CLOCKSOURCE: mips-gic: Update clockevent frequency on clock rate changes
This commit introduces the clockevent frequency update, using
a clock notifier. It will be used to support CPUFreq on platforms
using MIPS GIC based clockevents.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: James Hartley <James.Hartley@imgtec.com>
Cc: Govindraj Raja <Govindraj.Raja@imgtec.com>
Cc: Damien Horsley <Damien.Horsley@imgtec.com>
Cc: James Hogan <James.Hogan@imgtec.com>
Cc: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Patchwork: https://patchwork.linux-mips.org/patch/10782/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 22a4daf..a155bec 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -79,6 +79,13 @@
disable_percpu_irq(gic_timer_irq);
}
+static void gic_update_frequency(void *data)
+{
+ unsigned long rate = (unsigned long)data;
+
+ clockevents_update_freq(this_cpu_ptr(&gic_clockevent_device), rate);
+}
+
static int gic_cpu_notifier(struct notifier_block *nb, unsigned long action,
void *data)
{
@@ -94,10 +101,26 @@
return NOTIFY_OK;
}
+static int gic_clk_notifier(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct clk_notifier_data *cnd = data;
+
+ if (action == POST_RATE_CHANGE)
+ on_each_cpu(gic_update_frequency, (void *)cnd->new_rate, 1);
+
+ return NOTIFY_OK;
+}
+
+
static struct notifier_block gic_cpu_nb = {
.notifier_call = gic_cpu_notifier,
};
+static struct notifier_block gic_clk_nb = {
+ .notifier_call = gic_clk_notifier,
+};
+
static int gic_clockevent_init(void)
{
int ret;
@@ -160,6 +183,7 @@
static void __init gic_clocksource_of_init(struct device_node *node)
{
struct clk *clk;
+ int ret;
if (WARN_ON(!gic_present || !node->parent ||
!of_device_is_compatible(node->parent, "mti,gic")))
@@ -186,7 +210,12 @@
}
__gic_clocksource_init();
- gic_clockevent_init();
+
+ ret = gic_clockevent_init();
+ if (!ret && !IS_ERR(clk)) {
+ if (clk_notifier_register(clk, &gic_clk_nb) < 0)
+ pr_warn("GIC: Unable to register clock notifier\n");
+ }
/* And finally start the counter */
gic_start_count();