ARM: architected timers: add DT support
Add runtime DT support and documentation for the Cortex A7/A15
architected timers.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Conflicts:
[Resolve conflicts for adding support for the feature
ARCH_HAS_READ_CURRENT_TIMER]
arch/arm/kernel/arch_timer.c
Change-Id: I4b1d1dc2a8c69466497423475f7a3dd4d2c380c1
Signed-off-by: Sathish Ambley <sambley@codeaurora.org>
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index c6ff17c..8c5b581 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -18,6 +18,7 @@
#include <linux/jiffies.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
+#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/irq.h>
@@ -272,13 +273,10 @@
.stop = arch_timer_stop,
};
-int __init arch_timer_register(struct arch_timer *at)
+static int __init arch_timer_common_register(void)
{
int err;
- if (at->res[0].start <= 0 || !(at->res[0].flags & IORESOURCE_IRQ))
- return -EINVAL;
-
err = arch_timer_available();
if (err)
return err;
@@ -296,7 +294,6 @@
set_delay_fn(read_current_timer_delay_loop);
#endif
- arch_timer_ppi = at->res[0].start;
err = request_percpu_irq(arch_timer_ppi, arch_timer_handler,
"arch_timer", arch_timer_evt);
if (err) {
@@ -305,8 +302,7 @@
goto out_free;
}
- if (at->res[1].start > 0 && (at->res[1].flags & IORESOURCE_IRQ)) {
- arch_timer_ppi2 = at->res[1].start;
+ if (arch_timer_ppi2) {
err = request_percpu_irq(arch_timer_ppi2, arch_timer_handler,
"arch_timer", arch_timer_evt);
if (err) {
@@ -334,3 +330,54 @@
return err;
}
+
+int __init arch_timer_register(struct arch_timer *at)
+{
+ if (at->res[0].start <= 0 || !(at->res[0].flags & IORESOURCE_IRQ))
+ return -EINVAL;
+
+ arch_timer_ppi = at->res[0].start;
+
+ if (at->res[1].start > 0 && (at->res[1].flags & IORESOURCE_IRQ))
+ arch_timer_ppi2 = at->res[1].start;
+
+ return arch_timer_common_register();
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id arch_timer_of_match[] __initconst = {
+ { .compatible = "arm,armv7-timer", },
+ {},
+};
+
+int __init arch_timer_of_register(void)
+{
+ struct device_node *np;
+ u32 freq;
+ int ret;
+
+ np = of_find_matching_node(NULL, arch_timer_of_match);
+ if (!np) {
+ pr_err("arch_timer: can't find DT node\n");
+ return -ENODEV;
+ }
+
+ /* Try to determine the frequency from the device tree or CNTFRQ */
+ if (!of_property_read_u32(np, "clock-frequency", &freq))
+ arch_timer_rate = freq;
+
+ ret = irq_of_parse_and_map(np, 0);
+ if (ret <= 0) {
+ pr_err("arch_timer: interrupt not specified in timer node\n");
+ return -ENODEV;
+ }
+ arch_timer_ppi = ret;
+ ret = irq_of_parse_and_map(np, 1);
+ if (ret > 0)
+ arch_timer_ppi2 = ret;
+ pr_info("arch_timer: found %s irqs %d %d\n",
+ np->name, arch_timer_ppi, arch_timer_ppi2);
+
+ return arch_timer_common_register();
+}
+#endif