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-rw-r--r--arch/arm/mach-shmobile/timer.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c
index 62d7052d6f21..68bc0b82226d 100644
--- a/arch/arm/mach-shmobile/timer.c
+++ b/arch/arm/mach-shmobile/timer.c
@@ -21,6 +21,24 @@
#include <linux/platform_device.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
+#include <linux/of_address.h>
+
+void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz,
+ unsigned int mult, unsigned int div)
+{
+ /* calculate a worst-case loops-per-jiffy value
+ * based on maximum cpu core hz setting and the
+ * __delay() implementation in arch/arm/lib/delay.S
+ *
+ * this will result in a longer delay than expected
+ * when the cpu core runs on lower frequencies.
+ */
+
+ unsigned int value = HZ * div / mult;
+
+ if (!preset_lpj)
+ preset_lpj = max_cpu_core_hz / value;
+}
void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
unsigned int mult, unsigned int div)
@@ -39,6 +57,33 @@ void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
preset_lpj = max_cpu_core_mhz * value;
}
+void __init shmobile_init_delay(void)
+{
+ struct device_node *np, *parent;
+ u32 max_freq, freq;
+
+ max_freq = 0;
+
+ parent = of_find_node_by_path("/cpus");
+ if (parent) {
+ for_each_child_of_node(parent, np) {
+ if (!of_property_read_u32(np, "clock-frequency", &freq))
+ max_freq = max(max_freq, freq);
+ }
+ of_node_put(parent);
+ }
+
+ if (max_freq) {
+ if (of_find_compatible_node(NULL, NULL, "arm,cortex-a8"))
+ shmobile_setup_delay_hz(max_freq, 1, 3);
+ else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a9"))
+ shmobile_setup_delay_hz(max_freq, 1, 3);
+ else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a15"))
+ if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
+ shmobile_setup_delay_hz(max_freq, 2, 4);
+ }
+}
+
static void __init shmobile_late_time_init(void)
{
/*