1 files changed, 46 insertions, 9 deletions

diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c
index a68919727e2..68bc0b82226 100644
--- a/arch/arm/mach-shmobile/timer.c
+++ b/arch/arm/mach-shmobile/timer.c
@@ -19,9 +19,26 @@
  *
  */
 #include <linux/platform_device.h>
+#include <linux/clocksource.h>
 #include <linux/delay.h>
-#include <asm/mach/time.h>
-#include <asm/smp_twd.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)
@@ -40,6 +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)
 {
 	/*
@@ -60,10 +104,3 @@ void __init shmobile_earlytimer_init(void)
 	late_time_init = shmobile_late_time_init;
 }
 
-static void __init shmobile_timer_init(void)
-{
-}
-
-struct sys_timer shmobile_timer = {
-	.init		= shmobile_timer_init,
-};