clock: Add ClockEvent parameter to callbacks

The Clock framework allows users to specify a callback which is
called after the clock's period has been updated.  Some users need to
also have a callback which is called before the clock period is
updated.

As the first step in adding support for notifying Clock users on
pre-update events, add an argument to the ClockCallback to specify
what event is being notified, and add an argument to the various
functions for registering a callback to specify which events are
of interest to that callback.

Note that the documentation update renders correct the previously
incorrect claim in 'Adding a new clock' that callbacks "will be
explained in a following section".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
---
v2->v3: used 'unsigned int' instead of 'int' for parameters
and struct fields containing an event mask, as suggested by Philippe;
fixed events argument to qdev_init_clock_in() with NULL callback
pointer in npcm7xx_adc.c (spotted by Hao)

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/timer/npcm7xx_timer.c b/hw/timer/npcm7xx_timer.c
index 36e2c07db2..4efdf135b8 100644
--- a/hw/timer/npcm7xx_timer.c
+++ b/hw/timer/npcm7xx_timer.c
@@ -627,7 +627,7 @@ static void npcm7xx_timer_init(Object *obj)
     sysbus_init_mmio(sbd, &s->iomem);
     qdev_init_gpio_out_named(dev, &w->reset_signal,
             NPCM7XX_WATCHDOG_RESET_GPIO_OUT, 1);
-    s->clock = qdev_init_clock_in(dev, "clock", NULL, NULL);
+    s->clock = qdev_init_clock_in(dev, "clock", NULL, NULL, 0);
 }
 
 static const VMStateDescription vmstate_npcm7xx_base_timer = {