Re: [PATCH V5 4/4] clocksource: mips-gic: Add device-tree support

From: Daniel Lezcano
Date: Mon Nov 17 2014 - 16:28:41 EST


On 11/12/2014 08:43 PM, Andrew Bresticker wrote:
Parse the GIC timer frequency and interrupt from the device-tree.

Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>

Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>

---
Changes from v4:
- don't probe from irqchip; just warn if DT is wrong
Changes from v3:
- probe from GIC irqchip
New for v3.
---
drivers/clocksource/Kconfig | 1 +
drivers/clocksource/mips-gic-timer.c | 41 ++++++++++++++++++++++++++++++------
2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cb7e7f4..89836dc 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -226,5 +226,6 @@ config CLKSRC_VERSATILE
config CLKSRC_MIPS_GIC
bool
depends on MIPS_GIC
+ select CLKSRC_OF

endmenu
diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index a749c81..3bd31b1 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -11,6 +11,7 @@
#include <linux/interrupt.h>
#include <linux/irqchip/mips-gic.h>
#include <linux/notifier.h>
+#include <linux/of_irq.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/time.h>
@@ -101,8 +102,6 @@ static int gic_clockevent_init(void)
if (!cpu_has_counter || !gic_frequency)
return -ENXIO;

- gic_timer_irq = MIPS_GIC_IRQ_BASE +
- GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE);
setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction);

register_cpu_notifier(&gic_cpu_nb);
@@ -123,17 +122,45 @@ static struct clocksource gic_clocksource = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};

-void __init gic_clocksource_init(unsigned int frequency)
+static void __init __gic_clocksource_init(void)
{
- gic_frequency = frequency;
-
/* Set clocksource mask. */
gic_clocksource.mask = CLOCKSOURCE_MASK(gic_get_count_width());

/* Calculate a somewhat reasonable rating value. */
- gic_clocksource.rating = 200 + frequency / 10000000;
+ gic_clocksource.rating = 200 + gic_frequency / 10000000;

- clocksource_register_hz(&gic_clocksource, frequency);
+ clocksource_register_hz(&gic_clocksource, gic_frequency);

gic_clockevent_init();
}
+
+void __init gic_clocksource_init(unsigned int frequency)
+{
+ gic_frequency = frequency;
+ gic_timer_irq = MIPS_GIC_IRQ_BASE +
+ GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE);
+
+ __gic_clocksource_init();
+}
+
+static void __init gic_clocksource_of_init(struct device_node *node)
+{
+ if (WARN_ON(!gic_present || !node->parent ||
+ !of_device_is_compatible(node->parent, "mti,gic")))
+ return;
+
+ if (of_property_read_u32(node, "clock-frequency", &gic_frequency)) {
+ pr_err("GIC frequency not specified.\n");
+ return;
+ }
+ gic_timer_irq = irq_of_parse_and_map(node, 0);
+ if (!gic_timer_irq) {
+ pr_err("GIC timer IRQ not specified.\n");
+ return;
+ }
+
+ __gic_clocksource_init();
+}
+CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer",
+ gic_clocksource_of_init);



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