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-rw-r--r--arch/xtensa/kernel/time.c40
1 files changed, 39 insertions, 1 deletions
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index b9ad9fe..9a5bcd0 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -12,6 +12,8 @@
* Chris Zankel <chris@zankel.net>
*/
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/time.h>
@@ -134,16 +136,52 @@ void local_timer_setup(unsigned cpu)
0xf, 0xffffffff);
}
+#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
+#ifdef CONFIG_OF
+static void __init calibrate_ccount(void)
+{
+ struct device_node *cpu;
+ struct clk *clk;
+
+ cpu = of_find_compatible_node(NULL, NULL, "cdns,xtensa-cpu");
+ if (cpu) {
+ clk = of_clk_get(cpu, 0);
+ if (!IS_ERR(clk)) {
+ ccount_freq = clk_get_rate(clk);
+ return;
+ } else {
+ pr_warn("%s: CPU input clock not found\n",
+ __func__);
+ }
+ } else {
+ pr_warn("%s: CPU node not found in the device tree\n",
+ __func__);
+ }
+
+ platform_calibrate_ccount();
+}
+#else
+static inline void calibrate_ccount(void)
+{
+ platform_calibrate_ccount();
+}
+#endif
+#endif
+
void __init time_init(void)
{
+ of_clk_init(NULL);
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
printk("Calibrating CPU frequency ");
- platform_calibrate_ccount();
+ calibrate_ccount();
printk("%d.%02d MHz\n", (int)ccount_freq/1000000,
(int)(ccount_freq/10000)%100);
#else
ccount_freq = CONFIG_XTENSA_CPU_CLOCK*1000000UL;
#endif
+ WARN(!ccount_freq,
+ "%s: CPU clock frequency is not set up correctly\n",
+ __func__);
clocksource_register_hz(&ccount_clocksource, ccount_freq);
local_timer_setup(0);
setup_irq(this_cpu_ptr(&ccount_timer)->evt.irq, &timer_irqaction);
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