clockevents/drivers/timer-imx-gpt: Migrate to new 'set-state' interface

Migrate timer-imx-gpt 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:
- 'imx_timer.cem': 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.

- 'clock_event_mode_label': CLOCK_EVT_MODE_* shouldn't be used anymore
  by drivers. The prints are modified to print the set-state functions
  name now to debug the driver.

Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

diff --git a/drivers/clocksource/timer-imx-gpt.c b/drivers/clocksource/timer-imx-gpt.c
index 2d59038dec43512e40ca46f4a0989c3b1253e0af..85111a763bc8e6bd4ef52a3eb833168bfb7c58b5 100644 (file)
--- a/drivers/clocksource/timer-imx-gpt.c
+++ b/drivers/clocksource/timer-imx-gpt.c
@@ -83,7 +83,6 @@ struct imx_timer {
        struct clk *clk_ipg;
        const struct imx_gpt_data *gpt;
        struct clock_event_device ced;
-       enum clock_event_mode cem;
        struct irqaction act;
 };
 
@@ -212,18 +211,38 @@ static int v2_set_next_event(unsigned long evt,
                                -ETIME : 0;
 }
 
+static int mxc_shutdown(struct clock_event_device *ced)
+{
+       struct imx_timer *imxtm = to_imx_timer(ced);
+       unsigned long flags;
+       u32 tcn;
+
+       /*
+        * The timer interrupt generation is disabled at least
+        * for enough time to call mxc_set_next_event()
+        */
+       local_irq_save(flags);
+
+       /* Disable interrupt in GPT module */
+       imxtm->gpt->gpt_irq_disable(imxtm);
+
+       tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
+       /* Set event time into far-far future */
+       writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
+
+       /* Clear pending interrupt */
+       imxtm->gpt->gpt_irq_acknowledge(imxtm);
+
 #ifdef DEBUG
-static const char *clock_event_mode_label[] = {
-       [CLOCK_EVT_MODE_PERIODIC] = "CLOCK_EVT_MODE_PERIODIC",
-       [CLOCK_EVT_MODE_ONESHOT]  = "CLOCK_EVT_MODE_ONESHOT",
-       [CLOCK_EVT_MODE_SHUTDOWN] = "CLOCK_EVT_MODE_SHUTDOWN",
-       [CLOCK_EVT_MODE_UNUSED]   = "CLOCK_EVT_MODE_UNUSED",
-       [CLOCK_EVT_MODE_RESUME]   = "CLOCK_EVT_MODE_RESUME",
-};
+       printk(KERN_INFO "%s: changing mode\n", __func__);
 #endif /* DEBUG */
 
-static void mxc_set_mode(enum clock_event_mode mode,
-                               struct clock_event_device *ced)
+       local_irq_restore(flags);
+
+       return 0;
+}
+
+static int mxc_set_oneshot(struct clock_event_device *ced)
 {
        struct imx_timer *imxtm = to_imx_timer(ced);
        unsigned long flags;
@@ -237,7 +256,7 @@ static void mxc_set_mode(enum clock_event_mode mode,
        /* Disable interrupt in GPT module */
        imxtm->gpt->gpt_irq_disable(imxtm);
 
-       if (mode != imxtm->cem) {
+       if (!clockevent_state_oneshot(ced)) {
                u32 tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
                /* Set event time into far-far future */
                writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
@@ -247,37 +266,19 @@ static void mxc_set_mode(enum clock_event_mode mode,
        }
 
 #ifdef DEBUG
-       printk(KERN_INFO "mxc_set_mode: changing mode from %s to %s\n",
-               clock_event_mode_label[imxtm->cem],
-               clock_event_mode_label[mode]);
+       printk(KERN_INFO "%s: changing mode\n", __func__);
 #endif /* DEBUG */
 
-       /* Remember timer mode */
-       imxtm->cem = mode;
-       local_irq_restore(flags);
-
-       switch (mode) {
-       case CLOCK_EVT_MODE_PERIODIC:
-               printk(KERN_ERR"mxc_set_mode: Periodic mode is not "
-                               "supported for i.MX\n");
-               break;
-       case CLOCK_EVT_MODE_ONESHOT:
        /*
         * Do not put overhead of interrupt enable/disable into
         * mxc_set_next_event(), the core has about 4 minutes
         * to call mxc_set_next_event() or shutdown clock after
         * mode switching
         */
-               local_irq_save(flags);
-               imxtm->gpt->gpt_irq_enable(imxtm);
-               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;
-       }
+       imxtm->gpt->gpt_irq_enable(imxtm);
+       local_irq_restore(flags);
+
+       return 0;
 }
 
 /*
@@ -303,11 +304,11 @@ static int __init mxc_clockevent_init(struct imx_timer *imxtm)
        struct clock_event_device *ced = &imxtm->ced;
        struct irqaction *act = &imxtm->act;
 
-       imxtm->cem = CLOCK_EVT_MODE_UNUSED;
-
        ced->name = "mxc_timer1";
        ced->features = CLOCK_EVT_FEAT_ONESHOT;
-       ced->set_mode = mxc_set_mode;
+       ced->set_state_shutdown = mxc_shutdown;
+       ced->set_state_oneshot = mxc_set_oneshot;
+       ced->tick_resume = mxc_shutdown;
        ced->set_next_event = imxtm->gpt->set_next_event;
        ced->rating = 200;
        ced->cpumask = cpumask_of(0);