a88294e37216d7c562edb8a 100644 (file)
--- a/arch/arm/mach-imx/epit.c
+++ b/arch/arm/mach-imx/epit.c
@@ -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)